Original Article Retinal nerve fiber thickness is reduced in sleep apnea syndrome Sasan Moghimi a,b,⇑ , Aliasghar Ahmadraji a , Hamed Sotoodeh a , Khosro Sadeghniat c , Maryam Maghsoudipour d , Ghasem Fakhraie a , Golshan Latifi a , Nariman Nassiri b , JoAnn A. Giaconi b a Farabi Eye Research Center, Department of Ophthalmology, Tehran University of Medical Sciences, Tehran, Iran b Division of Glaucoma, Jules Stein Eye Institute, UCLA, Los Angeles, CA, USA c Sleep Medicine Department, Baharloo Hospital, Tehran University of Medical Sciences, Tehran, Iran d University of Social Welfare and Rehabilitation Science, Tehran, Iran article info Article history: Received 11 March 2012 Received in revised form 6 July 2012 Accepted 12 July 2012 Available online xxxx Keywords: Sleep apnea syndrome Retinal nerve fiber layer Visual field Glaucoma Intraocular pressure Hypopnea abstract Objective: To investigate the prevalence of glaucoma, visual field abnormalities, as well as changes in ret- inal nerve fiber layer in patients with obstructive sleep apnea syndrome (OSAS). Methods: In this cross-sectional study, 51 patients with OSAS were included. Based on apnea hypopnea index (AHI), there were 26, 6 and 19 cases of severe (AHI P 30), moderate (15 6 AHI < 30), and mild (5 6 AHI < 15) OSAS, respectively. The control group was matched for age, sex and body mass index. Prev- alence of glaucoma and ocular hypertension as well as the following values were assessed and compared between two groups: best-corrected visual acuity, intraocular pressure, central corneal thickness (CCT), cup:disk ratio, mean deviation (MD), pattern standard deviation, and retinal nerve fiber layer (RNFL) parameters using glaucoma diagnosis measurement (GDx). Results: Seven eyes (6.7%) had intraocular pressure (IOP) > 21 mm Hg; of these, four eyes (3.9%) had glau- coma. No significant difference was detected in CCT between the two groups. IOP was significantly higher in the OSAS group before (p < 0.001) and after (p < 0.001) correcting for CCT. There was a significant dif- ference between groups in MD and most GDx parameters including DISK (temporal–superior–nasal–infe- rior–temporal) average (p = 0.002), superior average (p = 0.05) and nerve fiber indicator (NFI) (p = 0.03), where those in the patient group showed lower values. There was a significant positive correlation between AHI and both IOP and NFI. Conclusions: OSAS patients had a higher prevalence of glaucoma and ocular hypertension. OSAS patients also had higher IOP, worse visual field indices, and lower RNFL parameters compared with the control group. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Obstructive sleep apnea syndrome (OSAS) is defined as recur- rent partial or complete obstruction of the upper airway during sleep that results in arousal from sleep. Most patients are unaware of these night-time events, which may occur frequently during their sleep. OSAS results in symptoms of excessive daytime sleep- iness, chronic fatigue, and decreased cognitive abilities. The preva- lence of OSAS is 2–5% in the middle-aged population. At least 4% of men, 2% of women, and 10% of people aged >65 years have this syndrome. Risk factors include obesity, male gender, thick neck, upper respiratory tract abnormality, consumption of alcohol, and snoring [1–3]. Diagnosis of OSAS is made by night-time polysom- nography [4]. The presence and severity of OSAS is defined by the apnea hypo- pnea index (AHI), which is the frequency of apneas and hypopneas per hour, and by the respiratory disturbance index (RDI), defined as the number of arousals per hour. An RDI score of P5 in combina- tion with typical daytime symptoms indicates the presence of SAS. OSAS-related hypoxia, hypercapnia, and decreased oxygen satura- tion have been shown to increase the risk of systemic blood and pulmonary hypertension, arrhythmia, myocardial infarction, con- gestive heart failure and stroke [5–9]. There have been reports that OSAS is also associated with oph- thalmic disorders, including glaucoma (and normal tension glau- coma), visual field changes, optic disk swelling, non-arteritic anterior ischemic optic neuropathy, central serous choroidoretin- opathy, and retinal vein occlusions [10–17]. Previous studies of glaucoma and OSAS use various study designs, patient populations, methods, and AHI cut-offs in their analyses. Only a few studies looking at normal tension glaucoma (NTG) measured central cor- neal thickness [11,13–18]. It has been shown that patients with 1389-9457/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.sleep.2012.07.004 ⇑ Corresponding author at: Farabi Eye Research Center, Tehran University of Medical Sciences, Quazvin Sq., Tehran, Iran. Tel./fax: +98 21 55416134. E-mail address: sasanimii@yahoo.com (S. Moghimi). Sleep Medicine xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Sleep Medicine journal homepage: www.elsevier.com/locate/sleep Please cite this article in press as: Moghimi S et al. Retinal nerve fiber thickness is reduced in sleep apnea syndrome. Sleep Med (2012), http://dx.doi.org/ 10.1016/j.sleep.2012.07.004