Prevalence, Features, and Outcomes of Type 1 Neovascularization in Eyes with Angioid Streaks

Abstract

This study aimed to delineate the characteristics, prevalence, and outcomes of neovascularization (NV), particularly aneurysmal Type 1 NV, in patients with angioid streaks (AS) secondary to pseudoxanthoma elasticum (PXE), and to introduce a clinical classification based on multimodal imaging (MMI). Retrospective longitudinal cohort study. 85 patients (168 eyes) with AS secondary to PXE at two tertiary referral centers. Data collection included demographic, medical, and ocular histories. Diagnostic methods comprised fundus photography, autofluorescence, indocyanine green angiography, optical coherence tomography (OCT), and OCT angiography. Prevalence of Type 1 NV, visual acuity (VA), risk of exudation. Type 1 NV was identified in 127 eyes (76%), with 85 of these (67%) showing exclusively Type 1 NV. These lesions often originated around the disc, at sites of Bruch's membrane dehiscences, and followed the path of AS, extending to the posterior pole in 101 eyes (80%). Despite 65% of Type 1 NV remaining non-exudative, 36% evolved into exudative over five years, and 11 eyes experienced mid-peripheral subretinal hemorrhages. Aneurysmal dilations, observed in 57% of cases, substantially increased exudation risk (hazard ratio = 3.86, p=0.02). Despite treatment, VA significantly deteriorated in exudative Type 1 NV (p=0.02). Type 2 NV, detected in 56 eyes (33%), often coexisted with Type 1 NV and was associated with poorer visual outcomes and higher rates of macular atrophy. A classification of AS was developed, ranging from empty AS (stage 0, no NV) to advanced NV (stage 3, both Type 1 and Type 2 NV). Type 1 NV predominates in AS. Although predominantly non-exudative, its progression correlates with substantial visual impairment, similar to the deficits observed with Type 2 NV. Aneurysmal Type 1 NV poses a significant exudation risk, underscoring the need for vigilant monitoring.