OPTICAL COHERENCE TOMOGRAPHY, FLUORESCEIN ANGIOGRAPHY, AND DIAGNOSIS OF CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION

Abstract

Purpose: To determine the sensitivity and specificity of different retinal imaging combinations for the diagnosis of choroidal neovascularization (CNV) in age-related macular degeneration.

Methods: Patients aged 50 years or older referred for suspicious recent-onset CNV related to age-related macular degeneration were prospectively included for 6 months. Data recorded included color fundus photographs (CFPs), spectral domain optical coherence tomography (SD-OCT), and fluorescein angiography (FA) images. Five retina specialists randomly interpreted SD-OCT combined with CFP, and then FA combined with CFP. The reference diagnosis of CNV was based on the agreement of two readers in the interpretation of the SD-OCT + FA + CFP combination.

Results: One hundred and forty-eight patients (148 eyes) were included. For the diagnosis of CNV, the sensitivity of both SD-OCT + CFP and FA + CFP was of 90.9%. Type 2 CNV was diagnosed in 98% to 100% of cases with SD-OCT + CFP or FA + CFP, whereas Type 1 CNV was diagnosed in 82.9% of cases with SD-OCT + CFP and 81.6% with FA + CFP.

Conclusion: When used as a first diagnostic test, SD-OCT combined with CFP had sensitivity and specificity similar to those of FA combined with CFP, for the diagnosis of CNV in age-related macular degeneration. This shows the increasingly important role of SD-OCT as a first-line test in the diagnosis of CNV.

Fig. 1.

Type 1 CNVs diagnosed with FA + CFP and not with SD-OCT + CFP. (Top left) Color fundus photograph shows confluent soft drusen in the macular area. Red and blue arrows represent the location of SD-OCT B-scans. The macular thickness mapping does not show evidence of retinal thickening. (Bottom left) Spectral domain OCT should have suspected CNV: SD-OCT B-scan passing through the foveal center (blue arrow) showing an irregular elevation of the RPE, without subretinal fluid or macular edema; SD-OCT B-scan passing under the foveal center (red arrow) showing shallow subretinal fluid. However, the diagnosis of CNV was not made by one reader of SD-OCT + CFP probably because of the presence of a minute shallow subretinal fluid only present on one B-scan. (Top and bottom right) Fluorescein angiography shows subretinal pigmentation followed by a progressive irregular staining and discrete fuzzy dye leakage in the lower part of the macula, which allowed the readers of FA + CFP to suspect Type 1 CNV.

Fig. 2.

Type 1 CNVs diagnosed with SD-OCT + CFP and not with FA + CFP. (Top left) Color fundus photograph shows drusen in the macular area. Red and blue arrows represent the location of SD-OCT B-scans. The macular thickness mapping shows a small inferomacular retinal thickening. (Bottom left) Spectral domain OCT suspected CNV: SD-OCT B-scan passing through the foveal center (blue arrow) showing an irregular elevation of the RPE, with a shallow subretinal fluid; SD-OCT B-scan passing under the blue arrow (red arrow) showing shallow subretinal fluid which allowed the readers of SD-OCT + CFP to suspect Type 1 CNV. (Top and bottom right) Fluorescein angiography shows pigment epithelium impairments and no evidence of progressive staining in the area of drusen interpreted as no CNV by one reader of FA + CFP. The patient was monitored for 6 months after the study without treatment and the SRF slowly increased, confirming the suspicion of the presence of CNV during the study.