Citation Nr: 21011116 Decision Date: 02/27/21 Archive Date: 02/27/21 DOCKET NO. 14-09 353 DATE: February 27, 2021 ORDER Entitlement to service connection for diabetes mellitus, type II, is denied. Entitlement to service connection for degenerative disk disease is denied. Entitlement to service connection for spinal stenosis is denied. Entitlement to service connection for a left knee condition is denied. Entitlement to service connection for a right knee condition is denied. Entitlement to service connection for glaucoma is denied. Entitlement to service connection for loss of visual field is denied. Entitlement to service connection for fibromyalgia is denied. Entitlement to service connection for carpal tunnel syndrome is denied. Entitlement to service connection for a respiratory condition is denied. FINDINGS OF FACT 1. The Veteran is not presumed to have been exposed to herbicide agents during his active service; actual in-service exposure to herbicide agents has not been shown; and the preponderance of the evidence is against finding that the Veteran’s diabetes mellitus, type II, began during active service, or is otherwise related to an in-service event, injury, or disease. 2. The preponderance of the evidence is against finding that the Veteran’s degenerative disk disease and spinal stenosis began during his active service, or are otherwise related to an in-service event, injury, or disease. 3. The preponderance of the evidence is against finding that the Veteran’s left and right knee conditions began during his active service, or are otherwise related to an in-service event, injury, or disease. 4. The preponderance of the evidence is against finding that the Veteran’s glaucoma and loss of visual field began during his active service, or are otherwise related to an in-service event, injury, or disease, to include exposure to ionizing radiation. 5. The preponderance of the evidence is against finding that the Veteran’s fibromyalgia began during his active service, or is otherwise related to an in-service event, injury, or disease. 6. The preponderance of the evidence is against finding that the Veteran’s carpal tunnel syndrome began during his active service, or is otherwise related to an in-service event, injury, or disease. 7. The preponderance of the evidence is against finding that the Veteran’s respiratory condition began during his active service, or is otherwise related to an in-service event, injury, or disease. CONCLUSIONS OF LAW 1. The criteria for entitlement to service connection for diabetes mellitus, type II, have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.307, 3.309. 2. The criteria for entitlement to service connection for degenerative disk disease have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303. 3. The criteria for entitlement to service connection for spinal stenosis have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303. 4. The criteria for entitlement to service connection for a left knee condition have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303. 5. The criteria for entitlement to service connection for a right knee condition have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303. 6. The criteria for entitlement to service connection for glaucoma have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.311. 7. The criteria for entitlement to service connection for loss of visual field have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.311. 8. The criteria for entitlement to service connection for fibromyalgia have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303. 9. The criteria for entitlement to service connection for carpal tunnel syndrome have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303. 10. The criteria for entitlement to service connection for a respiratory condition have not been met. 38 U.S.C. §§ 1110, 5103, 5107A; 38 C.F.R. §§ 3.102, 3.159, 3.303.   REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran had active service from October 1967 to October 1969. The Board remanded this case in May 2014, June 2016, and February 2020. The May 2014 remand directed the Agency of Original Jurisdiction (AOJ) to obtain the Veteran’s service personnel records, provide the Veteran a VA examination as to his claimed spinal conditions, provide the Veteran a VA examination to determine whether his right cataract was a posterior subcapsular cataract, and perform the development necessary to determine whether the Veteran’s post-operative left posterior subcapsular cataract and, if diagnosed, post-operative right posterior subcapsular cataract may have been caused by in-service exposure to ionizing radiation. The June 2016 remand again directed the AOJ to obtain an opinion as to whether the Veteran’s right cataract was a posterior subcapsular cataract and to perform the development regarding ionizing radiation exposure. The February 2020 remand directed the AOJ to perform the development necessary to determine whether the Veteran served on a ship that navigated within 12 nautical miles of the Republic of Vietnam, obtain an addendum opinion as to the Veteran’s claimed spinal conditions, and obtain an addendum opinions as to the Veteran’s claimed left and right knee conditions. The Board finds that VA at least substantially complied with the May 2014, June 2016, and February 2020 remands. Specifically, adequate development has been performed to determine whether the Veteran served on a ship that navigated within 12 nautical miles of the Republic of Vietnam and whether his post-operative left posterior subcapsular cataract may have been caused by in-service exposure to ionizing radiation. It also includes adequate opinions as to the claimed spinal conditions, left and right knee conditions, and right eye conditions. Finally, service personnel records have been associated with the record. See 38 U.S.C. § 5103A(b); Stegall v. West, 11 Vet. App. 268, 271 (1998); D’Aries v. Peake, 22 Vet. App. 97, 105 (2008). Neither the Veteran nor his representative has raised any issues with regard to the duty to notify or duty to assist as they pertain to the issues denied in this decision. See Scott v. McDonald, 789 F.3d 1375, 1381 (Fed. Cir. 2015) (holding that “the Board’s obligation to read filings in a liberal manner does not require the Board . . . to search the record and address procedural arguments when the veteran fails to raise them before the Board.”); Dickens v. McDonald, 814 F.3d 1359, 1361 (Fed. Cir. 2016) (applying Scott to a duty to assist argument). The analysis in this decision focuses on the most relevant evidence and on what the evidence shows or does not show with respect to the issues denied in this decision. The Veteran should not assume that evidence that is not explicitly discussed in the decision has been overlooked. See Timberlake v. Gober, 14 Vet. App. 122 (2000) (noting that the law requires only that reasons for rejecting evidence favorable to the claimant be addressed). Service Connection Service connection may be granted for disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. § 3.303. The three-element test for service connection requires evidence of: (1) a current disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the current disability and the in-service disease or injury. Shedden v. Principi, 381 F.3d 1163, 1166 -67 (Fed. Cir. 2004). 1. Entitlement to service connection for diabetes mellitus, type II The Veteran seeks entitlement to service connection for diabetes mellitus, type II, which he contends is due to in-service exposure to herbicide agents. In his substantive appeal, he asserted “I could have been exposed to chemicals aboard ship, helicopter, and plane that left and returned to the ship”. Certain diseases, to include diabetes mellitus, type II, may be presumed to have been incurred in service where a veteran was exposed to herbicide agents, such as Agent Orange, while on active service, even when there is no evidence of such a disease during the period of service. 38 U.S.C. § 1116; 38 C.F.R. §§ 3.307(a)(6), 3.309(e). Generally, the regulation applies where an enumerated disease becomes manifest to a compensable degree at any time after active service. 38 C.F.R. § 3.307(a)(6)(ii). Veterans who served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, are presumed to have been exposed to herbicide agents. 38 C.F.R. § 3.307(a)(6)(iii). Service in the Republic of Vietnam includes service offshore if the location is not more than 12 nautical miles seaward of a line commencing on the southwestern demarcation line of the waters of Vietnam and Cambodia and intersecting the points listed in 38 U.S.C. § 1116A(d). The Veteran has not contended, and the record does not show, that he had active service on the landmass of the Republic of Vietnam. Rather, he contends that he may have been exposed to chemicals while serving aboard a United States Navy ship. Therefore, the Board finds that in-service exposure to herbicide agents cannot be presumed based on service on the landmass of the Republic of Vietnam, and the Board will proceed to consider whether such exposure can be presumed on another basis and whether actual exposure to herbicide agents has been shown. The Veteran’s service personnel records show that he served aboard the USS Enterprise beginning in March 1968. The decklogs for that ship from December 1967 through October 1969 are of record. Those decklogs document the specific location, measured in latitude and longitude, of the USS Enterprise three times for each day. They show that the USS Enterprise patrolled the area around Yankee Station in the Gulf of Tonkin for several periods while the Veteran was on that ship. The Board has carefully reviewed the decklogs, to include the specific positions noted during the periods when the ship was stationed in the Gulf of Tonkin, and finds that none indicate that the USS Enterprise came within 12 nautical miles seaward of a line commencing on the southwestern demarcation line of the waters of Vietnam and Cambodia and intersecting the points listed in 38 U.S.C. § 1116A(d). They show that when the ship was stationed in the Gulf of Tonkin, it stayed well outside of 12 nautical miles from the landmass of the Republic of Vietnam. Therefore, in-service exposure to herbicide agents may not be presumed based on service within 12 nautical miles from the landmass of the Republic of Vietnam. Regarding the Veteran’s assertion that he may have been exposed to chemicals while serving aboard the USS Enterprise, to include through contact with helicopters and airplanes returning to the ship, the regulations do provide that exposure to herbicide agents will be presumed for individuals who performed service in the Air Force or Air Force Reserve under circumstances in which the individual concerned regularly and repeatedly operated, maintained, or served onboard C-123 aircraft known to have been used to spray an herbicide agent during the Vietnam era. See 38 C.F.R. § 3.307(a)(6)(v). However, in this case, the Veteran did not serve in the Air Force or Air Force Reserve and there is no evidence indicating that he regularly and repeatedly operated, maintained, or served onboard C-123 aircraft. His DD Form 214 shows that his military occupational specialty was gunner’s mate. As such, the presumption is not for application in this case. VA does not otherwise presume exposure to herbicide agents based on contact with aircraft, equipment, or people that had been to Vietnam. The appellant has not provided evidence to support his assertions, and his assertion that he “could have been exposed to chemicals” aboard a United States Navy ship is vague. Thus, those assertions are based on pure supposition. Therefore, the Board does not afford probative value to those assertions, and finds that the assertions do not show that it is at least as likely as not that the Veteran was exposed to herbicide agents during his active service. The Board acknowledges the appellant’s assertions to the effect that, based on the fact that he has a number of diseases and disabilities he believes may have been caused by exposure to herbicide agents, it may be deduced that he was exposed to herbicide agents. However, the diseases listed in 38 C.F.R. § 3.309(e) are only presumed to be caused by exposure to herbicide agents if exposure to herbicide agents is first shown. There are no provisions in the law that would allow VA to presume that those diseases are caused by exposure to herbicide agents when such exposure has not been shown, even for veterans who suffer from multiple disease that are on that list and for which no other medical etiology has been found. Therefore, the Board does not afford probative value to those assertions, and finds that the assertions do not show that it is at least as likely as not that the Veteran was exposed to herbicide agents during his active service. In addition, the Veteran’s service treatment records are absent for evidence of in-service treatment for diabetes mellitus, type II. There is no competent evidence of record linking the Veteran’s diabetes mellitus, type II, to any aspect of his active service on a direct basis. Therefore, the record does not show that the Veteran’s diabetes mellitus, type II, had its onset during his active service or is otherwise etiologically related to his active service on a direct basis. See Combee v. Brown, 34 F.3d 1039, 1043 (Fed. Cir. 1994). In summary, there is no competent, probative evidence of record linking the Veteran’s diabetes mellitus, type II, to his active service. In view of the foregoing, the Board concludes that the preponderance of the evidence is against the claim for entitlement to diabetes mellitus, type II. Because the preponderance of the evidence is against the claim, the doctrine of reasonable doubt is not for application, and the claim must be denied. 38 U.S.C. § 5107(b); see also Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 2. Entitlement to service connection for degenerative disk disease 3. Entitlement to service connection for spinal stenosis The Veteran seeks entitlement to service connection for degenerative disk disease and spinal stenosis, which he contends are due to in-service strenuous activities, including pulling lines on his ship, or due to in-service exposure to chemicals. The question for the Board is whether the Veteran has a current disability that began during service or is at least as likely as not related to an in-service injury, event, or disease. The Board concludes that, although the Veteran has current diagnoses of degenerative disk disease and spinal stenosis, he is competent and credible in his reports of engaging in strenuous activities during his active service, and the service treatment records show that he reported back pain in May 1968, the preponderance of the evidence weighs against finding that the Veteran’s degenerative disk disease and spinal stenosis began during service or are otherwise related to an in-service injury, event, or disease. The service treatment records show that the Veteran reported a two-week history of pain in the lower stomach and lower side of the back in May 1968. He was diagnosed at that time with psychogenic gastroenteritis. He was also diagnosed with a urinary tract infection two days later based on a urinalysis. The Veteran did not report back pain or other spinal symptoms during the remainder of his active service, nor was he diagnosed with a back, neck, or spinal condition during his active service. He had a normal clinical evaluation of the spine on examination for separation from active service in September 1969. The medical treatment records do not show the Veteran was diagnosed with degenerative disk disease, spinal stenosis, or other spinal disability until many years after his separation from active service. Therefore, the record does not show that the Veteran’s current degenerative disk disease or spinal stenosis had its onset during his active service. Regarding whether the current degenerative disk disease or spinal stenosis may be related to an in-service event, injury, or disease, to include the in-service complaint of back pain or the reported in-service strenuous activities, in May 2015 a VA examiner opined that the Veteran’s diagnosed spine disabilities are less likely than not related to an in-service injury, event, or illness. As a rationale for that opinion, the examiner explained that the Veteran’s symptoms on examination and x-ray findings are consistent with normal degenerative of the lumbar spine. The Veteran does not have a history of medical complaints or treatment of significance for back problems. The Veteran also has generalized degeneration in the spine involving all levels, as opposed to a specific level of an injury. The examiner also explained that the in-service back pain complaint was treated symptomatically with rest, and that the Veteran sought medical attention to his back two additional times post-service in 1979 and 1983. Both post-service instances of back pain were treated symptomatically with resolution. The examination report reflects that the examiner considered the Veteran’s reports that he spent extended periods of time pulling lines on his ship. In a January 2021 addendum opinion, another VA examiner opined that the Veteran’s spinal disabilities are not at least as likely as not related to an in-service injury, event, or disease. As a rationale for that opinion, the examiner explained that, in view of the contemporaneous description of the pain, the in-service complaint of back is most consistent with a muscle cramp. The described location of the pain was not near the vertebral column. In addition, in light of the associated lower stomach pain and the focus on history of bowel function at the time, the pain could have been intra-abdominal, mesenteric adenitis, kidney stone, or acute gastro-enteritis. If the pain was actually musculoskeletal, inflammation of the posterior-superior iliac spine is a common condition which somewhat matches the report. But, injury to the vertebral column does not match the description. Furthermore, the workup performed at the time discloses that the back pain originated in the urinary tract and not in the spine. Regarding the two post-service treatments for back pain, the examiner found that having had only two appointments in 30 years post-service would suggest an absence of a nexus with the Veteran’s active service. The May 2015 and January 2021 examiners’ opinions are probative because they are based on an accurate medical history and provide explanations that contain clear conclusions and supporting data. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008). The May 2015 VA examiner explained that the Veteran’s current spinal degeneration is of a generalized nature consistent with normal degeneration rather than an injury. The January 2021 VA examiner explained that the in-service low back complaint was due to a urinary tract condition or to inflammation that resolved, but was not due to an injury to the vertebral column. He also explained that the lack of treatment in the 30 years following separation from active service suggests that there is no nexus to service. The Board accepts the examiners’ opinions as probative evidence that the current spinal disabilities are not related to the Veteran’s active service, to include the May 1968 complaint of back pain and the reported in-service strenuous activities. The Board acknowledges the Veteran’s belief that his current degenerative disk disease and spinal stenosis are related to an in-service injury, event, or disease. However, the Veteran in this case is not considered competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of the pathology and progression of specific spinal disabilities. Therefore, it is outside the competence of the Veteran, as the record does not show that he has the medical training or credentials to make such a determination. Jandreau v. Nicholson, 492 F.3d 1372, 1377 n.4 (Fed. Cir. 2007); see also Kahana v. Shinseki, 24 Vet. App. 428 (2011). Consequently, his statements in that regard are not due probative value, and they do not weigh against the VA examiners’ probative opinions. Finally, the Board acknowledges the Veteran’s argument that his degenerative disk disease and spinal stenosis are due to in-service exposure to chemicals. As noted above, exposure to herbicide agents may not be presumed in this case. In addition, actual exposure to herbicide agents has not been shown. Moreover, degenerative disk disease and spinal stenosis are not on the list of diseases associated with exposure to certain herbicide agents under 38 C.F.R. § 3.309(e). The Veteran has not presented evidence—beyond his own unsupported assertions—of exposure to other chemicals that may have caused his degenerative disk disease and spinal stenosis. Therefore, the Board concludes that service connection may not be awarded based on the Veteran’s assertions of in-service exposure to chemicals. In summary, the preponderance of the evidence is against finding that the Veteran’s degenerative disk disease or spinal stenosis began during his active service, or is otherwise related to an in-service event, injury, or disease.. In view of the foregoing, the Board concludes that the preponderance of the evidence is against the claims for entitlement to service connection for degenerative disk disease and entitlement to service connection for spinal stenosis. Because the preponderance of the evidence is against the claims, the doctrine of reasonable doubt is not for application, and the claims must be denied. 38 U.S.C. § 5107(b); see also Gilbert, 1 Vet. App. 49. 4. Entitlement to service connection for a left knee condition 5. Entitlement to service connection for a right knee condition The Veteran seeks entitlement to service connection for left and right knee conditions, which he contends are due to in-service strenuous activities, including pulling lines on his ship, or due to in-service exposure to chemicals. The question for the Board is whether the Veteran has a current disability that began during service or is at least as likely as not related to an in-service injury, event, or disease. The Board concludes that, although the Veteran has a current diagnosis of degenerative joint disease of the knees and had prior treatment for torn meniscuses, he is competent and credible in his reports of engaging in strenuous activities during his active service, and the service treatment records show that he reported knee pain in February 1968, the preponderance of the evidence weighs against finding that the Veteran’s degenerative joint disease of the knees began during service or is otherwise related to an in-service injury, event, or disease. The service treatment records show that the Veteran endorsed a “trick” or locked knee on an April 1967 report of medical history for entrance into active service; however, no knee disability was noted at the time of his medical examination for entrance into active service. In June 1967, he reported that he injured his right knee while in grade school. X-rays taken at that time revealed normal knees except for a bipartite patella. In February 1968, the Veteran reported a two-week history of left knee pain. X-rays taken at that time showed that the left knee was within normal limits. The Veteran did not report knee pain or other knee symptoms during the remainder of his active service, nor was he diagnosed with a left or right knee condition during his active service. He had a normal clinical evaluation of the lower extremities on examination for separation from active service in September 1969. Given the Veteran’s statements on the April 1967 report of medical history and at the June 1967 treatment visit, there is a question as to whether the Veteran’s knee conditions preexisted his military service. A veteran will be considered to have been in sound condition when examined, accepted and enrolled for service, except as to defects, infirmities, or disorders noted at entrance into service, or where clear and unmistakable (obvious or manifest) evidence demonstrates that an injury or disease existed prior thereto and was not aggravated by such service. 38 C.F.R. § 3.304(b). This presumption of soundness applies only when a disease or injury not noted upon entry to service manifests in service, and a question arises as to whether it preexisted service. Gilbert v. Shinseki, 26 Vet. App. 48, 55 (2012), aff’d 749 F.3d 1370 (Fed. Cir. 2014). As noted above, the Veteran’s April 1967 entrance examination is absent for any notations of defects, infirmities, or disorders of the knees. Additionally, the evidence is at least in equipoise as to whether left and right knee conditions manifested during service. Therefore, with respect to left and right knee conditions, the presumption of soundness attaches. 38 C.F.R. § 3.304(b). Because the presumption of soundness attaches with respect to those disabilities, there must be clear and unmistakable evidence that the disabilities both pre-existed service and were not aggravated in service. Id; see also Wagner v. Principi, 370 F.3d 1089, 1096 (Fed. Cir. 2004). Clear and unmistakable evidence is defined as obvious or manifest. 38 C.F.R. § 3.306(b). Clear and unmistakable evidence means that the evidence “‘cannot be misinterpreted and misunderstood, i.e., it is undebatable.’” Quirin v Shinseki, 22 Vet. App. 390, 396 (2009). In this case, the only evidence that the Veteran’s left or right knee condition pre-existed his active service is the statement he made on the April 1967 report of medical history and the report he made at the June 1967 treatment visit. History of preservice existence of conditions recorded at the time of examination does not constitute a notation of such conditions but will be considered together with all other material evidence in determinations as to inception. 38 C.F.R. § 3.304(b)(1). The Board finds that the Veteran’s report of a history of knee injury on the April 1967 report of medical history, even in conjunction with his later statements as to his medical history at the June 1967 treatment visit, does not establish that he clearly and unmistakably had a preexisting left or right knee disability at the time of his entrance into active service. Therefore, the presumption of soundness has not been rebutted. When VA fails to carry its burden as to either preexistence or lack of aggravation, whether and to what extent the Veteran is entitled to compensation for the injury would be determined upon the assumption that the injury was incurred during service. It does not necessarily follow, however, that an unrebutted presumption of soundness will lead to service connection for the disease or injury. The Veteran must still demonstrate a current disability and a nexus between the current disability and the injury or disease in service. Horn v. Shinseki, 25 Vet. App. 231, 233 (2012). In that regard, in February 2012 a VA examiner opined that the Veteran’s left and right knee degenerative joint disease is less likely than not related to an in-service injury, event, or illness. As a rationale for that opinion, the examiner explained that the Veteran is obese and that being obese is “a major factor” in knee degenerative joint disease. In a January 2021 addendum opinion, another VA examiner opined that the Veteran’s left and right knee conditions are not at least as likely as not related to an in-service injury, event, or disease. As a rationale for that opinion, the examiner explained that the in-service report of knee pain was for pain superior to the joint of the left knee and not on the joint line and came after a period of intense exercise. Thus, the pain in the left knee appears to have been a single incident associated with overuse. Its location over the medial femoral condyle, superior to the joint line is consistent with symptomatic plica and not with meniscal tear, which the Veteran was treated for decades after his separation from active service. In addition, there are no service treatment records showing complaint of or treatment for a right knee condition. The current right knee condition originated with a torn meniscus in 2003, more than 30 years after the Veteran’s separation from active service. The February 2012 and January 2021 examiners’ opinions are probative because they are based on an accurate medical history and provide explanations that contain clear conclusions and supporting data. Nieves-Rodriguez, 22 Vet. App. at 304. The February 2012 VA examiner explained that the Veteran’s obesity, which is not a service-connected disability, is a factor in his development of degenerative joint disease of the bilateral knees. The January 2021 VA examiner explained that the in-service left knee complaint was consistent with a single incident associated with overuse rather than with the left and right knee disabilities the Veteran was diagnosed with and treated for many years after his separation from active service. The Board accepts the examiners’ opinions as probative evidence that the current left and right knee disabilities are not related to the Veteran’s active service, to include the February 1968 report of left knee pain. The Board acknowledges the Veteran’s belief that his current left and right knee conditions are related to an in-service injury, event, or disease. However, the Veteran in this case is not considered competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of the pathology and progression of specific knee disabilities. Therefore, it is outside the competence of the Veteran, as the record does not show that he has the medical training or credentials to make such a determination. Jandreau, 492 F.3d 1372, 1377 n.4; see also Kahana, 24 Vet. App. 428. Consequently, his statements in that regard are not due probative value, and they do not weigh against the VA examiners’ probative opinions. Finally, the Board acknowledges the Veteran’s argument that his left and right knee conditions are due to in-service exposure to chemicals. As noted above, exposure to herbicide agents may not be presumed in this case. In addition, actual exposure to herbicide agents has not been shown. Moreover, the Veteran’s diagnosed left and right knee conditions are not on the list of diseases associated with exposure to certain herbicide agents under 38 C.F.R. § 3.309(e). The Veteran has not presented evidence—beyond his own unsupported assertions—of exposure to other chemicals that may have caused his left and right knee conditions. Therefore, the Board concludes that service connection may not be awarded based on the Veteran’s assertions of in-service exposure to chemicals. In summary, the preponderance of the evidence is against finding that the Veteran’s left and right knee conditions began during his active service, or are otherwise related to an in-service event, injury, or disease. In view of the foregoing, the Board concludes that the preponderance of the evidence is against the claims for entitlement to service connection for a left knee condition and entitlement to service connection for a right knee condition. Because the preponderance of the evidence is against the claims, the doctrine of reasonable doubt is not for application, and the claims must be denied. 38 U.S.C. § 5107(b); see also Gilbert, 1 Vet. App. 49. 6. Entitlement to service connection for glaucoma 7. Entitlement to service connection for loss of visual field The Veteran seeks entitlement to service connection for glaucoma and loss of visual field, which he contends are due to in-service exposure to chemicals. The question for the Board is whether the Veteran has a current disability that began during service or is at least as likely as not related to an in-service injury, event, or disease. The Board concludes that, although the Veteran has current diagnoses of primary open angle glaucoma and bilateral pseudophakia, the preponderance of the evidence weighs against finding that those disabilities began during service or are otherwise related to an in-service injury, event, or disease. The service treatment records show that the Veteran was noted as having defective vision at the time of the April 1967 medical examination for entrance into active service. No other eye or vision condition was noted at that time. The Veteran was not treated for any eye or vision condition during service other than his defective vision. He had a normal clinical evaluation of the eyes on examination for separation from active service in September 1969. The medical treatment records do not show the Veteran was diagnosed with glaucoma, loss of visual field, cataracts, or any other eye or vision condition until many years after his separation from active service. Therefore, the record does not show that the Veteran’s current glaucoma and loss of visual field had their onset during his active service. The Board notes that the Veteran’s refractive error, which is noted in the service treatment records as defective vision, is considered a developmental defect and is not a disease or injury for VA disability compensation purposes. See 38 C.F.R. § 4.9. Therefore, the Veteran may not be service connected for refractive error. The Veteran’s service records include a DD Form 1141, Record of Occupational Exposure to Ionizing Radiation, that shows a total lifetime accumulated dose of 00.013 rem. Service connection based on exposure to ionizing radiation can be established under 38 C.F.R. § 3.303(d) with the assistance of the procedural advantages prescribed in 38 C.F.R. § 3.311 if the condition at issue is a radiogenic disease. A “radiogenic disease” means a disease that may be induced by ionizing radiation and includes posterior subcapsular cataracts. 38 C.F.R. § 3.311(b)(2). In this case, the record shows that the Veteran has a diagnosis of bilateral pseudophakia, status-post cataract removal. In July 2016, a VA examiner reviewed the record and clarified that the right cataract was a 2+ nuclear sclerosis cataract and the left cataract was a posterior subcapsular cataracts. Therefore, the issue of whether the left cataract and its residuals may be related to in-service exposure to ionizing radiation has been raised by the record. Under 38 C.F.R. § 3.311, in claims not involving participation in atmospheric nuclear testing or the American occupation of Hiroshima or Nagasaki, Japan, a request must be made for any available records concerning a veteran’s exposure to radiation. These records normally include but may not be limited to the Veteran’s DD Form 1141, if maintained, service treatment records, and other records which may contain information pertaining to the Veteran’s radiation dose in service. All such records will be forwarded to the Under Secretary for Health, who will be responsible for preparation of a dose estimate, to the extent feasible, based on available methodologies. 38 C.F.R. § 3.311(a)(2)(iii). The claim, including the dose estimate, will be reviewed by the Under Secretary for Benefits pursuant to 38 C.F.R. § 3.311(c). In July 2017,, the Director of Compensation Service referred the case to the VA Under Secretary for Health for preparation of a dose estimate and an opinion as to “whether it is likely, unlikely, or as likely as not” that the Veteran’s posterior subcapsular cataract of the left eye resulted from exposure to radiation in service. In August 2017, a response was provided by a health physicist examiner. The examiner noted review of the Veteran’s service records, including the DD Form 1141 showing a total lifetime accumulated radiation dose of 00.013 rem. The examiner further noted that the Veteran was approximately 19 years old at the time of initial exposure to ionizing radiation and that the posterior subcapsular cataract of the left eye was diagnosed 37 years after the initial exposure. He cited to information from the Health Physics Society, including that a person might accumulate an effective dose from natural background radiation of about 50 mSv (5 rem) in the first 17 years of life and about 250 mSv (25 rem) during an average 80-year lifetime, and that scientific data shows evidence of health effects following high-dose exposures, but that below levels of about 100 mSv (10 rem) above background from all sources combined, the observed radiation effects in people are not statistically different from zero. Based on a review of the Veteran’s relevant record and the information from the Health Physics Society, the examiner concluded that, because the Veteran’s lifetime total radiation dose did not exceed 100 mSv (10 rem) above natural background, it is unlikely that his posterior subcapsular cataract of the left eye was caused by exposure to ionizing radiation during military service. The Board notes that the health physicist examiner indicated that he is a medical doctor. The Board finds that the examiner’s dose estimate constitutes sound scientific and medical evidence. As a health physicist, the examiner is particularly qualified to provide statements as to environmental levels of radiation and as to the way in which radiation interacts with matter and living systems. The examiner accounted for the Veteran’s service aboard the USS Enterprise, his military occupational specialty, his age at the time of initial exposure, the DD Form 1141 contained in the service records, and the time between initial exposure and the diagnosis of posterior subcapsular cataract of the left eye. The examiner’s dose estimate therefore is consistent with current medical knowledge and based on the particular facts of the Veteran’s case. VA may therefore rely on that dose estimate and the examiner’s opinion to make a determination as to the Veteran’s claim. See 38 C.F.R. § 3.311(c); see also Skaar v. Wilkie, 32 Vet. App. 156 (2020). The Board affords great weight to the August 2017 examiner’s opinion because it was based on a review of the relevant service records and relevant medical literature. The examiner provided excerpts from that literature that support his conclusion that it is unlikely that the Veteran’s posterior subcapsular cataract of the left eye was caused by his in-service radiation exposure. He explained that the Veteran’s total lifetime radiation exposure, even in consideration of the DD Form 1141, did not exceed 100 mSv (10 rem) above natural background noise. This conclusion is consistent with the record, as the DD Form 1141 shows an additional ionizing radiation exposure of only 00.013 rem for the entirety of the Veteran’s active service. That measurement is far less than 10 rem, which is the level at which the Health Physics Society determined statistically significant differences become evident. See Nieves-Rodriguez, 22 Vet. App. 295. The Board acknowledges that the term “unlikely” is vague when considered in isolation. However, the Board finds that the term, as used by the August 2017 examiner, is adequately specific when considered in the context of the other evidence of record. Specifically, as summarized above, the July 2017 memorandum referring the case to the Under Secretary for Health asked for preparation of an opinion as to “whether it is likely, unlikely, or as likely as not” that the Veteran’s posterior subcapsular cataract of the left eye resulted from exposure to radiation in service. When compared to the other options of “likely” and “as likely as not”, the term “unlikely” clearly was intended to mean less likely than not. In using the term “unlikely”, the August 2017 examiner was merely providing the opinion requested by selecting from the options presented. Accordingly, the examiner also clearly intended the term to mean less likely than not. Therefore, the Board interprets the examiner’s use of the term as meaning less likely than not. As such, the opinion is adequate for decision-making purposes despite using a term that would otherwise be vague. The Board acknowledges the Veteran’s belief that his current glaucoma and loss of visual field are related to an in-service injury, event, or disease. However, the Veteran in this case is not considered competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of the pathology and progression of specific eye and vision conditions. Therefore, it is outside the competence of the Veteran, as the record does not show that he has the medical training or credentials to make such a determination. Jandreau, 492 F.3d 1372, 1377 n.4; see also Kahana, 24 Vet. App. 428. Consequently, his statements in that regard are not due probative value. Finally, the Board acknowledges the Veteran’s argument that his glaucoma and loss of visual field are due to in-service exposure to chemicals. As noted above, exposure to herbicide agents may not be presumed in this case. In addition, actual exposure to herbicide agents has not been shown. Moreover, the Veteran’s diagnosed glaucoma and loss of visual field are not on the list of diseases associated with exposure to certain herbicide agents under 38 C.F.R. § 3.309(e). The Veteran has not presented evidence—beyond his own unsupported assertions—of exposure to other chemicals that may have caused his glaucoma and loss of visual field. Therefore, the Board concludes that service connection may not be awarded based on the Veteran’s assertions of in-service exposure to chemicals. In summary, the preponderance of the evidence is against finding that the Veteran’s glaucoma and loss of visual field began during his active service, or are otherwise related to an in-service event, injury, or disease. The evidence is also against finding that the Veteran’s posterior subcapsular cataract of the left eye and its residuals are due to in-service exposure to ionizing radiation. In view of the foregoing, the Board concludes that the preponderance of the evidence is against the claims for entitlement to service connection for glaucoma and for entitlement to service connection for loss of visual field. Because the preponderance of the evidence is against the claims, the doctrine of reasonable doubt is not for application, and the claims must be denied. 38 U.S.C. § 5107(b); see also Gilbert, 1 Vet. App. 49. 8. Entitlement to service connection for fibromyalgia 9. Entitlement to service connection for carpal tunnel syndrome 10. Entitlement to service connection for a respiratory condition The Veteran seeks entitlement to service connection for fibromyalgia, carpal tunnel syndrome, and respiratory conditions, which he contends are due to in-service exposure to chemicals. The question for the Board is whether the Veteran has a current disability that began during service or is at least as likely as not related to an in-service injury, event, or disease. The Board concludes that, although the Veteran has current diagnoses of fibromyalgia, carpal tunnel syndrome, and respiratory conditions, to include asthma and chronic obstructive pulmonary disease, the preponderance of the evidence weighs against finding that those disabilities began during service or are otherwise related to an in-service injury, event, or disease. The service treatment records show that the Veteran had normal clinical evaluations of the head, face, neck, abdomen and viscera, upper extremities, lower extremities, feet, spine, and lungs both at his April 1967 medical examination for entrance into active service and at his September 1969 medical examination for separation from active service. The service treatment records do not show complaint of or treatment for respiratory symptoms, neurological symptoms consistent with carpal tunnel syndrome, or symptoms consistent with fibromyalgia. There is no competent evidence of record linking the Veteran’s fibromyalgia, carpal tunnel syndrome, and respiratory conditions to any aspect of his active service. Therefore, the record does not show that the Veteran’s fibromyalgia, carpal tunnel syndrome, and respiratory conditions had their onset during his active service or are otherwise etiologically related to his active service on a direct basis. The Board acknowledges the Veteran’s belief that his current fibromyalgia, carpal tunnel syndrome, and respiratory conditions are related to an in-service injury, event, or disease. However, the Veteran in this case is not considered competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of the pathology and progression of fibromyalgia, carpal tunnel syndrome, and respiratory conditions. Therefore, it is outside the competence of the Veteran, as the record does not show that he has the medical training or credentials to make such a determination. Jandreau, 492 F.3d 1372, 1377 n.4; see also Kahana, 24 Vet. App. 428. Consequently, his statements in that regard are not due probative value. Finally, the Board acknowledges the Veteran’s argument that his fibromyalgia, carpal tunnel syndrome, and respiratory conditions are due to in-service exposure to chemicals. As noted above, exposure to herbicide agents may not be presumed in this case. In addition, actual exposure to herbicide agents has not been shown. Moreover, the Veteran’s diagnosed fibromyalgia, carpal tunnel syndrome, and respiratory conditions are not on the list of diseases associated with exposure to certain herbicide agents under 38 C.F.R. § 3.309(e). The Veteran has not presented evidence—beyond his own unsupported assertions—of exposure to other chemicals that may have caused his fibromyalgia, carpal tunnel syndrome, and respiratory conditions. Therefore, the Board concludes that service connection may not be awarded based on the Veteran’s assertions of in-service exposure to chemicals. In summary, the preponderance of the evidence is against finding that the Veteran’s fibromyalgia, carpal tunnel syndrome, and respiratory conditions began during his active service, or are otherwise related to an in-service event, injury, or disease. In view of the foregoing, the Board concludes that the preponderance of the evidence is against the claims for entitlement to service connection for fibromyalgia, entitlement to service connection for carpal tunnel syndrome, and entitlement to service connection for respiratory conditions. Because the preponderance of the evidence is against the claims, the doctrine of reasonable doubt is not for application, and the claims must be denied. 38 U.S.C. § 5107(b); see also Gilbert, 1 Vet. App. 49. MICHAEL MARTIN Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board T. J. Anthony, 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.