# Assessment of Peripapillary Retinal Nerve Fibre Layer Thickness, Optic Nerve Head Rim Area, Anterior Chamber Parameters, and Axial Length in Myopic Eyes

## TL;DR

This study explores how myopia affects eye structures like retinal nerve fiber layer thickness and anterior chamber parameters.

## Contribution

The study identifies specific correlations between myopia severity and ocular structural changes using SS-OCT and Pentacam measurements.

## Key findings

- Myopia severity is strongly correlated with axial length (r = 0.545).
- Anterior chamber volume and depth increase with myopia severity.
- Peripapillary RNFL thickness and ONH rim area decrease with axial elongation.

## Abstract

Background: Myopic eyes commonly show structural changes, including optic nerve head (ONH) and altered anterior chamber parameters.

Aim: The study aimed to investigate the associations of peripapillary retinal nerve fibre layer (RNFL) thickness, optic disc rim area, anterior chamber parameters, and axial length in myopic eyes.

Methods: This cross-sectional study was conducted at the Royal Commission Medical Centre, Yanbu, Saudi Arabia, between February and May 2025 and included 152 myopic eyes. Refraction was measured using an autorefractometer. Swept-source optical coherence tomography (SS-OCT) scans (optic disc cube 200 × 200) were used to assess peripapillary RNFL thickness and optic disc rim area. Corneal and anterior chamber parameters, along with axial length, were measured using Pentacam AXL (OCULUS Optikgeräte GmbH, Wetzlar, Germany). Data analysis was conducted to assess the correlation between myopia severity and structural ocular changes.

Results: Myopic eyes (mean spherical equivalent: -2.02 ± 1.34 D) showed a significant inverse correlation with both central corneal thickness (r = -0.193, P < 0.05) and corneal thickness at the thinnest point (r = -0.225, P < 0.05). Anterior chamber volume (r = 0.266, P < 0.001) and anterior chamber depth (r = 0.259, P < 0.001) showed significant positive correlations with myopia, while the anterior chamber angle showed no significant association (P > 0.05). Axial length was strongly correlated with myopia severity (r = 0.545, P < 0.001). Inverse correlations were observed between myopia and both peripapillary RNFL thickness (r = -0.100, P > 0.05) and ONH rim area (r = -0.134, P > 0.05). A statistically significant inverse correlation was found between peripapillary RNFL thickness and axial length (r = -0.163, P < 0.05), as well as between ONH rim area and axial length (r = -0.167, P < 0.05).

Conclusion: The study revealed a significant positive correlation between myopia and both anterior chamber volume and anterior chamber depth, while the anterior chamber angle remained unaffected. The increase in myopia severity was correlated with thinning of the peripapillary RNFL and a reduction in ONH rim area. These findings underscore the importance of assessing axial elongation and structural changes in myopic eyes, particularly in the context of ocular diseases such as glaucoma, myopic macular degeneration, and retinal detachment.