Improved visualization of choroidal neovascularization in age-related macular degeneration with optical coherence tomography angiography compared to fluorescein angiography

Abstract

 

Purpose

 

To determine if novel optical coherence tomography (OCT) angiography can improve visualization of ill-defined choroidal neovascularization (CNV) in age-related macular degeneration (AMD) imaged with fluorescein angiography (FA).

 

Methods

 

Cases of neovascular AMD with ill-defined CNV with FA were defined as either occult CNV or CNV obscured by subretinal hemorrhage (SRH). OCT angiography images were obtained with a prototype high-speed (100K A scan/second) 1050 nm swept-source OCT. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. The volumetric angiogram was segmented between the outer plexiform layer (OPL) and Bruch’s membrane to identify pathologic flow associated with CNV. En face OCT angiogram of both CNV and segmented inner retinal angiogram (internal limiting membrane to OPL) were compared to early and late images obtained with FA. Depth-resolved CNV location was studied by overlaying color-coded flow data with structural OCT.

 

Results

 

In a case of occult CNV, OCT angiography demonstrated an easily visualized and well-defined vascular network in the outer retina (CNV) corresponding to a vague area of stippled hyperfluorescence with late leakage on FA. Depth resolved CNV localization with cross-sectional OCT angiograms revealed type I CNV. In a case with SRH, CNV is clearly visible on OCT angiography while it is obscured by the hemorrhage with FA. Cross-sectional OCT angiograms demonstrated type II CNV.

 

Conclusions

 

OCT angiography with the SSADA technology improves visualization of CNV tissue in cases ill-defined with conventional FA, including: occult CNV and CNV associated with SRH. Improved visualization of CNV tissue with OCT angiography may enhance CNV detection and help refine individualized treatment strategies.

 

 

Figure 1. (A) Color fundus photograph with black box outlining area of angiograms B, C and D. (B) Early phase angiogram with areas of hemorrhage outlined in dashed yellow lines. (C) Late phase angiogram showing leakage associated with hemorrhage. (D) Color-coded en face OCT angiogram of inner retina (pink) and outer retina (yellow) demonstrating CNV. Yellow dashed arrow indicates position of OCT in E. (E) Cross-sectional structural OCT with color-coded angiogram overlay. CNV flow is above retinal pigment epithelium consistent with type II CNV.

 

Keywords: 550 imaging/image analysis: clinical • 453 choroid: neovascularization • 412 age-related macular degeneration