Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea–hypopnea syndrome (OSAHS)

Objective To assess the peripapillary retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) morphologic parameters, and macular thickness and volume in patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS). Methods This prospective, observational case-control study consisted of 96 eyes of 50 OSAHS patients (mean age of 50.9 ± 12.4 years, best-corrected visual acuity ≥20/20, refractive error less than 3 spherocylindrical diopters, and intraocular pressure <21 mmHg) who were enrolled and compared with 64 eyes of 33 age-matched controls. Peripapillary RNFL thickness, ONH parameters, macular thickness and volume were measured by optical coherence tomography (OCT). Results OSAHS patients showed a significant reduction of the nasal quadrant RNFL thickness (74.7 ± 15.8 μm) compared with those values observed in control patients (81.1 ± 16.6 μm, p = 0.047, Student's t -test). No differences in peripapillary RNFL thickness were observed when dividing the OSAHS group in accordance with disease severity. Vertical integrated rim area (VIRA) (0.67 ± 0.41 mm 3 in OSAHS vs 0.55 ± 0.29 mm 3 in controls; p = 0.043, Student's t -test), horizontal integrated rim width (HIRW) (1.87 ± 0.31 mm 2 in OSAHS vs 1.8 ± 0.25 mm 2 in controls; p = 0.039, Student's t -test) and disc area (2.74 ± 0.62 mm 2 in OSAHS vs 2.48 ± 0.42 mm 2 in controls; p = 0.002, Student's t -test) showed significant differences, all of them being higher in the OSAHS group. Severe OSAHS had significant higher disc area (2.8 ± 0.7 mm 2 ) than controls (2.5 ± 0.4 mm 2 ; p = 0.016, ANOVA test). Temporal inner macular thickness was significantly higher in mild–moderate OSAHS patients (270 ± 12 μm) than in severe OSAHS patients (260 ± 19 μm; p = 0.021, ANOVA test). Conclusions OSAHS patients showed decreased peripapillary nasal RNFL thickness, and increased ONH area and volume parameters when they were evaluated by OCT. These findings suggest that neuronal degeneration might be present in the retina of OSAHS patients, as previously observed in some neurodegenerative disorders