Citation Nr: 1751956 Decision Date: 11/14/17 Archive Date: 11/22/17 DOCKET NO. 13-14 296 ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Montgomery, Alabama THE ISSUES 1. Entitlement to service connection for hypertension, to include as secondary to a service-connected disability. 2. Entitlement to service connection for coronary artery disease (CAD) to include as secondary to a service-connected disability. 3. Entitlement to service connection for sleep apnea, to include as secondary to a service-connected disability. 4. Entitlement to an initial rating in excess of 30 percent for service-connected headaches. 5. Entitlement to an effective date earlier than May 17, 2011, for the grant of service connection for glaucoma and ocular hypertension with dry eye syndrome. 6. Entitlement to a total disability rating based on individual unemployability due to service-connected disabilities (TDIU). REPRESENTATION Appellant represented by: The American Legion WITNESS AT HEARING ON APPEAL The Veteran ATTORNEY FOR THE BOARD S. Keyvan, Counsel INTRODUCTION The Veteran had active service from March 1974 to February 1976 and from April 1976 to April 1994. This matter comes before the Board of Veterans' Appeals (Board) on appeal from the January 2012, August 2014, December 2014, May 2015 and May 2016 rating decisions of the Department of Veterans Affairs (VA) Regional Office (RO) in Montgomery, Alabama. In the January 2012 rating decision, the RO denied the claim of entitlement to service connection for hypertension. The Veteran filed a notice of disagreement (NOD) with this decision in February 2012, and perfected a timely appeal of this decision in March 2013. In the August 2014 rating decision, the RO denied the claims seeking entitlement to service connection for CAD and entitlement to a TDIU. The Veteran filed an NOD with the denial of these claims in August 2014, and perfected a timely appeal of this decision in December 2014. In the December 2014 rating decision, the Decision Review Officer (DRO) granted service connection for glaucoma/ocular hypertension with dry eye syndrome and assigned a 10 percent disability rating, effective May 17, 2011. The Veteran filed an NOD with the effective date assigned for the grant of service connection for glaucoma/ocular hypertension in December 2014, and perfected a timely appeal of this claim in October 2015. In the May 2015 rating decision, the RO denied service connection for sleep apnea. The Veteran filed an NOD with the denial of this claim in July 2015, and he perfected a timely appeal of this decision in October 2015. In the May 2016 rating decision, the RO granted the claim seeking service connection for headaches, and evaluated it as 30 percent disabling, effective May 17, 2011. The Veteran filed an NOD with the 30 percent rating assigned for this disorder, and perfected a timely appeal of this decision in July 2016. In May 2015, the Veteran presented sworn testimony during a videoconference hearing before a Veterans Law Judge (VLJ). A transcript of the testimony has been associated with the Veteran's claims file. In an August 2017 letter, the Board informed the Veteran that the VLJ who conducted his hearing was no longer employed by the Board. Pursuant to 38 C.F.R. § 20.707, the VLJ who conducts a hearing shall participate in making the final determination of the claim. The August 2017 letter offered the Veteran the opportunity to testify at another videoconference hearing, as well as the option to testify either before a VLJ in-person at his local RO, or at the Board's offices in Washington DC. See 38 C.F.R. §20.717 (2017). The Veteran was also informed that he had 30 days to respond to this letter. In correspondence dated on August 7, 2017, the Veteran indicated that he did not wish to appear at another Board hearing, and requested that his case be considered based on the evidence of record. In his December 2014 notice of disagreement with the effective date assigned for service connection for glaucoma, the Veteran used the words "unmistakable error." If he wishes to file a request to revise the 1994 rating decision based on clear and unmistakable error, which he has not as yet requested, then he should consult his representative as to filing a request for revision of the 1994 decision. The issues of entitlement to service connection for hypertension and sleep apnea, to include as secondary to the service-connected glaucoma/ocular hypertension, and entitlement to a TDIU, are addressed in the REMAND portion of the decision below and are REMANDED to the Agency of Original Jurisdiction (AOJ). FINDINGS OF FACT 1. The Veteran's hypertension did not have its onset during, was not caused by active service, and was not caused or aggravated by his service-connected glaucoma/ocular hypertension with dry eye syndrome. 2. The Veteran's service-connected migraine headaches have not resulted in very frequent completely prostrating and prolonged attacks productive of severe economic inadaptability. 3. The RO denied service connection for glaucoma in an unappealed July 1994 rating decision. 4. The next claim of entitlement to service connection for glaucoma was received by VA in May 2011. CONCLUSIONS OF LAW 1. The criteria for service connection for hypertension have not all been met. 38 U.S.C. §§ 1110, 1131, 5107 (West 2012); 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.310 (2017). 2. The criteria for an initial rating in excess of 30 percent for migraine headaches have not been met. 38 U.S.C. §§ 1155, 5107 (West 2012); 38 C.F.R. §§ 3.102, 4.1, 4.2, 4.3, 4.7, 4.10, 4.21, 4.124a, Diagnostic Code 8100 (2017). 3. The July 1994 rating decision that denied entitlement to service connection for glaucoma is final. 38 U.S.C. § 7105 (West 2012); 38 U.S.C. §§ 20.302, 20.1103 (2017). 4. The requirements for an effective date prior to May 17, 2011, for the grant of entitlement to service connection for glaucoma, have not been met. 38 U.S.C. §§ 5101, 5110 (West 2012); 38 C.F.R. §§ 3.102, 3.155, 3.157, 3.159, 3.400 (2017). REASONS AND BASES FOR FINDINGS AND CONCLUSION I. Duties to Notify and Assist With respect to the Veteran's claims herein, VA has met all statutory and regulatory notice and duty to assist provisions. See generally, 38 U.S.C. §§ 5103, 5103A (West 2012); 38 C.F.R. § 3.159, 3.326 (2017); see also Scott v. McDonald, 789 F.3d 1375 (Fed. Cir. 2015). Pursuant to the August 2015 remand, the VA afforded the Veteran a relevant examination in April 2016 which addressed whether the Veteran's hypertension was incurred in service, or otherwise related to his military service and/or secondary to his service-connected glaucoma/ocular hypertension. The Board finds that this examination report is adequate for purposes of rendering a decision in the instant appeal. See 38 C.F.R. § 4.2 (2017); see also Barr v. Nicholson, 21 Vet. App. 303, 312 (2007). It reflects that the VA examiner reviewed the Veteran's past medical history, his current complaints, conducted/reviewed necessary testing and examination findings, and rendered appropriate diagnoses and opinions consistent with the remainder of the evidence of record. More importantly, with respect to the Veteran's claimed hypertension decided herein, the medical opinion addressed the questions listed in the August 2015 Board remand directives. Accordingly, the requirements of the August 2015 Remand were ultimately accomplished by way of this examination report. See Stegall v. West, 11 Vet. App. 268 (1998). As such, the Board finds that VA's duty to obtain a VA examination or opinion with respect to hypertension claim decided herein has been met. 38 C.F.R. § 3.159 (c)(4). II. Analysis Service Connection Service connection may be granted for a disability resulting from a disease or injury incurred in or aggravated by active service. See 38 U.S.C. §§ 1110, 1131 (West 2012); 38 C.F.R. 3.303 (a) (2017). "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"- the so-called "nexus" requirement." Holton v. Shinseki, 557 F.3d 1362, 1366 (Fed. Cir. 2010) (quoting Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Service connection for certain chronic diseases, including hypertension, may also be established based upon a legal "presumption" by showing that the disease manifested itself to a degree of 10 percent or more within one year from the date of separation from service. 38 U.S.C. §§ 1112, 1137 (West 2012); 38 C.F.R. §§ 3.307, 3.309 (2017). In addition, service connection may be granted for any disease diagnosed after service when all the evidence establishes that the disease was incurred in service. 38 C.F.R. § 3.303 (d) (2017). Disability which is proximately due to or the result of a service-connected disease or injury shall be service connected. 38 C.F.R. § 3.310 (a) (2017). The secondary condition shall be considered a part of the original condition. Id. The phrase "due to or the result of" encompasses disability caused by or aggravated by the service-connected disease or injury. See Allen v. Brown, 7 Vet. App. 439 (1995). "Aggravation" of a nonservice-connected condition by a service-connected condition means a chronic worsening of the nonservice-connected condition by the service-connected condition, not merely temporary or intermittent flare-ups. See Hunt v. Derwinski, 1 Vet. App. 292 (1991); Davis v. Principi, 276 F.3d 1341 (Fed. Cir. 2002). The Veteran primarily contends that his hypertension was incurred in service. In a March 2012 statement, the Veteran asserted that he was diagnosed with hypertension within 24 months of his discharge from service. In the alternative, the Veteran also contends that his hypertension is secondary to his service-connected glaucoma/ocular hypertension with dry eye syndrome. The Board notes that the term hypertension refers to persistently high arterial blood pressure. Medical authorities have suggested various thresholds ranging from 140 mm. Hg systolic and from 90 mm. Hg diastolic. See Dorland's Illustrated Medical Dictionary 909 (31st ed. 2007). Similarly, for VA rating purposes, the term hypertension means that the diastolic blood pressure is predominantly 90 mm. or greater. The term isolated systolic hypertension means that the systolic blood pressure is predominantly 160 mm. or greater with a diastolic blood pressure of less than 90 mm. See 38 C.F.R. § 4.104, Code 7101, Note 1 (2017). In considering the evidence of record under the laws and regulations as set forth above, the Board finds that the Veteran is not entitled to service connection for hypertension. In this regard, review of the service treatment records reflects that the Veteran underwent periodic medical examinations throughout his military service, the results of which were negative for any abnormalities in the heart and vascular system, and were further negative for any signs of elevated blood pressure readings. Indeed, at the September 1981 medical examination, the Veteran was shown to have a blood pressure reading of 114/74 while sitting and 114/76 while standing, and at the September 1982 medical examination, the Veteran was shown to have a blood pressure readings of 100/70 while sitting, and 106/70 while standing. At the November 1987 medical examination, the Veteran was shown to have a blood pressure reading of 100/72, and at the May 1991 medical examination, the Veteran was shown to have a blood pressure reading of 120/70. The Veteran also denied a medical history of high or low blood pressure in his periodic medical history reports. The remainder of the service treatment records is absent any indications of, or treatment for, elevated blood pressure, or symptoms referable to high blood pressure. At the October 1993 separation examination, the clinical evaluation of the heart and vascular system was shown to be normal, and the Veteran was shown to have a blood pressure reading of 114/79. At the July 1994 VA examination, it was noted that the Veteran had been discharged from the Army with complaints of borderline glaucoma. A review of the vascular and cardiac system was negative for any abnormalities, and physical examination of the Veteran's heart revealed a regular heart rate and rhythm without gallop, murmur or rub. In addition, the Veteran was shown to have a blood pressure reading of 144/92. Based on his discussion with, as well as his evaluation of, the Veteran, the VA examiner diagnosed the Veteran with having a history of borderline glaucoma and borderline diastolic hypertension. The examiner noted that the Veteran reported that he had been followed occasionally in service for his elevated blood pressure readings, and recommended that the Veteran return for follow-up treatment and care. A September 2003 cardiac catheterization report reflects that the Veteran was admitted to Baptist Health Hospital due to complaints of chest pain. During his admission, he underwent a percutaneous transluminal coronary angioplasty (PTCA) and stent implantation in the first diagonal branch of the left anterior descending (LAD) coronary artery via the left femoral artery, the results of which revealed a 90 percent stenosis of a large first diagonal branch. Based on the results of the procedure and the elective catheter revascularization due to these findings, the Veteran was discharged with diagnoses of ischemic heart disease, angina pectoris, hypertension and hyperlipidemia. In a July 2014 letter, the Veteran's cardiologist, J.M., M.D., noted that the Veteran was seen on a regular basis at their office for treatment of his CAD, hyperlipidemia, and his hypertension. The Veteran was afforded a VA examination in connection to his hypertension claim in November 2014, during which time, he provided his medical and military history and stated that he was unsure as to when he was diagnosed with hypertension. The Veteran recalled taking medication for his hypertension on a recurrent basis throughout the years in an effort to determine whether he really needed it. When asked whether the Veteran's treatment plan included taking continuous medication for his hypertension, the examiner marked that it did, and noted that the Veteran takes amlodipine on a daily basis for his hypertension. When asked whether the Veteran's initial diagnosis of hypertension or isolated systolic hypertension was confirmed by blood pressure readings taken two or more times on at least three different days, the examiner determined that this was unknown. Upon physical examination, the Veteran's blood pressure reading was shown to be 134/78, 137/78, and 143/79, with an average blood pressure reading of 138/78. Based on her discussion with, as well as her evaluation of the Veteran, the VA examiner diagnosed the Veteran with having hypertension, and determined that said disorder was less likely than not incurred in or caused by the claimed in-service injury, event or illness. In reaching this conclusion, the examiner again took note of the Veteran's in-service complaints of chest pain, but determined that these symptoms were not cardiac in nature. The examiner further reasoned that the Veteran was not diagnosed with having hypertension until 2003 as reflected on the discharge summary when he underwent the coronary stent placement procedure at Baptist Health Hospital. As such, the examiner concluded that it is less likely than not that the Veteran's hypertension is due to, or caused by, his military service. Pursuant to the August 2015 remand directives, the Veteran was afforded another VA examination in April 2016, during which time, he provided his military and medical history, and stated that he was diagnosed with having hypertension by a private treatment provider and prescribed with Lisinopril at onset, which he continued taking until his 2003 coronary stent placement procedure. When asked whether the Veteran's initial diagnosis of hypertension or isolated systolic hypertension was confirmed by blood pressure readings taken two more times on at least three different days, the examiner responded that it was unknown. On physical examination, the Veteran's blood pressure readings were shown to be 139/74, 135/72, and 135/75, with an average reading of 136/73. When asked whether the Veteran's hypertension impacts his ability to work, the examiner responded that it did not. Based on her discussion with, as well as her evaluation of the Veteran, the VA examiner determined that it was less likely than not that his hypertension was incurred in, or caused by, the claimed in-service injury, event or illness. In reaching this determination, the VA examiner explained that there was no evidence of a confirmed diagnosis of hypertension diagnosis until 2003 - the same time as the discovery of the Veteran's coronary artery disease. The VA examiner acknowledged the July 1994 VA examination report which documented a blood pressure reading of 144/92, and reflected a diagnosis of borderline diastolic hypertension. According to the VA examiner, this was an isolated elevated diastolic blood pressure reading "which is not sufficient for a diagnosis of [hypertension], and in fact he was not diagnosed with [hypertension] until 2003." The VA examiner explained that an isolated elevation in 1994 does not meet the American Heart Association (AHA) criteria for a diagnosis of hypertension. The VA examiner further concluded that the Veteran's service-connected glaucoma/ocular hypertension would have no influence on the Veteran's hypertension, and that this service-connected disorder neither caused, nor aggravated his current hypertension. Where a Veteran served continuously for 90 days or more during a period of war, or during peacetime service after December 31, 1946, and hypertension manifest to a degree of 10 percent or more within 1 year from date of termination of such service, such disease(s) shall be presumed to have been incurred in service, even though there is no evidence of such disease(s) during the period of service. See 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1131, 1137 (West 2012); 38 C.F.R. §§ 3.307, 3.309 (2017). Although the medical evidence reflected an impression of borderline diastolic hypertension in July 1994, the April 2016 VA examiner addressed this examination report, and explained that based on the medical findings documented during this evaluation, an isolated elevated diastolic blood pressure reading was not sufficient for a diagnosis of hypertension, and did not fall under the AHA criteria for a hypertension diagnosis. Following this isolated incident, the medical evidence of record does not show that the Veteran sought treatment for, or was diagnosed with having, hypertension for several years thereafter. Indeed, these records are also absent any signs, symptoms, or manifestations of hypertension, to include elevated blood pressure readings, for several years following the Veteran's military service. Therefore, the Board finds that hypertension did not manifest in service or within one year thereafter. With respect to direct service connection, the preponderance of evidence of record is against a finding that the Veteran's hypertension was incurred in, or related to his active service. Indeed, following the July 1994 examination, the remainder of the post-service record is negative for any findings of complaints, treatment or diagnoses of hypertension, until several years after service. In fact, the first post-service record reflecting a clear and definite diagnosis of hypertension is the September 2003 operative report. Indeed, both the November 2014 and April 2016 VA examiners determined that the September 2003 diagnosis was a clear and confirmed diagnosis of hypertension. A prolonged period without medical complaint can be considered, along with other factors concerning a claimant's health and medical treatment during and after military service, as evidence of whether an injury or disease was incurred in service which resulted in any chronic or persistent disability. See Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000). The evidence of record indicates that there was no confirmed diagnosis of hypertension until many years after service. Specifically, the evidence of record indicates that a confirmed diagnosis of hypertension did not manifest until at least nine years after the Veteran's separation from service. The Board acknowledges the Veteran's hearing testimony that he was treated for elevated blood pressure readings while he was service. However, a review of the service treatment records (a recitation of which has been provided above) is absent any notations, signs or evidence of elevated blood pressure readings. The Board finds the service treatment records to be more probative than the Veteran's recollection of what he was treated for during service. This is because the records were created at the time of his service and appear complete. In addition, there is nothing in the record to show that the Veteran's hypertension was incurred in service, and none of his treatment providers or VA examiners have found that his current hypertension was incurred in, or otherwise related to his military service. Indeed, the November 2014 VA examiner determined that based on a review of the available medical records and the Veteran's in-person medical history and physical examination, the Veteran's claimed hypertension was less likely than not incurred in or caused by an in-service event or illness. In reaching this conclusion, she (the examiner) determined that the Veteran's in-service complaints of chest pain were not cardiac-related, and the Veteran was not diagnosed with having hypertension until 2003 as reflected by the September 2003 discharge summary. The April 2016 VA examiner also determined that the Veteran's hypertension was less likely than not related to an in-service injury, event or illness. In reaching this conclusion, the VA examiner found no evidence of a confirmed hypertension diagnosis until 2003 - simultaneous to the time of discovery of his coronary artery disease. As discussed above, although the July 1994 VA examination reflected a blood pressure reading of 144/92 and an impression of borderline diastolic hypertension, the April 2016 VA examiner addressed this report and determined this to be an isolated reading that did not fall under the AHA criteria for a diagnosis of hypertension. Based on this examination report, there was no evidence of a confirmed diagnosis of hypertension until September 2003. Turning to the issue of service connection on a secondary basis, the Board notes that the Veteran has been diagnosed with having hypertension, and he is service-connected for his glaucoma/ocular hypertension with dry eye syndrome. See December 2014 rating decision. The remaining question, therefore, is whether there is medical evidence of a relationship between the Veteran's hypertension and his service-connected glaucoma/ocular hypertension with dry eye syndrome. In this case, the Board finds that the Veteran is not entitled to service connection for hypertension on a secondary basis because the most probative medical evidence of record, by way of the April 2016 opinion, has found that it is less likely than not that the hypertension was caused or aggravated by the service-connected glaucoma/ocular hypertension. The content of the examination report has been discussed and outlined above. After reviewing the service and post-service treatment records in full, and taking into consideration the VA optometry reports, the examiner found no evidence that that the Veteran's service-connected glaucoma/ocular hypertension caused or aggravated the Veteran's current hypertension. In reaching this determination, the VA examiner not only relied on the claims file, but also on her medical expertise and experience, as well as the medical principles as they currently stood. The Board finds that the opinions provided by the VA examiners to be well reasoned and supported by reference to objective medical evidence. Collectively, the medical opinions are based on a discussion with the Veteran regarding his medical history and current condition, a complete review of the medical records, and physical examinations. In addition, the VA medical opinions, in conjunction with one another, provided clear and detailed opinions addressing whether the Veteran's hypertension was incurred in, and/or proximately due to, or aggravated beyond a natural progression, by his service-connected glaucoma/ocular hypertension, and provided well-supported rationales that relied on the objective medical findings within the record, as well as the medical principles as they currently stood. See Prejean v. West, 13 Vet. App. 444, 448-9 (2000) (which holds that factors for assessing the probative value of a medical opinion are the treatment provider's access to the claims file and the thoroughness and detail of the opinion.) Further, and of particular significance to the Board in this matter, is the fact that no medical professional has provided any opinion indicating that the Veteran's hypertension was incurred in service, or in any way secondary to his service-connected glaucoma/ocular hypertension. Thus, the competent medical evidence of record reflects that the Veteran's hypertension is not secondary to his service-connected glaucoma/ocular hypertension. The Board acknowledges the Veteran's belief that his hypertension was incurred in service and/or related to his service-connected glaucoma/ocular hypertension. The Board notes that the Veteran is competent to testify as to a condition within his knowledge and personal observation. See Barr v. Nicholson, 21 Vet. App. 303, 308-10 (2007). However, it is clear, based on a detailed review of the statements overall, that the Veteran has no actual specialized knowledge of medicine in general, or cardiovascular medicine more particularly, and that he is merely speculating as to whether his hypertension was incurred in service and/or related to his service-connected glaucoma/ocular hypertension. In this regard, he is not competent to diagnose this condition or symptoms or relate such to his glaucoma, as such diagnosis and relationship are complex questions the answers to which require specialized medical knowledge and specific testing. The cause of hypertension manifesting relatively long after the period of service and whether one disorder pertaining to an organ caused or chronically worsened a disability of another organ are complex questions, not simple ones, and, under the facts of this case, not questions that can be answered by observation with ones senses. Medical expertise is required to provide competent opinions with regard to these questions. As such, the Veteran's statements to this effect are lacking in probative value. For the reasons and bases discussed above, the Board finds that a preponderance of the evidence is against the claim for service connection for hypertension, to include as secondary to his service-connected glaucoma/ocular hypertension and this claim must be denied. Increased Rating Disability ratings are determined by applying the criteria set forth in the VA's Schedule for Rating Disabilities, which is based on the average impairment of earning capacity. Individual disabilities are assigned separate diagnostic codes. 38 U.S.C. § 1155; 38 C.F.R. § 4.1. The basis of disability evaluations is the ability of the body as a whole, or of the psyche, or of a system or organ of the body to function under the ordinary conditions of daily life including employment. 38 C.F.R. § 4.10. In determining the severity of a disability, the Board is required to consider the potential application of various other provisions of the regulations governing VA benefits, whether or not they were raised by the Veteran, as well as the entire history of the Veteran's disability. 38 C.F.R. §§ 4.1, 4.2; Schafrath v. Derwinski, 1 Vet. App. 589, 595 (1991). If the disability more closely approximates the criteria for the higher of two ratings, the higher rating will be assigned; otherwise, the lower rating is assigned. 38 C.F.R. § 4.7. It is not expected that all cases will show all the findings specified; however, findings sufficiently characteristic to identify the disease and the disability therefrom and coordination of rating with impairment of function will be expected in all instances. 38 C.F.R. § 4.21. In deciding this appeal, the Board has considered whether separate ratings for different periods of time, based on the facts found, are warranted, a practice of assigning ratings referred to as "staging the ratings." See Fenderson v. West, 12 Vet. App. 119 (1999) The Veteran's service-connected migraine headaches have been evaluated under Diagnostic Code 8100, which provides that a 50 percent rating is warranted for headaches with very frequently completely prostrating and prolonged attacks productive of severe economic inadaptability. A 30 percent rating is warranted for headaches with characteristic prostrating attacks occurring on an average once a month over the last several months. A 10 percent rating is warranted for headaches with characteristic prostrating attacks averaging one in two months over the last several months. A noncompensable rating is warranted for headaches with less frequent attacks. See 38 C.F.R. § 4.124a, Diagnostic Code 8100 (2017). The Veteran's migraine headache disability, for which he was originally granted service connection by way of the May 2016 rating decision, was evaluated as 30 percent disabling, effective May 17, 2011 The Veteran disagreed with this rating, and perfected a timely appeal of this decision in July 2016. The Veteran contends that he is entitled to an initial increased rating for his migraine headaches. Specifically, the Veteran maintains that this disability is more severe than reflected by the current disability rating assigned. The Veteran's service-connected migraine headaches have been evaluated under Diagnostic Code 8100, which provides that a 50 percent rating is warranted for headaches with very frequently completely prostrating and prolonged attacks productive of severe economic inadaptability. A 30 percent rating is warranted for headaches with characteristic prostrating attacks occurring on an average once a month over the last several months. A 10 percent rating is warranted for headaches with characteristic prostrating attacks averaging one in two months over the last several months. A noncompensable rating is warranted for headaches with less frequent attacks. See 38 C.F.R. § 4.124a, Diagnostic Code 8100 (2017). Review of the service treatment records reflect that the Veteran was seen at the military clinic on a number of occasions between December 1976 to May 1980 with complaints of headaches lasting three to four days in duration. More often than not, the Veteran reported that the headache pain was located in the frontal portion of his head near his eyes, and he denied additional symptoms of photophobia, nausea, and vomiting during these visits. During a November 1987 clinical visit, the Veteran was seen for follow-up treatment for a pressure-like sensation surrounding his eyes. He also reported to experience ongoing headaches but stated that his vision was fine. After evaluating the Veteran, the in-service clinician diagnosed him with having intraocular tension. At the October 1993 separation examination, although the clinical evaluation of the head was shown to be normal, the Veteran did report a history of ongoing headaches in his medical history report. In a February 2012 treatment report issued from Merit Health Care, PC, the Veteran's healthcare provider noted that the Veteran was a patient at their facility, and had been seen twice in the last two months with complaints of headaches. According to his healthcare provider, the Veteran had a history of ocular hypertension, was at risk of developing glaucoma, and should undergo further evaluations with an ophthalmologist to determine if the condition is contributing to his headaches. The Veteran was afforded a VA examination for his claimed headache condition in November 2014, during which time, he provided his medical and military history and reported that he started experiencing headaches while serving as an Air Traffic Controller in the U.S. Army. According to the Veteran, he experienced a great deal of stress due to his military duties, and he had been experiencing recurrent headaches since service. The Veteran also reported to experience pain across his forehead which improves whenever he closes his eyes and lies down. The examiner noted that the Veteran's treatment plan included taking medication, to include Advil migraine and Zofran Prn, for his headache condition. The symptoms associated with the Veteran's headache pain included pulsating or throbbing head pain which affects both sides of his head and persists for less than a day in duration. The Veteran also reported to experience non-headache type symptoms such as nausea and sensitivity to light. The examiner noted that the Veteran did not experience characteristic prostrating attacks of migraine/non-migraine headache pain. When asked whether the Veteran's headache condition impacts his ability to work, the examiner marked that it did and noted that prior to his retirement in 2012, the Veteran had had to leave work early due to his headaches at least once a month,. A Disability Benefits Questionnaire (DBQ) in connection to his headache condition was completed in January 2015, the report of which reflects the physician's (S.H., M.D.) notation that the Veteran had been diagnosed with having migraines to include migraine variants since March 2013. Dr. H. also noted that the Veteran had experienced ongoing headaches since his period of service, as reflected by his service treatment records, to include the December 1976 clinical report. The Veteran reported a history of chronic headaches that had been ongoing since 1976, and stated that he had been treated for migraines since at least 2006 or earlier. When asked whether the Veteran experienced any form of headache pain, Dr. H. marked that he did and noted that the Veteran's symptoms included constant head pain, pulsating or throbbing head pain, pain on both sides of his head, and pain that worsens with physical activity. It was further noted that the Veteran also experienced non-headache type symptoms associated with his headaches, to include nausea, sensitivity to light and sensitivity to sound. The Veteran stated that typical head pain affects both sides of his head and last more than two days in duration. According to Dr. H., the Veteran experiences prostrating attacks of migraine headache pain more frequently than once a month. However, he did note that he did not experience prostrating attacks of non-migraine headache pain. When asked whether the Veteran's headache condition impacted his ability to work, Dr. H. noted that it did, and in the remarks section, Dr. H. wrote that the Veteran experienced consistent chronic headaches dating back to his service years in the 1970s, and his headaches are debilitating and disabling in nature. During an April 2016 VA treatment visit, the treatment provider noted that the Veteran had reportedly experienced migraines since the early 90s, but this disorder was not officially diagnosed until 2003. Since this time, his headaches had increased in frequency and severity, which he attributed to increasing stress. It was noted that his headaches were "L sided, throbbing, with photo/phonophobia, nausea. . ." and they lasted one to three days in duration, and were usually alleviated by lying down in a dark quiet room. According to the Veteran, he experienced headaches at least once a week that lasted between one to three days in duration. He also reported brief visual aura of flashing lights just before the onset of the headaches. The Veteran was afforded another VA examination in connection to his headache condition in April 2016, the examiner took note of the VA outpatient records which documented the Veteran's symptoms associated with his headaches, and specifically noted that a March 2013 VA treatment report of headache treatment. According to the Veteran, he experiences frontal headaches twice a week which persist for four to six hours in duration. The examiner noted that in addition to headache pain, the Veteran experienced non-headache symptoms associated with his headaches, to include nausea, sensitivity to light and sound, and changes in his vision. In addition, the examiner noted that the Veteran's head pain persists for less than one day in duration. When asked whether the Veteran experiences characteristic prostrating attacks of migraine/non-migraine headache pain, the examiner marked that he did, and added that these symptoms occur once every month. However, the examiner noted that the Veteran did not experience very prostrating and prolonged attacks of migraines/non-migraine pain productive of severe economic inadaptability. According to the examiner, the Veteran's headache condition does not impact his ability to work. In considering the evidence of record, including the Veteran's assertions, the Board concludes that the Veteran's claim for an initial rating in excess of 30 percent for his headaches must be denied. A higher rating of 50 percent presupposes that the headaches resulted in very frequent completely prostrating and prolonged attacks productive of severe economic inadaptability. Simply, the evidence of record does not demonstrate a disability picture characterized by very frequent completely prolonged and prostrating attacks productive of severe economic inadaptability at any point during the appeal period. The Board acknowledges the Veteran's contentions that he had a difficult time maintaining his employment as a result of his headaches. Indeed, the record reflects that the Veteran worked at the U.S. Postal Service from 1998 to 2012. In support of his appeal, the Veteran submitted documents from his FMLA claim which included the June 2006 Certification of Health Care Provider form. In the Certification form, the Veteran's physician noted that the health conditions affecting the Veteran's ability to work included hypertension and migraine headaches. The physician further noted that these health ailments commenced in 1996 and had continued to the present time. When asked whether it was necessary for the employee to take work only intermittently or to work on a less than full schedule as a result of his conditions, the physician indicated that it did, and noted that the probable duration was an estimated 10-20 times per year and two to three days per episode. The Veteran also submitted a copy of the July 2012 resignation letter, in which he informed union members that he would be resigning from the position as a union official due to personal and medical reasons. The Board acknowledges that the Veteran left his job due to medical reasons. However, as noted in an August 2013 letter, Dr. M. stated that he had treated the Veteran for his CAD for the past ten years, and that this disorder severely limited his ability to be gainfully employed. Also, while Dr. M. determined that the Veteran was unemployable in the July 2014 letter, he appeared to attribute the Veteran's unemployability to his CAD. Indeed, other than noting that the Veteran had a history of hypertension and hyperlipidemia, the focus of the letter centered around treatment provided for the Veteran's CAD. In addition, in his February 2014 TDIU claim, the Veteran attributed his inability to work to his CAD, not his headache condition. Furthermore, at the November 2014 VA examination, although the examiner determined that the Veteran's headache condition impacts his ability to work, he commented that prior to his retirement in 2012, he would sometimes have to take time off from work due to his headaches. This explanation does not lead to the conclusion that the effect of his headaches had resulted in severe economic inadaptability. The Board acknowledges that in the January 2015 DBQ report, Dr. H. noted that the Veteran's headache condition impacted his ability to work, and described the Veteran's headaches as debilitating and disabling in nature. However, in the most recent VA examination in connection to his headache condition, the April 2016 VA examiner determined that the Veteran's headaches did not impact his ability to work. Significantly, the Board notes that while some of the VA examiners addressed how the Veteran's ability to work was impacted, and at times limited, as a result of his headache condition, none of them found that his headache condition precluded his ability to work. Even taking into consideration the frequency of the Veteran's headaches which resulted in increased absenteeism and, at one point, the Veteran's request for leave under FMLA, the record reflects that the Veteran was successfully able to maintain his employment at the U.S. Postal Service until his voluntary retirement in July 2012. Indeed, there is nothing in the medical records and examination reports tending to show that the increased absenteeism equates to severe economic inadaptability. Although the Veteran has filed a claim for TDIU, and contends that multiple disorders, to include his headache condition, affected his ability to maintain his employment, the Board again reiterates that despite the increased absenteeism, the Veteran continued working at the U.S. Post Office until 2012, and transitioned from working as a mail processer to working as a union official until he voluntarily retired in July 2012. Moreover, the Veteran has primarily contended (and the records issued by his physician predominantly reflect) that his inability to obtain and maintain employment is due to his CAD. In conclusion, the Board finds that a scheduler rating in excess of 30 percent for the Veteran's headache condition have not been met. As discussed above, regardless of the severity of the Veteran's headaches, as no severe economic inadaptability has been shown throughout the appeal, the Board does not find that the Veteran's migraine headache symptoms to be of such severity as to warrant a 50 percent rating. Therefore, an evaluation in excess of 30 percent for the Veteran's headache condition is not warranted under Diagnostic Code 8100. See 38 C.F.R. § 4.124a, Diagnostic Code 8100. The Board has considered whether referral for an extraschedular rating is warranted for the period on appeal. The Board finds that the Veteran's symptoms associated with migraine headaches, to include symptoms of pain, nausea, prostrating attacks, vision loss, and sensitivity to light and sound, are aptly governed by the schedular rating criteria. Neither the facts of the case nor the Veteran's allegations raise the issue of extraschedular consideration. Thus, no analysis is required. See Yancy v. McDonald, 27 Vet. App. 484, 494 (2016) (holding that an extraschedular analysis is not warranted where it is not "specifically sought by the claimant nor reasonably raised by the facts found by the Board") (citing Dingess v. Nicholson, 19 Vet. App. 473, 499 (2006), aff'd, 226 Fed. Appx. 1004 (Fed. Cir. 2007). See also Doucette v. Shulkin, 28 Vet. App. 366, 369 (2017) (explaining that the Board had no obligation to analyze whether referral is warranted for extraschedular consideration if an extraschedular rating is not specifically sought by the claimant or reasonably raised by the facts found by the Board). Effective Date Under VA laws and regulations, a specific claim in the form prescribed by VA must be filed in order for benefits to be paid or furnished to any individual under laws administered by VA. 38 U.S.C. § 5101 (a) (West 2012); 38 C.F.R. § 3.151 (a) (2017). In general, the effective date of an award based on an original claim or a claim reopened after final adjudication of compensation shall be fixed in accordance with the facts found, but shall not be earlier than the date of the receipt of the application. 38 U.S.C. § 5110 (a) (West 2012); 38 C.F.R. § 3.400 (2017). However, if the claim is received within one year after separation from service, the effective date of an award of disability compensation shall be the day following separation from active service. 38 U.S.C. § 5110 (b)(1) (West 2012); 38 C.F.R. § 3.400 (b)(2)(i) (2017). The effective date of an award of disability compensation based on a claim to reopen after a final disallowance shall be the date of receipt of the new claim or the date entitlement arose, whichever is later. 38 U.S.C. § 5110 (a) (West 2012); 38 C.F.R. § 3.400 (q)(ii), (r) (2017). "Claim" is defined broadly to include a formal or informal communication in writing requesting a determination of entitlement or evidencing a belief in entitlement to a benefit. 38 C.F.R. § 3.1 (p); Brannon v. West, 12 Vet. App. 32, 34-5 (1998); Servello v. Derwinski, 3 Vet. App. 196, 199 (1992). Any communication or action indicating an intent to apply for one or more benefits under laws administered by VA from a claimant may be considered an informal claim. Such an informal claim must identify the benefits sought. Upon receipt of an informal claim, if a formal claim has not been filed, an application form will be forwarded to the claimant for execution. 38 C.F.R. § 3.155 (a) (2017). To determine when a claim was received, the Board must review all communications in the claims file that may be construed as an application or claim. See Quarles v. Derwinski, 3 Vet. App. 129, 134 (1992). In considering the evidence of record under the laws and regulations as set forth above, the Board finds that May 17, 2011, is the correct date for the grant of service connection for glaucoma suspect/ocular hypertension with dry eye syndrome. Although the Veteran has contended that he is entitled to an earlier effective date for his award of service connection for glaucoma suspect/ocular hypertension with dry eye syndrome, there is no basis under the governing legal criteria to establish that he is legally entitled to an earlier effective date. The Veteran first presented his claim for service connection for glaucoma/ocular hypertension in an application received on May 13, 1994. This claim was denied in a rating decision dated in July 1994. The Veteran was notified of the July 1994 rating decision denying his claim and of his appellate rights; however, he did not submit an NOD for this decision. In general, rating decisions that are not timely appealed by submission of an NOD are final, unless there is receipt of unaddressed new and material evidence within the appeal period. See 38 U.S.C. § 7105; 38 C.F.R. § 3.156 (b), 38 C.F.R. § 20.1103. In this case there were no documents submitted by the Veteran within the appeal period following the 1994 rating decision; thus there are no documents to be reviewed to determine if they constituted a notice of disagreement or new and material evidence. In fact, after the issuance of the 1994 rating decision and notice of this decision, the next documents submitted by the Veteran were dated in 2011. In a Report of General Information slip dated on May 17, 2011, it was documented that the Veteran contacted the Phoenix RO and requested that his claim for service connection for glaucoma be reopened. By way of the December 2014 rating decision, the RO granted the claim seeking service connection for glaucoma/ocular hypertension with dry eye syndrome, and evaluated it as 10 percent disabling, effective May 17, 2011. In this case, the Board looks to the Veteran's May 2011 petition to reopen his service connection claim to determine whether he is entitled to an earlier effective date. The proper effective date for new and material evidence other than service department records received after a final disallowance is the date of receipt of the claim to reopen or the date entitlement arose, whichever is later. 38 U.S.C. § 5110 (i); 38 C.F.R. § 3.400 (q)(2), 3.400(r). Although additional service treatment records were associated with the claims file in January 2011, these were duplicative of service treatment records associated with the claims file at the time of the July 1994 rating decision. Based upon the foregoing, the effective date of a claim received after a final disallowance is the date of receipt of the new claim or the date entitlement arose, whichever is the later. 38 C.F.R. § 3.400 (q)(2). Here, the Veteran's claim to reopen was received on May 17, 2011. He did not submit new or material evidence sufficient to reopen his service connection claim prior to May 17, 2011. As such, the assignment of an effective date of May 17, 2011 was proper, and entitlement to an earlier effective date for the grant of service connection for the Veteran's glaucoma/intraocular hypertension is not warranted. Accordingly, the Board concludes that the preponderance of the evidence is against the claim for an effective date prior to May 17, 2011, for the grant of entitlement to service connection for glaucoma/intraocular hypertension. ORDER Entitlement to service connection for hypertension, to include as secondary to service-connected glaucoma/ocular hypertension, is denied. Entitlement to an initial rating in excess of 30 percent for service-connected headaches is denied. Entitlement to an earlier effective date prior to May 17, 2011, for the grant of service connection for glaucoma/ocular hypertension with dry eye syndrome, is denied. (CONTINUED ON NEXT PAGE) REMAND Sleep Apnea The Veteran contends that his sleep apnea was incurred in service and/or is secondary to his service-connected glaucoma/ocular hypertension. See December 2014 claim and May 2015 Report of General Information. In statements dated in July 2015, the Veteran's wife and daughter asserted that throughout his period of service in the U.S. Army, the Veteran had always snored very loudly. According to the Veteran's wife, J.W., his loud snoring became so problematic that she had to sleep in a different room to get relief. J.W. also stated that the Veteran tended to fall asleep very quickly and easily and recalled the Veteran informing her of severals incidents in the late seventies when he accidentally fell asleep while driving from one U.S. Army installation to another. VA treatment records dated in April 2014 reflect that the Veteran underwent a sleep study, the findings of which revealed a diagnosis of sleep apnea. A February 2015 Disability Benefits Questionnaire (DBQ) reflects the Veteran's reported history of chronic snoring and daytime drowsiness. When asked whether continuous medication was required for treatment of this condition, the physician, S.H., M.D. indicated that it was not. However, Dr. H. did note that the Veteran required the use of a breathing assistance device such as a continuous positive airway pressure (CPAP) machine for treatment of his sleep condition. Dr. H. also noted that the Veteran experienced symptoms of persistent daytime hypersomnolence due to his sleep apnea. When asked whether the Veteran's sleep apnea affected his ability to work, Dr. H. marked that it did, and noted that the Veteran was retired, but did work around his home and drive a motor vehicle. Dr. H. also noted that the Veteran had glaucoma, and commented that incidences of glaucoma were increased in people with sleep apnea. The Veteran's claims file was referred to a VA physician for an addendum opinion regarding the etiology of his sleep apnea in May 2015. Based on her review of the claims file, the VA physician determined that the Veteran's sleep apnea is less likely than not proximately due to, or the result of, his service-connected glaucoma/ocular hypertension. In reaching this determination, the VA physician acknowledged and took into consideration Dr. H.'s notation in the February 2015 Sleep Apnea DBQ report wherein he indicated that the incidence of glaucoma is increased in people with sleep apnea. However, according to the VA physician, there is no evidence-based data suggesting that glaucoma/ocular hypertension with dry eye syndrome causes obstructive sleep apnea. According to this physician, the more likely risk factors for obstructive sleep apnea include being male, overweight, and/or over the age of forty. Risk factors also included (but are not limited to) having a large neck size, a family history of sleep apnea, large tonsils, nasal obstruction due to a deviated septum/allergies/sinus and/or having gastroesophageal reflux disease (GERD). If VA undertakes the effort to provide the Veteran with a medical examination, it must ensure that such exam is an adequate one. See Barr v. Nicholson, 21 Vet. App. 303, 311 (2007). As mentioned above, establishing service connection on a secondary basis requires evidence sufficient to show (1) that a current disability exists and (2) that the current disability was either (a) proximately caused by, or (b) proximately aggravated by, a service-connected disability. Allen v. Brown, 7 Vet. App. 439, 448 (1995) (en banc). Although the May 2015 VA examiner determined that the Veteran's sleep apnea was not caused by his service-connected glaucoma/ocular hypertension and listed the various risk factors for sleep apnea, she did not address whether the Veteran's current sleep apnea was aggravated by his service-connected glaucoma/ocular hypertension. As such, the Board does not find the May 2015 examination report to be adequate. In addition, in light of statements submitted by the Veteran and his family members, the Veteran also appears to contend that his sleep apnea was incurred in service. As this claim is being remanded for additional development, the Veteran should also be afforded an examination in connection to his claimed sleep apnea, to determine the nature and etiology of his sleep apnea. 38 C.F.R. § 3.159 (c)(4)(i). Coronary artery disease Pursuant to the August 2015 Board remand, the Veteran was afforded a more recent VA examination in connection to his CAD claim in April 2016, at which time, the VA examiner observed that the Veteran had been diagnosed with having CAD in 2003, as well as "mild LV [left ventricular] systolic dysfunction, grade 1 diastolic dysfunction" in 2013. The examiner noted that the Veteran was treated for chest pain on four separate occasions in service. According to the examiner, the Veteran was treated on four separate occasions for his chest pain in service, and during one visit, he was provided Maalox for these symptoms. The VA examiner noted that the remainder of the service treatment records contained no further notations or cardiac workup. In addition, the examiner noted that there was no mention of any cardiac issues at the Veteran's separation examination. The examiner also reviewed and provided a recitation of the Veteran's post-service treatment history for his cardiac condition. According to the examiner, the Veteran's CAD and the stenting procedures he underwent in 2003 and 2012 qualified within the generally accepted medical definition of ischemic heart disease. The examiner also noted that continuous medication is required for control of the Veteran's heart condition. After reviewing the claims file, and conducting a physical examination of the Veteran, the VA examiner determined that the Veteran's CAD was less likely than not incurred in, or caused by, the claimed in-service injury, event or illness. In reaching this determination, the VA examiner acknowledged that the Veteran was seen for chest pain during his active service, but noted that these symptoms resolved without the need for a cardiac work-up or referral to a cardiologist. The examiner also noted that the Veteran did not complain of chest pain on his annual evaluations or at his separation examination, and he was able to perform his physical training requirements without difficulty. According to the examiner, the Veteran was not diagnosed with CAD until 2003, when he underwent the stenting procedure for 90 percent stenosis. The examiner further determined that there was no clinical documentation or other way of knowing the onset of the Veteran's coronary artery condition given that there had been no cardiac testing or documentation until that time. The examiner reiterated the opinion provided by the previous examiner - that the Veteran's in-service complaints of chest pain were non-cardiac in nature and related to his gastritis. According to the examiner, the Veteran was not diagnosed with any cardiac condition at the time. The examiner acknowledged the August 2013 and July 2014 opinions issued by Dr. M. (the Veteran's cardiologist) but observed that in the July 2014 opinion, Dr. M. failed to note that the Veteran's current heart disability had its onset in 2003, as documented by the September 2003 hospital report. According to the VA examiner, this was nine years after the Veteran's discharge from service in 1994, and if the Veteran's in-service chest pains had been due to CAD, then the CAD would have presented itself shortly after his discharge from the service, not nine years later. The examiner also observed that the Veteran was in his twenties at the time of his chest pain symptoms, and it was less likely as not for someone in their twenties to have ischemic heart disease in the absence of other risk factors, and to do well until his diagnosis of CAD in September 2003, twenty-three years since his in-service complaints of chest pain (which were non cardiac in nature) and nine years since the isolated elevated diastolic blood pressure readings in July 1994. In addition to requesting a medical opinion as to whether the Veteran's CAD had its clinical onset during his military service or is otherwise related to service, the August 2015 Board remand directives also instructed the VA examiner to provide a medical opinion addressing whether the Veteran's CAD was caused or aggravated by his service-connected glaucoma/ocular hypertension. Unfortunately, the April 2016 VA examiner did not discuss whether the Veteran's CAD was secondary to his service-connected glaucoma/ocular hypertension. The Court has held "that a remand by this Court or the Board confers on the Veteran or other claimant, as a matter of law, a right to compliance with the remand orders." Stegall v. West, 11 Vet. App. 268, 271 (1998). As such, the Veteran's claim for service connection for CAD must be remanded for a clarifying medical opinion addressing whether his CAD is secondary to his service-connected glaucoma/ocular hypertension with dry eye syndrome. Also, as this claim is being remanded for additional development, the AOJ should also attempt to retrieve any outstanding VA and private medical records pertaining to treatment provided for the Veteran's CAD and sleep apnea. TDIU The Veteran contends that he is unable to obtain and maintain substantially gainful employment due to his service-connected disabilities. He is currently service-connected for headaches, which as determined above, is evaluated as 30 percent disabling. The Veteran is also service-connected for glaucoma/ocular hypertension, which is evaluated as 10 percent disabling. The Veteran predominantly contends that he is unable to work as a result of his CAD. In his February 2014 Application for Increased Compensation Based on Unemployability, the Veteran indicated that his CAD prevented him from securing or following any substantially gainful occupation. In additional statements submitted throughout the pendency of his appeal, the Veteran also contended that he was unemployable due to his hypertension. As noted above, in the August 2013 letter, Dr. M. stated that he had treated the Veteran for his CAD for the past ten years, and that said disorder severely limited the Veteran's ability to be gainfully employed. The record further reflects that the Veteran has been considered disabled under sections 216(i) and 223(d) of the Social Security Act since January 31, 2013, and is currently receiving SSA disability benefits, for his CAD, hypertension, and hyperlipidemia. In light of the fact that the Veteran has attributed his inability to work, in part, to his CAD, then his claim for a TDIU is dependent upon a determination of the Veteran's claim seeking service connection for CAD. As such, the Board finds that consideration of the Veteran's claim for a TDIU is inextricably intertwined and remains deferred pending adjudication of the claim seeking service connection for CAD. See Parker v. Brown, 7 Vet. App. 116 (1994); Harris v. Derwinski, 2 Vet. App. 180, 183 (1991) (issues are "inextricably intertwined" when a decision on one issue would have a "significant impact" on a veteran's claim for the second issue). Accordingly, the case is REMANDED for the following action: 1. Obtain all outstanding VA medical records from May 2016 to the present. 2. Ask the Veteran to identify any private medical care providers who treated him for the claimed disabilities. After securing any necessary authorization, obtain records from any identified providers. 3. Then, refer the claims file to the same VA examiner who conducted the April 2016 VA examination, or another VA examiner if that examiner is unavailable. Following a review of the record, the examiner must express an opinion as to whether it is at least as likely as not (i.e., a 50 percent probability or greater) that the Veteran's CAD was caused or aggravated (chronically worsened beyond normal progression) by his service-connected glaucoma/ocular hypertension with dry eye syndrome. If the examiner finds that the glaucoma/ocular hypertension has not caused the CAD, but rather has made it worse, the examiner should comment on when the onset of "aggravation" took place and whether the claims file contains sufficient medical evidence created before the onset of aggravation to establish a baseline of the level of severity of the Veteran's CAD. If a baseline is established, the examiner should comment on how much the CAD has worsened in severity as a result of the natural progress of the disability, if at all, from the time of the baseline to the current level of severity. The examiner must provide a thorough and well-reasoned rationale for all opinions provided. Stating, alone, that it is medically impossible to establish a cause and effect relationship or to establish aggravation is insufficient. If that is the examiner's conclusion, the examiner must explain why such determination is medically impossible. 4. Then, schedule the Veteran for an appropriate VA examination for the purpose of ascertaining the nature and etiology of any sleep apnea he may have. The claims file, must be made available to the examiner for review, and the examination report should reflect that the claims file was reviewed in conjunction with the examination. All indicated tests should be performed, and all pertinent pathology should be noted in the examination report. Consideration should be given to the Veteran's history and particularly to any statements regarding continuity of symptoms since service. Following a review of the record and an examination of the Veteran, the examiner should express an opinion as to whether it is at least as likely as not, i.e. a 50 percent or greater probability, that the Veteran's sleep apnea had its onset during his period of active service, or is otherwise related to his military service. If the examiner finds that the Veteran's sleep apnea is not related to his service, then he or she must provide an opinion as to whether it is at least as likely as not, i.e., a 50 percent probability or greater, that his sleep apnea was caused or aggravated (chronically worsened beyond normal progression) by the Veteran's service-connected glaucoma/ocular hypertension with dry eye syndrome. Specifically, the examiner is asked to address whether the Veteran's current sleep apnea was caused or made chronically worse as a result of the Veteran's glaucoma/ocular hypertension. If so, specify the baseline of disability but for such worsening, and the chronic, measurable increase in disability resulting from the aggravation. The examiner must provide a thorough and well-reasoned rationale for all opinions provided. If the examiner finds that the Veteran's sleep apnea is not related to his service, or secondary to his service-connected glaucoma/ocular hypertension , then he or she must provide a complete rationale upon which his or her opinion is based, and must include a discussion of the medical principles as applied to the medical evidence and facts used in establishing his or her opinion. If the examiner determines that an opinion cannot be provided without resorting to speculation, the examiner should explain the inability to provide an opinion, identifying precisely what facts could not be determined. In particular, the examiner should comment on whether an opinion could not be provided because the limits of medical knowledge have been exhausted or whether additional testing or information could be obtained that would lead to a conclusive opinion. 5. After completing the requested actions and any additional notification and/or development deemed warranted, the claims on appeal must be readjudicated. If any benefits sought on appeal remain denied, the Veteran and his representative must be furnished a supplemental statement of the case. An appropriate period of time should be allowed for response before returning the case to the Board, if otherwise in order. The Veteran has the right to submit additional evidence and argument on the matters the Board has remanded. Kutscherousky v. West, 12 Vet. App. 369 (1999). These claim must be afforded expeditious treatment. The law requires that all claims that are remanded by the Board or by the United States Court of Appeals for Veterans Claims (Court) for additional development or other appropriate action must be handled in an expeditious manner. See 38 U.S.C. §§ 5109B, 7112 (West 2012). ______________________________________________ JAMES G. REINHART Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs