Citation Nr: 22018303 Decision Date: 03/28/22 Archive Date: 03/28/22 DOCKET NO. 14-43 192 DATE: March 28, 2022 ORDER Entitlement to a disability rating in excess of 10 percent for right knee degenerative joint disease (DJD) with limitation of flexion is denied. Entitlement to a disability rating of 20 percent, but no higher, for right knee DJD with instability from February 10, 2012 is granted. Entitlement to a disability rating of 20 percent for symptomatic medial meniscal tear of the right knee from February 10, 2012 is granted. Entitlement to a disability rating in excess of 10 percent for left knee DJD with limitation of flexion is denied. Entitlement to a disability rating of 20 percent, but no higher, for left knee DJD with instability from February 10, 2012 is granted. Entitlement to a disability rating of 20 percent for residuals of meniscectomy of the left knee from February 10, 2012 is granted. Entitlement to service connection for bilateral hearing loss is denied. Entitlement to service connection for bilateral eye disability is denied. Entitlement to service connection for obstructive sleep apnea (OSA), to include as secondary to service-connected posttraumatic stress disorder (PTSD), is denied. FINDINGS OF FACT 1. Throughout the appeal period, the Veteran's right knee DJD has been manifested by flexion limited to no less than 80 degrees and extension to zero degrees. 2. From February 10, 2012, the Veteran's right knee disability has been manifested by moderate recurrent lateral instability with partial tears of the anterior cruciate ligament (ACL). 3. From February 10, 2012, tears of the medial meniscus of the right knee have been manifested by frequent episodes of locking and effusion. 4. Throughout the appeal period, the Veteran's left knee DJD has been manifested by flexion limited to no less than 55 degrees and extension to zero degrees. 5. From February 10, 2012, the Veteran's left knee disability has been manifested by moderate recurrent lateral instability with partial tears of the ACL. 6. From February 10, 2012, residuals of meniscectomy of the left knee have been manifested by frequent episodes of locking and effusion. 7. Right ear hearing loss did not have its clinical onset in service and is not otherwise related to active duty; a sensorineural hearing loss was not exhibited within the first post-service year and continuity of symptoms is not established. 8. The Veteran does not currently have a left ear hearing loss disability sufficient for VA compensation purposes. 9. A bilateral eye disability did not have its onset during the Veteran's active service and the current bilateral eye disability is not otherwise related to an in-service injury or disease. 10. OSA did not have its onset in service and is not otherwise related to the Veteran's active military service. 11. OSA is not caused or aggravated by a service-connected disability, to include PTSD. CONCLUSIONS OF LAW 1. Throughout the appeal period, the criteria for a disability rating in excess of 10 percent for right knee DJD with limitation of flexion have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.40, 4.45, 4.59, 4.71, 4.71a, Diagnostic Code (DC) 5003, 5260, 5261. 2. From February 10, 2012, the criteria for a disability rating of 20 percent, but no higher, for the service-connected instability of the right knee are met. 38 U.S.C. § 1155; 38 C.F.R. § 4.71a, DC 5257. 3. From February 10, 2012, the criteria for a separate rating of 20 percent for medial meniscal tears of the right knee are met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.159, 3.321, 4.1, 4.3, 4.27, 4.71a, DC 5258. 4. Throughout the appeal period, the criteria for a disability rating in excess of 10 percent for left knee DJD with limitation of flexion have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.40, 4.45, 4.59, 4.71, 4.71a, DC 5003, 5260, 5261. 5. From February 10, 2012, the criteria for a disability rating of 20 percent, but no higher, for the service-connected instability of the left knee are met. 38 U.S.C. § 1155; 38 C.F.R. § 4.71a, DC 5257. 6. From February 10, 2012, the criteria for a separate rating of 20 percent for residuals of meniscectomy of the left knee are met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.159, 3.321, 4.1, 4.3, 4.27, 4.71a, DC 5258. 7. The criteria for entitlement to service connection for bilateral hearing loss have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 5107(b); 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309, 3.385. 8. The criteria for service connection for a bilateral eye disability have not been met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303. 9. OSA was not incurred in or aggravated by the Veteran's military service, and may not be presumed to have been so incurred. 38 U.S.C. §§ 101, 1101, 1112, 1113, 1116, 1131, 1137, 5107; 38 C.F.R. §§ 3.6, 3.102, 3.303, 3.307, 3.309. 10. OSA is not proximately due to, or aggravated by, a service-connected disability. 38 U.S.C. §§ 1131, 5017; 38 C.F.R. §§ 3.303, 3.310(a). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from July 1989 to July 1993. This matter comes before the Board of Veterans' Appeals (Board) on appeal from an August 2013 rating decision of the Department of Veterans Affairs (VA) Regional Office (RO), which denied a disability rating in excess of 10 percent for right knee pain and instability and granted a temporary total disability rating based upon a surgical treatment necessitating a period of convalescence for left knee pain and instability from January 20, 2012 to March 1, 2012 and denied a rating in excess of 10 percent thereafter. The rating decision also granted separate disability ratings for DJD of the right and left knees with limitation of flexion and assigned 10 percent ratings from February 10, 2012. In addition, the rating decision denied service connection for bilateral hearing loss, a bilateral eye disability, and OSA. The Veteran filed a notice of disagreement (NOD) in May 2014 and a statement of the case (SOC) was issued in October 2014. The Veteran perfected a timely appeal in December 2014. In October 2017, the Veteran presented sworn testimony during a personal hearing in Washington D.C., which was chaired by the undersigned Veterans Law Judge. A transcript of the hearing has been associated with the Veteran's VA claims file. In a June 2018 Board decision, the claims were remanded for further evidentiary development. As will be described below, review of the record reflects substantial compliance with the Board's Remand directives. See Stegall v. West, 11 Vet. App. 268, 271 (1998). A supplemental statement of the case (SSOC) was issued in June 2021. The Veteran's VA claims file has been returned to the Board for further appellate proceedings. In a June 2021 rating decision, the RO increased the assigned disability rating for left knee instability to 20 percent from February 7, 2021. The Veteran has not expressed satisfaction with the increased disability rating; this matter thus remains in appellate status. See AB v. Brown, 6 Vet. App. 35, 38 (1993) (when a veteran is not granted the maximum benefit allowable under the VA Schedule for Rating Disabilities, the pending appeal as to that issue is not abrogated). Increased Ratings Disability ratings are determined by applying the criteria set forth in the VA Schedule for Rating Disabilities. 38 C.F.R. Part 4. The Board determines the extent to which a veteran's service-connected disability adversely affects his ability to function under the ordinary conditions of daily life, and the assigned rating is based, as far as practicable, upon the average impairment of earning capacity in civil occupations. 38 U.S.C. § 1155; 38 C.F.R. §§ 4.1, 4.10. Where there is a question as to which of two ratings should be applied, the higher rating will be assigned if the disability picture more nearly approximates the criteria required for that rating. Otherwise, the lower rating will be assigned. 38 C.F.R. § 4.7. In general, when an increase in the disability rating is at issue, it is the present level of disability that is of primary concern. See Francisco v. Brown, 7 Vet. App. 55, 58 (1994). However, staged ratings are also appropriate in any increased rating claim in which distinct time periods with different ratable symptoms can be identified. Hart v. Mansfield, 21 Vet. App. 505 (2007). Here, analysis in this decision has therefore been undertaken with consideration of the possibility that different ratings may be warranted for different time periods as to the pending claims. In all cases, the Board must determine the value of all evidence submitted, including lay and medical evidence. Buchanan v. Nicholson, 451 F.3d 1331 (Fed. Cir. 2006). The evaluation of evidence generally involves a three-step inquiry. First, the Board must determine whether the evidence comes from a "competent" source. The Board must then determine if the evidence is credible, or worthy of belief. Barr, at 308 (observing that once evidence is determined to be competent, the Board must determine whether such evidence is also credible). The third step of this inquiry requires the Board to weigh the probative value of the proffered evidence in light of the entirety of the record. In this function, the Board may properly consider internal inconsistency, facial plausibility, and consistency with other evidence submitted on behalf of the claimant. Caluza v. Brown, 7 Vet. App. 498, 511-12 (1995), aff'd, 78 F.3d 604 (Fed. Cir. 1996) (per curiam) (table). The Board has considered all evidence of record as it bears on the issues before it. See 38 U.S.C. § 7104(a) ("Decisions of the Board shall be based on the entire record in the proceeding and upon consideration of all evidence and material of record"); 38 U.S.C. § 5107(b) ("Secretary shall consider all information and lay and medical evidence of record in a case"). Although the Board has an obligation to provide reasons and bases supporting these decisions, there is no need to discuss, in detail, the extensive evidence of record. The Federal Circuit has held that the Board must review the entire record, but does not have to discuss each piece of evidence. Gonzales v. West, 218 F.3d 1378, 1380-81 (Fed. Cir. 2000). Therefore, the Board will summarize the relevant evidence where appropriate, and the Board's analysis below will focus specifically on what the evidence shows, or fails to show, as to the Veteran's appeal. The United States Court of Appeals for Veterans Claims (Court) has emphasized that when assigning a disability rating it is necessary to consider limitation of a joint's functional ability due to flare-ups, fatigability, incoordination, and pain on movement, or when it is used repeatedly over a period of time functional loss due to flare-ups, fatigability, incoordination, and pain on movement. See DeLuca v. Brown, 8 Vet. App. 202, 206-07 (1995); see also Mitchell v. Shinseki, 25 Vet. App. 32, 44 (2011). In Mitchell, the Court explained that pursuant to 38 C.F.R. §§ 4.40 and 4.45, the possible manifestations of functional loss include decreased or abnormal excursion, strength, speed, coordination, or endurance (38 C.F.R. § 4.40), as well as less or more movement than is normal, weakened movement, excess fatigability, and pain on movement (as well as swelling, deformity, and atrophy) that affects stability, standing, and weight-bearing (38 C.F.R. § 4.45). Joints should be tested for pain on both active and passive motion, in weight-bearing and nonweight-bearing and, if possible, with range of motion measurements of the opposite undamaged joint. 38 C.F.R. § 4.59; see also Correia v. McDonald, 28 Vet. App. 158, 169-170 (2016). 1. Entitlement to a disability rating in excess of 10 percent for service-connected right knee DJD with limitation of flexion. 2. Entitlement to a disability rating in excess of 10 percent for service-connected right knee instability. 3. Entitlement to a disability rating in excess of 10 percent for service-connected left knee DJD with limitation of flexion. 4. Entitlement to a disability rating in excess of 10 percent prior to February 7, 2021 and 20 percent thereafter for service-connected left knee instability. During the pendency of the appeal, the rating criteria for evaluating musculoskeletal disabilities under 38 C.F.R. § 4.71a were amended effective February 7, 2021. 85 Fed. Reg. 230 (Nov. 30, 2020). These amendments revised select diagnostic codes "to ensure that this portion of the rating schedule uses current medical terminology and provides detailed and updated criteria for the evaluation of musculoskeletal disabilities." Id. If a law or regulation changes during the course of a claim or an appeal, the version more favorable to the Veteran will apply, to the extent permitted by any stated effective date in the amendment in question. 38 U.S.C. § 5110(g). If the revised version of the regulation is more favorable, the implementation of that regulation under 38 U.S.C. § 5110(g) can be no earlier than the effective date of that change. If the former version is more favorable, VA can apply the earlier version of the regulation for the period prior to, and from, the effective date of the change. 38 U.S.C. § 5110. Therefore, the Board will consider the Veteran's claims under the old criteria prior to February 7, 2021 and both the old and revised rating criteria from February 7, 2021. The criteria that is more favorable to the Veteran will be applied. While portions of the rating schedule addressing the musculoskeletal system were revised effective February 7, 2021, Diagnostic Code 5003 was only changed to clarify that it applies specifically to degenerative arthritis. Diagnostic Code 5003 provides that degenerative arthritis that is established by x-ray findings will be rated on the basis of limitation of motion under the appropriate diagnostic codes for the specific joint or joints involved. When there is no limitation of motion of the specific joint or joints that involve degenerative arthritis, DC 5003 provides a 20 percent rating for degenerative arthritis with x-ray evidence of involvement of 2 or more major joints or 2 or more minor joint groups, with occasional incapacitating exacerbations, and a 10 percent rating for degenerative arthritis with x-ray evidence of involvement of 2 or more major joints or 2 or more minor joint groups. Note (1) provides that the 20 percent and 10 percent ratings based on x-ray findings will not be combined with ratings based on limitation of motion. Note (2) provides that the 20 percent and 10 percent ratings based on x-ray findings, above, will not be utilized in rating conditions listed under DCs 5013 to 5024, inclusive. When there is some limitation of motion of the specific joint or joints involved that is noncompensable (0 percent) under the appropriate diagnostic codes, DC 5003 provides a rating of 10 percent for each such major joint or group of minor joints affected by limitation of motion, to be combined, not added under DC 5003. Limitation of motion must be objectively confirmed by findings such as swelling, muscle spasm, or satisfactory evidence of painful motion. When there is limitation of motion of the specific joint or joints that is compensable (10 percent or higher) under the appropriate diagnostic codes, the compensable limitation of motion should be rated under the appropriate diagnostic codes for the specific joint or joints involved. 38 C.F.R. § 4.71a. Additionally, Diagnostic Codes 5260 (leg, limitation of flexion) and 5261 (leg, limitation of extension) were also not changed by the revisions to the musculoskeletal system, effective February 7, 2021. The general rating schedules for limitation of motion of the knee are set forth in 38 C.F.R. § 4.71a, DCs 5260 and 5261. Normal range of motion of the knee is to 0 degrees extension and to 140 degrees flexion. See 38 C.F.R. § 4.71a, Plate II. Under DC 5260, a 10 percent disability rating is warranted for flexion limited to 45 degrees. A 20 percent disability rating is assigned for flexion limited to 30 degrees; and a 30 percent disability rating is assigned for flexion limited to 15 degrees. Under DC 5261, a 10 percent disability rating is warranted for extension limited to 10 degrees. A 20 percent disability rating is assigned for extension limited to 15 degrees. A 30 percent disability rating is assigned for extension limited to 20 degrees. A 40 percent disability rating is assigned for extension limited to 30 degrees; and a 50 percent disability rating is assigned for extension limited to 45 degrees. See 38 C.F.R. § 4.71a. In addition, separate ratings may be assigned for compensable limitation of both flexion and extension. See VAOPGCPREC 09-04 (separate ratings may be granted based on limitation of flexion (DC 5260) and limitation of extension (DC 5261) of the same knee joint). Prior to the regulatory change DC 5257 provided the rating criteria for impairment of the knee manifested by recurrent subluxation and lateral instability. Under this diagnostic code provision, a 10 percent disability rating is warranted where there is slight recurrent subluxation or lateral instability of the knee. A 20 percent disability rating is warranted where the recurrent subluxation or lateral instability of the knee is moderate. The maximum 30 percent disability rating is warranted where there is severe recurrent subluxation or lateral instability of the knee. 38 C.F.R. § 4.71a, DC 5257. As of February 7, 2021, under the amended criteria, the DC 5257 indicated that knee, other impairment of should be rated as follows: Recurrent subluxation or instability: For unrepaired or failed repair of complete ligament tear causing persistent instability, and a medical provider prescribes both an assistive device (e.g., cane(s), crutch(es), walker) and bracing for ambulation, a 30 percent disability rating is warranted For one of the following a 20 percent disability rating is warranted: (a) Sprain, incomplete ligament tear, or repaired complete ligament tear causing persistent instability, and a medical provider prescribes a brace and/or assistive device (e.g., cane(s), crutch(es), walker) for ambulation; (b) Unrepaired or failed repair of complete ligament tear causing persistent instability, and a medical provider pre-scribes either an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation. For sprain, incomplete ligament tear, or complete ligament tear (repaired, unrepaired, or failed repair) causing persistent instability, without a prescription from a medical provider for an assistive device (e.g., cane(s), crutch(es), walker) or bracing for ambulation, a 10 percent disabling rating is warranted. Patellar instability: For a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for a brace and either a cane or a walker a 30 percent disabling rating is warranted. For a diagnosed condition involving the patellofemoral complex with recurrent instability after surgical repair that requires a prescription by a medical provider for one of the following: a brace, cane, or walker, a 20 disability rating is warranted. For a diagnosed condition involving the patellofemoral complex with recurrent instability (with or without history of surgical repair) that does not require a prescription from a medical provider for a brace, cane, or walker, a 10 percent disability rating is warranted. Note (1): For patellar instability, the patellofemoral complex consists of the quadriceps tendon, the patella, and the patellar tendon. Note (2): A surgical procedure that does not involve repair of one or more patellofemoral components that contribute to the underlying instability shall not qualify as surgical repair for patellar instability (including, but not limited to, arthroscopy to remove loose bodies and joint aspiration). Diagnostic Codes 5258 and 5259 were not changed by the revisions to the musculoskeletal code. DC 5258 provides that a 20 percent rating is warranted for dislocated semilunar cartilage with frequent episodes of "locking," pain, and effusion into the joint. 38 C.F.R. § 4.71a, DC 5258. DC 5259 provides that a 10 percent rating is warranted for symptomatic removal of semilunar cartilage. 38 C.F.R. § 4.71a, DC 5259. In this case, the Veteran's DJD disabilities of the right and left knees with limitation of flexion are assigned 10 percent ratings pursuant to DC 5261. A separate 10 percent rating is assigned for right knee DJD with instability under DC 5257 from February 10, 2012. A separate 10 rating for left knee DJD with instability under DC 5257 from February 10, 2012 (as noted above a temporary total disability rating is assigned based upon a surgical treatment necessitating a period of convalescence from January 20, 2012 to March 1, 2012); a 20 percent increased rating for left knee instability was granted from February 7, 2021. See the rating decision dated June 2021. A temporary total rating was also granted for the right knee DJD with limitation of flexion from January 14, 2014 to April 1, 2014. See the Board decision dated June 2018 and the implementing rating decision dated April 2020. As such, the Board will consider the increased rating claims excluding the assigned temporary total periods. For the reasons set forth below, the Board finds that higher disability ratings are not warranted for the service-connected right or left knee disabilities based upon limitation of motion. However, the Board does find that 20 percent disability ratings, but no higher, are warranted for right and left knee instability from February 10, 2012, the date of the increased rating claim. The Board also finds that a separate 20 percent rating is warranted for symptomatic meniscal tear of the right knee from February 10, 2012 and a separate 20 percent rating is warranted for residuals of meniscectomy of the left knee from February 10, 2012. Private treatment records dated in February 2011 reported that the Veteran underwent "[e]xamination under anesthetic of the left knee followed by arthroscopic evaluation of left knee followed by arthroscopic synovectomy and removal of scar in the anterior fat pad and medial joint space." In March 2011, the Veteran was noted to be status-post arthroscopic debridement of the left knee and right knee pain with ACL instability. Magnetic resonance imaging (MRI) conducted in April 2011 indicated status-post ACL graft repair with a "[c]omplex tear of the posterior horn [of] the meniscus extending to the junction with the body." Private treatment records dated in October 2011 indicated that the Veteran experienced pain in the back part of his knee and feels like his knee gives out on him. He was noted to have a chronic ACL tear of the left knee. In January 2012, the Veteran underwent left knee ACL ligament reconstruction with hamstring autograft. Private treatment records dated in April 2012 indicated that the Veteran reinjured his right knee four days prior in a twisting and hyperextension type motion. He was diagnosed with status-post left ACL reconstruction, right knee effusion, right knee questionable medial and lateral meniscal tears, and right knee chronic ACL insufficiency. Private treatment records dated in December 2012 noted that the Veteran's "left knee is causing so much pain." The Veteran was afforded a VA knee examination in August 2013 at which time the examiner noted diagnoses of bilateral knee pain and instability, as well as residual DJD. The examiner also indicated that the Veteran had bilateral ACL repairs with retained metallic hardware screws in the right knee. The examiner reported that the "Veteran is walking with [a] cane, cannot walk distances even between buildings at his work. Both knees give away. [The] Veteran has been told he will eventually need bilateral total knee replacements." The Veteran endorsed flare-ups. Range of motion testing showed right and left knee flexion to 90 degrees with pain and extension to zero degrees without pain. There was no additional limitation of motion on repetitive use testing. The Veteran exhibited less movement than normal, weakened movement, pain on movement, instability of station, disturbance of locomotion, and interference with sitting, standing, and weight-bearing. The Veteran had pain on palpation and tenderness in his right knee. Muscle strength was reduced to 4/5 in the bilateral knees on flexion and extension. Joint stability testing was normal. There was no history of recurrent patellar subluxation/dislocation. The examiner noted that the Veteran had a history of bilateral meniscal conditions. The examiner indicated that the meniscal impairment was demonstrated by frequent episodes of joint locking in the left knee and frequent episodes of joint pain, bilaterally. The Veteran underwent a medial meniscal repair of the left knee in 1987. The examiner further indicated that the Veteran had knee surgeries in 1987, 1988, 1992, 1998, 2008, 2011, and 2012. The examiner indicated that the Veteran regularly uses a brace and a cane. A February 2011 imaging report showed, "DJD [of the] bilateral knees, left worse than right; retained metallic hardware screws in both the tibia and fibula." The examiner indicated that the Veteran's bilateral knee disabilities do impact his ability to work; specifically, the "Veteran works full-time in IT state government and missed [about] 20 days for knee surgery, follow-up visits, therapy, and knee pain." In an August 2013 statement, the Veteran described extreme pain, as well as constant swelling and giving way of the knees. In January 2014, the Veteran underwent right knee ACL reconstruction. He was noted to have a medial meniscus tear of the body and posterior horn. Private treatment records dated in January 2014 documented moderate knee effusion. In March 2014, the Veteran was noted to have knee pain and mild crepitation at the patellofemoral joint. VA treatment records dated in July 2015 noted that the Veteran was prescribed a replacement cane, as well as right and left ACL braces. VA treatment records dated in March 2017 noted that the Veteran experiences knee pain with moderate to severe exertion. He did not have swelling, but he reported that his knee gives out at times. He further endorsed popping in the knee joint. At the October 2017 Board hearing, the Veteran testified that he experiences extreme pain and limited mobility in his knees. See the Board hearing transcript, pg. 7. The Veteran endorsed flare-ups, as well as swelling and flare-ups in the knees. Id. at pg. 9. He reported the use of a cane and bilateral knee braces. Id. at pg. 10. He also described locking of the bilateral knee joints. Id. at pg. 13. He indicated that he loses 20 days of work per year due to his knee disabilities. Id. at pgs. 13-14. VA treatment records dated in February 2020 documented the Veteran's report of chronic progressive worsening left knee pain. He was noted to be pending left knee surgery from a private treatment provider. The Veteran was afforded a VA examination in November 2020 at which time the examiner diagnosed bilateral degenerative arthritis. The Veteran described current symptoms of sharp, aching, generalized pain in the right knee that occurs 2-4 times weekly. The Veteran indicated that right knee pain was 7/10 and his knee buckles 2 to 3 times weekly. As to the left knee, the Veteran endorsed constant throbbing, sharp, generalized pain with a popping sound when walking, his knee buckles daily. His left knee pain is 9/10. He indicated that he treats his bilateral knee symptoms with hydrocodone and acetaminophen. The Veteran described flare-ups of right knee symptoms manifested by sharp and throbbing pain, occurring once weekly. Right knee flare-ups are 8/10 in severity with a duration of a half day. He indicated that left knee flare-ups are manifested by "[e]xtreme sharp and throbbing left knee pain which makes me have to stay in bed because I am unable to walk." The Veteran reported that left knee flare-ups occur twice weekly and are 10/10 in severity with a duration of up to one day. The Veteran described the following functional loss, "I have difficulty walking. I can't run." Range of motion testing revealed right knee flexion to 90 degrees, left knee flexion to 65 degrees, and extension to zero degrees, bilaterally. Pain was noted on examination and causes functional loss. There was pain with weight-bearing and objective evidence of crepitus. The examiner indicated that the Veteran did not exhibit additional limitation of motion on repetitive use motion testing. The examiner reported that pain significantly limits functional ability with repeated use over a period of time. The examiner estimated that with repeated use over a period of time right knee flexion was limited to 85 degrees with extension to zero degrees and left knee flexion to 60 degrees with extension to zero degrees. The examiner further stated that right and left knee pain significantly limits functional ability with flare-ups. The examiner estimated that with flare-ups right knee flexion was limited to 80 degrees with extension to zero degrees and left knee flexion to 55 degrees with extension to zero degrees. Muscle strength was 4/5 in bilateral flexion and extension. There was no atrophy or ankylosis. The examiner indicated that the Veteran did not have a history of recurrent subluxation or lateral instability. The Veteran did have a history of recurrent effusion and reported that he has fluid removed from both knees about once every two years. Joint stability testing was normally, bilaterally. However, the examiner noted the Veteran to have been "[v]ery stiff and guarded during knee exam." There was no recurrent patellar dislocation. The examiner indicated that the Veteran had a bilateral meniscal condition manifested by frequent episodes of joint pain, bilaterally, and frequent episodes of joint locking in the left knee. The examiner noted that the Veteran regularly uses bilateral knee braces and constantly uses a cane. The examiner opined that the Veteran's right and left knee disabilities do impact his ability to perform any type of occupational tasks. The examiner explained that the Veteran works as an IT technician and has lost one to two weeks of work time in the last twelve months. The examiner opined that the Veteran's "[a]bility to work [is] impacted by bilateral DJD limitation of flexion with painful motion and right and left knee pain and instability, resulting in bilateral knee pain." The examiner stated that the "Veteran would have difficulty walking, sitting and rising from a sitting position, interfering with ability to complete normal working activities required in an 8 hour workday." The examiner further reported that there was objective evidence of pain on passive range of motion and in weight-bearing. Right knee With respect to the right knee, the Veteran is currently assigned a 10 percent rating for DJD with limitation of flexion. He is also assigned a separate 10 percent rating for instability of the right knee. Based on the evidence of record, as detailed in pertinent part above, the Board finds that a right knee disability rating in excess of 10 percent for limitation of flexion is not warranted. VA examination and treatment records referenced above demonstrated, at worst, 80 degrees of flexion and zero degrees of extension (as documented by the November 2020 VA examiner and taking into account additional limitation on repetitive use and during flare-ups). Such findings warrant noncompensable disability ratings under DC 5260 and 5261. Thus, a disability rating in excess of 10 percent for limitation of flexion is not warranted during the appeal period. Critically, functional loss must be rated under the diagnostic code pertaining to limitation of motion of the affected joint, pursuant to 38 C.F.R. § 4.40; Schafrath v. Derwinski, 1 Vet. App. 589, 592 (1991) (noting that functional loss due to pain is to be rated at the same level as where motion is impeded); DeLuca v. Brown, 8 Vet. App. 202, 205-06 (noting that the disabling effect of painful motion must be considered when rating joint disabilities) (1995); Mitchell v. Shinseki, 25 Vet. App. 32, 37 (2011) (stating that functional loss caused by pain must be rated at the same level as if that functional loss were caused by some other factor that actually limited motion)); c.f., Petitti v. McDonald, 27 Vet. App. 415 (2015). Hence, there is no basis upon which to find additional limitation due to functional factors. See 38 C.F.R. §§ 4.40, 4.45; DeLuca, 8 Vet. App. at 202; Mitchell, 25 Vet. App. at 32. As indicated above, the Veteran's functional impairment and impaired motion during flare-ups is contemplated in the assigned disability rating. As set forth above, the Veteran does not meet the criteria for the assignment of separate compensable disability ratings for limitation of flexion or extension in his right knee under VAOPGCPREC 09-2004, VAOPGCPREC 23-97, or VAOPGCREC 9-98 during the appeal period. As indicated above, the Veteran is assigned a separate disability rating for instability of the right knee pursuant to DC 5257, evaluated as 10 percent. Review of the record shows that, throughout the appeal period, the Veteran complained of right knee instability related to chronic ACL insufficiency. See the private treatment records dated April 2012 and January 2014, the Board hearing transcript dated October 2017, and the VA examinations dated August 2013 and November 2020. Although joint stability testing did not document objective evidence of instability, the Veteran's surgical and treatment records documented recurrent instability with chronic ACL laxity in the right knee. In addition, examination and treatment records show that the Veteran relies on the use of a cane and knee braces. Accordingly, the Board finds that a 20 percent rating under DC 5257 for moderate lateral instability is warranted from February 10, 2012, the date of the increased rating claim. The Board has considered whether a higher rating would be warranted, including under the revised DC 5257 (in effect from February 7, 2021). To this end, although there is evidence of ACL tears with recurrent surgical intervention for laxity, in addition to the Veteran's report of persistent instability and the use of a cane and brace, the service-connected right knee ACL tears were not shown to be complete and the Veteran does not contend otherwise. See the service treatment records (STRs) dated December 1992, the MRI report dated April 2011, and the private treatment records dated April 2012. As such, a disability rating in excess of 20 percent is not warranted under the revised version of DC 5257. Additionally, the Board finds that a separate 20 percent rating for dislocated semilunar cartilage with frequent episodes of locking, pain, and effusion into the right knee joint is warranted from February 10, 2012, the date of the increased rating claim. Here, the evidence clearly documents a meniscal tear of the right knee, coupled with documentation of stiffness, locking, popping, crepitus, and effusion. See, e.g., the MRI report dated April 2011, private treatment records dated April 2012, January 2014, and March 2014, VA treatment records dated March 2017, and the Board hearing transcript dated October 2017. Accordingly, a separate 20 percent rating is warranted for the right medial meniscal tear under DC 5258 from February 10, 2012. A 30 percent disability rating may be assigned for ankylosis at a favorable angle in full extension, or in slight flexion between zero and 10 degrees. 38 C.F.R. § 4.71a, DC 5256. However, as indicated above, none of the other examination and treatment records nor the lay evidence contained in the claims file documents ankylosis of the right knee or symptoms producing the functional equivalent of ankylosis. As such, the Board finds that a higher disability rating under DC 5256 is not warranted. The Board has also considered whether DC 5055 (knee replacement) is applicable in this matter. However, a total knee replacement was not performed; as such, DC 5055 is not for application. Left knee With respect to the left knee, the Veteran is currently assigned a 10 percent disability rating for left knee DJD with limitation of flexion from February 10, 2012. A separate disability rating for left knee instability is assigned under DC 5257 and evaluated as 10 percent prior to February 7, 2021 and 20 percent thereafter. Based on the evidence of record, as detailed in pertinent part above, the Board finds that a left knee disability rating in excess of 10 percent for limitation of flexion is not warranted. VA examination and treatment records referenced above demonstrated, at worst, 55 degrees of flexion and zero degrees of extension (as documented by the November 2020 VA examiner and taking into account additional limitation on repetitive use and during flare-ups). Such findings warrant a 10 percent disability rating under DC 5260. As such, a disability rating in excess of 10 percent for painful flexion is not warranted during the appeal period. Functional loss must be rated under the diagnostic code pertaining to limitation of motion of the affected joint, pursuant to 38 C.F.R. § 4.40; Schafrath, 1 Vet. App. at 592 (noting that functional loss due to pain is to be rated at the same level as where motion is impeded); DeLuca, 8 Vet. App. at 205-06 (noting that the disabling effect of painful motion must be considered when rating joint disabilities); Mitchell, 25 Vet. App. at 37 (stating that functional loss caused by pain must be rated at the same level as if that functional loss were caused by some other factor that actually limited motion)); c.f., Petitti, supra. Hence, there is no basis upon which to find additional limitation due to functional factors. See 38 C.F.R. §§ 4.40, 4.45; DeLuca, 8 Vet. App. at 202; Mitchell, 25 Vet. App. at 32. As indicated above, the Veteran's functional impairment and impaired motion during flare-ups is contemplated in the assigned disability ratings. As set forth above, the Veteran does not meet the criteria for the assignment of separate compensable disability ratings for limitation of extension in his left knee under VAOPGCPREC 09-2004, VAOPGCPREC 23-97, or VAOPGCREC 9-98. With regard to the assigned disability ratings for left knee instability under DC 5257, the Board finds that a 20 percent disability rating, but no higher, is warranted from February 10, 2012, the date of the increased rating claim. The evidence of record demonstrates that the Veteran reported left knee instability related to chronic ACL insufficiency during the appeal period. See the private treatment records dated October 2011, January 2012, and April 2012, the Board hearing transcript dated October 2017, and the VA examinations dated August 2013 and November 2020. Although joint stability testing did not document objective evidence of instability, the Veteran's surgical and treatment records document recurrent instability with chronic ACL laxity in the left knee. Additionally, examination and treatment records show that the Veteran relies on the use of a cane and knee braces. The Board therefore finds that the 20 percent rating under DC 5257 for moderate lateral instability is warranted from February 10, 2012, the date of the increased rating claim. The Board has considered whether a higher rating would be warranted, including under the revised DC 5257 (in effect from February 7, 2021). To this end, although there is evidence of an ACL tear with recurrent surgical intervention for laxity, in addition to the Veteran's report of persistent instability and the use of a cane and brace, the service-connected left knee ACL tears were not shown to be complete and the Veteran does not contend otherwise. See the Medical Board proceedings dated March 1993, private treatment records dated February 2011, October 2011, and January 2012; see also the VA examination reports dated August 2013 and November 2020. As such, a rating in excess of 20 percent is not warranted under the revised version of DC 5257. Additionally, the Board finds that a separate 20 percent rating for dislocated semilunar cartilage with frequent episodes of locking, pain, and effusion into the joint is warranted from February 10, 2012, the date of the increased rating claim. Here, the evidence shows that the Veteran underwent a meniscectomy in 1987 and has since reported stiffness, locking, popping, crepitus, and effusion. See, e.g., the private treatment records dated February 2011, March 2011, October 2011, December 2012, and March 2014, the VA examination reports dated August 2013 and November 2020, VA treatment records dated March 2017, and the Board hearing transcript dated October 2017. Accordingly, a separate 20 percent rating is warranted for the meniscectomy residuals of the left knee under DC 5258 from February 10, 2012. A 30 percent disability rating may be assigned for ankylosis at a favorable angle in full extension, or in slight flexion between zero and 10 degrees. 38 C.F.R. § 4.71a, DC 5256. However, as indicated above, none of the other examination and treatment records or the lay evidence contained in the claims file documents ankylosis of the left knee or symptoms producing the functional equivalent of ankylosis. As such, the Board finds that a higher disability rating under DC 5256 is not warranted. The Board has also considered whether DC 5055 (knee replacement) is applicable in this matter. However, a total knee replacement was not performed; as such, DC 5055 is not for application. In sum, the Board has considered the entire record, including the Veteran's reported symptomatology and the objective clinical evidence. For the reasons set forth above, the Board finds that disability ratings in excess of 10 percent are not warranted for DJD of the right and left knees with limitation of flexion. The Board further finds that separate 20 percent disability ratings are warranted for right and left knee instability under DC 5257 from February 10, 2012, the date of the increased rating claim. The Board additionally finds that separate 20 percent ratings are warranted for the right and left knee disabilities under DC 5258 from February 10, 2012 based upon the torn medial meniscus in the right knee and residuals of meniscectomy in the left knee. Service Connection Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303(a). Service connection may also be granted for any disease diagnosed after discharge, when all of the evidence, including that pertinent to service, establishes that the disease was incurred in active service. 38 C.F.R. § 3.303(d). To establish entitlement to service connection on a direct basis, the record must contain competent evidence of (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated in service. Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). In rendering a decision on appeal, the Board must analyze the credibility and probative value of the evidence, account for the evidence which it finds to be persuasive or unpersuasive, and provide the reasons for its rejection of any material evidence favorable to the claimant. Gabrielson v. Brown, 7 Vet. App. 36, 39-40 (1994). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the benefit of the doubt shall be given to the claimant. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102. 5. Entitlement to service connection for bilateral hearing loss. In addition, certain enumerated diseases will be service connected on a presumptive basis if they manifested to a compensable degree within one year after active duty service. See 38 U.S.C. §§ 1101, 1112; 38 C.F.R. §§ 3.307(a)(3), 3.309(a). A nexus between the current disability and service may be established by evidence of continuity of symptomatology since service for a listed chronic disability. 38 C.F.R. § 3.303(b); Walker v. Shinseki, 708 F.3d 1331, 1338-40 (Fed. Cir. 2013). VA deems sensorineural hearing loss to be an organic disease of the nervous system for purposes of 38 C.F.R. § 3.309(a). See Veterans Benefits Administration (VBA) Fast Letter 10-02 (Mar. 18, 2010); Memorandum, Characterization of High Frequency Sensorineural Hearing Loss, Under Secretary for Health, October 4, 1995. The threshold for normal hearing is from 0 to 20 decibels, and higher threshold levels indicate some degree of hearing loss. Hensley v. Brown, 5 Vet. App. 155, 157 (1993). For the purposes of applying the laws administered by VA, impaired hearing will be considered to be a disability when the auditory threshold in any of the frequencies 500, 1000, 2000, 3000, 4000 Hertz is 40 decibels or greater; or when the auditory thresholds for at least three of the frequencies 500, 1000, 2000, 3000, or 4000 Hertz are 26 decibels or greater; or when speech recognition scores using the Maryland CNC Test are less than 94 percent. 38 C.F.R. § 3.385. Service connection will be granted for a hearing loss disability where the evidence establishes a nexus between the current hearing loss and a disease or injury suffered while in military service. Godfrey v. Derwinski, 2 Vet. App. 352, 356 (1992). VA regulations do not preclude service connection for a hearing loss which first met VA's definition of disability after service. Hensley, 5 Vet. App. at 159. Here, the Veteran contends that he developed bilateral hearing loss as a result of his military service. For the reasons set forth below, the Board concludes that service connection is not warranted. The first critical element in this matter is whether at any time during the current appeal the Veteran has been diagnosed with a hearing loss disability as defined under VA regulation 38 C.F.R. § 3.385. See 38 U.S.C. §§ 1110, 1131. As noted above, the Veteran served on July 1989 to July 1993. His service treatment records (STRs) include the Veteran's July 1989 enlistment examination showed the following audiometric thresholds: HERTZ 1000 2000 3000 4000 Average RIGHT 0 5 5 5 3.75 LEFT 0 5 0 5 2.5 A January 1990 reference audiogram documented the following audiometric thresholds: HERTZ 1000 2000 3000 4000 Average RIGHT 0 5 10 10 6.25 LEFT 5 5 10 15 6.25 The January 1990 reference audiogram indicated that the Veteran was "[r]outinely exposed to hazardous noise." In addition, he was assigned a hearing loss profile of H1 under the PULHES classification system. The PULHES classification system reflects the overall physical and psychiatric condition of a veteran on a scale of 1 (high level of fitness) to 4 (a medical condition or physical defect which is below the level of medical fitness for retention in the military service). See Odiorne v. Principi, 3 Vet. App. 456, 457 (1992). A November 1991 audiogram showed the following audiometric thresholds: HERTZ 1000 2000 3000 4000 Average RIGHT 10 0 10 15 8.75 LEFT 5 10 10 5 7.5 An audiogram conducted in May 1992 documented the following audiometric thresholds: HERTZ 1000 2000 3000 4000 Average RIGHT 5 5 10 15 8.75 LEFT 5 10 15 20 12.5 In a March 1993 Report of Medical History, the Veteran denied experiencing hearing loss. The Veteran was afforded a VA audiology examination in August 2013 at which time the examiner documented the following audiometric thresholds: HERTZ 1000 2000 3000 4000 Average RIGHT 15 10 10 20 14 LEFT 10 10 20 20 15 The August 2013 VA examiner also noted that the speech recognition scores were 100 percent in each ear. At the October 2017 Board hearing, the Veteran presented personal testimony that his hearing loss symptomatology has worsened. See, e.g., the Board hearing transcript dated October 2017. Pursuant to the June 2018 Board Remand, the Veteran underwent a VA audiology examination in May 2020 at which time the examiner documented the following puretone thresholds: HERTZ 1000 2000 3000 4000 Average RIGHT 35 30 30 30 31 LEFT 25 25 30 25 26 The May 2020 examiner documented a speech recognition score of 100 percent in the right ear and 92 percent in the left ear. The examiner indicated that "[t]he use of the word recognition score is not appropriate for this Veteran because of language difficulties, cognitive problems, inconsistent word recognition scores, etc., that make combined use of puretone average and word recognition scores inappropriate." The examiner additionally stated, "[s]peech discrimination testing above was not completed using recorded Maryland CNC word lists, thus making these scores not appropriate in determining level of hearing impairment." Accordingly, the May 2020 examiner documented right ear hearing loss sufficient for VA compensation purposes pursuant to 38 C.F.R. § 3.385; however, left ear hearing loss sufficient for VA compensation purposes was not demonstrated. As to the question of nexus, the VA examiner indicated that the Veteran's right ear hearing loss is not at least as likely as not (50 percent probability or greater) caused by or a result of an event in military service. The examiner explained that the Veteran's right ear hearing loss is at least as likely as not caused by or a result of an event in military service. The examiner indicated that "[h]earing tests in service showed a decrease at the 4000 Hz threshold from enlistment in 1989 to an exam for medical board in 1992, which indicates the presence of acoustic trauma." The examiner continued, "[r]eview of records found a positive history of hazardous noise in service (artillery in live fire and combat) and recreational noise exposures have been denied." The examiner also rendered a positive nexus opinion as to the left ear hearing loss. The Veteran was afforded a VA audiology examination in March 2021. The examiner noted, "[a] review of in-service audiograms revealed significant permanent positive threshold shifts at 3 and 4 hertz in the left ear. All thresholds were within normal limits at entrance and separation." The examiner documented the following audiometric thresholds: HERTZ 1000 2000 3000 4000 Average RIGHT 25 25 30 25 26 LEFT 15 25 35 30 26 The March 2021 VA examiner also noted that the speech recognition scores were 94 percent in each ear. The examiner determined that the use of speech discrimination scores, in this examination, are appropriate for this Veteran. The March 2021 VA examiner clarified that "[s]ignificant in-service threshold shifts occurred only in the left ear, opinions are provided for each ear separately." As to the right ear, the examiner indicated, "a review of in-service audiograms revealed no significant permanent positive threshold shifts. Although noise exposure is conceded and the relationship of noise, auditory damage and hearing loss is well-established, auditory damage and hearing loss are not conceded based on noise alone." The examiner continued, "[t]here must be a nexus of auditory damage to relate current hearing loss to military noise and not another etiology. The evidence is against a nexus in this case, therefore it is less likely than not that the hearing loss is related to military noise exposure." The examiner rendered a positive nexus opinion with respect to the left ear. As set forth above, the Veteran's left ear hearing thresholds as documented by the multiple service audiograms and the August 2013, May 2020, and March 2021 VA audiology examiners are below those recognized by VA as denoting hearing impairment. See 38 C.F.R. § 3.385. Although the May 2020 VA audiology examiner documented a speech recognition score of 92 percent, the examiner indicated that the use of word recognition scores at that examination were not appropriate. The Veteran's speech recognition scores, as documented by the August 2013 and March 2021 VA examiners, are above those recognized by VA as denoting a hearing loss disability pursuant to 38 C.F.R. § 3.385. Significantly, the evidence of record including in-service and post-service audiometric testing shows that the Veteran does not meet the criteria for a current hearing loss disability in the left ear for VA purposes. 38 C.F.R. § 3.385 dictates that service connection may not be established for disability due to impaired hearing unless the auditory threshold in any of the frequencies 500, 1000, 2000, 3000, or 4000 Hertz is 40 decibels or greater; or when the auditory threshold for at least three of the frequencies are 26 decibels or greater; or when speech recognition scores using the Maryland CNC Test are less than 94 percent. Congress specifically limits entitlement for service-connected disease or injury to cases where in-service incidents have resulted in a disability. See 38 U.S.C. §§ 1110, 1131; Gilpin v. West, 155 F.3d 1353 (Fed. Cir. 1998) (holding VA's interpretation of the provisions of 38 U.S.C.§ 1110 to require evidence of a present disability to be consistent with congressional intent). In other words, the law limits entitlement to compensation to cases where the underlying in-service incident has resulted in a current disability. Degmetich v. Brown, 104 F.3d 1328 (Fed. Cir. 1997). VA has promulgated regulations specifically defining a hearing loss disability. See 38 C.F.R. § 3.385. Although the Veteran has contended that he has left ear hearing loss, the record contains audiometric test results which establish that any decreased hearing acuity he perceives does not meet the criteria set forth in section 3.385, a necessary prerequisite to an award of service connection for bilateral hearing loss. The Veteran is competent to describe decreased hearing acuity; however, he is not competent to state that his hearing acuity meets the required puretone thresholds, in decibels. Accordingly, there is no other post-service clinical evidence establishing a current left ear hearing loss disability for VA purposes. The Veteran does not meet the criteria under 38 C.F.R. § 3.385 to have left ear hearing loss for VA compensation purposes at this time. Absent probative evidence of a current left ear hearing loss disability, the claim must be denied. As to the right ear, the Board recognizes that the May 2020 VA examiner rendered a positive nexus opinion based upon a finding that acoustic trauma was demonstrated by in-service hearing tests showing a decrease at the 4000 Hz threshold from enlistment in 1989 to the medical board exam in 1992. However, as noted by the March 2021 VA examiner, significant in-service threshold shifts occurred only in the left ear. The March 2021 examiner explained that a nexus was not indicated because auditory damage and hearing loss are not conceded based on noise alone. The March 2021 VA medical opinion was based on a review of the record, including the lay statements and evidence submitted by the Veteran, and thoughtful analysis of the Veteran's medical history. For these reasons, the Board places significant weight on the findings of the March 2021 VA examiner. See Nieves-Rodriguez, 22 Vet. App. at 295 (the probative value of a medical opinion comes from when it is the factually accurate, fully articulated, and sound reasoning for the conclusion); see also Bloom v. West, 12 Vet. App. 185, 187 (1999) (the probative value of a physician's statement is dependent, in part, upon the extent to which it reflects "clinical data or other rationale to support his opinion"). The Board finds that the competent medical evidence demonstrating the absence of nexus between the currently diagnosed right ear hearing loss and the Veteran's military service outweighs the evidence suggestive of nexus. In Hensley v. Brown, 5 Vet. App. 155 (1993), the Court stated that 38 C.F.R. § 3.385 does not preclude service connection for a current hearing disability where hearing was within normal limits on audiometric testing at separation from service. However, there is no lay or clinical evidence of a right ear hearing loss disability in service or for years after the Veteran's military discharge. Continuity is not established. As to the right ear hearing loss, the Board is charged with weighing the positive and negative evidence; resolving reasonable doubt in the Veteran's favor when the evidence is in equipoise. Considering the overall evidence, including the STRs, the VA examination reports and medical opinions, as well as the lay evidence presented by the Veteran, the Board finds that the negative evidence is more persuasive and of greater probative value. In conclusion, the Board finds that the evidence is not in approximate balance and is persuasively against the Veteran's claim of entitlement to service connection for bilateral hearing loss; thus, the benefit of the doubt rule is inapplicable. See 38 U.S.C. § 5107(b); Lynch v. McDonough, No. 20-2067 (Fed. Cir. 2021). 6. Entitlement to service connection for a bilateral eye disability. The Veteran has contended that he incurred a bilateral eye disability during his deployment to Southwest Asia. See, e.g., the October 2017 Board hearing transcript, pg. 16. Specifically, he described experiencing eye dryness, redness, sensitivity to light, and impaired vision. Id. at pgs. 16-17. He reported that he continues to experience these bilateral eye symptoms, for which he self-medicates. Id. at pgs. 17-18. To this end, the Veteran's STRs dated in June 1990 documented his report of blurry vision with eye redness. A notation of irritation of the bilateral eyes was also indicated at that time. Post-service treatment records dated in September 2001 noted that the Veteran experiences chronic eye irritation, which he asserted had begun during his Persian Gulf service. A diagnosis of "suspect possibly an iritis" was indicated. Private treatment records dated in December 2012 noted the Veteran's complaint of recurrent eye irritation over the last two years. The Veteran reported that he "[h]as been having chronic irritation since the Persian Gulf, but it has gotten worse over the last 1-2 years." He additionally stated that he does not remember the diagnosis, but he was given eye drops in service. Pursuant to the June 2018 Board Remand, the Veteran was afforded a VA examination in June 2021 at which time the examiner diagnosed bilateral dry eye syndrome. The examiner determined that the Veteran's bilateral dry eye syndrome was less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness. The examiner opined, In regards to the dry eye syndrome, bilateral (claimed as bilateral eye condition): There was no bilateral eye condition noted during service, thus, there is no nexus to the Veteran's currently diagnosed dry eye syndrome. The Veteran's dry eye syndrome was first diagnosed 08/10/2012 by Virginia Eye Institute (outside records) which is 19 years after the Veteran's service. Dry eye syndrome is from poor quality tears or lack of tears on the front surface of the eye resulting in many symptoms. The risk factors for dry eye syndrome are age, medications (i.e., antihistamines), conditions (Sjogren's syndrome, vitamin a deficiency, diabetes, etc.), eye surgeries (i.e., LASIK), tear gland damage from radiation, environmental (wind, smoke, etc.), reduced blink rate (ie from computer work or conditions like Parkinson's), eyelid anatomy problems (entropion, ectropion, lagophthalmos) hormonal changes, poor diet, and contact lens wear. Dry eye syndrome can be secondary to environmental factors, however, after being removed from those factors the condition typically improves. The environmental factors the Veteran was exposed to in service would also not result in a delayed onset dry eye syndrome and would rather be present consistently since then. The Veteran's dry eye syndrome is more consistent with aging changes. When assessing the probative value of a medical opinion, the access to claims files and the thoroughness and detail of the opinion must be considered. The opinion is considered probative if it is definitive and supported by detailed rationale. See Prejean v. West, 13 Vet. App. 444, 448-49 (2000). The Court has held that claims file review, as it pertains to obtaining an overview of a claimant's medical history, is not a requirement for private medical opinions. A medical opinion that contains only data and conclusions is not entitled to any weight. Further a review of the claims file cannot compensate for lack of the reasoned analysis required in a medical opinion, which is where most of the probative value of a medical opinion comes from. "It is the factually accurate, fully articulated, sound reasoning for the conclusion, not the mere fact that the claims file was reviewed, that contributes probative value to a medical opinion." See Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008). In this matter, the Board finds that the most probative evidence of record demonstrates that the Veteran's claimed bilateral eye disability was not incurred in his active duty service. Crucially, the June 2021 VA examiner explicitly considered the Veteran's contentions of in-service symptoms and injuries, but nonetheless concluded that these reports were inconsistent with the onset of the current bilateral eye disability in service. Moreover, the findings of the June 2021 VA examiner were thoroughly explained and fully supported by the evidence of record. The Board notes that the June 2021 medical opinion was based on a review of the record, including the statements and evidence submitted by the Veteran, and the examiner explained the reasons for his conclusions based on an accurate characterization of the evidence of record. The Board therefore places significant weight on the findings of the June 2021 VA examiner. See Nieves-Rodriguez, supra; see also Bloom v. West, 12 Vet. App. 185, 187 (1999) (the probative value of a physician's statement is dependent, in part, upon the extent to which it reflects "clinical data or other rationale to support his opinion"). Accordingly, the Board finds that the competent medical evidence demonstrating the absence of nexus between the claimed bilateral eye disability and the Veteran's active duty service outweighs any medical evidence suggestive of a nexus. The Board has carefully considered the contentions of the Veteran that he has a bilateral eye disability which was incurred during service. To this end, the Board recognizes that lay witnesses are competent to opine as to some matters of diagnosis and etiology, and the Board must determine on a case by case basis whether a veteran's particular disability is the type of disability for which lay evidence is competent. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009); Kahana v. Shinseki, 24 Vet. App. 428, 433, n. 4 (2011). In this case, the Veteran's assertions as to etiology concern an internal medical process, which extends beyond an immediately observable cause-and-effect relationship that is of the type that the courts have found to be beyond the competence of lay witnesses. Cf. Jandreau, 492 F.3d at 1376 (lay witness capable of diagnosing dislocated shoulder); Barr v. Nicholson, 21 Vet. App. 303, 308-9 (2007); Falzone v. Brown, 8 Vet. App. 398, 403 (1995) (lay person competent to testify to pain and visible flatness of his feet); with Clemons v. Shinseki, 23 Vet. App. 1, 6 (2009) ("It is generally the province of medical professionals to diagnose or label a mental condition, not the claimant"); Woehlaert v. Nicholson, 21 Vet. App. 456, 462 (2007) (unlike varicose veins or a dislocated shoulder, rheumatic fever is not a condition capable of lay diagnosis); Jandreau, 492 F.3d at 1377, n. 4 ("sometimes the layperson will be competent to identify the condition where the condition is simple, for example a broken leg, and sometimes not, for example, a form of cancer"). See also Colantonio v. Shinseki, 606 F.3d 1378, 1382 (Fed. Cir.2010) (recognizing that in some cases lay testimony "falls short" in proving an issue that requires expert medical knowledge). Questions of competency notwithstanding, the Veteran's lay theories regarding the onset and etiology of his bilateral eye disability are contradicted by the conclusions of the June 2021 VA examiner who specifically considered the Veteran's lay statements in rendering the negative opinion. The Board finds the specific, reasoned opinion of the trained health care provider who conducted the June 2021 VA opinion to be of greater probative weight than the more general lay assertions of the Veteran. The Board has also considered that lay evidence concerning continuity of symptoms after service, if credible, is ultimately competent, regardless of the lack of contemporaneous medical evidence. Buchanan, supra. Crucially, the June 2021 VA examiner specifically considered the lay assertions and inferences contained in the record in rendering the negative nexus opinion. The Board is charged with weighing the positive and negative evidence; resolving reasonable doubt in the Veteran's favor when the evidence is in equipoise. Considering the record, including post-service medical evidence, June 2021 VA medical opinions, and lay evidence presented by the Veteran, the Board finds that the negative evidence is more persuasive and of greater evidentiary weight. In conclusion, as the evidence is not in approximate balance and is persuasively against the Veteran's claim, the benefit of the doubt rule is inapplicable. See 38 U.S.C. § 5107(b); Lynch v. McDonough, No. 20-2067 (Fed. Cir. 2021). 7. Entitlement to service connection for OSA, to include as secondary to service-connected PTSD. Service connection may be granted for a disability that is proximately due to, the result of, or aggravated by a service-connected disability. See 38 C.F.R. § 3.310(a); see also Harder v. Brown, 5 Vet. App. 183, 187 (1993). Additional disability resulting from the aggravation of a nonservice-connected condition by a service-connected condition is also compensable under 38 C.F.R. § 3.310(a). See Allen v. Brown, 7 Vet. App. 439, 448 (1995). The Board notes that there has been an amendment to the provisions of 38 C.F.R. § 3.310. See 71 Fed. Reg. 52,744 -47 (Sept. 7, 2006). The amendment sets a standard by which a claim based on aggravation of a non-service-connected disability by a service-connected one is judged. The Veteran asserts entitlement to service connection for OSA, which he contends was incurred during his military service. He alternatively contends that he developed OSA secondary to PTSD. See the Board hearing transcript dated October 2017. The Veteran's STRs do not document findings of sleep apnea or complaints relating to sleep impairment. In his March 1993 Report of Medical History at separation, he specifically denied having or ever having had pertinent symptoms, including frequent trouble sleeping. Private treatment records dated in August 2013 noted a history of sleep apnea with a CPAP prescription. The Veteran was afforded a VA examination in August 2013 at which time the examiner confirmed a diagnosis of OSA. The examiner noted that the Veteran was diagnosed with sleep apnea in 2010. The Veteran reported, "I have always had a hard time sleeping, nightmares. I always felt tried because of it." The examiner determined that the claimed OSA is less likely than not proximately due to or the result of the Veteran's service-connected PTSD. The examiner's rationale was non-specific as to the Veteran's case. In particular, the August 2013 examiner cited obesity as a pertinent risk factor for sleep apnea; however, medical evidence demonstrates that the Veteran is not obese. The examiner additionally stated that "PTSD is not a medically acknowledged risk factor for sleep apnea." In support of his claim, the Veteran submitted multiple internet articles in support of his contention that sleep apnea may be caused or aggravated by PTSD. Given the inadequacies of the August 2013 VA examiner's opinion, as well as the additional evidence submitted by the Veteran, the Board remanded the claim in order to afford the Veteran a new VA medical opinion to address the outstanding question of nexus. Pursuant to the June 2018 Board Remand, the Veteran was afforded a VA medical opinion in May 2021 at which time the examiner determined that the claimed OSA was less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness. The examiner explained, DEMO exam dated 4/22/1991 make no mention of sleep related issues. The remainder of the service record makes no mention of sleep related issues or fatigue. The Veteran did not give a history of hypersomnolence while in service. The Veteran states that his kids at various times would comment on his snoring however he does not recall his wife commenting on apneas. Snoring, while a symptom of obstructive sleep apnea OSA), is not diagnostic of OSA and can have other causes. A sleep study is required for the diagnosis of OSA. VA records document sleep complaints starting in 2000 and he was diagnosed with OSA by an overnight sleep study in 2010, seventeen years after separation. Therefore, there is no evidence to support a diagnosis of obstructive sleep apnea during service. As such, it is less likely than not that the diagnosed obstructive sleep apnea had its onset in service, or is otherwise the result of a disease or injury in service, as there are no documented conditions in the service treatment records which would result in a diagnosis of sleep apnea. The May 2020 VA examiner further indicated that the OSA is not at least as likely as not (50 percent or greater probability) proximately due to or the result of the Veteran's PTSD. The examiner explained, The Veteran complained of sleep related issues in primary care notes dated 12/2000 and 1/2001 and again in 9/12/2007, along with possible depression. Primary care notes thereafter continue to document depression related concerns. A mental health note from 7/10/2012 documents significant sleep issues related to nightmares and flashbacks with a probable diagnosis of PTSD. He is currently service connected for PTSD. He was diagnosed with obstructive sleep apnea in 2010 based on a sleep study from 3/2010 which was done in response to his new wife mentioning noted apneas while he was sleeping. He was started on CPAP which he states has been beneficial in terms of decreasing snoring, witnessed apneas and some fatigue, hypersomnolence. He is followed by a private sleep clinic outside of the VA system and records from this clinic are not available for review. The etiology of his sleep apnea if defined, is not available for review, [h]owever the etiology of sleep apnea is not always pursued as long as treatment with CPAP is tolerated and is successful. Obesity is one of the most common risk factors for OSA and the Veteran's weight has fluctuated greatly, being as high as 213 lbs. in 2003, 190lb at the time of his sleep study in 2010, and 176lb most recently in 2020. These weight fluctuations very likely contributed to his sleep apnea symptoms. Risk factors for obstructive sleep apnea include but are not limited to age, male gender, obesity, genetics and certain craniofacial or upper airway structural issues. Smoking may be a risk factor as well. PTSD is certainly associated with disordered sleep and can result in many symptoms which overlap with sleep apnea such as frequent night-time awakenings, daytime hypersomnolence, fatigue and poor concentration. However, PTSD is not an established risk factor for obstructive sleep apnea and a search of the peer reviewed literature did not reveal any causal association between PTSD and obstructive sleep apnea. There are several studies which have identified an increased prevalence of obstructive sleep apnea in people with PTSD. Summaries of several of the studies are included in the references below, however, none of them establish a causal relationship between PTSD and obstructive sleep apnea. To specifically address the information submitted by the Veteran, the article by Allison Reddick does not provide any references to any research studies or any reference material at all and therefore is difficult to comment on. In addition to PTSD, the Veteran is service connected for bilateral degenerative joint disease of the knees, knee pain and instability, bilateral tinnitus, irritable bowel syndrome, penile lesions and a skin rash of the back and chest. None of these conditions are related to obstructive sleep apnea and there is no known mechanism by which any of these conditions would cause OSA. The May 2020 VA examiner additionally determined that the Veteran's OSA is not aggravated beyond its natural progression by a service-connected disability, to include PTSD. The examiner explained that [t]he Veteran reports having had his symptoms relating to PTSD since returning from deployment. He reports the symptoms as having been more severe in the past and stated that although still persisting, are better now than they used to be." The examiner explained, "[t]he Veteran was diagnosed with sleep apnea in 2010, 17 years after separation and years after the Veteran's reported symptoms of PTSD therefore establishing a baseline for obstructive sleep apnea prior to possible aggravation by PTSD is not possible." The examiner further explained, As noted in the multiple studies above looking at PTSD and OSA, (see second opinion above), there seems to be an increased prevalence of OSA in people diagnosed with PTSD. The risk of OSA seems to increase as the severity of PTSD increases. However, cause and effect of either condition on the other has not been established. It is also possible that both conditions arise from similar or overlapping risk factors. Without established causality, aggravation of one condition to the other cannot be determined. In addition to PTSD, the Veteran is service connected for bilateral degenerative joint disease of the knees, knee pain and instability, bilateral tinnitus, irritable bowel syndrome, penile lesions and a skin rash of the back and chest. None of these conditions are related to obstructive sleep apnea and there is no known mechanism by which any of these conditions would aggravate OSA. As such, the obstructive sleep apnea is less likely than not aggravated beyond its natural progression by a service connected disability, to specifically include PTSD. The Veteran was subsequently afforded a VA examination in November 2020, at which time the examiner confirmed a continuing diagnosis of OSA. In a separate November 2020 VA medical opinion, the examiner indicated that the diagnosed OSA is not at least as likely as not proximately or the result of the Veteran's service-connected PTSD. The examiner explained that "[t]he conditions of OSA and PTSD are not medically related. The OSA is a separate entity entirely from the posttraumatic stress disorder and unrelated to it." The examiner continued, "[w]hile some studies have suggested an association between OSA and PTSD, they do not show causality. The conditions of sleep apnea and PTSD may co-exist; however, sleep apnea is an obstructive process of the oral-pharyngeal airway, a separate and unrelated entity to the PTSD/mental health condition that does not cause the physical airway obstruction." The examiner concluded, "[t]here is no established causal relationship between PTSD and sleep apnea. A thorough review of medical literature failed to demonstrate a causal relationship. A nexus has not been established." When assessing the probative value of a medical opinion, the access to claims files and the thoroughness and detail of the opinion must be considered. The opinion is considered probative if it is definitive and supported by detailed rationale. See Prejean, 13 Vet. App. at 448-49. The Court has held that claims file review, as it pertains to obtaining an overview of a claimant's medical history, is not a requirement for private medical opinions. A medical opinion that contains only data and conclusions is not entitled to any weight. Further a review of the claims file cannot compensate for lack of the reasoned analysis required in a medical opinion, which is where most of the probative value of a medical opinion comes from. "It is the factually accurate, fully articulated, sound reasoning for the conclusion, not the mere fact that the claims file was reviewed, that contributes probative value to a medical opinion." See Nieves-Rodriguez, supra. In this matter, the Board finds that the May 2020 and November 2020 medical opinions were based on a review of the record, including the statements and evidence submitted by the Veteran, and the examiners explained the reasons for their conclusions based on an accurate characterization of the evidence of record. The Board therefore places significant weight on the cumulative findings expressed in the May 2020 and November 2020 VA medical opinions. See Nieves-Rodriguez, supra; see also Bloom, 12 Vet. App. at 187 (the probative value of a physician's statement is dependent, in part, upon the extent to which it reflects "clinical data or other rationale to support his opinion"). Accordingly, the Board finds that the competent medical evidence demonstrating the absence of nexus between the claimed OSA and the Veteran's active duty service, as well as his service-connected PTSD, outweighs any medical evidence suggestive of a nexus or aggravation. The Board has carefully considered the contentions of the Veteran that he has OSA, which were incurred during service and/or as secondary to his service-connected PTSD. To this end, the Board recognizes that lay witnesses are competent to opine as to some matters of diagnosis and etiology, and the Board must determine on a case by case basis whether a veteran's particular disability is the type of disability for which lay evidence is competent. See Davidson, 581 F.3d at 1316; Kahana, 24 Vet. App. at 433, n. 4. In this case, the Veteran's assertions as to etiology concern an internal medical process, which extends beyond an immediately observable cause-and-effect relationship that is of the type that the courts have found to be beyond the competence of lay witnesses. Cf. Jandreau, 492 F.3d at 1376 (lay witness capable of diagnosing dislocated shoulder); Barr, 21 Vet. App. at 308-9; Falzone, 8 Vet. App. at 403 (lay person competent to testify to pain and visible flatness of his feet); with Clemons, 23 Vet. App. at 6 ("It is generally the province of medical professionals to diagnose or label a mental condition, not the claimant"); Woehlaert, 21 Vet. App. at 462 (unlike varicose veins or a dislocated shoulder, rheumatic fever is not a condition capable of lay diagnosis); Jandreau, 492 F.3d at 1377, n. 4 ("sometimes the layperson will be competent to identify the condition where the condition is simple, for example a broken leg, and sometimes not, for example, a form of cancer"). See also Colantonio, 606 F.3d at 1382 (recognizing that in some cases lay testimony "falls short" in proving an issue that requires expert medical knowledge). Questions of competency notwithstanding, the Veteran's lay theories regarding the onset and etiology of his OSA are contradicted by the conclusions of the May 2020 and November 2020 VA examiners who specifically considered the Veteran's lay statements in rendering the negative opinions. The Board finds the specific, reasoned opinion of the trained health care providers who conducted the May2020 and November 2020 VA opinions to be of greater probative weight than the more general lay assertions of the Veteran. The Board has considered that lay evidence concerning continuity of symptoms after service, if credible, is ultimately competent, regardless of the lack of contemporaneous medical evidence. Buchanan, supra. Crucially, the May 2020 and November 2020 VA medical opinions specifically considered the lay assertions and inferences contained in the record in rendering the negative nexus opinions. The Board is charged with weighing the positive and negative evidence; resolving reasonable doubt in the Veteran's favor when the evidence is in equipoise. Considering the record, including post-service medical evidence, May 2020 and November 2020 VA medical opinions, and lay evidence presented by the Veteran, the Board finds that the negative evidence is more persuasive and of greater evidentiary weight. In conclusion, as the evidence is not in approximate balance and is persuasively against the Veteran's claim, the benefit of the doubt rule is inapplicable. See 38 U.S.C. § 5107(b); Lynch v. McDonough, No. 20-2067 (Fed. Cir. 2021). K. Conner Veterans Law Judge Board of Veterans' Appeals Attorney for the Board K. K. Buckley, Counsel The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.