The Peri-Papillary Choroidal and Retinal Nerve Fiber Layer Thickness in Mild to Moderate Axial Myopia



Fard MA¹ ; Mohammadi SF¹ ; Ashrafi E¹ ; Lashay MR¹ ; Moghimi S¹ ; Naderifar H¹ ; Mirshahi A¹ ; Lashay A¹ Show Affiliations
Source: Journal of Iranian Medical Council Published:2019

Abstract

Background: This study aimed to measure Peri-papillary Choroidal Thickness (PCT) and Retinal Nerve Fiber Layer Thickness (RNFLT) in mild to moderate axial myopic eyes and compare their average values with those of normal control participants. Methods: Twenty-five mild to moderate axial myopic eyes were included in this study. The data of 27 normal eyes were also considered as the control group. Subjects underwent a refractive error examination and axial length measurements. Then, the RNFLT, as well as the choroid borders (outer and inner) were measured. Optical Coherence Tomography (OCT) measurement of both eyes was done using Spectral Domain Optical Coherence Tomography (SD-OCT). Results: The average PCT of the eyes of the myopic subjects and normal controls was 161.7±29.6 and 166.18±39.8 μm, respectively. All the regional values of PCT and its average were not significantly different between myopic and the control eyes. However RNFLT values were significantly lower in the superior (p=0.004), inferior (p=0.01), and nasal (p<0.001) sectors among the myopic eyes in comparison with the control eyes. There was a negative association between axial length and choroidal thickness in temporal r=0.12 (p=0.023), superior r=-0.2(p=0.04), nasal [r=-0.34 (p<0.001] and inferior [r=-0.32 (p=0.001)] segments, respectively that of them it was not statistically significant for the temporal segment. Conclusion: Although RNFLT values were lower in the most regions of myopic eyes versus the controls, no significant difference was statistically found in the PCT using Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT) from mild to moderate axial myopic cases and the control eyes. The choroidal thickness in temporal, superior, nasal segments were negatively correlating with axial length. © Journal of Iranian Medical Council 2019.