Abstract
Purpose :
To explore the prevalence of subclinical choroidal neovascularization (CNV) in fellow eyes of patients with unilateral exudative age-related macular degeneration (AMD). Previous studies have reported a range of prevalence of subclinical CNV from 6.25-27%, irrespective of the stage of AMD. Eyes with subclinical CNV are at risk for future progression to clinical leakage and vision loss. In the current study, we performed a cross-sectional study of the prevalence of subclinical CNV in fellow eyes of patients undergoing treatment for unilateral exudative AMD by three retina specialists (A.A.F., R.G.M., M.K.G.).
Methods :
Retrospective review of spectral-domain optical coherence tomography angiography (SD-OCTA) 3 x 3 mm2 and 6 x 6 mm2 macular scans. An en face slab of the outer retina extending into the choriocapillaris was used to detect evidence of subclinical CNV. We verified the presence of CNV by ensuring that the location of flow signal in the corresponding B-scans was at a level above Bruch’s membrane. Two masked graders independently reviewed all scans.
Results :
Thirty-four fellow eyes of patients with unilateral exudative AMD were imaged between October 2016 and September 2017. Of these, subclinical CNV was detected in 5 eyes (14.7%). Four of the five lesions were type 1 CNVs and one was a type 3 CNV. All type 1 subclinical CNVs were juxtafoveal and the type 3 subclinical CNV was extrafoveal in location. Average size of the subclinical CNV lesions was 0.2097 ± 0.0509 mm2 (range = 0.1598- 0.2836).
Conclusions :
OCTA is a rapid, noninvasive modality to detect subclinical CNV in fellow eyes of patients with unilateral exudative AMD. In our population, we found that 15% of patients with unilateral exudative AMD have evidence of subclinical CNV in their fellow eye. Once a subclinical CNV is detected, these fellow eyes may need to be monitored more closely due to a potential 15.2 times greater risk of exudation within one year as compared to eyes without subclinical CNV (de Oliveira Dias et al Ophthalmology 2017).
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.