# Scleral thickness in patients with obstructive sleep apnea syndrome

## TL;DR

This study found that patients with severe obstructive sleep apnea have thicker sclera compared to healthy individuals and those with milder forms of the condition.

## Contribution

The study identifies a potential link between severe obstructive sleep apnea and increased scleral thickness, possibly due to extracellular matrix accumulation.

## Key findings

- Scleral thickness was significantly higher in all quadrants for severe OSAS patients at 6 mm posterior to the scleral spur.
- Significant differences in scleral thickness were observed between severe OSAS patients and healthy controls at multiple positions.
- Extracellular matrix accumulation is suggested as a possible cause for increased scleral thickness in severe OSAS.

## Abstract

Evaluation of scleral thickness with anterior segment optical coherence tomography (AS-OCT) in patients with obstructive sleep apnea syndrome (OSAS).

Cross-sectional study.

A total of 30 severe (Group 1), 30 moderate (Group 2) and 30 mild (Group 3) OSAS patients and 22 healthy volunteers (Group 4) were included in the study. Scleral thickness measurements were taken with AS-OCT, 6 mm, 4 mm and 2 mm posterior to the scleral spur, in four gaze positions. Data and findings were examined comparatively.

At 6 mm posterior to the scleral spur, the mean thickness was found to be significantly higher in all quadrants in Group 1 (p<0.05 for all). Superior thickness was higher in Group 2 compared to Group 4 (p=0.034). At 4 mm posterior to the scleral spur; in Group 1, the mean thickness was found higher than Group 2 and 3 only in the inferior (p=0.01, p=0.021, respectively) and was found higher than Group 4 in the nasal and inferior (p<0.001, p=0.006, respectively). At 2 mm posterior to the scleral spur; significant difference was observed between Groups 1 and 2 only in the inferior (p=0.002), between Groups 1 and 3 in the nasal and inferior (p=0.029, p=0.002), and between Groups 1 and 4 the in nasal and inferior (p=0.002, p<0.001).

The scleral thickness measured from 6 mm posterior to the scleral spur was higher in all quadrants in patients with severe OSAS. It is possible that the increase in scleral thickness, especially in severe OSAS, is due to extracellular matrix accumulation in the scleral tissue.