Citation Nr: 21064307 Decision Date: 10/19/21 Archive Date: 10/19/21 DOCKET NO. 15-02 104A DATE: October 19, 2021 ORDER Entitlement to service connection for hypertension is denied. Entitlement to service connection for diabetes mellitus is denied. Entitlement to service connection for congestive heart failure is denied. Entitlement to service connection for a right eye disability is denied. Entitlement to a total disability rating based upon individual unemployability (TDIU) is denied. FINDINGS OF FACT 1. The Veteran's hypertension was not incurred during, and was not otherwise related to, the Veteran's period of active service. 2. Symptoms of the Veteran's hypertension were not continuous since separation from service and did not manifest to a compensable degree in the year following separation from service. 3. The Veteran's diabetes was not incurred during, and was not otherwise related to, the Veteran's period of active service. 4. Symptoms of the Veteran's diabetes were not continuous since separation from service and did not manifest to a compensable degree in the year following separation from service. 5. The Veteran's congestive heart failure was not incurred during, and was not otherwise related to, the Veteran's period of active service. 6. The Veteran's congestive heart failure was not caused, or aggravated by, a service-connected disability. 7. The Veteran's retinopathy of the right eye was not incurred during, and was not otherwise related to, the Veteran's period of active service. 8. The Veteran's retinopathy of the right eye was not caused, or aggravated by, a service-connected disability. 9. The Veteran did not meet the schedular criteria for a TDIU throughout the period on appeal. 10. The Veteran's service-connected disabilities did not cause functional impairment that resulted in an inability to obtain or maintain substantially gainful employment so as to warrant referral for consideration of a TDIU on an extraschedular basis. CONCLUSIONS OF LAW 1. The criteria for service connection for hypertension were not met. 38 U.S.C. §§ 1101, 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.307, 3.309. 2. The criteria for service connection for diabetes mellitus were not met. 38 U.S.C. §§ 1101, 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.307, 3.309. 3. The criteria for service connection for congestive heart failure have not been met. 38 U.S.C. §§ 1110, 1131, 5103, 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304. 4. The criteria for service connection for a right eye disability have not been met. 38 U.S.C. §§ 1110, 1131, 5103, 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.310. 5. The criteria for entitlement to a TDIU were not met. 38 U.S.C. § 1155; 38 C.F.R. §§ 3.340, 3.341, 4.16(a); 4.16(b). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from July 1974 to August 1982. He died in May 2018. The appellant, the Veteran's surviving spouse, was granted substitution as claimant for the issues on appeal. This matter comes to the Board of Veterans' Appeals (Board) on appeal of a rating decision by a U.S. Department of Veterans Affairs (VA) Regional Office (RO). In March 2018, the Veteran testified at a hearing before the Board. A copy of the hearing transcript has been associated with the claims file. The Board remanded the claims for additional development in August 2018, August 2020, and April 2021. Review of the completed development reveals that, at the very least, substantial compliance with the remand directives was obtained. Stegall v. West, 11 Vet. App. 268 (1998); Dyment v. West, 13 Vet. App. 141, 146-47 (1999). Factual History In August 2005, the Veteran submitted an application for service connection for hypertension. The Veteran reported onset of hypertension, diabetes, and hyperlipidemia in 1974 and stated that there was evidence of these disabilities in his service treatment records (STR). On the Veteran's application, he denied exposure to Agent Orange or other herbicide agents. The Veteran submitted a July 2005 statement from J.T.K., D.O. who reported that the Veteran was under his care for hypertension and diabetes. The physician stated that it was his understanding that the Veteran "was originally diagnosed with hypertension while still under military service. He was also found to have abnormal glucose tolerance tests." The Veteran also submitted an August 2005 statement from D.L., M.D. The physician stated that "the Veteran has a history of diabetes that more likely than not started during or because of his military tour of duty. This includes diabetes and/or metabolic syndrome, as well as, hypertension." Medical Records from the Palo Alto VA Health Care System (HCS) in June 2005 indicate that the Veteran was establishing care at the VA. The Veteran reported that he was diagnosed with diabetes while he served on active duty. It was reported that he worked with airplanes that had dropped Agent Orange. His prior medical history indicated hypertension and diabetes since the 1970s. In April 2012, the Veteran filed another claim for diabetes and hypertension (claimed as high blood pressure). He reported that his diabetes began in 1983 and that his high blood pressure began in 1980. He also filed claims for congestive heart failure that developed in February 2012 and a right eye disability (due to a stroke) that had onset in January 2006. He reported that he was seeking service connection for conditions related to exposure to Agent Orange or other herbicide agents, which included diabetes, congestive heart failure, and hypertension. The Veteran submitted a February 2011 letter from J.T.K., D.O. The physician stated that "the Veteran is under my care. He has been diagnosed with diabetes, hypertension, and hyperlipidemia back in 1983 by another Kaiser Provider at the Vallejo Kaiser in 1983." The Veteran also submitted a November 2012 statement from his brother, W.J.M., M.D. The Veteran's brother stated the following: Sometime in 1981, I spoke to a Cpt. Bogdanovich, M.D. of the US Air Force Family Practice at David Grant Medical Center, Travis Air Force Base. The conversation was regarding the Veteran while he was in active duty with the Air Force. I was concerned about his high fasting blood sugar levels. The doctor informed me that the Veteran's glucose tolerance results were also abnormally high. Bernard's test results indicate that he is a diabetic. At that time, Dr. Bogdanovich told me that the Veteran also had a high cholesterol and triglyceride blood levels. I spoke with the doctor regarding the Veteran's hypertension which was being treated with a medicine called Coreg. In reference to his diabetes at that time, Dr. Bogdanovich said he would initially treat the Veteran with diet, weight control, and exercise. In November 2012, the Veteran's representative submitted argument that medical service records show that in May of 1974 that the Veteran's blood pressure levels were high and classified in the prehypertensive range and that he had a body mass index that placed him in the overweight category with a height of 75.5 inches and a weight of 234 pounds. Further, medical records from June 1984 show that his weight had increased to 258 pounds and he was not in compliance with Army standards. The representative also argued that the statement from W.J.M., M.D., the Veteran's brother and a medical doctor, substantiates the fact that, although the diagnosis was not formally made until 1983, blood tests performed by the military indicated, diabetes as early as 1981. In February 2013, the Veteran submitted a VA 21-8940 Veterans Application for Increased Compensation Based on Unemployability reporting that he became too disabled to work in February 2010 due to diabetic neuropathy, diabetic retinopathy, and his high blood pressure. In March 2018, the Veteran provided testimony regarding his claims on appeal. The Veteran reported that he had been diagnosed with diabetes during his period of active service. Hearing Testimony (H.T), pp. 2-3. He stated that "During the years that I served, there was family doctor by the name of Dr. Bernanovich, and he said my Glucophage was elevated; that's an indicator you already have the disease. So, my brother is a doctor; Board Certified Internal Medicine doctor and I was talking to Dr. Bernanovich, because it hit me hard and I said, please talk to my brother, explain to him what's going on. And my brother, W.J.M., M.D., talked to Dr. Bernanovich... and provided a letter." H.T., p.3. The Veteran also stated that he was being treated during service for his hypertension with Coreg; however, he stated he stopped taking it based upon the advice of his brother. H.T., pp. 4, 8. He indicated that after separation from service he was treated for his hypertension with multiple medications. H.T., p.9. The Veteran also reported his contention that his congestive heart failure and stroke were due to his diabetes and that he stopped working due to undergoing open heart surgery. H.T., pp. 12, 18. Service Connection, Generally Service connection is warranted where the evidence of record establishes that a particular injury or disease resulting in disability was incurred in the line of duty in the active military service or, if pre-existing such service, was aggravated thereby. 38 U.S.C. § 1110; 38 C.F.R. § 3.303. Establishing service connection generally requires competent evidence of three things: (1) a current disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship, i.e., a nexus, between the current disability and the disease or injury incurred or aggravated during service. See Shedden v. Principi, 381 F. 3d 1163, 1167 (Fed. Cir. 2004). Service connection is also warranted for disability, which is proximately due to, the result of, or aggravated by service-connected disease or injury. Allen v. Brown, 7 Vet. App. 439 (1995); 38 C.F.R. § 3.310. The Board must determine the value of all evidence submitted, including lay and medical evidence. Buchanan v. Nicholson, 451 F.3d 1331 (Fed. Cir. 2006). The evaluation of evidence generally involves a three-step inquiry. First, the Board must determine whether the evidence comes from a "competent" source. The Board must then determine if the evidence is credible, or worthy of belief. Barr v. Nicholson, 21 Vet. App. 303, 308 (2007). The third step of this inquiry requires the Board to weigh the probative value of the evidence in light of the entire record. A layperson is competent to report on the onset and continuity of current symptomatology based on personal knowledge. See Layno v. Brown, 6 Vet. App. 465, 470 (1994). Lay evidence can also be competent and sufficient evidence of a diagnosis or to establish etiology if the layperson: (1) is competent to identify the medical condition, (2) is reporting a contemporaneous medical diagnosis, or (3) is describing symptoms that support a later diagnosis by a medical professional. Jandreau v. Nicholson, 492 F.3d 1372, at 1376-77 (Fed. Cir. 2007). In weighing credibility, VA may consider interest, bias, inconsistent statements, bad character, internal inconsistency, facial plausibility, self-interest, consistency with other evidence of record, malingering, desire for monetary gain, and demeanor of the witness. See Caluza v. Brown, 7 Vet. App. 498 (1995). In determining whether service connection is warranted for a disability, VA is responsible for determining whether the evidence supports the claim or is in relative equipoise, with the Veteran prevailing in either event, or whether a preponderance of the evidence is against the claim, in which case the claim is denied. 38 U.S.C. § 5107; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination, the benefit of the doubt is afforded. 1. Entitlement to service connection for hypertension The Veteran contended that he developed and was diagnosed with hypertension during his period of active service. Unfortunately, the Board finds that the weight of the credible evidence of record is against a finding that the Veteran's hypertension was incurred in, or is otherwise due to, his period of active service. Initially, the Board notes that several alternative paths to service connection exist for certain chronic diseases identified in 38 C.F.R. § 3.309 (a), including hypertension. 38 C.F.R. § 3.309. Service connection may be awarded if a chronic disease manifests itself and is identified as such in service, or within the presumptive period under 38 C.F.R. § 3.307, and the Veteran presently has the same condition, unless the condition is clearly attributable to intercurrent causes. 38 U.S.C. § 1112; 38 C.F.R. §§ 3.307, 3.309; see Walker v. Shinseki, 708 F.3d 1331, 1336 (Fed. Cir. 2013). Additionally, the continuity of symptomatology provision of 38 C.F.R. § 3.303 (b) has been interpreted as an alternative to service connection for the chronic diseases listed in 38 C.F.R. § 3.309 (a). See Walker, at 1331. The Board finds, however, that service connection for hypertension is not available under 38 C.F.R. § 3.309 (a) as the credible evidence of record weighs against a finding that the Veteran had hypertension during service or within a year of separation from service. The Board notes that in August 2016 the Veteran was informed that some of his STR were unavailable for review. Review of the claims file indicates that many pages are not legible, despite indication that the best copy has been uploaded to the claims file. In these circumstances, when a Veteran's STRs are unavailable through no fault of his own, VA's duties to assist, to provide reasons and bases for its findings and conclusions, and to carefully consider the benefit-of-the-doubt rule are heightened. Milostan v. Brown, 4 Vet. App. 250, 252 (1993). Unfortunately, to the extent that the Veteran's service treatment records have been associated with the claims file, the Veteran's records are silent with report of a diagnosis of hypertension during service or within a year of separation from active service. Despite the Veteran's reports, his STR do not report any history of hypertension or that he was being treated with Coreg or any medication for hypertension during active service. The Veteran's STR associated with the claims file demonstrate blood pressure readings that were reported to be within normal limits on two separate days (November 5, 1981 and November 19, 1981) by the May 2021 VA examiner. Further, the Veteran's November 1981 separation examination did not report any defect of the Veteran's heart or vascular system. To the extent that the Veteran reported that he was diagnosed with hypertension and treated with Coreg during service for this condition, the Board does not find these reports to be credible. On an October 1982 Report of Medical History (after separation from active service), the Veteran denied taking any current medications and denied a history of high blood pressure. Additionally, review of private treatment records from Kaiser Permanente in February 1988, over 6 years after separation from service, reports that the Veteran had a blood pressure reading of 160/100. An assessment of borderline blood pressure was provided, and it was noted that the Veteran was very anxious that day. In April 1988, another assessment of borderline blood pressure was provided after a reading of 140/94. The Board does not find it credible that if the Veteran had a history of hypertension that had required medication that the Veteran's physician in 1988 would not be aware of this history or that the Veteran would not have reported it his physician at that time. The Board also does not find credible the report of the Veteran's brother, W.J.M., M.D., that he spoke to the Veteran's physician during his period of active service regarding his diagnosis of hypertension and his prescription for Coreg. The Board again finds probative the reports from the Veteran's physician in 1988 and the Veteran's failure to report a prior history of hypertension at that time to indicate that these reports of a diagnosis prior to separation from service by the Veteran's brother to be not credible. The Board also finds the opinions provided by J.T.K., D.O and D.L., M.D. to lack probative value regarding the onset of the Veteran's hypertension as these reports were based upon the Veteran's statements regarding the onset of his condition that have been determined not to be credible. The Board finds that the weight of the competent, credible evidence of record does not support a finding that the Veteran's hypertension began during service or manifested to a compensable degree within a year of separation from active service. Accordingly, the Board finds that service connection for hypertension is not warranted based upon presumptive service connection for a chronic condition. 38 C.F.R. §§ 3.307, 3.309. Service connection may also be granted on a presumptive basis for certain diseases associated with exposure to certain herbicide agents, even though there is no record of such disease during service, if the requirements of § 3.307(a)(6) are met and the rebuttable presumption provisions of § 3.307(d) are also satisfied. 38 U.S.C. § 1113; 38 C.F.R. §§ 3.307, 3.309. To the extent that the Veteran contended that his hypertension was due to exposure to herbicide agents in service, the Board notes that hypertension is not listed as a condition that is presumed to be the result of exposure to herbicides. Further, with regard to this claim on a direct basis, the Board does not find the Veteran's reports of in-service exposure to herbicide agents to be credible. The Veteran's records do not support, nor did the Veteran contend that he served in Vietnam; as such, presumptive exposure to herbicide agents on that basis is not warranted. Further, the Veteran's personnel records and his DD-214 do not report that the Veteran regularly and repeatedly operated, maintained, or served onboard C-123 aircraft. 38 C.F.R. §§ 3.307(6)(v). Moreover, the Board notes that the Veteran specifically denied exposure to Agent Orange and herbicide agents on his August 2005 application for service connection. Based upon these contradictory statements and the lack of other evidence supporting exposure to herbicide agents during active service, the Board finds the Veteran's reports of exposure to herbicide agents to not be credible. As such, entitlement to service connection for hypertension due to exposure to herbicide agents on a presumptive or direct basis is not warranted. When a Veteran is found not to be entitled to a regulatory presumption of service connection for a given disability, the claim must nevertheless be reviewed to determine whether service connection can be established on another basis. Combee v. Brown, 34 F. 3d. 1039 (Fed. Cir. 1994). As such, the Board will also consider whether service connection is warranted based upon a direct relationship between the Veteran's condition and his period of active service. Unfortunately, the Board finds that the competent, credible evidence of record weighs against a finding that the Veteran's hypertension was directly due to his period of active service. The Board finds the most probative evidence of record to be the opinion provided by the May 2021 VA examiner. The examiner opined that it is less likely than not that the Veteran had diagnosis of hypertension during service and that it is also less likely than not his hypertension was related to an in-service injury, event, or disease. The examiner noted that there were no blood pressure readings in service or within several years of separation that are consistent with a diagnosis of hypertension that is documented in the claims file. Further, the examiner stated that this opinion was supported by the notation that provided by the Veteran's doctor in October 1988 that his elevated blood pressure was likely due to anxiety of being in office. The examiner provided a thorough rationale that is supported by the evidence of record, including consideration of the statements provided by the Veteran and the available medical records, including the November 1981 EKG finding of minor, non-specific ST-T wave changes and his August 1982 finding of elevated cholesterol. As such, the Board finds the May 2021 VA examiner's medical opinion to be highly probative evidence weighing against a relationship to between the Veteran's hypertension and his period of active service. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008). The Board notes the reports of the Veteran and his brother, W.J.M., M.D., that the Veteran's hypertension began during his period of service. For the reasons discussed above, the Board does not find these reports to be credible. As such, the report provided by W.J.M., M.D. is afforded no probative value. The Board also finds the opinions provided by J.T.K., D.O and D.L., M.D. to be of less probative value than the opinion provided by the 2021 VA examiner as these opinions were based upon the Veteran's statements regarding the onset of his condition that have been determined to be not credible. In summary, the Board finds that the preponderance of the evidence weighs against a finding that the Veteran's hypertension was due to the Veteran's period of active service. The evidence also weighs against a finding that the Veteran's hypertension began during service or manifested to a compensable degree within a year of separation from active service. Consequently, the benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107 (b); Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). 2. Entitlement to service connection for diabetes mellitus The Veteran has also contended that he developed and was diagnosed with diabetes during his period of active service. Unfortunately, the Board finds that the weight of the credible evidence of record is against a finding that the Veteran's diabetes was incurred in, or is otherwise due to, his period of active service. Initially, the Board notes that several alternative paths to service connection exist for certain chronic diseases identified in 38 C.F.R. § 3.309 (a), including diabetes mellitus. 38 C.F.R. § 3.309. See Walker. The Board finds, however, that service connection for diabetes is not available under 38 C.F.R. § 3.309 (a) as the credible evidence of record weighs against a finding that the Veteran had diabetes during service or that the condition manifested to a compensable degree within a year of separation from service. To the extent that the Veteran's service treatment records have been associated with the claims file, the Veteran's records are silent with report of a diagnosis of diabetes during service or within a year of separation from active service. Despite the Veteran's reports, his STR do not report any history of diabetes or abnormal glucose tolerance during active service. The Veteran's separation examination in November 1981 indicates his answer to the regarding his present health was "Excellent - No meds." The May 2021 VA examiner stated that there is no indication or a lab finding or of symptoms found in his STRs consistent with the diagnosis of diabetes mellitus. To the extent that the Veteran has reported that he was diagnosed with diabetes or demonstrated impaired fasting glucose during service, the Board does not find these reports to be credible. On an October 1982 Report of Medical History (after separation from active service), the Veteran denied taking any current medications and denied history of significant illness since his last examination. Review of private treatment records from Kaiser Permanente in February 1988, over 6 years after separation from service, reports that the Veteran was referred from an urgent care facility based upon increased blood sugar levels. The physician stated that the Veteran had no prior known diabetes. More significantly, the Veteran's doctor in October 1988 notes that the Veteran "still presents with a lot of denial regarding diagnosis of diabetes" and an assessment of borderline diabetes was provided at that time. The Board does not find it credible that if the Veteran had a history of diabetes or a longstanding history of impaired fasting glucose that the Veteran would be in denial about a potential diagnosis of diabetes in 1988. The Board also does not find credible the report of the Veteran's brother, W.J.M., M.D., that he spoke to the Veteran's physician during his period of active service regarding a diagnosis of diabetes or test results indicating glucose tolerance levels that were abnormally high. The Board again finds probative the reports from the Veteran's physician in 1988 that provided borderline readings several years after separation from service and the fact that the Veteran was in denial about the test results at that time. The Board does not find it credible that W.J.M., M.D. would have spoken to the Veteran's physician about abnormal glucose test results in service and then the Veteran would be in denial about similar results several years later. It also does not correspond with the Veteran's reports in February 1988 that he had no prior known diabetes. As such, the Board does not find the reports of W.J.M., M.D. regarding in-service diabetes or abnormal glucose test results to be credible. The Board also finds the opinions provided by J.T.K., D.O and D.L., M.D. to lack probative value regarding the onset of the Veteran's diabetes as these reports were based upon the Veteran's statements regarding the onset of his condition that have been determined not to be credible. The Board finds that the weight of the competent, credible evidence of record does not support a finding that the Veteran's diabetes began during service or manifested to a compensable degree within a year of separation from active service. Accordingly, the Board finds that service connection for diabetes is not warranted based upon presumptive service connection for a chronic condition. 38 C.F.R. §§ 3.307, 3.309. Service connection may also be granted on a presumptive basis for certain diseases associated with exposure to certain herbicide agents, even though there is no record of such disease during service, if the requirements of § 3.307(a)(6) are met and the rebuttable presumption provisions of § 3.307(d) are also satisfied. 38 U.S.C. § 1113; 38 C.F.R. §§ 3.307, 3.309. While diabetes is a disease presumed to be related to in-service exposure to herbicide agents, as discussed above, the Board does not find the Veteran's reports of exposure to herbicide agents to be credible. The Board finds probative the Veteran's own August 2005 reports that he was not exposed to herbicide agents and the lack of other evidence in the Veteran's personnel records supporting exposure to herbicide agents during active service; accordingly, the Board finds the Veteran's reports of exposure to herbicide agents to be not credible. Therefore, entitlement to service connection for diabetes due to exposure to herbicide agents on a presumptive or direct basis is not warranted. However, the Board will also consider whether service connection is warranted based upon a direct relationship between the Veteran's condition and his period of active service. See Combee. Unfortunately, the Board finds that the competent, credible evidence of record weighs against a finding that the Veteran's diabetes was directly due to his period of active service. The Board finds the most probative evidence of record to be the opinion provided by the May 2021 VA examiner. The examiner opined that it is less likely than not that the Veteran had diagnosis of diabetes during service and that it is also less likely than not his diabetes was related to an in-service injury, event, or disease. The examiner noted that there were no symptoms or lab findings in the Veteran's STRs consistent with a diagnosis of diabetes mellitus, and that there is no medical evidence in any medical record within several years of separation to support that "he was found to have abnormal glucose tolerance tests" in service. The examiner noted that the Veteran was found to have "borderline diabetes" in October 1988, several years after separation from service. The examiner provided a thorough rationale that is supported by the evidence of record, including consideration of the statements provided by the Veteran and the available medical records, including the November 1981 EKG finding of minor, non-specific ST-T wave changes and his August 1982 finding of elevated cholesterol. As such, the Board finds the May 2021 VA examiner's medical opinion to be highly probative evidence weighing against a relationship to between the Veteran's diabetes mellitus and his period of active service. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008). The Board notes the reports of the Veteran and his brother, W.J.M., M.D., that the Veteran's diabetes began during his period of service. For the reasons discussed above, the Board does not find these reports to be credible. The Board also finds the opinions provided by J.T.K., D.O and D.L., M.D. to be of less probative value than the opinion provided by the 2021 VA examiner as their opinions were based upon the Veteran's statements regarding the onset of his condition that have been determined to be not credible. In summary, the Board finds that the preponderance of the evidence weighs against a finding that the Veteran's diabetes was due to the Veteran's period of active service. The evidence also weighs against a finding that the Veteran's diabetes began during service or manifested to a compensable degree within a year of separation from active service. Consequently, the benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107 (b); Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). 3. Entitlement to service connection for congestive heart failure The Veteran also asserted that service connection was warranted for congestive heart failure that had onset in 2012. The Veteran primarily contended that his congestive heart failure was secondary to his diabetes and hypertension. During his March 2018 Board hearing, he stated with reference to his congestive heart failure that, "the increase in my blood pressure readings as a result of the diabetes and this is a constant bombardment on my heart. So, I was also advised by the doctors, eventually because of your diabetes, these things may occur to you different and it is almost guaranteed." H.T., p.7. Unfortunately, to the extent that the Veteran indicated that his congestive heart failure was due to hypertension and diabetes, the Board notes that service-connection these conditions has not been granted; accordingly, service connection for congestive heart failure on secondary basis cannot be granted as a matter of law. See 38 C.F.R. § 3.310. The Board has also considered whether service-connection for congestive heart failure was warranted on a direct basis; however, the weight of the competent medical evidence of record does not indicate a link between the Veteran's congestive heart failure and his period of active service. Particularly, the Board finds probative the opinion provided by the May 2021 VA examiner that opined that it is less likely than not that the Veteran had a diagnosis of a heart condition during service and that it is less likely than not that his eventual cardiac condition was related to any injury, event, or disease from his period of active service. The examiner specifically noted the November 1981 EKG finding was reported to show minor nonspecific ST-T wave changes. Further, the examiner requested a cardiologist to review the EKG itself, which was reported to look "normal." The cardiologist reported that there is minor J point elevation and T wave flattening visible for lead III, but these would not be considered abnormal. The examiner provided a rationale that is supported by the evidence of record, including consideration of the lay statements provided by the Veteran, and available medical records. As such, the Board finds the May 2021 VA medical opinion to be highly probative evidence weighing against a relationship to between the Veteran's congestive heart failure and the Veteran's active service. See Nieves-Rodriguez. Further, none of the medical evidence of record provides a nexus between the Veteran's congestive heart failure and the Veteran's period of active service. In summary, the Board finds that the preponderance of the evidence weighs against a finding that any heart disability of the Veteran, to include congestive heart failure, began during, or is otherwise due to, the Veteran's period of active service. Consequently, the benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107 (b); Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). 4. Entitlement to service connection for a right eye disability The Veteran also asserted that service connection was warranted for a right eye disability. The Veteran contended that his right eye disability was due to his diabetes. During his March 2018 Board hearing, he stated, "Diabetes weakens the arteries or the blood vessel of the eye; they really educate me on it. What occurs is this, through time, through years your vessels weaken; that's why you're susceptible even to a regular CDA stroke and a right eye closure, as they may say. You're basically a time-bomb regarding diabetes." Unfortunately, to the extent that the Veteran indicated that his right eye disability was due to diabetes, the Board notes that service-connection for this condition has not been granted; accordingly, service connection for a right eye disability on secondary basis cannot be granted as a matter of law. See 38 C.F.R. § 3.310. Further, none of the medical evidence of record provides a nexus between the Veteran's right eye disability and the Veteran's period of active service. In summary, the Board finds that the preponderance of the evidence weighs against a finding that any right eye disability was either due to a service-connected disability or any incident of his active service. Consequently, the benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107 (b); Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). 5. Entitlement to a TDIU Where the schedular rating is less than total, a total disability rating may be assigned when the disabled person is unable to secure or follow a substantially gainful occupation as a result of service-connected disabilities, provided that, if there is only one such disability, this disability shall be ratable at 60 percent or more, or if there are two or more disabilities, there shall be at least one disability at 40 percent or more, and sufficient additional disability to bring the combined rating to 70 percent or more. 38 C.F.R. § 4.16 (a). For purposes of this provision, disabilities of one or both upper extremities, or of one or both lower extremities, including the bilateral factor, will be considered one disability. Prior to his death, the Veteran was service-connected for posttraumatic stress disorder, rated 30 percent disabling from March 23, 2015; and tinnitus, rated 10 percent disabling from April 6, 2012. Throughout the appeal period, the Veteran had a combined rating less than 70 percent, and did not have a rating of 60 percent due to one disability. Thus, the threshold requirements for a TDIU rating on a schedular basis were not met and entitlement to a schedular TDIU is denied. See 38 C.F.R. § 4.16 (a). With regard to whether TDIU is warranted on an extraschedular basis, the Board finds that the evidence of record does not support that the Veteran was unable to secure or follow a substantially gainful occupation due to his service-connected disabilities and referral for extraschedular consideration of TDIU is not warranted. The central inquiry for entitlement to TDIU is "whether the veteran's service-connected disabilities alone are of sufficient severity to produce unemployability." Hatlestad v. Brown, 5 Vet. App. 524, 529 (1993). Consideration may be given to his or her level of education, special training, and previous work experience, but advancing age and the impairment caused by nonservice-connected disabilities are not for consideration in determining whether such a total disability rating is warranted. See 38 C.F.R. §§ 3.341, 4.16, 4.19; Van Hoose v. Brown, 4 Vet. App. 361, 363 (1993). While the Veteran contended that a TDIU was warranted, the Veteran himself provided statements indicating that conditions that have not been granted service connection were part of the reason he was unable to work prior to his death. In his February 2013 VA 21-8940, the Veteran stated that he was unable to work due to diabetic neuropathy, diabetic retinopathy, and his high blood pressure. None of these conditions have been granted service connection. Additionally, during his 2018 Board hearing, the Veteran stated that he stopped working due to undergoing heart surgery for a condition that has not been granted service connection. See H.T., p.18. Additionally, records from the Social Security Administration indicate that the Veteran was determined to be disabled due to multiple nonservice-connected conditions including stroke, diabetes, neuropathy, glaucoma, retinopathy; blindness; osteomyelitis; hypertension; arthritis; and balance issues. As mentioned above, however, the central inquiry for entitlement to TDIU is "whether the veteran's service-connected disabilities alone are of sufficient severity to produce unemployability." Hatlestad, 5 Vet. App. at 529 (1993) (emphasis added). While the Veteran may have other disabling conditions that are not service-connected, a TDIU is not warranted unless the service-connected conditions by themselves cause impairment that is sufficient to produce unemployability. As none of the evidence of record, including the Veteran's own statements, supports that he was unable to work due to his service-connected disabilities alone (PTSD and tinnitus), the Board finds that referral for consideration of TDIU on an extraschedular basis is not warranted, and the appeal in this matter must be denied. See 38 C.F.R. §§ 3.102, 3.340, 3.341, 4.16. K. Parakkal Veterans Law Judge Board of Veterans' Appeals Attorney for the Board P.M. Johnson, 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.