Citation Nr: 21012723 Decision Date: 03/05/21 Archive Date: 03/05/21 DOCKET NO. 17-02 592 DATE: March 5, 2021 ORDER Entitlement to service connection for a left hip disability is denied. Entitlement to service connection for a skin disability, to include psoriasis, tinea pedis and tinea corporis is denied. Entitlement to service connection for restless leg syndrome (RLS) is denied. Entitlement to service connection for sleep apnea is denied. Entitlement to service connection for residuals of esophageal diverticulum is denied. Entitlement to service connection for a left eye condition (other than ocular migraines) is denied. FINDINGS OF FACT 1. The Veteran’s left hip disability was not manifest in service, was not manifest within one year of separation and is not related to service. 2. The Veteran’s skin disability is not related to an in-service injury, disease, or event. 3. The Veteran’s RLS disability is not related to service, and is not caused or aggravated by a service-connected disability. 4. The Veteran’s sleep apnea disability is not related to an in-service injury, disease, or event. 5. The Veteran’s residuals of esophageal diverticulum disability is not related to an in-service injury, disease, or event. 6. The preponderance of the evidence is against a finding that the Veteran’s left eye condition (other than ocular migraines) is etiologically related to service. CONCLUSIONS OF LAW 1. A left hip disability was not incurred in or aggravated by service, and may not be presumed to have been incurred therein. 38 U.S.C. §§ 1110, 1112, 1131, 5107 (2012); 38 C.F.R. §§ 3.303, 3.307, 3.309 (2020). 2. A skin disability was not incurred in active military service. 38 U.S.C. §§ 1101, 5107 (2012); 38 C.F.R. § 3.303 (2020). 3. Entitlement to service connection for RLS, to include as secondary to a service-connected disability, is not warranted. 38 U.S.C. §§ 1110, 1131 (2012)38 C.F.R. §§ 3.303, 3.304, 3.310, 3.317 (2020). 4. A sleep apnea disability was not incurred in active military service. 38 U.S.C. §§ 1101, 5107 (2012); 38 C.F.R. § 3.303 (2020). 5. A residuals of esophageal diverticulum disability was not incurred in active military service. 38 U.S.C. §§ 1101, 5107 (2012); 38 C.F.R. § 3.303 (2020). 6. The criteria for service connection for a left eye condition (other than ocular migraines) are not met. 38 U.S.C. §§ 1110, 1131, 5103, 5103A, 5107 (2012); 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 4.9 (2020). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from August 1951 to August 1971. This matter comes before the Board of Veterans’ Appeals (Board) on appeal from the September 2013 decision of the Department of Veterans Affairs (VA) Regional Office (RO). The Veteran testified before the Board at a February 2018 hearing and a transcript is of record. In June 2018 and April 2020, the Board remanded these issues for additional development. The Veteran raised a new claim of service connection for a neck condition during his February 2018 Board hearing, as the Board does not have jurisdiction over the matter, it is again referred to the Agency of Original Jurisdiction (AOJ) for appropriate action. 38 C.F.R. § 19.9 (b) (2020). Service Connection Laws and Regulations Service connection will be granted if the evidence demonstrates that a current disability resulted from an injury or disease incurred in or aggravated by active military service. 38 U.S.C. § 1131; 38 C.F.R. § 3.303(a). To establish a right to compensation for a present disability, a Veteran must show: “(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 during service.” Davidson v. Shinseki, 581 F.3d 1313, 1315-16 (Fed. Cir. 2009); Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Certain diseases, to include arthritis may be presumed to have been incurred in service when manifest to a compensable degree within one year of discharge from active duty. 38 U.S.C. § 1112 (2012); 38 C.F.R. §§ 3.307, 3.309 (2020). Under 38 C.F.R. § 3.303(b), an alternative method of establishing the second and third Shedden for certain chronic disabilities such as arthritis and peripheral neuropathy is through a demonstration of continuity of symptomatology. In relevant part, 38 U.S.C. § 1154(a) requires that the VA give “due consideration” to “all pertinent medical and lay evidence” in evaluating a claim to disability or death benefits. Lay evidence can be competent and sufficient to establish a diagnosis of a condition when (1) a layperson is competent to identify the medical condition, (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional.” Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed.Cir.2007). In fact, competent medical evidence is not necessarily required when the determinative issue involves either medical etiology or a medical diagnosis. Id. at 1376-77; see also Buchanan v. Nicholson, 451 F.3d 1331, 1337 (Fed. Cir. 2006); Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). Once evidence is determined to be competent, the Board must determine whether such evidence is also credible. See Layno, supra (distinguishing between competency (“a legal concept determining whether testimony may be heard and considered”) and credibility (“a factual determination going to the probative value of the evidence to be made after the evidence has been admitted”). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the VA shall give the benefit of the doubt to the claimant. 38 U.S.C. § 5107(b). Under 38 C.F.R. § 3.310(a), service connection may be granted for disability that is proximately due to or the result of a service- connected disease or injury. Such permits a grant of service connection not only for disability caused by a service-connected disability, but for the degree of disability resulting from aggravation to a nonservice- connected disability by a service- connected disability. Id. See also Allen v. Brown, 7 Vet. App. 439, 448 (1995); 38 C.F.R. § 3.310(b). In order to prevail on the issue of entitlement to secondary service connection, there must be (1) evidence of a current disability; (2) evidence of a service-connected disability; and (3) nexus evidence establishing a connection between the service-connected disability and the current disability. See Wallin v. West, 11 Vet. App. 509, 512 (1998). The Board observes that the Veteran served in the Republic of Vietnam. Veterans who, during active service, served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, shall be presumed to have been exposed to an herbicide agent, unless there is affirmative evidence of non-exposure. 38 U.S.C. §§ 1116; 38 C.F.R. § 3.307. “Service in the Republic of Vietnam” includes service in the waters offshore and service in other locations if the conditions of service involved duty or visitation in the Republic of Vietnam. 38 C.F.R. §§ 3.307(a) (6) (iii), 3.313(a). If a veteran was exposed to a herbicide agent (to include Agent Orange) during active military, naval or air service and has contracted an enumerated disease to a degree of 10 percent or more at any time after service (except for chloracne and acute and subacute peripheral neuropathy which must be manifested within a year of the last exposure to an herbicide agent during service), the veteran is entitled to a presumption of service connection even though there is no record of such disease during service. 38 U.S.C. § 1116; 38 C.F.R. § 3.307, 3.309(e). The enumerated diseases are AL amyloidosis; chloracne or other acneform diseases; Type II diabetes; Non-Hodgkin’s lymphoma; Hodgkin’s disease; chronic lymphocytic leukemia; multiple myeloma; acute and subacute peripheral neuropathy; porphyria cutanea tarda; respiratory cancers; prostate cancer; and soft-tissue sarcoma (other than osteosarcoma, chondrosarcoma, Kaposi’s sarcoma, or mesothelioma). The term “soft-tissue sarcoma” includes adult fibrosarcoma, dermatofibrosarcoma protuberans, malignant fibrous histiocytoma, liposarcoma; leiomyosarcoma; epithelioid leiomyosarcoma (malignant leiomyoblastoma); rhabdomyosarcoma; ectomesenchymoma; angiosarcoma (hemangiosarcoma and lymphangiosarcoma); proliferating (systemic) angioendotheliomatosis; malignant glomus tumor; malignant hemangiopericytoma; synovial sarcoma (malignant synovioma); malignant giant cell tumor of tendon sheath; malignant schwannoma, including malignant schwannoma with rhabdomyoblastic differentiation (malignant Triton tumor), glandular and epithelioid malignant schwannomas; malignant mesenchymoma; malignant granular cell tumor; alveolar soft part sarcoma; epithelioid sarcoma; clear cell sarcoma of tendons and aponeuroses; extraskeletal Ewing’s sarcoma; congenital and infantile fibrosarcoma; malignant ganglioneuroma; and amyotrophic lateral sclerosis (ALS). 38 U.S.C. § 1116; 38 C.F.R. §§ 3.307(a) (6) (iii), 3.309(e), 3.313, 3.318. Left Hip The Veteran’s service treatment records demonstrate that the Veteran was hospitalized in September 1958 after an aircraft accident. The Veteran was treated for a head laceration and left shoulder injury after the accident where the Veteran’s airplane crashed and burned while attempting to take off from the runway. The service treatment records however are negative for complaints, treatments or diagnoses related to a left hip disability. Notably, the Veteran’s February 1971 separation examination was entirely negative for any complaints regarding his left hip. A February 2007 private treatment report noted degenerative changes with both hips with the Veteran’s left hip being worse than his right hip. Per the June 2018 Board remand instructions, the Veteran underwent a VA examination in January 2020. The examiner opined that it was less likely than not that the Veteran’s left hip replacement due to arthritis was due to service. The examiner noted that the Veteran did not mention hip complaints on his retirement history and there were no active duty records documenting complaints of left hip pain. However, as noted by the Board in its April 2020 remand, the examiner failed to specifically address whether the Veteran’s left hip was due to trauma incurred in the 1958 aircraft injury as well as the Veteran’s lay assertions of continuity of symptomatology. Per the April 2020 Board remand instructions, a VA examiner provided an opinion after a records review in December 2020. The examiner opined that it was less likely than not that the Veteran’s left hip disability was due to service. The examiner noted that the Veteran’s lay statements were reviewed and although it was within the realm of possibility that the Veteran’s current left hip disability was related to the 1958 in-service plane crash, it did not meet the standard of at least as likely as not. The examiner noted that hip osteoarthritis with resultant hip replacement was common in the aging population. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for a left hip disability is not warranted. As there is a current diagnosis of osteoarthritis of the left hip and resultant hip replacement surgery, the first element of service connection is satisfied. However, a veteran seeking disability benefits must establish not only the existence of a disability, but also an etiological connection between his military service and the disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000); D’Amico v. West, 209 F.3d 1322, 1326 (Fed. Cir. 2000); Hibbard v. West, 13 Vet. App. 546, 548 (2000). As noted above, service connection may be granted on a presumptive basis for certain chronic diseases, including arthritis, if such disease is shown to be manifest to a degree of 10 percent or more within one year following the Veteran’s separation from active military service. See 38 U.S.C. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309. In this instance however, service connection for a left hip disability on a presumptive basis is not warranted as the record does not show evidence of arthritis of the left hip during the Veteran’s period of active military service, or within one year of his separation from active duty. Accordingly, service connection for a left hip disability on a presumptive basis is not warranted as a chronic disease did not manifest to a degree of 10 percent or more within one year following the Veteran’s separation from active military service. To the extent that the Veteran asserted that he experienced left hip pain and continuing symptoms thereafter, the Board acknowledges that a layperson is competent to testify in regard to the onset and continuity of symptomatology. Heuer v. Brown, 7 Vet. App. 379, 384 (1995); Falzone v. Brown, 8 Vet. App. 398, 403 (1995); Caldwell v. Derwinski, 1 Vet. App. 466 (1991). Furthermore, lay witnesses may, in some circumstances, opine on questions of diagnosis and etiology. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009) (finding that the Board’s categorical statement that “a valid medical opinion” was required to establish nexus, and that a layperson was “not competent” to provide testimony as to nexus because she was a layperson, conflicts with Jandreau). Again, the Veteran contended that his left hip disability was the result of his in-service aircraft accident in September 1958. However, in a December 2020 addendum opinion, a VA examiner specifically addressed the report of continuity of symptomatology and noted the Veteran’s lay statements. The examiner found that while the left hip disability being a result of the 1958 in-service accident was within the realm of possibility, it did not meet the standard of at least as likely as not as hip osteoarthritis with resultant hip replacement was common in the aging population. As a result, the Board concludes that the weight of the evidence is against a finding of any continuity of symptomatology. See Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000); Shaw v. Principi, 3 Vet. App. 365 (1992). Accordingly, service connection for a left hip disability on a presumptive basis for substitution purposes is not warranted as the Veteran’s arthritis did not manifest to a degree of 10 percent or more within one year following the Veteran’s separation from active military service. Regarding service connection on a direct basis, the Board finds that the evidence is against a finding that the Veteran’s left hip disability is otherwise etiologically related to his service. Notably, the Veteran’s service treatment records reflect that he was injured in a September 1958 aircraft accident. However, the Veteran’s service treatment records, including the Veteran’s February 1971 separation examination, were negative for left hip treatments or complaints after the incident. Furthermore, the only medical opinions addressing the etiology of the left hip disability weigh against the claim. As noted above, a VA examiner in January 2020 and December 2020 opinions, while specifically noting the Veteran’s reported in-service left hip disability, indicated that it was less likely than not that the Veteran’s left hip disability was related to service to include the September 1958 aircraft accident. The Board affords the VA examiner’s January 2020 and December 2020 opinions, which are supported by a detailed rationale and medical knowledge, great probative value. In forming his opinion, the VA examiner specifically discussed the in-service aircraft accident and noted the Veteran’s lay assertions regarding his left hip disability while clearly acknowledging his lay statements regarding the in-service incurrence of these injuries. None of the competent medical evidence of record refutes these conclusions, and the Veteran has not presented or identified any such existing medical evidence or opinion. Thus, the Board finds the examiner’s January 2020 and December 2020 opinions to be persuasive. In sum, for the reasons and bases expressed above the Board finds that the preponderance of the evidence is against the Veteran’s claim of entitlement to service connection for a left hip. The benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107(b). Skin Disability A July 1957 service treatment record noted dermatitis. A February 1961 service treatment report noted that the Veteran recently had treatment for facial impetigo which disappeared with treatment. A December 1964 service treatment record indicated that the Veteran had tinea on the soles of his feet. In October 1966, the Veteran had surgical removal of a cyst from his neck. Notably, the Veteran’s February 1971 separation examination was negative for any complaints regarding a skin disability. In an April 2013 private Disability Benefits Questionnaire (DBQ), a private physician noted that the Veteran had psoriasis and tinea corporis. The physician indicated that the Veteran had a history of sun exposure and skin cancer. The Veteran underwent a VA examination in September 2013. The examiner noted that the Veteran had tinea pedis in 1951 and tinea corporis in 1960. The Veteran developed athletes foot in service and currently noted “occasional” episodes of athletes foot. His last episode of tinea pedis was over a year ago. His tinea corporis began on the face in the 1960’s and had resolved for years. He however had tinea corporis on his left arm a year ago which resolved with anti-fungal cream. The examiner determined that there was no clinical evidence of tinea pedis or tinea corporis at the time of the examination. The examiner opined that without resorting to mere speculation, he was unable to relate any skin conditions to the Veteran’s service as no ringworm or tinea pedis was identified on the examination. Per the June 2018 Board remand instructions, the Veteran underwent a VA examination in January 2020. The examiner opined that it was less likely than not that the Veteran’s tinea pedis and psoriasis were due to service. The examiner indicated that the Veteran was noted to have tinea pedis on an examination in 1968 but did not currently have any problems with tinea pedis or tinea corporis. The examiner also noted that there was no mention of psoriasis in his active duty records and the Veteran noted an onset of psoriasis in 1990. However, as noted by the April 2020 Board remand, while the January 2020 VA examiner opined that it was less likely than not that the Veteran’s tinea pedis and psoriasis were due to service, the examiner failed to specifically address whether the Veteran’s skin disability was a result of his presumed herbicide exposure. Per the April 2020 Board remand instructions, a VA examiner provided an opinion after a records review in December 2020. The examiner opined that it was less likely than not that the Veteran’s current psoriasis, tinea pedis and tinea corporis were incurred in or caused by the Veteran’s in-service herbicide exposure. The examiner noted that the Veteran’s lay statements were reviewed but there was no evidence in the medical literature that linked psoriasis, tinea pedis or tinea corporis to herbicide exposure. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for a skin disability, to include psoriasis, tinea pedis and tinea corporis, to include as secondary to herbicide exposure is not warranted. The Board parenthetically notes that the Veteran has been granted service connection for skin cancer to include squamous cell carcinoma. As a result, the Veteran’s residuals of skin cancer have already been accounted for and are not part of the Veteran’s appeal for service connection. Initially, the Board notes that there is a question as to whether the Veteran has a current skin disability. Notably, a private physician on an April 2013 DBQ found that the Veteran had psoriasis and tinea corporis while the September 2013 VA examiner determined that there was no clinical evidence of tinea pedis or tinea corporis at the time of the examination. Additionally, the January 2020 VA examiner noted that the Veteran did not currently have any problems with tinea pedis or tinea corporis. When affording the Veteran the benefit of the doubt, the Board finds that there is a current diagnosis of a skin disability and the first element of service connection is satisfied. However, a veteran seeking disability benefits must establish not only the existence of a disability, but also an etiological connection between his military service and the disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000); D’Amico v. West, 209 F.3d 1322, 1326 (Fed. Cir. 2000); Hibbard v. West, 13 Vet. App. 546, 548 (2000). The Board again notes that in some instances presumptive service connection is warranted based on Agent Orange exposure. In this case, exposure to herbicide agents such as Agent Orange is again conceded, as the service personnel records show that the Veteran did serve in the Republic of Vietnam. However, while the Veteran served in Vietnam, and his exposure to herbicides is therefore presumed, the Board finds that skin disabilities, to include psoriasis, tinea pedis and tinea corporis, are not one of the conditions for which VA has specifically determined a presumption of service connection is warranted. Accordingly, entitlement to service connection on a presumptive basis based on exposure to herbicides is not warranted. The Board must also consider whether the Veteran’s skin disability, to include psoriasis, tinea pedis and tinea corporis is directly caused by herbicide exposure. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). A presumption of service connection provided by law is not the sole method for showing causation in establishing a claim for service connection for disability due to herbicide exposure. See Stefl v. Nicholson, 21 Vet. App. 120 (2007). Regarding service connection on a direct basis, the Veteran’s service treatment records detail multiple incidents where the Veteran presented with complaints related to his skin. Despite these complaints and diagnosis, the service treatment records, however, were negative for any or diagnoses of any chronic skin disability. Notably, the Veteran’s February 1971 separation examination was negative for complaints or diagnoses of a skin disability. The Board finds that the weight of the evidence is against a finding that a current skin disability is etiologically related to the Veteran’s military service. In fact, the only medical opinions addressing the etiology of the claimed skin disability weigh against the claim. As noted above, the January 2020 VA examiner opined that it was less likely than not that the Veteran’s tinea pedis and psoriasis were due to service and in an April 2020 addendum opinion, opined that it was less likely than not that the Veteran’s current psoriasis, tinea pedis and tinea corporis were incurred in or caused by the Veteran’s in-service herbicide exposure. In making this conclusion, the examiner specifically noted that the Veteran’s lay statements were reviewed but there was no evidence in the medical literature that linked psoriasis, tinea pedis or tinea corporis to herbicide exposure. None of the competent medical evidence currently of record refutes this conclusion, and the Veteran has not presented any such existing medical evidence or opinion. In sum, the Board finds that service connection for a skin disability, to include psoriasis, tinea pedis and tinea corporis, to include as secondary to herbicide exposure must be denied. In reaching this conclusion, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, as the preponderance of the evidence is against the claim, that doctrine is not applicable. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 53-56 (1990). RLS The Veteran’s service treatment records demonstrate that the Veteran was hospitalized in September 1958 after an aircraft accident. The service treatment records however are negative for complaints, treatments or diagnoses related to a RLS disability. Notably, the Veteran’s February 1971 separation examination was entirely negative for any complaints regarding RLS. Per the June 2018 Board remand instructions, the Veteran underwent a VA examination in January 2020. The examiner found that the Veteran had RLS which was diagnosed in 2008. The examiner opined that it was less likely than not that the Veteran’s RLS was due to service as there was no mention of RLS while in active service. The examiner again noted that the first mention of RLS was in a 2008 treatment note. The examiner also opined that it was less likely than not that the Veteran’s RLS was caused or aggravated by his service-connected low back or radiculopathy of the left lower extremity disability. Per the April 2020 Board remand instructions, a VA examiner provided an opinion after a records review in December 2020. The examiner opined that it was less likely than not that the Veteran’s RLS disability was incurred in or caused by the claimed herbicide exposure or September 1958 in-service aircraft accident. The examiner noted that the Veteran’s lay statements were reviewed and that 50 percent of RLS was familial as RLS has been linked to deficient iron stores and dopaminergic neurotransmission in the brain. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for RLS, to include as secondary to herbicide exposure and as secondary to a service-connected disability, is not warranted. As there is a current diagnosis of RLS, the first element of service connection is satisfied. However, a veteran seeking disability benefits must establish not only the existence of a disability, but also an etiological connection between his military service and the disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000); D’Amico v. West, 209 F.3d 1322, 1326 (Fed. Cir. 2000); Hibbard v. West, 13 Vet. App. 546, 548 (2000). The Board again notes that in some instances presumptive service connection is warranted based on Agent Orange exposure. However, RLS is not included in the diseases subject to presumptive service connection due to herbicide exposure for veterans who served in Vietnam during the Vietnam era. As a result, while the Veteran served in Vietnam, and his exposure to herbicides is therefore presumed, the Veteran’s RLS is not amongst the conditions for which VA has specifically determined a presumption of service connection is warranted. Accordingly, entitlement to service connection on a presumptive basis based on exposure to herbicides is not warranted. The Board must also consider whether the Veteran’s RLS is directly caused by herbicide exposure. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). A presumption of service connection provided by law is not the sole method for showing causation in establishing a claim for service connection for disability due to herbicide exposure. See Stefl v. Nicholson, 21 Vet. App. 120 (2007). Regarding service connection on a direct basis, the Veteran’s service treatment records were negative for any complaints, treatment, or diagnoses of RLS. Further, there is no competent evidence or opinion otherwise suggesting that there exists a nexus between a current RLS disability and the Veteran’s service to include as due to herbicide exposure, and neither the Veteran nor his representative have presented or identified any such existing medical evidence or opinion. Moreover, none of the competent medical evidence of record reflects that the Veteran’s RLS is related to his presumed exposure to herbicides. Significantly, the only medical opinions addressing the etiology of the claimed RLS weigh against the claims as the VA examiner on a January 2020 VA examination report and December 2020 addendum opinion opined that the Veteran’s RLS was less likely than not incurred in or caused by the claimed in-service injury, event or illness to include herbicide exposure and the September 1958 aircraft accident. The Board affords the VA examiner’s opinions, which are supported by detailed rationales and medical knowledge, great probative value. In forming his opinions, the VA examiner specifically noted the Veteran’s lay assertions regarding his RLS as being due to conceded herbicide exposure or the in-service aircraft accident. The examiner notably found that the Veteran’s RLS started many years after separation and that 50 percent of RLS was familial as RLS has been linked to deficient iron stores and dopaminergic neurotransmission in the brain. None of the competent medical evidence of record refutes these conclusions, and the Veteran has not presented or identified any such existing medical evidence or opinion. Thus, the Board finds the examiner’s January 2020 and December 2020 opinions to be persuasive. Regarding service connection on a secondary basis, the Board again notes that the Veteran contends that his RLS and is the result of service to include as secondary to his service-connected low back or radiculopathy of the left lower extremity disability. However, the Board finds that the weight of the evidence is against a finding that a current RLS is related to service or caused or aggravated by a service-connected disability. Again, the only medical opinions addressing the etiology of the RLS disability on a secondary basis weigh against the claim as the January 2020 VA examiner indicated that the Veteran’s RLS was less likely than not as due to or aggravated by his service-connected low back or radiculopathy of the left lower extremity disability. None of the competent medical evidence currently of record refutes these conclusions, and the Veteran has not presented or identified any such existing medical evidence or opinion. Consequently, entitlement to service connection for RLS is not warranted on a presumptive, direct or secondary basis. In sum, for the reasons and bases expressed above the Board finds that the preponderance of the evidence is against the Veteran’s claim of entitlement to service connection. The benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107(b). Sleep Apnea The Veteran’s service treatment records demonstrate that a December 1959 report indicated that the Veteran had complaints of allergic rhinitis on and off for the past 15 years. The service treatment records however are negative for complaints, treatments or diagnoses related to a sleep apnea disability. Notably, the Veteran’s February 1971 separation examination was entirely negative for any complaints regarding a sleep disability. Per the June 2018 Board remand instructions, the Veteran underwent a VA examination in January 2020. The examiner opined that it was less likely than not that the Veteran’s sleep apnea was due to service as the Veteran first had sleep trouble in 2004 and there were no records in his active duty addressing sleep issues. Per the April 2020 Board remand instructions, a VA examiner provided an opinion after a records review in December 2020. The examiner opined that it was less likely than not that the Veteran’s current sleep apnea was incurred in or caused by the Veteran’s in-service herbicide exposure, documented seasonal hay fever and allergy rhinitis and/or reports of allergies experienced in service. The examiner noted that the Veteran’s lay statements were reviewed but indicated that there was no evidence in the medical literature that linked sleep apnea to herbicide exposure, documented seasonal hay fever and allergy rhinitis and/or reports of allergies experienced in service. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for a sleep apnea disability, to include as secondary to herbicide exposure is not warranted. As there is a current diagnosis of a sleep apnea disability and the first element of service connection is satisfied. However, a veteran seeking disability benefits must establish not only the existence of a disability, but also an etiological connection between his military service and the disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000); D’Amico v. West, 209 F.3d 1322, 1326 (Fed. Cir. 2000); Hibbard v. West, 13 Vet. App. 546, 548 (2000). The Board again notes that in some instances presumptive service connection is warranted based on Agent Orange exposure. In this case, exposure to herbicide agents such as Agent Orange is again conceded, as the service personnel records show that the Veteran did serve in the Republic of Vietnam. However, while the Veteran served in Vietnam, and his exposure to herbicides is therefore presumed, the Board finds that sleep apnea is not one of the conditions for which VA has specifically determined a presumption of service connection is warranted. Accordingly, entitlement to service connection on a presumptive basis based on exposure to herbicides is not warranted. The Board must also consider whether the Veteran’s sleep apnea is directly caused by herbicide exposure. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). A presumption of service connection provided by law is not the sole method for showing causation in establishing a claim for service connection for disability due to herbicide exposure. See Stefl v. Nicholson, 21 Vet. App. 120 (2007). Regarding service connection on a direct basis, the Veteran’s service treatment records detail where the Veteran presented with complaints related to his allergies. Despite these complaints, the service treatment records, however, were negative for any or diagnoses of any chronic sleep apnea disability. Notably, the Veteran’s February 1971 separation examination was negative for complaints or diagnoses of a sleep apnea disability. The Board finds that the weight of the evidence is against a finding that a current sleep apnea disability is etiologically related to the Veteran’s military service. In fact, the only medical opinions addressing the etiology of the claimed sleep apnea disability weigh against the claim. As noted above, the January 2020 VA examiner opined that it was less likely than not that the Veteran’s sleep apnea was due to service and in an April 2020 addendum opinion, opined that it was less likely than not that the Veteran’s sleep apnea was incurred in or caused by the Veteran’s in-service herbicide exposure, documented seasonal hay fever and allergy rhinitis and/or reports of allergies experienced in service. The examiner noted that the Veteran’s lay statements were reviewed but indicated that there was no evidence in the medical literature that linked sleep apnea to herbicide exposure, documented seasonal hay fever and allergy rhinitis and/or reports of allergies experienced in service. None of the competent medical evidence currently of record refutes this conclusion, and the Veteran has not presented any such existing medical evidence or opinion. In sum, the Board finds that service connection for sleep apnea must be denied. In reaching this conclusion, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, as the preponderance of the evidence is against the claim, that doctrine is not applicable. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 53-56 (1990). Esophageal diverticulum The Veteran testified that he experienced symptoms such as difficulty swallowing since service. Notably, the Veteran’s February 1971 separation examination was negative for any complaints regarding an esophageal disability. The Veteran underwent a VA examination in September 2013. The examiner noted that the Veteran had been diagnosed with an esophageal diverticulum in 2008. The examiner opined that it was less likely than not that the Veteran’s esophageal diverticulum was secondary to skin disease or any other treated condition in service. Per the June 2018 Board remand instructions, the Veteran underwent a VA examination in January 2020. The Veteran was diagnosed with gastroesophageal reflux disease (GERD) and esophageal diverticulum with an onset of 2004. The examiner opined that it was less likely than not that the Veteran’s GERD and diverticulum were due to service as there was no evidence in the record of the Veteran presenting for the evaluation or treatment of an esophageal condition while in active service and it had appeared that the diverticulum was first diagnosed in 2008. Per the April 2020 Board remand instructions, a VA examiner provided an opinion after a records review in December 2020. The examiner opined that it was less likely than not that the Veteran’s esophageal diverticulum disability was incurred in or caused by the claimed herbicide exposure. The examiner noted that the Veteran’s lay statements were reviewed and that upper esophageal diverticulum was thought to be caused by increased hypopharyngeal pressure that resulted from decreased compliance and impaired opening of the upper esophageal sphincter. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for esophageal diverticulum, to include as secondary to herbicide exposure is not warranted. As there is a current diagnosis of GERD and esophageal diverticulum, the first element of service connection is satisfied. However, a veteran seeking disability benefits must establish not only the existence of a disability, but also an etiological connection between his military service and the disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000); D’Amico v. West, 209 F.3d 1322, 1326 (Fed. Cir. 2000); Hibbard v. West, 13 Vet. App. 546, 548 (2000). The Board again notes that in some instances presumptive service connection is warranted based on Agent Orange exposure. In this case, exposure to herbicide agents such as Agent Orange is again conceded, as the service personnel records show that the Veteran did serve in the Republic of Vietnam. However, while the Veteran served in Vietnam, and his exposure to herbicides is therefore presumed, the Board finds that GERD and esophageal diverticulum are not one of the conditions for which VA has specifically determined a presumption of service connection is warranted. Accordingly, entitlement to service connection on a presumptive basis based on exposure to herbicides is not warranted. The Board must also consider whether the Veteran’s skin disability, to include psoriasis, tinea pedis and tinea corporis is directly caused by herbicide exposure. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). A presumption of service connection provided by law is not the sole method for showing causation in establishing a claim for service connection for disability due to herbicide exposure. See Stefl v. Nicholson, 21 Vet. App. 120 (2007). Regarding service connection on a direct basis, the Veteran’s service treatment records are negative for any or diagnoses of any chronic esophageal disability. Notably, the Veteran’s February 1971 separation examination was negative for complaints or diagnoses of an esophageal disability. The Board finds that the weight of the evidence is against a finding that a current esophageal diverticulum disability is etiologically related to the Veteran’s military service. In fact, the only medical opinions addressing the etiology of the claimed esophageal diverticulum disability weigh against the claim. As noted above, the January 2020 VA examiner opined that it was less likely than not that the Veteran’s esophageal diverticulum were due to service and in an April 2020 addendum opinion, opined that it was less likely than not that the Veteran’s current GERD and esophageal diverticulum were incurred in or caused by the Veteran’s in-service herbicide exposure. In making this conclusion, the examiner specifically noted that the Veteran’s lay statements that he experienced symptoms such as difficulty swallowing since service were reviewed. None of the competent medical evidence currently of record refutes this conclusion, and the Veteran has not presented any such existing medical evidence or opinion. In sum, the Board finds that service connection for esophageal diverticulum, to include as secondary to herbicide exposure must be denied. In reaching this conclusion, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, as the preponderance of the evidence is against the claim, that doctrine is not applicable. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 53-56 (1990). Left Eye Disability The Veteran’s service treatment records reflect that the Veteran bruised his left eye in the September 1958 aircraft accident. Notably, the Veteran’s February 1971 separation examination was negative for any complaints regarding a left eye disability. An August 2007 private treatment report noted that the Veteran eye floaters with an uncertain etiology which were most likely caused by vitreous degeneration. The eye examination was consistent with cataracts of the left eye. On a September 2013 VA eye examination, the examiner noted that the Veteran had an ocular migraine with aura of his left eye and pseudophakia of both eyes. The Veteran had cataract surgery on both eyes. There was no ocular pathology noted on the examination. The Veteran also reported that his left eye got a blind spot and kaleidoscope for 1 to 4 hours. The opined that it was as likely as not that the Veteran’s visual disturbance in his left eye (ocular migraine with aura) was related to the in-service TBI in 1958. However, no opinion was provided to address whether any other eye disability, to include pseudophakia, was related to the Veteran’s in-service eye trauma. As noted above, the Veteran has been diagnosed an ocular migraine with aura of the left eye. However, the Veteran’s complaints of visual aura accompanying his migraine headaches were addressed in the evaluation of the Veteran’s service-connected TBI with residual headaches. The issue before the Board has accordingly been recharacterized as a claim for entitlement to service connection for a left eye condition (other than ocular migraines) as the Veteran’s ocular migraine with aura of the left eye is already accounted for in his evaluation of his service-connected TBI with migraine headache disability. Per the April 2020 Board remand, the Veteran underwent a VA eye examination in October 2020. The examiner noted that the Veteran had a history of dry eye, refractive error, slight entropion and had cataract surgery in 2008 on both eyes. He was currently pseudophakic. He currently had dry eye syndrome, pseudophakia, and general contraction of visual fields. The Veteran reported that he currently had a “halo effect” as he saw a “kaleidoscope” in his left eye vision and then lost vision for about 15-20 minutes which was then followed by a mild headache. This occurred twice a year. The examiner opined that it was less likely than not that the Veteran’s left eye disability was incurred in or caused by the claimed in-service event, injury or illness. The examiner noted that the Veteran’s diagnosed dry eye syndrome, pseudophakia, or general contraction of visual fields would not be considered a left eye disability. The examiner also noted that there was no evidence that any of these diagnoses have been caused by the in-service aircraft accident the Veteran experienced in September 1958. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for a left eye condition (other than ocular migraines) is not warranted. While the October 2020 VA examiner determined that the Veteran’s diagnosed dry eye syndrome, pseudophakia, or general contraction of visual fields would not be considered a left eye disability, when affording the Veteran the benefit of the doubt, the Board finds that there are current diagnoses of a left eye disability and the first element of service connection is satisfied. However, a veteran seeking disability benefits must establish not only the existence of a disability, but also an etiological connection between his military service and the disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000); D’Amico v. West, 209 F.3d 1322, 1326 (Fed. Cir. 2000); Hibbard v. West, 13 Vet. App. 546, 548 (2000). The Veteran’s service treatment records reflect that the Veteran bruised his left eye in the September 1958 aircraft accident. Despite these complaints and diagnosis, the service treatment records, however, were negative for any or diagnoses of any chronic left eye disability. Notably, the Veteran’s February 1971 separation examination was negative for complaints or diagnoses of a left eye disability. The Board finds that the weight of the evidence is against a finding that a current a left eye condition (other than ocular migraines) is etiologically related to the Veteran’s military service. In fact, the only medical opinions addressing the etiology of the claimed left eye disability weigh against the claim. As noted above, the October 2020 VA examiner opined that it was less likely than not that the Veteran’s current left eye disability was incurred in or caused by the claimed in-service event, injury or illness. In making this conclusion, the examiner specifically noted that there was no evidence that any of these diagnoses have been caused by the in-service aircraft accident the Veteran experienced in September 1958. None of the competent medical evidence currently of record refutes this conclusion, and the Veteran has not presented any such existing medical evidence or opinion. In sum, the Board finds that service connection for a left eye condition (other than ocular migraines) must be denied. In reaching this conclusion, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, as the preponderance of the evidence is against the claim, that doctrine is not applicable. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 53-56 (1990). All Disabilities The Board notes the Veteran and his representative’s contentions regarding the etiology of his claimed left hip disability, skin disability, RLS, sleep apnea, residuals of esophageal diverticulum and a left eye disability. To the extent that the Veteran and his representative themselves contend that a medical relationship exists between his claimed left hip disability, skin disability, RLS, sleep apnea, residuals of esophageal diverticulum and a left eye disability and his service, the Board acknowledges that the Veteran is competent to testify as to his observations. Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). Furthermore, lay witnesses may, in some circumstances, opine on questions of diagnosis and etiology. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009) (finding that the Board’s categorical statement that “a valid medical opinion” was required to establish nexus, and that a layperson was “not competent” to provide testimony as to nexus because she was a layperson, conflicts with Jandreau). In the instant case, however, the Board finds that left hip disability, skin disability, RLS, sleep apnea, residuals of esophageal diverticulum and a left eye disability are not a disabilities subject to lay diagnosis as these diagnoses require medical training. More significantly, the Veteran and his representative do not have the medical expertise to provide an opinion regarding the claimed left hip disability, skin disability, RLS, sleep apnea, residuals of esophageal diverticulum and a left eye disability etiologies. Specifically, where the determinative issue is one of medical causation, only those with specialized medical knowledge, training, or experience are competent to provide evidence on the issue. See Jones v. West, 12 Vet. App. 460, 465 (1999). Thus, the Veteran and his representative’s assertions that there is a relationship between his claimed left hip disability, skin disability, RLS, sleep apnea, residuals of esophageal diverticulum and a left eye disability and his service are not sufficient in this instance and are outweighed by other probative evidence of record. Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007). In sum, for the reasons and bases expressed above the Board finds that the preponderance of the evidence is against the Veteran’s claims of entitlement to service connection. The benefit-of-the-doubt rule does not apply, and the claims must be denied. 38 U.S.C. § 5107(b). MICHAEL LANE Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board James A. DeFrank, 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.