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Clinical science - Extended reports: Jian Li, Gerald McGwin, Jr, Michael S Vaphiades, and Cynthia Owsley Non-arteritic anterior ischaemic optic neuropathy and presumed sleep apnoea syndrome screened by the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) Br J Ophthalmol 2007; 91: 1524-1527 [Abstract] [Full text] [PDF]

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Authors' reply

Gerald McGwin Jr., Cynthia Owsley   (28 July 2008)

Sleep apnoea in the eye clinic

Anju Kadyan, Soupramanien Sandramouli, Consultant Ophthalmologist   (18 January 2008)

Authors' reply 28 July 2008
Gerald McGwin Jr. University of Alabama at Birmingham, Cynthia Owsley Send letter to journal: Re: Authors' reply Gerald.McGwin{at}ccc.uab.edu Gerald McGwin Jr., et al.	Dear Editors We appreciate Dr. Kadyan’s letter regarding our study “Non-arteritic anterior ischaemic optic neuropathy and presumed sleep apnoea syndrome screened by the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ)” [1]. He requests clarification on several issues and, to the best of our ability we will attempt to respond to each in turn. Regarding the proportion of cases and controls diagnosed with glaucoma, this information appears in Table 1 of the published manuscript. Regarding exclusion criteria for the control group, as stated in the published manuscript the controls were randomly selected from patients seen in the Department of Ophthalmology clinic for reasons other than NAION; there were no other exclusionary criteria. With respect to the other ocular diagnoses of the control group, we did not collect this information. We also do not have information on the results of any sleep studies the study participants may have obtained. Finally, regarding which of the specific sleep apnea syndrome symptoms in the SA-SDQ were associated with NAION, it appears that the cases reported more frequent loud snoring (or bothering others), having nose block up when wanting to sleep, and snoring/breathing getting worse when sleeping on the back compared to controls. There were no statistically significant differences for the other SAS specific items nor for any of the non-SAS items (e.g., body mass index, smoking status). Furthering these analyses to create a weighted score is an interesting idea and something we may consider pursuing in the future. Regards, Gerald McGwin, Jr., M.S., Ph.D. Cynthia Owsley, Ph.D., M.S.P.H. Departments of Epidemiology and Ophthalmology University of Alabama at Birmingham Birmingham, Alabama References 1. Li J, McGwin G, Vaphiades, Owsley C. Non-arteritic anterior ischaemic optic neuropathy and presumed sleep apnoea syndrome screened by the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ). Br J Ophthalmol. 2007;91:1524-7.
Sleep apnoea in the eye clinic 18 January 2008
Anju Kadyan, Specialist Registrar, Ophthalmology Wolverhampton and Midland Counties Eye Infirmary, UK, Soupramanien Sandramouli, Consultant Ophthalmologist Send letter to journal: Re: Sleep apnoea in the eye clinic anjukadyan{at}btinternet.com Anju Kadyan, et al.	Dear Editor, We agree with the authors’ recommendation on the need for a sleep history in the eye clinic and probably having a lower threshold for referral to sleep physicians for further sleep studies.[1] However, we would like to bring to their attention other epidemiological studies where screening tools/sleep history have shown a high prevalence of sleep disorders in patients with ocular disorders other than non- arteritic anterior ischaemic optic neuropathy (NAION). These include primary open angle glaucoma (POAG), normal tension glaucoma (NTG), floppy eye lid syndrome (FES) and more recently central serous chorio-retinopathy (CSCR).[2-5] The evidence from these studies is summarized in table 1. The literature shows a higher prevalence of sleep disorder than that reported in the general population in the United Kingdom by Ohayon et al (1.9% of population sample, n=4972) based on the minimal criteria of the International Classification of Sleep Disorders.[6] We note the authors have adjusted the statistical analysis for glaucoma among other factors, but the proportion of patients diagnosed with glaucoma in the study and control groups is not mentioned. They also do not mention the ocular diagnosis of the randomly selected control group from the ophthalmology clinics and if any exclusion criteria, other than NAION was used. This may be the reason for their study having a lower proportion of patients with symptoms consistent with SAS than previously reported. The other reason can be the different screening methods used in these studies. Also, the authors do not mention if the patients scoring positive on the Sleep Apnoea scale of the Sleep Disorders Questionnaire (SA-SDQ) were referred for sleep studies. Offering polysomnography or even limited sleep study to the study sample and comparing the outcomes with the SA-SDQ scores could provide the required evidence or validation, as mentioned by the authors, on the need for lower cut-off points for this patient sub-group. We recently conducted a similar study in the general eye clinic population, which is under consideration for publication at the present time. Following a review of the various components of the screening questionnaire; patients with glaucoma were more likely to report episodes of apnoea, morning headaches, short term memory loss and poor concentration. We therefore suggest the authors also do a further analysis of the responses obtained to the 8 questions addressing the specific symptoms of SAS in the SA-SDQ, as they might be able to provide an additional weighted score for screening in their patient subgroup. References 1. Li J, McGwin G, Vaphiades MS, Owsley C. Non-arteritic anterior ischaemic optic neuropathy and presumed sleep apnoea syndrome screened by the Sleep Apnoea scale of the Sleep disorders Questionnaire (SA-SDQ). Br J Ophthalmol 2007; 91:1524-1527. 2. Hakki Onen S, Mouriaux F, Berramdane L, Dascotte JC, Kulik JF, Rouland JF. High prevalence of sleep disordered breathing in patients with primary open angle glaucoma. Acta Ophthalmol Scand 2000; 78: 638-641. 3. Marcus DM, Costarides AP, Gokhale P, Papastergiou G, Miller JJ, Johnson MH, Choudhary BA. Sleep Disorders: A risk factor for normal tension glaucoma. J Glaucoma 2001; 10: 177-183. 4. McNab AA, The eye and sleep. Clinical Experimental Ophthalmology 2005; 33: 117-25. 5. Leveque TK, Yu L, Musch DC, Chervin RD, Zacks DN. Central serous chorioretinopathy and risk for obstructive sleep apnoea. Sleep Breath 2007; 11: 253-257. 6. Ohayon MM, Guilleminault C, Priest RG, Caulet M (1997) Snoring and breathing pauses during sleep: telephone interview survey of a United Kingdom population sample. BMJ, 314, 860–863.