Abstract
Purpose :
To study the prevalences of Beta zone peripapillary atrophy (PPA) and Gamma zone PPA defined by optical coherence tomography (OCT) and their associations in a subgroup of a population-based Study.
Methods :
The population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6 ± 9.8 years (range: 50-93 years). Individuals without any ocular disease and with best corrected visual acuity of no less than 16/20 were randomly selected after stratification based on the refractive error. Beta zone PPA was defined as the peripapillary zone with existing Bruch's membrane without retinal pigment epithelium and Gamma zone was the region from the Bruch’s membrane's end to the optic disc margin. The maximum width of Beta zone and Gamma zone was measured.
Results :
A total of 590 eyes were randomly selected (refractive error -1 to +1dpt: n=267 eyes; -2 to -1dpt: n=159; -3 to -2dpt: n=65; -4 to -3dpt: n=50; -5 to -4dpt: n=49). The prevalence of Beta zone and Gamma zone were 74.5±2.7% and 22.1±2.5%, respectively, in emmetropic eyes, and 95.0±5.0% and 70.0±10.5%, respectively, in eyes with a refractive error between -5 to -4dpt. The mean maximum width was 349 ± 169 µm (112 µm to 1499 µm), and 281 ± 172 µm (59 µm to 910 µm), for Beta zone and Gamma zone, respectively. The location of maximum PPA width was the temporal region for Beta zone, and the infero-temporal region for Gamma zone. After multivariate analysis, wider width of Beta zone was significantly associated with older age (P<0.001; standaradized regression coefficient ß=0.33), higher best corrected visual acuity (P=0.023; ß=0.11), and longer axial length (P<0.001; ß=0.22). Wider width of Gamma zone was associated with longer axial length (P<0.001ß=0.49), and wider horizontal Bruch’s membrane opening (BMO) diameter (P<0.001; ß=0.31).
Conclusions :
The prevalence of Beta zone and Gamma zone PPA as measured by OCT were higher than as determined previously on fundus photographs. The presence and size of PPA increased with age and myopic refractive error for Beta zone, and increased with axial length and horizontal BMO diameter for Gamma zone.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.