Normal Variation of Photoreceptor Outer Segment Volume With Age, Gender, Refractive Error, and Vitreomacular Adhesion

Area of Science:

• Ophthalmology
• Retinal Imaging
• Anatomy

Background:

• Photoreceptor outer segment (PROS) layer thickness and volume changes are linked to various ocular diseases.
• Limited data exist on normal anatomical variations of the PROS layer.
• Spectral-domain optical coherence tomography (SD-OCT) is a key imaging modality for retinal analysis.

Purpose of the Study:

• To evaluate the correlation of PROS volume with age, gender, refractive error, and vitreomacular adhesion (VMA) in healthy subjects.
• To establish normative data for PROS volume in a healthy population using SD-OCT.

Main Methods:

• Analysis of SD-OCT scans from 68 normal eyes.
• Automated segmentation of the ellipsoid zone and apical retinal pigment epithelium boundary.
• Calculation of PROS volume within a 6-mm diameter circle centered at the fovea using a general linear model.

Main Results:

• PROS volume demonstrated a significant positive correlation with age (P = .013).
• Gender, refractive error, and the presence of VMA were found to be insignificant factors influencing PROS volume.
• Age is a significant determinant of PROS volume in healthy eyes.

Conclusions:

• PROS volume, as measured by routine SD-OCT, increases with age in healthy individuals.
• This age-related increase is independent of gender, refractive error, and VMA.
• Findings contribute to understanding normal retinal anatomy and variations detectable by SD-OCT.