Abstract
Purpose: :
Obstructive sleep apnoea (OSA) is associated with hypoxia and blood pressure spikes and in theory it can cause endothelial cell damage. In this study, we assess the prevalence of OSA in patients with clinically significant diabetic macular edema (CSDME) and investigate whether OSA increases the rate of co-existing proliferative diabetic retinopathy (PDR).
Methods: :
Patients with Type 2 diabetes treated with focal or grid laser for CSDME over 9 consecutive months were identified from laser treatment records and invited to take part in the study. Respiratory physicians screened patients for OSA and grouped them according to the presence or absence of OSA. The level of diabetic retinopathy for each patient in the study was determined by the grading of colour photographs by an ophthalmologist who was masked to the results of OSA screening. The worst eye was used as the study eye.
Results: :
There were 58 patients enrolled in the study, with equal numbers of men and women. The mean age was 67.7 years (range 49-84 years). 37 patients were positive for OSA (63.8%) as compared to 4% of the general population. Ten out of 37 patients (27.0%) in the OSA group had PDR compared to 2 out of 21 (9.5%) in the non-OSA group.
Conclusions: :
OSA is 16 times more common in Type 2 diabetic patients with CSDME as compared to the general population. Furthermore, OSA appears to be associated with a higher incidence of PDR in this group of patients. We can postulate that identifying and treating OSA might be beneficial in patients with type 2 diabetes.
Keywords: diabetic retinopathy • hypoxia • retinal neovascularization