Abstract
Purpose :
Myopia is the most common ocular disorder worldwide and axial elongation in myopic eyes is accompanied by scleral remodeling of around the optic nerve head (ONH).This study aims to assess the characteristics and the prevalence of the peripapillary gamma zone among the myopic, emmetropic, and hyperopic eyes of Chinese children.
Methods :
This is a population-based study. 1274 children aged 6–8 years were recruited from the Hong Kong Children Eye Study (HKCES). All participants completed ocular examinations, including cycloplegic auto-refraction and axial length (AL) measurements. The optic disc was imaged using a Spectralis OCT unit (Heidelberg Engineering, Heidelberg, Germany), adopting a protocol with 24 equally spaced radial B-scans. The peripapillary gamma zone was defined as the region between the Bruch’s membrane opening (BMO) and the border of the optic disc, which was defined by the peripapillary border tissue.
Results :
The prevalence of the peripapillary gamma zone was much higher in myopic eyes (36.3%) than in emmetropic (16.1%) and hyperopic eyes (11.5%; P<0.001). In the subgroup analysis, the axial length (AL) of eyes with a peripapillary gamma zone was significantly longer than for eyes without a peripapillary gamma zone among the myopia group (24.28mm vs. 23.79mm; P<0.001), but not in the emmetropia (23.21mm vs. 23.15mm; P=0.117) or hyperopia groups (22.79mm vs. 22.67mm; P=0.119). Longer AL was associated with a higher chance of peripapillary gamma zone occurrence in the myopic eyes (OR=1.874, P<0.001), but not in the emmetropic (OR=1.033, P=0.913) or hyperopic eyes (OR=1.044, P=0.883) after adjusting for demographic, systematic, and ocular variables. The locations of the peripapillary gamma zone were different between myopic and non-myopic eyes (P<0.001).
Conclusions :
The peripapillary gamma zone was observed in both myopic and non-myopic children, whereas it was associated with an AL elongation only in myopic eyes, suggesting that the mechanisms peripapillary gamma zone were different in myopic and non-myopic eyes.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.