Abstract
Purpose :
The location of the fovea is clinically important. It was the purpose to study the location of the fovea with respect to the optic disc margin and to determine its correlates with optic disc and retinal nerve fiber layer.
Methods :
400 eyes of 200 subjects (108 females) were included. All subjects underwent an ophthalmic evaluation, biometry and fundus photography and SDOCT. The distance of the fovea to the disc margin temporally and distance to the margin of the PPA was measured using the caliper device in the spectralis. The mean age was 26.51+-12.04 yrs. Mean values for Visual Acuity Decimal units was 0.85+-0.24DU, sph. equivalent was -4.96+-3.52 D and axial length was 24.95+-1.41 mm. The horizontal and vertical disc diameters were 1538.67+-240.3 and 1608.55+-239.1 u
Results :
The mean fovea to disc angle was -7.0 +- 4.3 deg. Gamma zone PPA was seen in 178/400 eyes. The mean distance from fovea to disc margin was 3717.30+-378.94 u ( range 2736-5039) from fovea to PPA margin was 3478.56+-357.33 u. ( range 2285-4356). The distance of fovea to center of disc margin temporally showed significant positive bivariate correlations with vertical diameter of disc (P=0.037;r=0.104), width of temporal gamma zone (P<0.001;r=0.551), distance from fovea to margin of PPA ( P<0.001;r=0.611), keratometry readings vertical (P=0.013;r=0.126), temporal RNFLT ( P<0.001;r=0.538), Naso inferior RNFLT ( P=0.013;r-0.124), Temporal inferior RNFLT (P<0.001;r =0.172) , temporo superior ( P=0.036;r=0.174),and negatively with horizontal DD ( P=0.012;r=-0.126), sph.equ (P=0.001;r=-0.212) and anterior chamber depth ( P=0.013;r=-0.126). On multivariate analysis with disc margin to fovea distance as dependant variable and all other significant variables as independant variable, correlations were seen with Temporal RNFLT (P<0.007; B: 0.693; 95% CI 8.84, 34.4), TI RNFLT ( P=0.010; B: 0.455; 95% CI 3.38, 15.15), and width of temporal gamma zone (P=0.028; B:0.66; 95% CI 0.17, 1.93)
Conclusions :
The distance of the fovea from disc margin was determined in myopia. The location of the fovea may differ significantly in myopic eyes and is significantly correlated in myopic eyes with the width of gamma zone and with the Temporal and Temporo inferior RNFLT. The distance of the fovea from the optic disc may be important from the clinical standpoint and has implications for the assessment of the RNFLT in glaucoma with myopia
This is a 2020 ARVO Annual Meeting abstract.