Abstract
Purpose :
The purpose of this study is to compare the morphological changes of the foveal pit for myopic, hyperopic, and emmetropic eyes.
Methods :
Eighty-five participants were evaluated (47 men and 38 women) with ages ranging from 18 to 27 years old. The experiment was divided into two parts: the clinical evaluation (represented in 1) and the model calculation (2). (1) The axial length (AL) and spherical equivalent (SE) of each participant was obtained with an IOL Master 7000 and an autorefractometer, and the spherical equivalent was corroborated with retinoscopy under cycloplegia. We separated the participants into three groups based on their AL: short-eye (AL >= 21mm, n = 36), normal-eye (AL >= 23mm, n=30) and long-eye (AL >= 25mm, n =19). (2) A Spectralis OCT from Heidelberg Engineering provided images (14 for each participant) of the macula from the three groups in order to reconstruct a 3D model of the retina. We calculated central foveal rim disk area, average pit depth, slope disk area, pit volume and average disk diameter.
Results :
(1) The groups were measured in terms of their mean AL and SE, respectively: the short-eye group with an AL of 22.5 mm (23.08/24.46 mm) and SE of +0.5 D (+0.25/+1.5 D), the emmetropic group with 23.62 mm (21.82/22.89) and -0.25 D (-2.0/+1.25 D), and the long-eye group with 25.48 mm (24.7/26.60 mm) and -3.75 D (-6.0/+0.5 D). (2) The average disk diameter (F =3.502, p< 0.01) and major and minor axis rim disks (F = 4.06, p <0.01) had statistically significant differences between the eye groups. Post-hoc tests showed that the differences were statistically significant between the short-eye and long-eye groups in their morphological structures, but no differences between emmetropic and ametropic eyes were observed in any scenario.
Conclusions :
Axial-refractive errors correlate with certain morphological retinal differences, such as pit volume and central foveal rim-disk shape. Our research shows that the average disk diameter and the major and minor axis of the rim disk in short eyes are statistically different and larger in long eyes. Moreover, the shape of the rim disk is also correlated with the presence of axial refractive errors. The difference in foveal average disk diameter between long and short eyes appears to be a biomarker for patients with higher risk of suffering from axial myopia progression.
This is a 2020 ARVO Annual Meeting abstract.