Prevalence of normal tension glaucoma in obstructive sleep apnea syndrome patients

Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome: a systematic review and Meta-analysis

AIM

To evaluate the retinal nerve fiber layer (RNFL) thickness changes in patients with obstructive sleep apnoea syndrome (OSAS), and detect possible prevalence of glaucoma in this population.

METHODS

Comprehensive studies were conducted on the Cochrane Library, PubMed and Embase through March, 2015. Only studies that fit the selection criteria about RNFL and OSAS would be included. For the measures, we calculated the 95% confidence interval (CI) and weighted mean differences (WMD). The systematic review and Meta-analysis was performed by RevMan 5.2 software.

RESULTS

Nine case-control studies were analyzed containing a total of 1086 cases and 580 controls. Average RNFL thickness in OSAS was reduced significantly compared with healthy controls in random effects model (WMD=-2.56, 95% CI: -4.82 to -0.31, P =0.003, I²=57%). A significant RNFL thickness reduction were found between the two groups in inferior quadrant (WMD=-3.11, 95% CI: -5.53 to -0.69, P=0.01), superior quadrant (WMD=-2.37, 95%CI: -4.7 to 0.04, P=0.05). In nasal quadrant (WMD=-2.54, 95% CI: -6.53 to 1.45, P=0.21) and temporal quadrant (WMD=-1.26, 95% CI: -2.19 to 0.47, P=0.15) there was no difference of RNFL thickness between the two groups.

CONCLUSION

The results show that RNFL thickness is lower in patients with moderate or severe OSAS than in normal subjects or patients with mild OSAS according to the nine homogeneity studies.

Medical Management of Glaucoma in the 21st Century from a Canadian Perspective

Glaucoma is a medical term describing a group of progressive optic neuropathies characterized by degeneration of retinal ganglion cells and retinal nerve fibre layer and resulting in changes in the optic nerve head. Glaucoma is a leading cause of irreversible vision loss worldwide. With the aging population it is expected that the prevalence of glaucoma will continue to increase. Despite recent advances in imaging and visual field testing techniques that allow establishment of earlier diagnosis and treatment initiation, significant numbers of glaucoma patients are undiagnosed and present late in the course of their disease. This can lead to irreversible vision loss, reduced quality of life, and a higher socioeconomic burden. Selection of therapeutic approaches for glaucoma should be based on careful ocular examination, patient medical history, presence of comorbidities, and awareness of concomitant systemic therapies. Therapy should also be individualized to patients' needs and preferences. Recent developments in this therapeutic field require revisiting treatment algorithms and integration of traditional and novel approaches in order to ensure optimal visual outcomes. This article provides an overview of recent developments and practice trends in the medical management of glaucoma in Canada. A discussion of the surgical management is beyond the scope of this paper.

The association between ophthalmologic diseases and obstructive sleep apnea: a systematic review and meta-analysis

PURPOSE

The purpose of this study was to evaluate the association between obstructive sleep apnea (OSA) and ophthalmologic diseases, specifically glaucoma, nonarteritic anterior ischemic optic neuropathy (NAION), retinal vein occlusion (RVO), central serous chorioretinopathy (CSR), and floppy eyelid syndrome (FES), by performing a systematic review and meta-analysis of published studies.

METHODS

PubMed, Embase, and Scopus databases were searched for observational studies on OSA and its association with select ophthalmologic diseases. Data was pooled for random-effects modeling. The association between OSA and ophthalmologic diseases was summarized using an estimated pooled odds ratio with a 95 % confidence interval.

RESULTS

Relative to non-OSA subjects, OSA subjects have increased odds of diagnosis with glaucoma (pooled odds ratio (OR) = 1.242; P < 0.001) and floppy eyelids syndrome (pooled OR = 4.157; P < 0.001). In reverse, the overall pooled OR for OSA was 1.746 (P = 0.002) in the glaucoma group, 3.126 (P = 0.000) in the NAION group, and 2.019 (P = 0.028) in the CSR group. For RVO, one study with 5965 OSA patients and 29,669 controls demonstrated a 1.94-fold odds increase in OSA patients.

CONCLUSIONS

Our results suggest significant associations between OSA and glaucoma, NAION, CSR, and FES. Screening for OSA should be considered in patients with glaucoma, NAION, CSR, or FES.

Changes in Retinal Nerve Fiber Layer Thickness in Obstructive Sleep Apnea/Hypopnea Syndrome: A Meta-Analysis

PURPOSE

To evaluate and compare changes in retinal nerve fiber layer (RNFL) thickness in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS).

METHODS

The Cochrane Library, Medline, and Embase were screened using our key words. Results were carefully reviewed to ensure that the included studies met the inclusion/exclusion criteria, and the quality of the studies was assessed using the Newcastle-Ottawa Scale. All included studies categorized patients with OSAHS into 3 groups (mild, moderate, and severe), and measured average and 4-quadrant (temporal, superior, nasal, and inferior) RNFL thickness. All studies included a healthy control group. The weighted mean differences and 95% confidence intervals were calculated for the continuous outcomes.

RESULTS

Ten case-control studies were included in the meta-analysis, consisting of a total of 811 OSAHS group and 868 healthy eyes. A meta-analysis of the data showed that the average RNFL thicknesses in the mild, moderate, and severe OSAHS groups were significantly decreased compared to healthy controls. Additionally, RNFL thickness was significantly reduced in all but the temporal quadrant in the moderate and severe OSAHS groups when compared to healthy controls.

CONCLUSIONS

On the basis of these results, we suggest that peripapillary RNFL thickness as measured by optical coherence tomography could be a useful tool to monitor and assess the severity of OSAHS in patients. Further studies are required in order to differentiate these RNFL changes from glaucomatous changes. This has not been properly examined in any of the studies we were able to identify.

Retinal Nerve Fiber Layer Thickness Alteration in Apneic Children

PURPOSE

We examined retinal nerve fiber layer (RNFL) thickness alterations in children with chronic upper airway obstructions (UAOs) and obstructive sleep apnea syndrome (OSAS). We also investigated whether it was affected by an adenotonsillectomy operation.

METHODS

Forty-two children aged 3 to 8 years with chronic UAO resulting from adenotonsillar enlargement and 34 age-matched controls were included in the study. Patients underwent a Brouillette scoring questionnaire to be divided into mild (N = 10), moderate (N = 22), severe (N = 10), and total (N = 42) UAO groups. According to the scoring, the severe UAO group was defined as the severe OSAS group, the moderate group was suspicious for OSAS, and the mild UAO group was defined as the non-OSAS group. The patients' demographic data for age, sex, and body mass index were obtained. Ophthalmologic evaluations were performed with optical coherence tomography. Central corneal thickness, macular thickness, intraocular pressure (IOP), and RNFL thickness were measured. An adenotonsillectomy was performed on all patients, and eye examinations and scoring were repeated after the surgery.

RESULTS

Higher IOP levels were obtained between the total UAO group and the control group (p > 0.05). There were significant differences between UAO groups and the control group except for the moderate UAO group. There was no significant difference in RNFL thickness (p > 0.05) between preoperative UAO groups and the control group. However, after surgery, some significant differences emerged in the superior, inferior, and average RNFL thickness (p < 0.05). Also, IOP levels were significantly lower in the mild, moderate, and total UAO groups after the operation (p < 0.05).

CONCLUSIONS

Upper airway obstruction and OSAS seem to worsen some RNFL and IOP parameters in children, and eye examinations may be useful in these patients.

Meta-Analysis of Association of Obstructive Sleep Apnea With Glaucoma

OBJECTIVES

Previous studies suggested that obstructive sleep apnea (OSA) was associated with glaucoma. However, data on this issue are controversial. This study aims to use meta-analysis to determine whether OSA is related to glaucoma.

MATERIALS AND METHODS

We searched PubMed, Embase, the Cochrane library, the Web of Science, and the Chinese BioMedical Literature Database disk databases up to November 20, 2014 for related literature. The association of OSA with glaucoma was assessed by odds ratio (OR) with 95% confidence interval (CI) as the effect size. Then subgroup analysis was performed according to area and glaucoma type.

RESULTS

Six primary studies (3 cohort study and 3 case-control studies) were included in this meta-analysis involving 2,288,701 participants. There was a significant association between OSA and glaucoma (adjusted-effect summary for case-control studies OR=2.46; 95% CI, 1.32-4.59, P=0.005) (adjusted-effect summary for cohort studies OR=1.43; 95% CI, 1.21-1.69, P=0.000). There was no significant publication bias.

CONCLUSION

OSA was a risk factor for glaucoma. A large number of studies is needed to explore the mechanisms that link OSA with glaucoma.

Associations between obstructive sleep apnoea, primary open angle glaucoma and age-related macular degeneration: record linkage study

BACKGROUND

Primary open angle glaucoma (POAG) is thought to be associated with obstructive sleep apnoea (OSA) but previous studies are conflicting and have methodological limitations. This potential relationship has implications for investigation and treatment strategies, and may provide insights into disease pathogenesis. The relationship between OSA and age-related macular degeneration (AMD) is unknown.

METHODS

A sleep apnoea cohort of 67 786 people was constructed from linked English hospital episode statistics (1999-2011). We compared this cohort with a reference cohort (2 684 131 people) for rates of subsequent POAG and AMD. A POAG cohort (comprising 87 435 people) and an AMD cohort (248 408 people) were also constructed and compared with the reference cohort for rates of subsequent sleep apnoea. All analyses were restricted to people aged 55 and over and, within this age range, were age standardised using 5-year age groups.

RESULTS

Risk of POAG following sleep apnoea was not elevated: the rate ratio for POAG was 1.01 (95% CI 0.85 to 1.19). Similarly, the risk of sleep apnoea following POAG was not elevated: the rate ratio was 1.00 (0.86 to 1.17). These findings held true across subgroup analysis according to sex and age group. By contrast, the risk of AMD following sleep apnoea was significantly elevated, with rate ratio 1.44 (1.32 to 1.57).

CONCLUSIONS

Although plausible mechanisms exist to consider a link between OSA and POAG, the two conditions are not positively associated. This holds true in either temporal direction. By contrast, OSA is positively associated with AMD. While potential confounding factors may contribute, obesity does not appear sufficient to explain this association.

Retina nerve fiber layer and choroidal thickness changes in obstructive sleep apnea syndrome

OBJECTIVES

The purpose of this study was to determine the effects of obstructive sleep apnea syndrome (OSAS) on the submacular and peripapillary retinal nerve fiber layer (RNFL) and choroidal thickness (ChT).

METHODS

Eighty-four eyes of 42 male patients with OSAS and 112 eyes of 56 aged-matched and body mass index-matched healthy male subjects were enrolled in this case-control study. The ChT and peripapillary RNFL thickness was measured using enhanced depth imaging optical coherence tomography. The ChT and RNFL thickness measurements of the groups were compared, and correlations among the Apnea Hypopnea Index (AHI) values and these measurements were calculated. Right and left eyes were separately evaluated.

RESULTS

There were no significant differences in the subfoveal and temporal ChT between the groups (p > 0.05). The OSAS group had significantly thicker ChT at 0.5 and 1.5 mm nasal to the fovea in both eyes than the control group (p < 0.05). The peripapillary ChT were significantly thicker in the OSAS group at all segments except for the temporal and superotemporal segments when compared with the control group (p < 0.05 for all quadrants except temporal and superotemporal). When compared with controls, the OSAS group had significantly thinner nasal RNFL thickness in the right eye (p = 0.01) and thinner mean RNFL thickness in both eyes (p < 0.001). Other RNFL thickness measurements were similar between groups (p > 0.05). Between AHI and mean RNFL thickness showed a median negative correlation (r = - 0.411, p = 0.001).

CONCLUSION

The choroidal thickening in patients with OSAS may be associated with the pathophysiology of the neurodegeneration process of the disease.

Choroidal thickness changes in obstructive sleep apnea syndrome: a systematic review and meta-analysis

PURPOSE

Obstructive sleep apnea syndrome (OSAS) is a common chronic disorder associated with hypoxia and endothelial and vascular dysfunction. Many studies have analyzed choroidal thickness measurements in patients with different severities of OSAS versus normal subjects by optical coherence tomography (OCT), but the results have been inconsistent. Therefore, a meta-analysis was performed to evaluate the choroidal thickness changes in OSAS measured by OCT.

METHODS

Pertinent studies were retrieved by a comprehensive search of PubMed, Embase, Web of Science, and the Cochrane Library from inception to August 2015. For continuous outcomes, the weighted mean difference (WMD) and 95 % confidence interval (CI) were calculated by using a random effects model.

RESULTS

Seven case-control studies were included in the final meta-analysis, containing a total of 784 eyes (558 in the OSAS group and 226 in normal controls). The results showed that subfoveal choroidal thickness (SFCT) was significantly reduced compared with normal controls, with pooled WMD -8.06 (95 % CI -15.72 to -0.41) for mild OSAS, -29.99 (95 % CI -52.40 to -7.58) for moderate OSAS, and -53.72 (95 % CI -88.95 to -18.48) for severe OSAS. Choroidal thickness at 1 mm temporal to the fovea and at 1 mm nasal to the fovea were also significantly lower than those in the normal controls (WMD = -28.94, 95 % CI -43.78 to -14.10 and WMD = -20.90, 95 % CI -36.62 to -5.18).

CONCLUSION

This meta-analysis suggests that choroidal thickness was reduced in OSAS. Considering the non-invasive nature of OCT, OCT could be a useful tool for grading the severity of OSAS.

Glaucoma and its association with obstructive sleep apnea: A narrative review

Obstructive sleep apnea (OSA) is one of the systemic risk factors for glaucoma which causes irreversible visual field (VF) damage. We reviewed the published data of all types of studies on the association between these two conditions and papers regarding functional and structural changes related to glaucomatous damage using Scopus, web of science, and PubMed databases. There is evidence that the prevalence of glaucoma is higher in OSA patients, which independent of intraocular pressure (IOP). Studies have reported thinning of retinal nerve fiber layer (RNFL), alteration of optic nerve head, choroidal and macular thickness, and reduced VF sensitivity in patients of OSA with no history glaucoma. A negative correlation of apnea-hypopnea index with RNFL and VF indices has been described in some studies. Raised IOP was noted which is possibly related to obesity, supine position during sleep, and raised intracranial pressure. Diurnal fluctuations of IOP show more variations in OSA patients before and after continuous positive airway pressure (CPAP) therapy when compared with the normal cases. The vascular factors behind the pathogenesis include recurrent hypoxia with increased vascular resistance, oxidative stress damage to the optic nerve. In conclusion, comprehensive glaucoma evaluation should be recommended in patients with OSA and should also periodically monitor IOP during CPAP treatment which may trigger the progression of glaucomatous damage.

Optic Nerve Dysfunction in Obstructive Sleep Apnea: An Electrophysiological Study

STUDY OBJECTIVES

The aim of this study was to evaluate the integrity of the visual system in patients affected by obstructive sleep apnea (OSA) by means of electroretinogram (ERG) and visual evoked potential (VEP).

METHODS

We performed electrophysiological study of the visual system in a population of severe OSA (apnea-hypopnea events/time in bed ≥ 30/h) patients without medical comorbidities compared to a group of healthy controls similar for age, sex, and body mass index. Patients and controls did not have visual impairment or systemic disorders with known influence on the visual system. ERG and VEP were elicited by a reversal pattern generated on a television monitor at low (55') and high (15') spatial frequencies stimulation. Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS) in both patients and controls.

RESULTS

In comparison with healthy controls (n = 27), patients with OSA (n = 27) showed a significant latency delay coupled with a significant amplitude reduction of P100 wave of VEP at all spatial frequencies in both eyes. No significant differences between groups were detected as concerning ERG components. No correlations were found between polygraphic parameters, ESS scores, or VEP and ERG components in OSA patients.

CONCLUSIONS

This study documented that patients with OSA, without medical comorbidities, present VEP alteration as documented by lower amplitude and longer latency of the P100 component than healthy controls. These altered electrophysiological findings may be the expression of optic nerve dysfunction provoked by hypoxia, acidosis, hypercarbia and airway obstruction, frequently observed in patients with OSA. Hence, we hypothesize that OSA per se may impair optic nerve function.

Effects of Use of a Continuous Positive Airway Pressure Device on Glaucoma

Background

The aim of this study was to investigate the prevalence of glaucoma in obstructive sleep apnea syndrome (OSAS) and to determine the efficacy of the equipment used in the treatment of this disease.

Material/Methods

In this cross-sectional study, 38 patients with OSAS used the continuous positive airway pressure (CPAP) device (Group 1) and 32 patients with OSAS refused CPAP device (Group 2). Thirty-six patients did not have OSAS (Group 3).

Results

Patient age, gender, height, weight, and neck circumference did not differ among groups (p>0.05); and the apnea-hypopnea index (AHI) and respiratory disturbance index (RDI) values did not differ between Groups 1 and 2 (p>0.05). Vision and pachymetric values did not differ among groups (p>0.05). The IOP was significantly higher in Group 2 than in Group 1 (p<0.05) but did not differ between Groups 1 and 3 (p>0.05). The fundus C/D ratio was significantly higher (p<0.05) in Group 2 than in the other groups but did not differ between Groups 1 and 3 (p>0.05). In Group 1, 2, and 3, 5.2%, 12.5%, and 0%, respectively, of patients had glaucoma.

Conclusions

OSAS should be considered a significant risk factor for glaucoma. Eye tests may help to identify individuals with undiagnosed OSAS, and such testing of patients with diagnosed OSAS may allow early detection of glaucoma and referral of such patients for CPAP therapy to prevent development of complications.

New directions in the treatment of normal tension glaucoma

Glaucoma is a progressive optic neuropathy that causes characteristic changes of the optic nerve and visual field in relation to intraocular pressure (IOP). It is now known that glaucoma can occur at statistically normal IOPs and prevalence studies have shown that normal tension glaucoma (NTG) is more common than previously thought. While IOP is believed to be the predominant risk factor in primary open angle glaucoma (POAG), IOP-independent risk factors, such as vascular dysregulation, are believed to play an important part in the pathogenesis of NTG. Though certain distinguishing phenotypic features of NTG have been reported, such as an increased frequency of disc hemorrhages, acquired pits of the optic nerve and characteristic patterns of disc cupping and visual field loss, there is much overlap of the clinical findings in NTG with POAG, suggesting that NTG is likely part of a continuum of open angle glaucomas. However, IOP modification is still the mainstay of treatment in NTG. As in traditional POAG, reduction of IOP can be achieved with the use of medications, laser trabeculoplasty or surgery. Studies now show that the choice of medication may also be important in determining the outcomes of these patients. Though it is likely that future treatment of NTG will involve modification of both IOP and IOP-independent risk factors, current efforts to develop IOP-independent neuroprotective treatments have not yet proven to be effective in humans.

[Prevalence of glaucoma in obstructive sleep apnea]

BACKGROUND

A causal relationship between glaucoma and obstructive sleep apnea has been postulated in several clinical studies but also refuted by others. The aim of this study was to determine the prevalence of glaucoma in a cohort of patients with well-established obstructive sleep apnea in comparison to the published data on this topic.

METHODS

A total of 100 consecutive patients (male:female  80:20, mean age 59 ± 11 years SD) with polysomnographically established obstructive sleep apnea underwent an ophthalmological examination including tonometry, static perimetry and dilated fundus photography. Visual fields and fundus photographs of the patients were classified as glaucomatous or non-glaucomatous by two independent examiners.

RESULTS

The prevalence of glaucoma in the study patients was 2 % which corresponded to the published prevalence of glaucoma in the normal population. Intraocular pressure did not correlate with the respiratory index, body mass index or sex.

CONCLUSION

The data from this study shed doubt on a causal relationship between obstructive sleep apnea and glaucoma.

Association between glaucoma and obstructive sleep apnea syndrome: a meta-analysis and systematic review

Background

Obstructive sleep apnea syndrome (OSAS) is a common disease that increases the risk of diabetes, heart disease, and stroke. However, studies of an association between OSAS and glaucoma neuropathy have reported controversial findings.

Objective

The main purpose of this study was to evaluate whether a significant association exists between OSAS and glaucoma by performing a meta-analysis of previous studies.

Methods

A comprehensive literature search using the PubMed and Embase databases was performed to identify cross-sectional, case-control, and cohort studies related to the topic. We estimated a pooled odds ratio (OR) for the association between OSAS and glaucoma, by a fixed- or random-effects model.

Results

In total, 16 studies with 2,278,832 participants met the inclusion criteria: one retrospective cohort study reported an adjusted hazard ratio of glaucoma of 1.67 (95% CI = 1.30–2.17). Using a fixed-effects model, the pooled OR of six case-control studies was 1.96 (95% CI = 1.37 2.80). A significant association was also identified in a meta-analysis of nine cross-sectional studies using a random-effects model, which showed a pooled OR of 1.41 (95% CI = 1.11 1.79). However, the reported pooled estimates for case control studies and cross-sectional studies were based on unadjusted ORs.

Conclusions

Our results suggest that OSAS is associated with the prevalence of glaucoma. However, this result was based only on unadjusted estimates. Prospective cohort studies designed to take into consideration potential confounders, or examination of data from interventional trials to determine whether a reduction in OSAS status is associated with a reduced incidence of glaucoma, are needed to clarify whether OSAS is an independent risk factor for glaucoma.

Obstructive sleep apnea and optic neuropathy: is there a link?

Over the last decade, there has been an emerging interest in the link between obstructive sleep apnea (OSA) and ocular health. Though the evidence for OSA playing a role in cerebrovascular disease risk seems clear, the same cannot be said for optic neuropathies. The association between OSA and glaucoma or non-arteritic anterior ischemic optic neuropathy (NAION) has been postulated to be secondary to direct hypoxia or mechanisms of optic nerve head vascular dysregulation. Papilledema and increased intracranial pressure have also been reported in OSA and are thought to be due to increased cerebral perfusion pressure and cerebral venous dilation secondary to hypoxia and hypercapnia. This article reviews the evidence for possible pathophysiological links between OSA and optic nerve pathology. The epidemiologic and clinical evidence for an association, direct or indirect, between OSA and glaucoma, non-arteritic anterior ischemic optic neuropathy (NAION), and papilledema or idiopathic intracranial hypertension is presented.

Long-term effects of PAP on ocular surface in obstructive sleep apnea syndrome

OBJECTIVE

To assess the long-term effects of positive airway pressure (PAP) therapy on the ocular surface and eyelid in patients with obstructive sleep apnea hypopnea syndrome (OSAHS).

DESIGN

Single-centred, prospective, and double-blinded study.

PARTICIPANTS

Fifty-one patients with OSAHS.

METHODS

Fifty-one patients with OSAHS were treated with PAP for a period of 18 months. The pre- and post-PAP values for eye examination scores (presence of floppy eyelid syndrome [FES], results of the Ocular Surface Disease Index [OSDI] questionnaire, Schirmer I test, tear film break-up time [TBUT] values, and corneal staining stages) were compared.

RESULTS

Based on the apnea-hypopnea index, 17 patients were followed with moderate and 34 patients were followed with severe OSAHS. The presence of FES before and after PAP was 56.9% and 74.5% (p < 0.01). FES stage was determined as 1.41 ± 0.98 before PAP and 0.78 ± 0.78 after PAP (p < 0.01). Pre-PAP and post-PAP OSDI results were 47.79 ± 21.04 and 42.17 ± 19.97, respectively (p < 0.01). Schirmer values before and after PAP were 7.23 ± 1.95 and 8.49 ± 1.79 mm, respectively (p < 0.01). TBUT values before and after PAP were 7.11 ± 1.82 and 8.68 ± 1.76 seconds, respectively (p < 0.01). Scores of the corneal staining stages before and after PAP were 1.05 ± 0.75 and 0.68 ± 0.54, respectively (p < 0.01).

CONCLUSIONS

OSAHS is associated with low Schirmer and TBUT values, and high scores in OSDI questionnaire, and high corneal staining stage. An appropriate PAP therapy helps to relieve both the systemic findings and the ocular surface problems most likely by providing a return to normal sleep patterns. We believe that long-term (at least 1 year) use of PAP improves the clinical picture of FES and can overcome the problem of ocular irritation that is encountered in the early stage of PAP.

Prevalence of glaucoma in patients with moderate to severe obstructive sleep apnea: ocular morbidity and outcomes in a 3 year follow-up study

PURPOSE

This study was conducted to investigate the prevalence and progression of glaucoma in patients receiving treatment for obstructive sleep apnea (OSA). We also investigated whether there is an association between severity of OSA and the incidence of glaucoma.

METHODS

A total of 39 patients aged >30 years who had been diagnosed with moderate and severe OSA in the sleep clinic at Hamad General Hospital were assessed for the presence of glaucoma. The severity of OSA was graded as mild, moderate, or severe based on American Association of Sleep Medicine (AASM) criteria using the apnea hypopnea index. Before enrollment, all patients underwent a complete ophthalmic examination including serial visual field tests, optical coherence tomography (OCT) with fundus photographs, and pachymetry. Enrolled patients were followed up in the ophthalmology outpatient clinic and sleep clinic for a period of 3 years.

RESULTS

Examinations found that 8 (20.5%; 95% confidence interval (CI) 9.9-37%) of the 39 patients with OSA had glaucoma. Six (75%; 95% CI 36-96%) of these patients had normal-tension glaucoma (NTG) and two (25%; 95% CI 4.5-64.4%) patients had high-tension glaucoma. Among the 27 patients with severe OSA, 7 (25.9%; 95% CI 8-34%) had glaucoma, and among 12 patients with moderate OSA, 1 (8.3%; 95% CI 0.1-15%) had glaucoma. During the course of follow-up, two patients who previously did not have glaucoma were reclassified as NTG and two patients with glaucoma deteriorated. A higher prevalence of glaucoma in the severe OSA group compared with the moderate OSA group was found, albeit a statistically significant difference could not be attained (P=0.4).

CONCLUSIONS

Our study showed that severe OSA is an important risk factor for developing glaucoma. Adequate treatment of OSA, along with optimal ophthalmic care, resulted in better control of glaucoma.

Obstructive sleep apnea patients having surgery are less associated with glaucoma

Objective. To investigate if different treatment strategy of obstructive sleep apnea (OSA) was associated glaucoma risk in Taiwanese population. Methods. Population-based retrospective cohort study was conducted using data sourced from the Longitudinal Health Insurance Database 2000. We included 2528 OSA patients and randomly selected and matched 10112 subjects without OSA as the control cohort. The risk of glaucoma in OSA patients was investigated based on the managements of OSA (without treatment, with surgery, with continuous positive airway pressure (CPAP) treatment, and with multiple modalities). The multivariable Cox regression was used to estimate hazard ratio (HR) after adjusting for sex, age, hypertension, diabetes, hyperlipidemia, and coronary artery disease. Results. The adjusted HR of glaucoma for OSA patients was 1.88 (95% CI: 1.46–2.42), compared with controls. For patients without treatment, the adjusted HR was 2.15 (95% CI: 1.60–2.88). For patients with treatments, the adjusted HRs of glaucoma were not significantly different from controls, except for those with CPAP (adjusted HR = 1.65, 95% CI = 1.09–2.49). Conclusions. OSA is associated with an increased risk of glaucoma. However, surgery reduces slightly the glaucoma hazard for OSA patients.

Changes in choroidal thickness in patients with obstructive sleep apnea syndrome

BACKGROUND AND OBJECTIVE

To evaluate choroidal thickness using spectral-domain optical coherence tomography (SD-OCT) in patients with obstructive sleep apnea syndrome (OSAS) in comparison to healthy controls.

PATIENTS AND METHODS

This observational, comparative study consisted of 35 patients with OSAS and 32 age- and sex-matched controls. The controls did not have systemic or ocular diseases. All study participants underwent complete ophthalmic examination as well as choroidal thickness measurement using a high-speed, high-resolution SD-OCT device.

RESULTS

The mean horizontal and vertical choroidal thicknesses, respectively, were 237.84 ± 69.9 μm and 234.97 ± 62.0 μm (P = .654) in patients with OSAS and 244.09 ± 41.2 μm and 241.88 ± 40.9 μm (P = .590) in the healthy controls. The mean choroidal thicknesses were thinner in patients with OSAS, but the difference was not significant (P > .05 for all values).

CONCLUSION

No differences in choroidal thickness were found between patients with OSAS and healthy controls.

Relationship between severity of obstructive sleep apnea syndrome and retinal nerve fiber layer thickness

PURPOSE

To determine whether there is a significant correlation among the peripapillary retinal nerve fiber layer (RNFL) thickness, foveal thickness, total macular volume, and severity of obstructive sleep apnea syndrome.

DESIGN

Prospective study.

METHODS

We studied 124 consecutive subjects who underwent polysomnography. Optical coherence tomography (OCT) was used to measure the peripapillary RNFL, foveal thickness, and total macular volume. The Pearson correlation coefficient was used to determine the relationship between the apnea-hypopnea index and OCT and other parameters. Multiple regression analysis was used to determine the independent factors for the RNFL sectors that were the most strongly correlated with the apnea-hypopnea index.

RESULTS

The apnea-hypopnea index was significantly and negatively correlated (right eye, r = -0.31, P = 0.0004; left eye, r = -0.39, P < 0.0001) with the nasal RNFL thickness (Pearson correlation analysis). The foveal thickness and total macular volume were not correlated. The intraocular pressure, body mass index, plaque score, and incidence of hypertension were negatively correlated, and the lowest oxygen saturation and mean oxygen saturation were positively correlated with the nasal RNFL thickness in the left eye. Multiple regression analysis showed that the apnea-hypopnea index and age were independent contributors to the nasal RNFL thickness in the left eye (apnea-hypopnea index, standard regression coefficient, -0.30, t value, -2.76, P = 0.007; age, -0.24, -2.36, 0.02, respectively). The nasal RNFL thickness in both eyes decreased significantly based on the severity of the obstructive sleep apnea syndrome.

CONCLUSION

Exacerbation of obstructive sleep apnea syndrome may produce unique retinal neurodegenerative disorders that decrease the nasal RNFL thickness.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) and glaucomatous optic neuropathy

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is becoming widely accepted as a risk factor for glaucoma. We discuss the proposed mechanism involved in the pathogenesis of glaucoma in OSAHS, and review the published data on the association between these two conditions, as well as papers regarding functional and structural tests related with glaucomatous damage. There is increasing evidence that the prevalence of glaucoma is higher in OSAHS patients, especially in those with severe disease with apnea-hypopnea index (AHI) >30, and also that sleep disorders may be more frequent in patients with glaucoma, especially in those with normal tension glaucoma (NTG). Several ophthalmic signs and symptoms have been associated with this condition. Raised intraocular pressure (IOP), possibly related to increased body mass index, thinning of retinal nerve fiber layer (RNFL), and alteration of visual field (VF) indices has been demonstrated in many studies, in patients with no history of glaucoma or evidence of glaucomatous changes in the ophthalmic examination. A correlation of AHI with RNFL and VF indices has been described in some studies. Finally, corneal thinning, suspicious glaucomatous disc changes and anomalies in electrophysiological tests such as multifocal visual evoked potential have been described in patients with OSAHS, even in patients with normal findings in the optic nerve and VF, suggesting subclinical optic nerve involvement not detectable in conventional ophthalmic examinations. The pathogenesis of optic nerve involvement has been related to vascular and mechanical factors. Vascular factors include recurrent hypoxia with increased vascular resistance, autonomic deregulation, oxidative stress and inflammation linked to hypoxia and subsequent reperfusion, decreased cerebral perfusion pressure and direct hypoxic damage to the optic nerve. Proposed mechanical factors include increased IOP at night related to supine position and obesity, raised intracranial pressure and elastic fiber depletion in the lamina cribosa and/or trabeculum. In conclusion, ophthalmic evaluation should be recommended in patients with severe OSAHS, and the presence of sleep disorders should be investigated in patients with glaucoma, especially in NTG patients and in those with progressive damage despite controlled IOP, as treatment with continuous positive airway pressure may contribute to stabilizing the progression of glaucomatous damage.

Normal-tension glaucoma and obstructive sleep apnea syndrome: a prospective study

BACKGROUND

Today, identified risk factors for normal-tension glaucoma (NTG) include abnormal ocular blood flow, abnormal blood coagulation, systemic hypotension, ischemic vascular disorders, and autoimmune diseases. However, pathogenesis of the condition remains unclear. On the other hand, there are also a few studies suggesting that the obstructive sleep apnea syndrome (OSAS) may compromise optic nerve head perfusion and cause glaucomatous optic neuropathy by creating transient hypoxemia and increasing vascular resistance. In this study, we evaluated the possible association between OSAS and NTG.

METHODS

We recruited 24 patients with NTG and 24 age and sex matched controls who were also similar for systemic risk factors such as diabetes mellitus (DM), hypertension (HT) and hypercholesterolemia. All patients and controls underwent over-night polysomnography (PSG) for the diagnosis of OSAS and calculation of Apnea-Hypopnea Index (AHI).

RESULTS

Patients and controls were statistically similar in terms of age, sex, gender, smoking, systemic risk factors, neck circumference and body mass index. The subjects with AHI ≥ 20 were accepted as OSAS. Ten (41.7%) of 24 patients with NTG and 3 (12.5%) of 24 controls had OSAS (p < 0.05).

CONCLUSIONS

The prevalence of OSAS was higher in patients with NTG and the difference between patient and control groups was statistically significant (p < 0.05).

The evaluation of retinal nerve fiber layer thickness in patients with obstructive sleep apnea syndrome

Aim. To evaluate the retinal nerve fiber layer (RNFL) thickness in patients with obstructive sleep apnea syndrome (OSAS) by optical coherence tomography (OCT). Materials and Method. We studied 43 new diagnosed OSAS patients and 40 healthy volunteers. Patients underwent an overnight sleep study in an effort to diagnose and determine the severity of OSAS. RNFL analyses were performed using Stratus OCT. The average and the four-quadrant RNFL thickness were evaluated. Results. There was no difference between the average and the four-quadrant RNFL thickness in OSAS and control groups. There was no correlation between apnea-hypopnea index and intraocular pressure. Body mass index of patients with moderate and severe OSAS was significantly higher in patients with mild OSAS. Conclusion. Mean RNFL thickness did not differ between the healthy and the OSAS subjects, however, the parameters were more variable, with a larger range in OSAS patients compared to controls.

The assessment of sleep apnoea as a risk factor in glaucoma

BACKGROUND

The risk of developing open angle glaucoma increases in the presence of associated disorders such as hypertension, Diabetes mellitus and migraine. In recent years, sleep apnoea is also being investigated as a risk factor in the development of open angle glaucoma.

AIM

To ascertain the significance of sleep apnoea as a risk factor in patients with glaucoma. Study Setting and Design: A non - randomised, cross sectional study was undertaken at an urban teaching hospital.

MATERIAL AND METHOD

A sleep disturbance questionnaire and the Epworth sleepiness scale were used to screen the potential cases of sleep apnoea amongst 40 glaucomatous subjects, with both Primary Open Angle Glaucoma (POAG) and Normotensive Glaucoma (NTG), as well as 40 controls. Those which gave a positive response to the questionnaire were subjected to poly-somnography for the diagnosis of sleep apnoea, with the calculation of the Apnoea Hypopnoea Index. The data was analysed by using the Chi - square test and the odds ratio calculations.

RESULTS

Positive responses to the sleep apnoea questionnaire were obtained from a total of twenty participants, 16 (40%) from the glaucoma Group and four (10%) were obtained from the control Group. In the glaucoma Group, ten (37.03%) of the 27 POAG individuals, and six (46.15%) of the 13 NTG cases showed significant positive responses to the questionnaire. Four subjects (10%) (1POAG, 3 NTG) from the glaucoma Group and one (2.5%) from the control Group were diagnosed to have sleep apnoea by polysomnography. The percentage of the sleep apnoea positive cases was higher among the NTG subjects (23.07%) than among the POAG subjects (3.7 %). This study had an odds ratio of 4.333 (>1) and a p value of 0.382.

CONCLUSION

Although the odds ratio was significant, this study did not find the association between sleep apnoea and glaucoma to be statistically significant.

Optic disc and retinal nerve fiber layer parameters as indicators of neurodegenerative brain changes in patients with obstructive sleep apnea syndrome

PURPOSE

Retina is a unique part of the central nervous system (CNS) for visualizing the processes of axonal and neuronal degeneration. Optical coherence tomography (OCT) allows direct visualization and measurement of retinal nerve fiber layer (RNFL) thickness, macular volume, and optic disc (OD) parameters. One of the disorders associated with atrophy in different brain regions is obstructive sleep apnea syndrome (OSAS). In the present study, we aimed to determine OD and RNFL changes measured by OCT for investigating the progress of neurodegeneration development in OSAS, excluding all the other conditions that can directly affect RNFL thickness and optic nerve parameters.

METHODS

Both eyes of 101 patients with OSAS and 20 controls were investigated by OCT. Full-night polysomnography (PSG) and ophthalmologic examination including automated visual field (VF) examination and OCT were performed in all of the patients.

RESULTS

According to the OSAS grading, patients were grouped as mild (n=15), moderate (n=27), and severe (n=59). We found significant decrease in RNFL thickness only in the patients with severe OSAS compared with the other groups and decreased macular ganglion cell thickness in the severe OSAS group compared with the control group. VF parameters were significantly worsened in all the OSAS subgroups compared to the control group. We found different data such as normal or increased optic nerve parameters as result of subtle OD edema, which may mask possible peripapillar axonal loss.

CONCLUSIONS

We think that evaluation of neurodegeneration in OSAS is not always possible by examining OD and RNFL because there are difficulties due to the confounding issues of cerebral atrophy and OD edema.

Changes in the circadian rhythm in patients with primary glaucoma

Purpose

The current study was undertaken to investigate whether glaucoma affects the sleep quality and whether there is any difference between patients with primary glaucoma (primary open angle glaucoma, POAG and primary angle-closure glaucoma, PACG) and healthy subjects, using a validated self-rated questionnaire, the Pittsburgh Sleep Quality Index (PSQI).

Methods

The sleep quality of patients with POAG and PACG was tested against normal controls. Subjects were divided into three sub-groups according to age. Differences in the frequency of sleep disturbances (PSQI score >7) were assessed. The differences of sleep quality within the three groups and within the POAG group depending on the patients’ intraocular pressure (IOP) and impairment of visual field (VF) were also studied.

Results

92 POAG patients, 48 PACG patients and 199 controls were included. Sleep quality declined with age in control and POAG group (tendency chi-square, P<0.05). The prevalence of sleep disturbances was higher in POAG and PACG group than in the control group, the differences were statistically significant. The prevalence of sleep disturbances was higher in patients with PACG, compared to POAG patients in the age interval of 61–80. In POAG group, the ratio of patients with sleep disorders increased with augmented impairment of VF, but the differences were not statistically significant (χ²-test, P>0.05). No significant differences were found in POAG group between patients with a highest IOP in daytime and at nighttime (χ²-test, P>0.05).

Conclusions

The prevalence of sleep disorders was higher in patients with POAG and PACG than in controls. PACG patients seemed to have a more serious problem of sleep disorders than POAG patients between 61 to 80 years old. No correlation was found between the prevalence of sleep disorders and impairment of VF or the time when POAG patients showed a highest IOP.

Retinal nerve fiber thickness is reduced in sleep apnea syndrome

OBJECTIVE

To investigate the prevalence of glaucoma, visual field abnormalities, as well as changes in retinal 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⩾30), moderate (15⩽AHI<30), and mild (5⩽AHI<15) OSAS, respectively. The control group was matched for age, sex and body mass index. Prevalence 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)>21mmHg; of these, four eyes (3.9%) had glaucoma. 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 difference between groups in MD and most GDx parameters including DISK (temporal-superior-nasal-inferior-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.

The effect of continuous positive airway pressure treatment for obstructive sleep apnea syndrome on the ocular surface

PURPOSE

To evaluate the effect of continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea syndrome on the ocular surface.

METHODS

This is a prospective, sectional cohort study of 80 eyes of 40 patients diagnosed with obstructive sleep apnea syndrome. Routine ophthalmologic examination and ocular surface evaluation, including biomicroscopy, Schirmer 1 testing, tear break-up time measurement, ocular surface staining, and conjunctival impression cytology, were performed in both of each patient's eyes before and 4 months after starting CPAP therapy.

RESULTS

After CPAP therapy, increases in squamous metaplasia (Nelson classification: t = 0.34, P = 0.014) and Schirmer 1 score (t = 3.20, P = 0.008), and decreases in tear break-up time (t = -1.38, P = 0.008) in the right eyes were statistically significant, as compared with the pretreatment values. Although these parameters changed in a similar fashion in the left eyes, differences between the pre-CPAP and post-CPAP values were not significant.

CONCLUSIONS

The findings indicate that CPAP therapy increased ocular irritation, tear evaporation, and squamous metaplasia in the conjunctiva of the patients' right and left eyes. Although the parameters measured were similar in both eyes before CPAP therapy, these parameters changed significantly after CPAP therapy only in the right eyes. The observed differences between the right and left eyes require further investigation to determine the possible effects of sleeping position, CPAP mask displacement, and the other factors involved.

Ocular surface assessment in patients with obstructive sleep apnea-hypopnea syndrome

PURPOSE

The aim of this study was to assess the correlation between ocular surface changes and disease severity in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

Two hundred eighty patients with OSAHS were compared with respect to the presence of a floppy eyelid syndrome (FES), Ocular Surface Disease Index (OSDI) questionnaire, the corneal fluorescein staining stages, the Schirmer I test, and tear film break-up time (TBUT) values.

RESULTS

Based on the apnea-hypopnea index, the presence of FES was detected at the following rates: 23.1 % in non-OSAHS group (A), 41.7 % in mild group (B), 66.7 % in moderate group (C), and 74.6 % in severe group (D); severe and moderate stage of FES was found in groups C and D and mild stage of FES in group B (p < 0.01). OSDI questionnaire values were as follows: group A, 12.57 ± 17.64; group B, 22.90 ± 16.78; group C, 45.94 ± 22.03; and group D, 56.68 ± 22.85(p < 0.01). Schirmer values were as follows: group A, 10.76 ± 3.58 mm; group B, 9.83 ± 2.53 mm; group C, 7.73 ± 2.42 mm; and group D, 6.97 ± 2.15 mm (p < 0.01). The TBUT values were as follows: group A, 10.53 ± 3.64 s; group B, 9.46 ± 2.40 s; group C, 7.29 ± 2.13 s; and group D, 6.82 ± 2.20 s (p < 0.01). Corneal staining scores are as follows: 0.26 ± 0.60 in group A, 0.40 ± 0.71 in group B, 0.98 ± 0.72 in group C, and 1.14 ± 0.90 in group D, and the differences were statistically significant among the groups(p < 0.01).

DISCUSSION

OSAHS, particularly the moderate and severe forms, is associated with low Schirmer and TBUT values and high scores in OSDI questionnaire and corneal staining pattern stage. The presence of FES is observed as a practically constant finding in OSAHS. If complaints such as burning, stinging, and itching which can be commonly observed in middle-aged patients are accompanied by FES, the patient should be evaluated for sleep disorders. We speculate that appropriate treatment of OSAHS may result in better control of these symptoms.

Ophthalmic features of systemic diseases

The eye is intricately integrated with the functions of the body. Ocular changes may precede or run concurrently with various systemic conditions and often represent important prognostic indicators of disease progression. In addition to a thorough diagnostic evaluation and treatment of underlying processes, individuals with systemic diseases and concurrent ocular changes may need comprehensive ophthalmic examination to reduce the risk of visual impairment and morbidity. In this review the authors highlight the clinically relevant ocular signs that occur parallel with systemic conditions. In particular, the study focuses on the varied clinical presentations that can lead to rapid diagnosis to improve management of eye disorders that accompany systemic diseases.

Glaucoma and obstructive sleep apnoea syndrome

Glaucoma is increasingly recognized as a manifestation of both ocular and systemic risk factors. A number of disorders associated with reduced blood flow and ischaemia, collectively termed vascular risk factors, such as migraine, Raynaud's phenomenon, atrial fibrillation and reduced nocturnal blood pressure, lead to decreased ocular perfusion pressure. During sleep, alterations occur in cardiovascular physiology that are balanced by autoregulation to maintain homeostasis. However, in obstructive sleep apnoea (OSA), the normal physiological balance is upset. A potentially modifiable risk factor, OSA has been increasingly associated with glaucoma independent of intraocular pressure. OSA may alter blood flow to the optic nerve head and, in combination with other predisposing factors, lead to decreased ocular perfusion pressure. This in turn may directly affect the optic nerve or it may indirectly increase its susceptibility to other insults. The purpose of this review is to shed light on the association between OSA and glaucoma.

Evaluation of the visual function in obstructive sleep apnea syndrome patients and normal-tension glaucoma by means of the multifocal visual evoked potentials

BACKGROUND

This study was designed to objectively evaluate visual function and the causal relationship between sleep apnea and optic nerve dysfunction in patients with obstructive sleep apnea syndrome (OSAS) with or without diagnosis of normal-tension glaucoma (NTG) using multifocal visual evoked potentials (mfVEP).

METHODS

This observational, cross-sectional study assessed 20 patients with recently diagnosed OSAS with or without NTG. Diagnosis of sleep apnea was based on overnight polysomnography (ApnoeScreen). All participants underwent a complete physical and ophthalmologic examination. MfVEP recordings obtained using VERIS software (Electro-Diagnostic Imaging, San Mateo, USA), SITA-standard 30-2 automated perimetry (Humphrey Visual Field Analyzer II) and optic coherence tomography (Topcon 3D OCT-1000) exams were performed to evaluate the changes.

RESULTS

Abnormal mfVEP amplitudes defects (interocular and monocular probability analysis) were found in 40% of the eyes in the non-glaucoma group and in 90% of eyes of the NTG patients. As well, delayed mfVEP latencies (interocular and monocular probability analysis) were seen in 30 and 60% of the eyes of the non-glaucoma and NTG groups, respectively. The average RNFL (retinal nerve fiber layer) thickness was significantly reduced in the NTG eyes compared to the control database and the non-glaucoma eyes. On the Humphrey Visual Field total deviation analysis, all the NTG eyes showed significant clusters of abnormal points but none was detected in the non-glaucoma group eyes. However, the mfVEP amplitude and latency did not show any significant correlation with the standard perimetry and OCT variables, because the mfVEP technique was able to detect far more early visual defects in these patients. Systolic blood pressure, sleep efficiency, arousal index, mean and minimum arterial oxygen saturation (SaO(2)), time SaO(2) < 90%, oxyhemoglobin desaturation index, number of central and mixed apneas and apnea-hipopneas index were shown to be significantly correlated with mfVEP amplitude and latency.

CONCLUSIONS

A significant incidence of subclinical optic nerve involvement, not detected with other structural and psychophysics diagnostic techniques was seen by means of the mfVEP. In this sense, the mfVEP may be a useful diagnostic tool in the clinic for early diagnosis and monitoring of optic nerve function abnormalities in patients with OSAS.

The association between glaucomatous and other causes of optic neuropathy and sleep apnea

PURPOSE

To determine whether an association exists between sleep apnea and open-angle glaucoma, normal-tension glaucoma, nonarteritic ischemic optic neuropathy (NAION), papilledema, or idiopathic intracranial hypertension (IIH) and whether treatment with continuous positive airway pressure affects the development of these conditions.

DESIGN

Retrospective, longitudinal cohort study.

METHODS

Billing records for beneficiaries 40 years of age and older enrolled in a large United States managed care network from 2001 through 2007 were reviewed. Incidence of open-angle glaucoma, normal-tension glaucoma, NAION, papilledema, and IIH were determined for the beneficiaries and were stratified by sleep apnea status. Cox regression analyses determined the hazard of each of these conditions developing among individuals with and without sleep apnea, with adjustment for sociodemographic, ocular, and medical conditions.

RESULTS

Among the 2 259 061 individuals in the study, 156 336 (6.9%) had 1 or more sleep apnea diagnoses. The hazard of open-angle glaucoma was no different among persons with sleep apnea either treated (adjusted hazard ratio [HR], 0.99; 95% confidence interval [CI], 0.82 to 1.18) or untreated with continuous positive airway pressure (HR, 1.01; 95% CI, 0.98 to 1.05) and individuals without sleep apnea. Similar findings were observed when assessing the hazard of normal-tension glaucoma developing (P > .05 for both comparisons). A significantly increased hazard of NAION developing (HR, 1.16; 95% CI, 1.01 to 1.33) and IIH (HR, 2.03; 95% CI, 1.65 to 2.49) was observed among individuals with sleep apnea who were not receiving continuous positive airway pressure therapy as compared with individuals without sleep apnea, although similar increased risks could not be demonstrated among continuous positive airway pressure-treated sleep apnea patients for these conditions (P > .05 for both comparisons).

CONCLUSIONS

Patients with untreated sleep apnea are at increased risk for IIH and NAION. Clinicians should consider appropriate screening for these conditions in sleep apnea patients.

Sleep apnea syndrome represents a risk for glaucoma in a veterans' affairs population

Purpose. To determine whether the diagnosis of sleep apnea syndrome (SAS) represents a risk-factor for glaucoma. Design. Retrospective records review. Methods. Records in an electronic database which exists at the Birmingham, Alabama Veterans' Affairs Medical Center (BVAMC) permit data retrieval and sorting based on diagnostic and procedural codes. Deidentified data of those having had an eye examination and a diagnostic code (ICD-9) for either sleep apnea or glaucoma were included. Statistical Analyses. SPSS version 19 was used to produce crosstabs and to conduct a bivariate logistic regression that examined the relationship between SAS and glaucoma. Results. A total of 70,960 unique records were included for analysis. Of the 2,725 patients with a diagnosis of sleep apnea, 228 (8.37%) also had a diagnosis of glaucoma. Diagnosis of glaucoma was present in 3,410 patients among 68,235 patients (5.00%) without sleep apnea. Bivariate logistic regression analysis yielded an odds ratio of 1.736 (P < 0.001) suggesting that individuals with SAS are more likely to have a coexisting diagnosis of glaucoma than individuals without SAS. Conclusions. Results of this investigation suggest that SAS may represent a significant risk factor for glaucoma and this should be considered when managing patients who report that diagnosis.

[Glaucoma and sleep apnea syndrome]

Glaucomatous optic neuropathy is multifactorial, with currently one known and modifiable risk factor, with good results on the prognosis and intraocular pressure. Nevertheless, some patients may experience progression of their neuropathy even though their intraocular pressure seems appropriately controlled. Vascular risk factors are hypothesized and researched. Obstructive sleep apnea syndrome (OSAS) could be considered one of these risk factors. Screening for this cardiovascular risk factor in glaucomatous patients presenting evocative signs, should be proposed.

Pulsatile ocular blood flow in subjects with sleep apnoea syndrome

INTRODUCTION

The aim of the study was to determine the correlation between pulsatile ocular blood flow (POBF) and sleep apnoea syndrome (SAS).

MATERIAL AND METHODS

Patients were recruited from those who underwent polysomnography in the "Sleep Unit" of the physiology department (Medical University, Lodz, Poland). A total of 52 Caucasian patients, 34 with SAS and 18 age- and gender-matched controls, were included in the study. Comprehensive ophthalmic examination included the pulsatile ocular blood flow (POBF) measurements, disc analysis with Heidelberg Retina Tomograph II and Oculus Centerfield computerized perimetry as well as the best visual acuity, a slit lamp and indirect ophthalmoscopic evaluation of anterior and posterior segments and applanation tonometry.

RESULTS

The observed prevalence of glaucoma in SAS patients was 5.9% (2 of 34). The mean values of POBF were 1069.21 ±235.94 µl/min in the SAS group and 1061.78 ±174.63 µl/min in the control group. The study revealed that the differences of mean POBF between the SAS patients and the control group were not statistically significant: Mann-Whitney U-test p > 0.05. No correlations were found between sleep apnoea syndrome and mean intraocular pressure (IOP), mean retinal nerve fibre layer (RNFL) thickness and visual field mean defect (MD).

CONCLUSIONS

No correlation was found between pulsatile ocular blood flow and sleep apnoea syndrome. Although some previous studies found an association between IOP, MD, RNFL thickness and sleep apnoea syndrome, our study did not confirm that. However, a high prevalence of glaucoma was found among SAS patients in Poland.

Decreased retinal nerve fiber layer thickness in patients with obstructive sleep apnea/hypopnea syndrome

BACKGROUND

To compare parameters for retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) measurements, and macular thickness in patients with different severities of obstructive sleep apnea/hypopnea syndrome (OSAHS) versus normal controls.

METHODS

Patients presenting with snoring and daytime sleepiness who underwent overnight polysomnography to determine OSAHS severity were recruited, and subsequently referred for ophthalmologic evaluation. Optical coherence tomography was used to evaluate the retinal nerve fiber layer (RNFL), optic nerve head topography, and macular thickness for early detection of glaucoma. Patients determined not to have OSAHS were included as controls.

RESULTS

A total of 127 subjects were recruited, including 105 patients with OSAHS and 22 normal control subjects. RNFL thickness was significantly lower for the severe OSAHS group than for the control and mild OSAHS groups in the average (p < 0.0001) and in the superior quadrant (p = 0.0007). When subjects without OSAHS or with mild disease (AHI < 15) were grouped together and compared with patients with moderate/severe OSAHS (AHI ≧ 15), RNFL thickness measurements for the latter group were significantly lower in the average (p < 0.0001), and in the superior (p = 0.001), inferior (p = 0.029), and temporal (p = 0.007) quadrants. Positive correlations were identified between lowest oxygenation saturation on PSG and RNFL thickness in the average (r = 0.260), superior (r = 0.200) and nasal (r = 0.156) quadrants.

CONCLUSIONS

Compared to patients without OSAHS or those with mild disease, RNFL thickness was lower in patients with moderate/severe OSAHS. Lowest saturation of oxygen in the moderate/severe OSAHS group correlated with decreased RNFL thickness. Patients with moderate and severe OSAHS are at increased risk for glaucoma.

Multiplex cytokine analysis reveals elevated concentration of interleukin-8 in glaucomatous aqueous humor

PURPOSE

To test the hypothesis that immune activation occurs in glaucoma by comparing concentrations of multiple cytokines in aqueous humor (AH) from patients with primary open angle glaucoma (POAG) and from cataract patients without glaucoma as controls.

METHODS

Cytokine concentrations in AH obtained during surgery were measured using microparticle-based immunoassays. Localized expression of IL-8 protein was investigated by immunohistochemistry of human eyes.

RESULTS

Eight cytokines (IL-1β, IL-2, IL-4, IL-5, IL-10, IL-12, IFN-γ, and TNF-α) were below the limits of detection, and two cytokines (IL-18 and IL-15) were detected at low levels or in only a few patients. Although IL-6 was detected in 26 of 30 control patients (median, 2.7 pg/mL) and in 23 of 29 POAG patients (median, 1.6 pg/mL), the difference was not statistically significant. IL-8 was detected in 28 of 30 control patients (median, 1.8 pg/mL) and in all 29 POAG patients (median, 4.9 pg/mL). The higher IL-8 concentration in the AH of POAG patients was statistically significant (P < 0.001). In pairs of eyes from patients with asymmetric glaucomatous optic nerve damage, IL-8 concentration was higher in the AH of the more severely affected eye (P < 0.05). Patients with severe visual field defects had higher IL-8 concentrations in the AH than did patients with mild visual field defects. IL-8 protein expression was found in human retina and optic nerve.

CONCLUSIONS

Concentration of the inflammatory cytokine IL-8 is significantly elevated in the AH of POAG patients, supporting the hypothesis that immune activation occurs in glaucoma.