Commentary: Ocular features of cardiac and cardiovascular diseases

The Indian Journal of Ophthalmology (IJO) in this issue reports an interesting case of a 50-year-old male patient with amaurosis fugax and central retinal arterial occlusion (CRAO) due to a patent foramen ovale (atrial septal defect, ASD) and right to left shunt.[1] The patient improved after surgical management of ASD. The eye is a unique organ where the neural system and vascular system can be examined directly. Optimal evaluation of the eyes may give diagnostic clues and even guide follow-up of certain disorders of the cardiovascular system (CVS). In 2004, Wong and Mitchell classified hypertensive retinopathy (HTNR) into four grades according to the systemic association.[2] The “none” grade of HTNR is not associated with any retinal sign or systemic association. “Mild” HTNR is associated with retinal arteriolar changes (generalized or focal arteriolar narrowing, arteriovenous nicking, and copper wiring) and there is a “modest” association with coronary heart disease, clinical or subclinical stroke, and death.[2] The “moderate” HTNR is characterized by retinal hemorrhages, exudates (hard or soft), and microaneurysms. There is a strong association with cognitive decline, clinical or subclinical stroke, and death from CVS diseases. Malignant HTNR, denoted by the presence of papilledema in addition to moderate HTNR (after excluding anterior ischemic optic neuropathy), has a strong association with death. Hypertension may be associated with other diseases affecting the eye including palsy of the third, fourth, or sixth cranial nerve; retinal venous or arteriolar occlusion, anterior ischemic optic neuropathy; diabetic retinopathy, retinal arterial macroaneurysm,[3] retinal arterial emboli, and age-related macular degeneration. Nocturnal hypotension has been implicated in anterior ischemic optic neuropathy and open-angle glaucoma. Cardiovascular risk factors (including age, gender, smoking status, systolic blood pressure, and major adverse cardiovascular events) were predicted by artificial intelligence employing deep learning and big data[4] by evaluating fundus photos by a study done at Google Research, Verily Life Sciences, and Stanford School of Medicine.[5] CRAO is an important condition that requires extensive CVS evaluation to rule out the source of embolus as was highlighted in the case report.[1] Echocardiography, carotid doppler, and cardiology referral should be done. Specifically, heart valve disorders, atrial fibrillation, atherosclerosis, thromboembolic disorders, and infective endocarditis should be ruled out. Another important cause of CRAO in very elderly patients is giant cell arteritis, which if not detected and treated can lead to bilateral CRAO or arteritic anterior ischemic optic neuropathy and eventual blindness in both eyes. Cardiac myxoma may lead to CRAO and may be associated with lentigines at the eyelid of conjunctiva or myxomas involving the eyelid or orbit (Carney complex). A symptom of amaurosis fugax should invite extensive systemic and cardiovascular evaluation. Roth spots (white-centered retinal hemorrhages) are crucial signs of infective endocarditis though other causes exist. Infective endocarditis may also present as metastatic or endogenous endophthalmitis[6] characterized by hypopyon, vitritis, and retinal, and/or choroidal lesions including retinitis and subretinal abscess. Other features include preretinal hemorrhage, vitreous hemorrhage, optic neuritis, CRAO, and ophthalmic arterial occlusion. Carotid atherosclerosis is the predominant cause of ocular ischemic syndrome, which resolves after adequate management of the carotid arterial disease.[7] Takayasu arteritis may be associated with ocular ischemic syndrome, peripheral arteriovenous shunts, and mid-peripheral microaneurysms on fluorescein angiogram. Pulmonary hypertension is associated with venous stasis retinopathy (dilated episcleral vessels, dilated retinal vessels, central retinal venous occlusion). Bilateral corneal epithelial vortex keratopathy should raise the suspicion of the use of amiodarone, which is used for the management of arrhythmia. Kearns–Sayre syndrome characterized by cardiac conduction defects along with retinitis pigmentosa and chronic progressive external ophthalmoplegia needs an electrocardiogram and cardiological evaluation. Congenital heart diseases may be associated with dilated conjunctival and episcleral vessels, retinal vascular tortuosity, and dilation with darkening, which may resolve after the management of the disease. Severe dyslipidemia (chylomicronemia) can give a milky (creamy white) hue to the retinal vessels (lipemia retinalis).[8] Iris flocculations may be associated with familial thoracic aortic aneurysm and dissection (TAAD) related to a mutation in the ACTA2 gene. Carotid arterial dissection may cause neck pain, headache, Horner syndrome, amaurosis fugax, ischemic optic neuropathy, and ocular ischemic syndrome. Vertebral arterial dissection can cause neck pain and lateral medullary syndrome (Wallenberg syndrome, ptosis due to Horner syndrome, oscillopsia due to rotary nystagmus, and skew deviation). Recently modified Ghent criteria for Marfan syndrome make the diagnosis of Marfan syndrome “unequivocal” if both ectopia lentis and aortic root dilation are present even in the absence of family history. The absence of pupillary reflex is a criterion for defining brain death. In summary, this paper[1] again reiterates that knowledge and evaluation of the systemic association of ocular diseases are vital in providing holistic care to the patient to improve the visual prognosis and morbidity.