Primary open-angle glaucoma in patients with obstructive sleep apnoea in a Colombian population: a cross-sectional study

OBJECTIVE: Determine the prevalence, functional and structural alterations of primary open-angle glaucoma (POAG) in patients with obstructive sleep apnoea (OSA). DESIGN: Cross-sectional. SETTING: Tertiary hospital associated with specialised center in ophthalmologic images in Bogota, Colombia. PARTICIPANTS: 150 patients, for a sample of 300 eyes, 64 women (42.7%) and 84 men (57.3%) between 40 and 91 years old with a mean age of 66.8 (±12.1) years. INTERVENTIONS: Visual acuity, biomicroscopy, intraocular pressure, indirect gonioscopy and direct ophthalmoscopy. Patients classified as glaucoma suspects underwent automated perimetry (AP) and optical coherence tomography of the optic nerve OUTCOME MEASURE: The primary outcomes are the determination of prevalence of glaucoma suspects and POAG in patients with OSA. Secondary outcomes are the description of functional and structural alterations in computerised exams of patients with OSA. RESULTS: The prevalence of glaucoma suspect was 12.6%, and for POAG was 17.3%. No alterations in the appearance of the optic nerve was seen in 74.6%, focal or diffuse thinning of the neuroretinal rim (16.6%) was the most frequently finding, followed by asymmetry of the disc>0.2 mm (8.6%) (p=0.005). In the AP, 41% showed arcuate, nasal step and paracentral focal defects. The mean retinal nerve fiber layer (RNFL) was normal (>80 µM) in 74% of the mild OSA group, 93.8% of the moderate group and 17.1% of the severe group. Similarly, normal (P5-90) ganglion cell complex (GCC) in 60%, 68% and 75%, respectively. Abnormal results in the mean RNFL was seen in 25.9%, 6.3% and 23.4% of the mild, moderate and severe groups, respectively. In the GCC, 39.7%, 33.3% and 25% of the patients in the aforementioned groups. CONCLUSION: It was possible to determine the relationship between structural changes in the optic nerve and the severity of OSA. No relationship with any of the other studied variables was identified.