# Obstructive Sleep Apnea in Patients With and Without Diabetic Retinopathy: An Observational Study and Comparative Analysis

## TL;DR

This study explores the link between obstructive sleep apnea and diabetic retinopathy in Indian patients with type 2 diabetes, finding trends but no statistical significance.

## Contribution

The study introduces novel trends in AHI-sleep parameters and advocates for OSA screening in diabetic retinopathy clinics.

## Key findings

- High OSA risk correlated with longer diabetes duration, elevated HbA1c, and other metabolic factors.
- DR prevalence was higher in high-risk OSA patients, though not statistically significant.
- PSG results showed a trend toward greater oxygen desaturation in the DR group.

## Abstract

Introduction

Obstructive sleep apnea (OSA) causes intermittent hypoxia that may amplify retinal ischemia, accelerating the onset and progression of diabetic retinopathy (DR), specifically proliferative diabetic retinopathy (PDR). This study investigates the association between OSA and DR, including PDR, in an Indian cohort of type 2 diabetes mellitus (T2DM) patients.

Methods

In a prospective observational study conducted from October 2022 to December 2023 at a tertiary care centre, 85 T2DM patients (45 with DR, 40 without DR) underwent OSA screening using the Epworth Sleepiness Scale (ESS). High-risk patients (ESS ≥10) underwent polysomnography (PSG), with OSA severity graded by Apnea-Hypopnea Index (AHI).

Results

High OSA risk significantly correlated with longer diabetes duration (p=0.033), elevated HbA1c (p=0.030), dyslipidemia (p=0.003), hypertension (p=0.005), neck circumference (p=0.02), and BMI (p<0.001). DR prevalence was higher in high-risk OSA patients (58.33% vs. 52.05%, p=0.686), with a trend toward PDR (57.14% vs. 42%, p=0.943). PSG in nine patients revealed a trend showing greater oxygen desaturation index (ODI) and AHI in the DR group, albeit without statistical significance (p>0.05).

Conclusion

Though OSA association with DR and PDR remains statistically inconclusive, the results are exploratory and hypothesis-generating. Screening for OSA in resource-limited, busy DR clinics can detect additional risk factors. The novel AHI-sleep parameter trends advocate for further studies to validate OSA as a modifiable risk factor.