Obstructive sleep apnoea (OSA) is a disorder characterised by brief interruptions of breathing during sleep and results from complete or partial collapse of the pharyngeal airway. This study investigated the prevalence and progression of glaucoma in 39 patients receiving treatment for OSA. Participants were over 30 years and had been diagnosed with moderate and severe OSA in the sleep clinic at Hamad General Hospital in Qatar. The severity of OSA was graded as mild, moderate, or severe based using the apnoea hypopnea index. All patients underwent ophthalmological examination including visual field testing, optical coherence tomography and pachymetry. Study patients were followed up in the ophthalmology and sleep clinics for a period of three years at six monthly intervals. Most patients were male with a mean age of 52 years; 27 patients had severe and 12 moderate OSA. Examinations found that eight (20%) of the 39 OSA patients had glaucoma. Six of these patients had normal-tension glaucoma and two had high-tension glaucoma. Among the 27 patients with severe OSA, seven had glaucoma, and among 12 patients with moderate OSA, one had glaucoma. There was a prevalence of glaucoma in the severe OSA group compared with the moderate OSA group without statistical significance (P=0.4). The results of this small scale study confirm previous findings that severe OSA is a risk factor for glaucoma.