Abstract
Purpose :
To explore the regional distribution of retinal angiomatous proliferation (RAP) in the macula.
Methods :
We investigated the distribution of RAP lesions according to a modified ETDRS grid in a consecutive case series of 77 eye of 77 patients. The diagnosis of RAP was secured by fluorecein angiography, spectral-domain optical coherence tomography, color fundus photos, and elective indocyanine green angiography. After applying the grid on a good quality, early phase fluorecein image, the location of the shunt of RAP was determined according to each ETDRS subfield and also in the foveal avascular zone (FAZ). Then, the difference in the regional distribution of RAP lesions was measured statistically.
Results :
We found 82 RAP lesions in 77 eyes (5 eyes had 2 seperated lesions) distributed as follows: 66% (54/82), 22%(18/82),12%(10/82) lesions in temporal, nasal, and central subfields respectively.
All lesions involving the central subfield (10) were found outside the FAZ. All other lesions were distributed in the inner subfields, except 2 cases which situated in the outer subfields. The differences in the distribution of RAP lesions between the nasal and temporal, central and temporal lesions were statistically significant (p<0.05).
Conclusions :
RAP is not evenly distributed across the macula. It is usually seen temporal to the fovea between 0,5 to 1,5 mm . Moreover, it does not occupy the FAZ, in contrast to type 1 and 2 of choroidal neovascularization. This characteristic distribution of RAP suggests that its development and progression is necessarily dependent on corresponding regional rather than diffuse pathological changes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.