No association between sleep apnoea and macular telangiectasia type 2 and its markers of severity and progression: a case–control study and retrospective cohort study

Importance: Idiopathic Macular Telangiectasia Type 2 (MacTel) is an uncommon, progressive retinal disease usually affecting both eyes. Currently there is no know treatment however with similar comorbidities to Obstructive Sleep Apnoea (OSA) there is plausibility of an association which may accelerate disease progression. Background: To identify an association between MacTel and OSA and whether OSA may result in increased disease progression. Design: Matched case–control study and retrospective cohort analysis. Participants: Fifty-seven patients with MacTel and 165 matched controls from the Busselton Health Study. Methods: MacTel participants were matched based on age, gender and body mass index (BMI) (and where possible hypertension and diabetes) on a 3:1 ratio with controls from the Busselton Health Study. Participants undertook a sleep questionnaire using a previously validated questionnaire. In a subset sleep apnoea severity was objectively measured via overnight ambulatory polygraphy (30 cases and 83 matched controls; ApneaLink device; ResMed, Sydney, Australia). In a retrospective analysis of the suspected MacTel cases we assessed whether major markers of OSA severity and MacTel progression were associated. Main Outcome Measures: Apnoea Hypopnea Index along with key markers of MacTel progression. Results: MacTel patients did not have a higher risk of sleep apnoea when compared to age, sex and BMI -matched controls (mean ± SD Apnoea hypopnea index [AHI] cases 9.6 ± 14.7 vs. controls 9.7 ± 10.8, P = 0.95). No markers of disease progression in the cases were associated with any marker of OSA severity. Conclusions and Relevance: Sleep apnoea does not increase the risk or accelerate the progression of MacTel.