Retinal vaso-occlusive disorders are common causes of vision loss and blindness in the world. Diabetic retinopathy, the most prevalent retinal vascular disease, is a leading cause of blindness in patients between 20 to 74 years of age in the U.S.
Retinal vaso-occlusive disorders are common causes of vision loss and blindness in the world. Diabetic retinopathy, the most prevalent retinal vascular disease, is a leading cause of blindness in patients between 20 to 74 years of age in the U.S.1
Other conditions such as retinal vein and artery occlusions and hypertensive retinopathy are also commonly encountered conditions with their share of visual morbidity. The circumstances that lead to retinal vaso-occlusive disease can be described by three principles. These are conditions that alter the rate of blood flow, conditions resulting in physical alteration of blood vessels, and conditions that result in the consistency of the blood itself. The end result to the retinal function can be solely caused by one or all these mechanisms.
For example, hyperglycemia caused by diabetes results in vascular endothelial damage as well as increased blood viscosity, which in turn decreases blood flow. The cascading consequence of these mechanical and/or chemical alterations is increased vascular permeability, resulting in excessive extravascular leakage. The other catastrophic consequence is hypoxia, which directly reduces tissue function and ultimately results in neovascularization and its sequelae.
There are a number of considerations when assessing and managing posterior segment vascular diseases. One such consideration is to avoid overlooking choroidal circulations-while these disorders are usually lumped under “retinal vascular diseases,” the choroidal circulations also play an imperative role in both normal retinal function and its vascular disease state. Another consideration is the body as a whole. Although there are a handful of primary chorioretinal vascular diseases, the majority of these conditions have an underlying systemic etiology (see Table 1). The end organ toll is not only the visual system, and ocular signs are potential warnings of underlying conditions and other co-morbidities.
With this in mind, the eye then can be compared to the canary’s death in a coalmine as an indicator of gas poisoning. Optometrists involved in the care of patients suffering with these disorders have to properly manage the ocular findings as well as direct the patient to care of the underlying systemic condition(s).
The following is a case exemplifying the complexity of posterior segment vascular disease.
Case report: considering underlying factors
A 58-year-old white male was referred by his optometrist for evaluation of retinal hemorrhages of the right eye. He was complaining of sudden onset loss of vision and seeing a “sun spot” OD since that morning. Patient ocular history was remarkable for non-complicated LASIK in both eyes 8 years ago. His medical history was remarkable for well-controlled systemic hypertension for 10 years, as well as history of hyperlipidemia and heart disease for which he was being treated by his cardiologist. His medications included niacin 50 mg, simvastatin (Zocor, Merck) 40 mg, metoprolol (Lopressor, Novartis) 25 mg, lisinorpil (Zestril, AstraZeneca) 5 mg, aspirin 81 mg, and folic acid. Additionally, he underwent surgery for a herniated disc 1 year ago and was taking naproxen (Aleve, Bayer) 500 mg and hydrocodone/acetaminophen (Vicodin, Abbott) on an as-needed basis.
Patient examination was remarkable for visual acuities OD: 4/200, OS: 20/25. Intraocular pressures were 14 mm Hg each eye. Patient pupils were dilated at the time of arrival; therefore, they could not be properly evaluated. Motilities and confrontation fields were normal. Slit-lamp examination was remarkable for 1+ nuclear sclerosis in each eye. Funduscopic examination OD was remarkable for peripapillary subretinal hemorrhage-view of the optic nerve head was obscured by retinal hemorrhage, retinal whitening superior to macula indicative of a branch arterial occlusion and scattered intraretinal and blot hemorrhages associated with the deeper retinal capillary plexus. (This is more commonly seen in retinal vasculopathy associated with hematologic disorders). OS fundus examination was remarkable for very mild arteriosclerosis. (see Figure 1a and b). Optical coherence tomography (OCT) OD showed hyperreflectance and thickening of inner retinal segment associated with arterial occlusive disease in the region of the retinal whitening. (see Figure 1c). Fluorescein angiography was normal OS; however, OD showed significant arterial nonperfusion of the superior aspect of the papillomacular bundle and multiple foci of “masking hypofluorescence” caused by the deeper retinal hemorrhages. There was no significant leakage or sign of retinal neovascularization or peripheral nonperfusion (Figure 1d and e).
Diagnosis of combined retinal arteriovenous occlusion OD was made. The patient was referred to his cardiologist for re-assessment of his cardiovascular disease. Additionally, it was requested that the patient undergo carotid artery evaluation and hematologic studies to rule out blood dyscrasia and hypercoagulability. No ocular treatments were administered. Subsequently, the patient was evaluated by cardiology, neurology, and hematology. He was cleared of any active cardiovascular or neurologic disorders but was found to have an excess of Factor XII of the coagulation cascade. The patient was placed on ciopidogel (Plavix, Bristol-Myers Squibb) as a precautionary measure.
Two weeks later on follow-up examination, OD vision measured at 5/200. There was evidence of resolving both arterial and venous aspect of the retinal findings (Figure 2a). There was reduced reflectance of inner retina on OCT (Figure 2b). Because it was postulated that most of the visual loss was caused by the arterial occlusive disease and that specific ocular treatment would have limited benefit in the overall visual prognosis OD, therefore none was administered. The patient was encouraged to follow up with the hematologist as well as the cardiologist and was asked to adhere to current systemic therapy.
On one-month follow-up, visual acuity had recovered to 20/30, although the patient continued to have subjective visual complaints consistent with the damage due to the arterial occlusive event. Fundus exam showed further resolution of the retinopathy with evidence of mild optic disc pallor (Figure 2c). OCT exhibited reduced reflectance but early typical ischemic inner retinal atrophy (Figure 2d).
The patient was followed 3 months later. Vision remained at OD 20/30 and OS 20/20. A complete resolution of retinal hemorrhages and further atrophy of the retina was noted on fundus and OCT exam (Figure 2e and f). OS examination remained unremarkable.
At the 4-month follow-up visit, all findings were stable. The patient was asked to follow up with his local optometrist in 6 months and return in 1 year or as needed.
Ten months later, he returned with vague visual complaints OS. Although the visual acuities at OD 20/30 and OS 20/20, and all other findings, including the fundus exam OD (Figure 3a), remained unchanged, the funduscopic findings OS resembled the initial presentation OD without any significant arterial component (Figure 3b). The patient’s cardiologist and hematologist were consulted to assess his current cardiovascular and hematologic status. Additionally, the neurologist was consulted to consider a magnetic resonance venogram (MRV). This was to determine if cerebral venous sinus thrombosis could be associated with the retinal presentation. The MRV results revealed an absence of flow within the left transverse and sigmoid sinus, confirming the venous thrombosis. Based on this and the retinal findings, the hematologist altered the anti-coagulation regimen.
Two weeks later, which was 1 day after the hematologist’s new anticoagulation therapy, the patient returned. The visual acuity and his symptoms had remained the same. However, the funduscopic appearance had worsened (Figure 3c). Based on the spontaneous resolution of OD hemorrhages following the initial systemic therapy and the fact that additional anticoagulant were just added, the decision was made with the consent of the patient to closely monitor the retinal findings without any ocular intervention, such as anti-VEGF therapy. The patient returned 2 weeks later with some degree of subjective relief, and the fundus examination revealed improvement as well (Figure 3d). At the time of this report, the patient is soon due for a 1-month return.
Assess for best course of action
Optometrists in various clinical settings frequently encounter patients suffering from posterior segment vascular diseases. With an increasing incidence of risk factors for retinal and choroidal vascular disease, such as the aging population, obesity, diabetes, and cardiovascular disease, we will face a bigger challenge dealing with this potentially devastating group of ocular diseases. In order to effectively manage these patients, we have to consider both the underlying factors as well as the effect of the disease and assess the best course of action to achieve the best visual and lifespan outcomes.
1. Zhang X, Saaddine JB, Chou CF, Cotch MF, et al. Prevalence of diabetic retinopathy in the United States, 2005-2008. JAMA. 2010 Aug 11; 304(6):649-56.