Eye Signs of Systemic Disease: Case 5 Central Retinal Vein Occlusion

An 87-year-old woman complained ofseeing a red tinge on the wallpaper inher house through her right eye. Thepatient had mild memory loss andmoderate hypertension, for whichshe took atenolol. She had quit smokingcigarettes many years earlier.Visual acuity in both eyes was20/25. The patient had pseudophakiaof the right eye from previouscataract surgery. A funduscopic examinationof the eye revealed dilated and tortuous veins, flame-shapedhemorrhages, dot-blot hemorrhages,and retinal edema. No cotton-woolspots were present, and the maculawas spared (A), which explained thegood visual acuity in the right eye. Afluorescein angiogram showed goodperfusion, minimal capillary dropout,and no neovascularization. A nonischemiccentral retinal vein occlusionwas diagnosed.It is thought that the underlyingcause of central retinal vein occlusionmay be compression of the vein bya thickened artery, which results in thrombus formation.The ability of both the artery and the vein to expand islimited, because their lumens narrow when they passthrough the sieve-like lamina cribosa of the optic nervehead. The adjacency of the vessels leads to thrombus formationfrom turbulent blood flow.This condition typically develops in persons who areolder than 50 years. Patients may have generalized arterioscleroticdisease and, often, associated diabetes, cardiovasculardisease, hypertension, elevated cholesterol andtriglyceride levels, temporal arteritis, and a history ofsmoking.Five weeks after the patient's initial visit, her visionhad deteriorated to 20/200 in the right eye. Funduscopicexamination demonstrated macular edema and macularhemorrhages. The optic disc was significantly more congestedthan several weeks earlier. Signs of ischemia--such as cotton-wool spots and neovascularization--wereabsent (B).One month later (9 weeks after initial presentation),the patient's vision had further deteriorated; she was ableto count fingers at only 4 feet. More retinal and macularedema was present on fundus evaluation, and cotton-woolspots were seen (C). Significant retinal hemorrhaging andedema precluded the use of laser photocoagulation.A new surgical procedure--pars plana vitrectomywith radial optic neurotomy--was offered to the patient.In this operation, the vitreous is removed and a posteriorradial stab incision is used to cut part of the optic nervehead, lamina cribosa, and scleral ring and the adjacentsclera. This "relaxes" or "decompresses" the confinedchannel through which the central retinal vein travels.A recent study found that visual acuity improved in80% of patients who underwent radial optic neurotomy; itworsened in the remaining 20% of patients.¹In addition,80% of participants experienced less optic disc congestionand more rapid intraretinal hemorrhage reabsorption thanis expected in untreated patients.¹