Ocular vascular occlusive disorders: Natural history of visual outcome

Abstract

Ocular vascular occlusive disorders collectively constitute the most common cause of visual disability. Before a disease can be managed, it is essential to understand its natural history, so as to be able to assess the likely effectiveness of any intervention. I investigated natural history of visual outcome in prospective studies of 386 eyes with non-arteritic anterior ischemic optic neuropathy (NA-AION), 16 eyes with non-arteritic posterior ischemic optic neuropathy, 697 eyes with central retinal vein occlusion (CRVO), 67 eyes with hemi-CRVO (HCRVO), 216 eyes with branch retinal vein occlusion (BRVO), 260 eyes with central retinal artery occlusion (CRAO), 151 eyes with branch retinal artery occlusion (BRAO) and 61 eyes with cilioretinal artery occlusion (CLRAO). My studies have shown that every one of these disorders consists of multiple distinct clinical sub-categories with different visual findings. When an ocular vascular occlusive disorder is caused by giant cell arteritis, which is an ophthalmic emergency, it would be unethical to do a natural history study of visual outcome in them, because in this case early diagnosis and immediate, intensive high-dose steroid therapy is essential to prevent any further visual loss, not only in the involved eye but also in the fellow, normal eye. In NA-AION in eyes seen ≤2 weeks after the onset, visual acuity (VA) improved in 41% of those with VA 20/70 or worse, and visual field (VF) improved in 26% of those with moderate to severe VF defect. In non-ischemic CRVO eyes with VA 20/70 or worse, VA improved in 47% and in ischemic CRVO in 23%; moderate to severe VF defect improved in 79% in non-ischemic CRVO and in 27% in ischemic CRVO. In HCRVO, overall findings demonstrated that initial VA and VF defect and the final visual outcome were different in non-ischemic from ischemic HCRVO – much better in the former than the latter. In major BRVO, in eyes with initial VA of 20/70 or worse, VA improved in 69%, and moderate to severe VF defect improved in 52%. In macular BRVO with 20/70 or worse initial VA, it improved in 53%, and initial minimal-mild VF defect was stable or improved in 85%. In various types of CRAO there are significant differences in both initial and final VA and VF defects. In CRAO eyes seen within 7 days of onset and initial VA of counting fingers or worse, VA improved in 82% with transient non-arteritic CRAO, 67% with non-arteritic CRAO with cilioretinal artery sparing, 22% with non-arteritic CRAO. Central VF improved in 39% of transient non-arteritic CRAO, 25% of non-arteritic CRAO with cilioretinal artery sparing and 21% of non-arteritic CRAO. Peripheral VF improved in non-arteritic CRAO in 39% and in transient non-arteritic CRAO in 39%. In transient CRAO, finally peripheral VFs were normal in 93%. In non-arteritic CRAO eyes initially 22% had normal peripheral VF and in the rest it improved in 39%. Final VA of 20/40 or better was seen in 89% of permanent BRAO, and in 100% of transient BRAO and non-arteritic CLRAO. In permanent BRAO eyes, among those seen wit...

Optical coherence tomography angiography of retinal vascular occlusions produced by imaging-guided laser photocoagulation

“…First, producing retinal vascular occlusions using RB, although similar to producing a thrombus, is similar, but not equivalent, to the pathogenesis of human retinal occlusive diseases. For example, the pathogenesis of the disease for BRVO's in humans is believed to result from arterial compression of venules by stiffened arteries at arterio-venous crossings [1]. Additionally, thrombus formations usually cause CRVO's, but emboli usually account for BRAOs [1,30].…”

“…For example, the pathogenesis of the disease for BRVO's in humans is believed to result from arterial compression of venules by stiffened arteries at arterio-venous crossings [1]. Additionally, thrombus formations usually cause CRVO's, but emboli usually account for BRAOs [1,30]. Nevertheless, the RB method provides a reliable method to produce an animal model with similarities to human retinal vascular occlusions, such as the inner retinal edema.…”

“…Retinal vascular occlusive diseases represent the most common cause of visual disability in the elderly population [1]. Two important vascular occlusive diseases are retinal vein occlusions (RVO), and retinal artery occlusions (RAO), with each having different etiologies, pathogenesis, and visual outcomes.…”

Acute Visual Loss

“…The process leading to NA-AION appears to be complex and multifactorial. 28 The precise cause is unknown. A small cup-to-disc ratio ("disc at risk") may be a risk factor.…”

Wet age-related macular degeneration combined with branch retinal vein occlusion

“…Major BRVO refers www.journals.viamedica.pl/ophthalmology_journal to occlusion of a retinal vein that drains one of the quadrants. Macular BRVO refers to occlusion of a venule within the macula [11]. Some risk factors leading to BRVO are age, hypertension, hyperlipidaemia, ocular hypertension, and glaucoma [12,13].…”