The incidence of neovascular subtypes in newly diagnosed neovascular age-related macular degeneration

Abstract

Purpose: To determine the frequency of neovascularization subtypes as determined by fluorescein angiography (FA) alone vs FA and optical coherence tomography (OCT) grading in age-related macular degeneration (AMD).

Design: Retrospective cohort.

Methods: participants: Newly diagnosed neovascular AMD patients who initiated intravitreal anti-vascular endothelial growth factor therapy by 1 physician from October 1, 2005 to December 1, 2012. interventions: Two independent graders classified the baseline lesions using FA alone and FA+OCT. main outcome measures: Analysis of the frequency of lesion subtypes by FA alone or FA+OCT and agreement between both classification systems was performed.

Results: A total of 232 patients (266 eyes) fit the inclusion criteria. Mean age was 86.3 years; 67.7% of eyes (180/266) were from female patients, and 95.5% (254/266) were from white patients. The distribution using FA alone was 49.6% (132/266), 12.0% (32/266), 28.6% (76/266), and 9.8% (26/266) among occult, classic, retinal angiomatous proliferation, and mixed choroidal neovascularization, respectively. With FA+OCT, 39.9% (106/266), 9.0% (24/266), 34.2% (91/266), and 16.9% (45/266) were type 1 (sub-retinal pigment epithelium), type 2 (subretinal), type 3 (intraretinal), and mixed neovascularization (NV), respectively. The κ statistic was 0.65 (standard error ±0.37, P < .001) between the 2 classification systems, representing good agreement.

Conclusion: With both FA-alone and FA+OCT grading, we found a higher incidence of type 3 NV in eyes with newly diagnosed neovascular AMD than that reported in prior studies. The κ statistic between the 2 classification systems showed "good" agreement. The discrepancies are likely attributable to the identification of a higher frequency of type 3 and mixed NV and a lower frequency of type 1 NV with the aid of OCT.