Optical coherence tomography angiography of long-term progression of type 1 neovascularization in age-related macular degeneration

Abstract

Purpose : To evaluate the optical coherence tomography angiography (OCTA) long term growth of type 1 neovascularization (NV) in patients with wet age-related macular degeneration (AMD).

Methods : This was a retrospective case series of patients with type 1 NV who underwent OCTA imaging at baseline, 1 year and last available follow up (range: 11-27 months). Patients received routine anti-VEGF therapy and had received injections prior to enrollment. The area of choroidal neovascularization (CNV) and vascular density on OCTA was measured by 2 graders and compared by paired t test. The rate of CNV growth was classified into three groups: at least doubling in area, modest growth of less than 50% of baseline area, and shrinkage. OCTA microvascular morphologic features were qualitatively graded, and the association of growth to morphologic features was assessed by Fischer exact test.

Results : Forty-one eyes were analyzed. Mean CNV area was 1.60 ± 1.84 mm² at baseline and 1.80 ± 1.84 mm² at 1 year. 33 (80%) eyes displayed increased CNV area with a mean increase of 0.30 ± 0.32 mm² (p=0.001). Vascular density did not change over time (p=0.75). 11 eyes (27%) displayed CNV area doubling, 19 (46%) eyes illustrated modest growth, and 6 (15%) eyes showed shrinkage. Three major morphologic forms of CNV were identified: immature, mature and hypermature. Features including immature lesion morphology (OR=4.2, p=0.015) and capillary fringe (OR=5.3, p=0.036) were significantly associated with CNV doubling. Other biomarkers including secondary branching, mature core vessels, peripheral arcades, anastomotic loops, and a perilesional halo did not correlate with CNV growth.

Conclusions : Quantitative OCTA analysis of type 1 NV illustrated sustained growth of CNV in most eyes with AMD despite continued anti-VEGF therapy. Three major OCTA morphologic forms of CNV were identified: immature, mature, and hypermature. Long term quantitative OCTA analysis may provide an important biomarker of NV activity.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.

 

OCTA and SD-OCT of type 1 NV displaying an immature lesion characterized by a multi-lobulated rosette with multifocal indistinct capillary fringe (arrowheads).

 

OCTA and SD-OCT of type 1 NV at baseline (A), 12 months (B) and 16 months (C) demonstrating evolution from an immature to mature NV and more than doubling of CNV area. CNV area increased by 340% from 0.1 mm² to 0.44 mm² over 16 months.