Obstructive Sleep Apnoea and Retinopathy in Patients with Type 2 Diabetes: A Longitudinal Study.

AIMS To assess the relationship between obstructive sleep apnoea (OSA) and diabetic retinopathy (DR) in patients with type 2 diabetes (T2D) and to assess whether OSA is associated with its progression). METHODS A longitudinal study from diabetes clinics in two UK hospitals was conducted. Patients known to have any respiratory disorder (including OSA) were excluded. DR was assessed using 2x45degrees retinal images per eye. OSA was assessed using a home-based, multi-channel cardiorespiratory device. RESULTS 230 patients were included. Sight threatening DR (STDR) and OSA prevalence was 36.1% and 63.9% respectively. STDR prevalence was higher in patients with OSA (OSA+) vs. those without (OSA-) (42.9% vs. 24.1% (p0.004). After adjustment for confounders, OSA remained independently associated with STDR (OR 2.3, 95%CI 1.1-4.9, p=0.04). After a median (IQR) follow-up of 43.0 (37.0-51.0) months, OSA+ patients were more likely to develop pre-/proliferative DR compared to OSA- patients (18.4% vs. 6.1%, p=0.02). After adjustment for confounders, OSA remained an independent predictor of progression to pre-/proliferative DR (OR 5.2, 95%CI 1.2-23.0, p=0.03). Patients who received continuous positive airway pressure (CPAP) treatment were significantly less likely to develop pre-/proliferative DR. CONCLUSIONS OSA is associated with STDR in patients with T2D. OSA is an independent predictor for the progression to pre-/proliferative DR. CPAP treatment was associated with reduction in pre-/proliferative DR. Interventional studies are needed to assess the impact of OSA treatment on STDR