Choroidal Neovascularization After Central Retinal Vein Occlusion in a 47-Year-Old Man

A 46-year-old white man was referred to The Wilmer OphthalmologicalInstitute, Baltimore, Md, for evaluation of macular edema. He had been diagnosedas having a nonperfused central retinal vein occlusion (CVO) in the righteye 5 months previously, as documented by photographs and a fluorescein angiogramfrom his referring ophthalmologist (Figure1). Medical history was positive for hypercholesterolemia. Medicationsincluded aspirin and a lipid-lowering agent.

Visual acuity at the time of referral was 20/160 in the right eye and20/20 in the left eye. There was no iris or angle neovascularization. Intraocularpressure was 16 mm Hg in each eye. Ophthalmoscopic examination showed resolvingintraretinal hemorrhages in all 4 quadrants in the right eye, with fovealthickening and cystic edema (Figure 2).The patient was diagnosed as having a nonperfused CVO with macular edema.Observation by his referring ophthalmologist for development of any neovascularizationwas recommended. He was told to return to The Wilmer Ophthalmological Institutein approximately 6 months to determine whether he still had macular edemawith perfusion of macular capillaries. If edema persisted, laser photocoagulationmight be considered, because a trend toward an increased chance of stablevisual acuity after photocoagulation, compared with observation, had beendemonstrated in younger patients with perfused macular edema in the CentralVein Occlusion Study.¹

Six months later, 11 months after the onset of the CVO, the patientreported a slight improvement in vision, although measured visual acuity remainedunchanged at 20/160 in the right eye. No neovascularization was seen in theanterior segment. Ophthalmoscopic examination showed resolution of the intraretinalhemorrhages. However, a new subretinal hemorrhage was seen in the macula withfibrovascular tissue that just extended into the fovea from the superonasalaspect of the macula. There was cystoid macular edema at the inferotemporalaspect of this lesion (Figure 3A).An early-phase frame from a fluorescein angiogram (Figure 3B) showed an anastomosis between a retinal arteriole andthe fibrovascular lesion, as well as an anastomosis between a retinal venuleand the lesion. Within the fibrovascular tissue, early, intense, and well-circumscribedhyperfluorescence with late leakage was seen. There also was late leakageof dye in a petalloid pattern at the inferotemporal aspect of the fibrovascularlesion corresponding to the cystoid macular edema (Figure 3C). A diagnosis of subfoveal, predominantly classic choroidalneovascularization (CNV) was made. Although the cause of the CNV was not clear,photodynamic therapy (PDT) was recommended because the lesion was subfovealand because it was predominantly classic. Extrapolation from the Treatmentof Age-Related Macular Degeneration With Photodynamic Therapy Investigation² was judged applicable to this patient to reducethe risk of moderate and severe visual acuity loss compared with no treatment.The patient underwent PDT with verteporfin (Visudyne; Novartis Pharma AG,Basel, Switzerland), without complications.

Three months later, visual acuity was 20/250 in the right eye. Ophthalmoscopicexamination showed resolution of much of the subretinal hemorrhage but somesubretinal fibrosis (Figure 4A).Fluorescein angiography showed continued leakage from CNV and cystoid macularedema (Figure 4B and C). Becauseof the continued fluorescein leakage from the CNV, a second course of PDTwas performed. Seven months after the patient's first course of PDT and 18months after the recognition of his CVO, the visual acuity remained 20/250in the right eye. Ophthalmoscopic examination showed a decreased amount ofsubretinal fluid and more subretinal fibrosis. Some intraretinal hemorrhagesoverlay the subretinal fibrosis (Figure 5A). Angiography showed minimal fluorescein leakage from CNV, resolutionof the leakage from the cystoid macular edema, and staining around the fibrovascularlesion. The anastomoses between the fibrovascular tissue and the retina showedlittle flow of fluorescein (Figure 5Band C). With only little fluorescein leakage from the CNV, PDT was not repeated.

Documentation of development of macular CNV after CVO, with retinalarteriole or venous anastomosis to the CNV, is of interest because of therecent attention given to retinal vascular anastomoses to CNV lesions.^3-7 Ourliterature search disclosed no previous reports of CNV occurring in youngpatients within a short time after a CVO. One report documented CNV occurringin an older individual years after a vein occlusion.⁸ Althoughthese 2 diseases (CNV and CVO) could occur in the same eye, independent ofeach other, a causal relationship appears to exist in this case. This is supportedby the following: (1) the absence of any other known causes of CNV in thisyoung patient; (2) the temporal relationship of developing CNV within 6 monthsafter documentation of the CVO; and (3) the retinal anastomoses to the CNVthat were observed at the initial presentation of the CNV.

What could be the relationship of the CVO to the CNV? One could postulatethat chronic edema of the retina led to progressive damage of the retinalpigment epithelium, with disruption to the Bruch's membrane, that was associatedwith the growth of CNV. It is also possible that some CNV lesions begin inthe retina and extend to the choroid, as has been documented previously inidiopathic parafoveal telangectasia⁹ andmore recently suggested in age-related macular degeneration.⁶ Increasedhydrostatic pressure in venovenous collaterals, secondary to the CVO, couldhave either initiated or potentiated the development of such anastomoses.As shown in Figure 3A, the retinalhemorrhages caused by the CVO largely disappeared at about the same time thatanastomoses between the fibrovascular lesion and the retina were first observed.This suggests the possibility that these spontaneously occurring anastomosesdecompressed the occluded retinal venous vasculature into the fibrovascularlesion and into the choroid. Such retinal venous decompression has been documentedtherapeutically, after intense laser photocoagulation designed to rupturethe Bruch's membrane and create anastomoses between the retina and choroid.¹⁰

Whatever the cause of the CNV, the PDT was associated with a diminutionof fluorescein leakage from CNV, despite the presence of anastomoses betweenthe retina and the fibrovascular tissue. The PDT appeared to have had littleimmediate effect on the retinal vessels, although the anastomotic vesselsbecame nonperfused over time. Regardless of the cause of the CNV after CVO,whether or not there is a causal relationship, we believe that this is thefirst well-documented case of CNV developing in a relatively young patientwith a preexisting CVO. However, retinal anastomoses and cystoid macular edemawere observed. In addition, PDT appeared to have a typical involutional effecton the fibrovascular lesion.

This study was supported by the Heed Foundation, Cleveland, Ohio (DrDiLoreto); the Ronald G. Michels Fellowship, Scarsdale, NY (Dr DiLoreto);the Herman Knapp Testimonial Fund, Cleveland (Dr DiLoreto); the Altsheler-DurrellFoundation, Louisville, Ky; and the Guerrieri Retinal Research Fund and WilmerMacular Degeneration Research Fund, The Johns Hopkins University, Baltimore,Md.

The Johns Hopkins University, Dr Bressler's employer, but not Dr Bressler,is paid for Dr Bressler to provide consultation to Novartis Ophthalmics andQLT Inc; neither company had any input into the design or completion of thisstudy. The terms of this institutional consultant agreement are managed byThe Johns Hopkins University in accordance with its conflict-of-interest policies.

Correspondence: Dr Bressler, The Wilmer Eye Institute, The JohnsHopkins University School of Medicine, 550 N Broadway, Suite 115, Baltimore,MD 21205-2002 (nmboffice@jhmi.edu).