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

[Primary open angle glaucoma and sleep apnea syndrome: A review of the literature]

The relationship between glaucoma and Obstructive Sleep Apnea Syndrome (OSAS) has long been discussed, with conflicting study findings. OSAS appears in the most recent studies to be more of an aggravating factor than an independent risk factor for glaucoma. Patients with OSAS may develop a more rapid progression of primary open-angle glaucoma (POAG). OSAS may damage the optic nerve not only by increasing the intraocular pressure (IOP) but also by altering the blood supply to the optic nerve as shown by more recent work with OCT-Angiography. Although the systemic benefits of Continuous Positive Airway Pressure (CPAP) have been demonstrated, few studies have evaluated its effect on the optic nerve. CPAP might act on glaucomatous neuropathy by improving the blood supply to the optic nerve. The study of this mechanism of action might provide new insights into the relationship between OSAS and glaucoma.

Obstructive sleep apnoea and glaucoma: a systematic review and meta-analysis

INTRODUCTION

Obstructive sleep apnoea (OSA) has been thought to be associated with glaucoma, however there are many conflicting studies on this topic. With many new studies having been published since the previous meta-analysis, we believe it is important to clarify this association. Hence, in this study we meta-analyse the recent literature regarding the association between OSA and glaucoma.

METHODS

Pubmed, Embase, Scopus and Cochrane Library were searched from inception till the 28th February 2022 for observational as well as cross-sectional studies examining the association between OSA and glaucoma. Two reviewers selected studies, extracted data, graded the quality of included non-randomized studies using the Newcastle-Ottawa scale. The overall quality of evidence was assessed using GRADE. Random-effects models were used to meta-analyse the maximally covariate- adjusted associations.

RESULTS

48 studies were included in our systematic review, with 46 suitable for meta-analysis. Total study population was 4,566,984 patients. OSA was associated with a higher risk of glaucoma (OR 3.66, 95% CI 1.70 to 7.90, I2 = 98%, p < 0.01). After adjustment for various important confounders including age, gender and patient comorbidities such as hyperlipidaemia, hypertension, cardiovascular diseases and diabetes, patients with OSA had up to 40% higher odds of glaucoma. Substantial heterogeneity was eliminated through subgroup and sensitivity analyses after consideration of glaucoma subtype, OSA severity and adjustment for confounders.

CONCLUSIONS

In this meta-analysis, OSA was associated with higher risk of glaucoma, as well as more severe ocular findings characteristic of the glaucomatous disease process. We suggest more clinical studies looking into the effects of OSA treatment on the progression of glaucoma to help clinical decision making for patients.

Pilot study of contactless sleep apnea detection based on snore signals with hardware implementation

Objective.Sleep apnea has a high incidence and is a potentially dangerous disease, and its early detection and diagnosis are challenging. Polysomnography (PSG) is considered the best approach for sleep apnea detection, but it requires cumbersome and complicated operations. Thus, it cannot satisfy the family healthcare needs.Approach.To facilitate the initial detection of sleep apnea in the home environment, we developed a sleep apnea classification model based on snoring and hybrid neural network, and implemented the well trained model in an embedded hardware platform. We used snore signals from 32 patients at Shenzhen People's Hospital. The Mel-Fbank features were extracted from snore signals to build a sleep apnea classification model based on Bi-LSTM with attention mechanism.Main results.The proposed model classified snore signals into four types: hypopnea, normal condition, obstructive sleep apnea, and central sleep apnea, with 83.52% and 62.31% accuracies, corresponding to the subject-dependence and subject-independence validation, respectively. After pruning and model quantization, at the cost of 0.81% and 0.95% accuracy loss of the subject dependence and subject independence classification, respectively, the number of model parameters and model storage space were reduced by 32.12% and 60.37%, respectively. The model exhibited accuracies of 82.71% and 61.36% based on the subject dependence and subject independence validations, respectively. When the well trained model was successfully porting and running on an STM32 ARM-embedded platform, the model accuracy was 58.85% for the four classifications based on leave-one-subject-out validation.Significance.The proposed sleep apnea detection model can be used in home healthcare for the initial detection of sleep apnea.

Visualising structural and functional characteristics distinguishing between newly diagnosed high-tension and low-tension glaucoma patients

PURPOSE

To determine whether there are quantifiable structural or functional differences that can distinguish between high-tension glaucoma (HTG; intraocular pressure [IOP] > 21 mm Hg) and low-tension glaucoma (LTG; IOP ≤ 21 mm Hg) at diagnosis.

METHOD

This was a retrospective, cross-sectional study. Clinical results of one eye from 90 newly diagnosed HTG and 319 newly diagnosed LTG patients (117 with very-low-tension glaucoma [vLTG; ≤15 mm Hg] and 202 with middling LTG [mLTG; >15 mm Hg, ≤21 mm Hg]) were extracted, which included relevant demographic covariates of glaucoma, quantitative optical coherence tomography (including the optic nerve head, retinal nerve fibre layer and ganglion cell-inner plexiform layer) measurements and standard automated perimetry global metrics. We used binary logistic regression analysis to identify statistically significant clinical parameters distinguishing between phenotypic groups for inclusion in principal component (PC) (factor) analysis (PCA). The separability between each centroid for each cohort was calculated using the Euclidean distance (d(x,y)).

RESULTS

The binary logistic regression comparing HTG and all LTG identified eight statistically significant clinical parameters. Subsequent PCA results included three PCs with an eigenvalue >1. PCs 1 and 2 accounted for 21.2% and 20.2% of the model, respectively, with a d(x,y) = 0.468, indicating low separability between HTG and LTG. The analysis comparing vLTG, mLTG and HTG identified 15 significant clinical parameters, which were subsequently grouped into five PCs. PCs 1 and 2 accounted for 24.1% and 17.8%, respectively. The largest separation was observed between vLTG and HTG (d(x,y) = 0.581), followed by vLTG and mLTG (d(x,y) = 0.435) and lastly mLTG and HTG (d(x,y) = 0.210).

CONCLUSION

Conventional quantitative structural or functional parameters could not distinguish between pressure-defined glaucoma phenotypes at the point of diagnosis and are therefore not contributory to separating cohorts. The overlap in findings highlights the heterogeneity of the primary open-angle glaucoma clinical presentations among pressure-defined groups at the cohort level.

Glaucoma and Systemic Disease

Glaucoma is the leading cause of irreversible blindness in the world. Due to its potential to cause permanent vision loss, it is important to understand how systemic conditions and their respective treatments can be associated with or increase the risk for developing glaucoma. In this review, we examined the literature for up-to-date discussions and provided commentary on glaucoma, its pathophysiology, and associated risk factors. We discuss systemic diseases and the impact, risk, and mechanism for developing glaucoma, including pharmacologically induced glaucoma; inflammatory and auto-immune conditions; infectious, dermatologic, cardiovascular, pulmonary, renal, urologic, neurologic, psychiatric and systemic malignancies: intraocular tumors; as well as pediatric, and genetic conditions. The goal of our discussion of systemic conditions including their commonality, mechanisms, treatments, and associations with developing glaucoma is to emphasize the importance of ocular examinations and follow-up with the multidisciplinary teams involved in the care of each patient to prevent unnecessary vision-loss.

Bariatric surgery reduces sleep apnea in obese patients with obstructive sleep apnea by increasing pharyngeal cross-sectional area during the early postoperative period

OBJECTIVE

Bariatric surgery (BS) is considered one of the most effective treatments for obese individuals with Obstructive Sleep Apnea (OSA). However, otolaryngologists have raised concerns about the structural alterations caused by BS on the upper respiratory tract, especially, on the pharyngeal cavity.

METHODS

In this study, we recruited 42 individuals who underwent BS at our hospital. They were divided into two groups based on apnea-hypopnea index (AHI): mild group (5 ≤ AHI < 15) and moderate-severe group (AHI ≥ 15). The participants were followed up for 12 months and several indicators, including body mass index (BMI), polysomnography (PSG), and acoustic pharyngometry (APh), were assessed repeatedly before surgery and at 3, 6, and 12 months (m) after surgery.

RESULTS

Participants exhibited significant decreases in BMI (F = 128.1, P = 0.001) and total weight loss (F = 176.7, P < 0.001) after BS. The AHI value among obese patients with mild OSA decreased significantly within three months after surgery (0 day vs. 3 months, P < 0.01), and decreased significantly more than 12 months with moderate-to-severe patients (0 day vs. 3 months, 3 months vs. 6 months, 6 months vs. 12 months, P < 0.01). The therapeutic effect of OSA of the mild group was significantly better compared with that of the moderate-severe group at 6 months (mean rank = 28.13 vs. 14.21, P < 0.001) and 12 m (mean rank = 26.75 vs. 15.52, P = 0.001). The APh results revealed that the pharyngeal volume of the two groups increased significantly between 0 day and 6 months after surgery (P < 0.01). The oropharyngeal junction (OPJ) area and the glottal area were increased significantly between 0 day and 6 m after surgery (P < 0.01).

CONCLUSION

BS can relieve apnea and OSA symptoms among obese patients with OSA, especially in the early postoperative period. Moreover, OSA severity was closely associated with OPJ and glottal areas, rather than pharyngeal cavity volume.

Association Between Risk of Obstructive Sleep Apnea and Glaucoma: The Singapore Epidemiology of Eye Diseases Study

PRCIS

In this population-based, cross-sectional study of Indian and Malay adults in Singapore aged 40 years or above, intermediate or high risk of obstructive sleep apnea (OSA) was associated with 50% higher odds of having glaucoma.

BACKGROUND/AIMS

The relationship between OSA and glaucoma is unclear. We assessed the association between the risk of OSA and glaucoma in an Asian population.

MATERIALS AND METHODS

In this population-based, cross-sectional study, we included Indian and Malay adults aged 40 years or above recruited between 2011 and 2015. Glaucoma was assessed by trained ophthalmologists and classified into primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG). OSA risk was assessed with the Snoring, Tiredness, Observed apnea, High blood pressure, Body mass index, Age, Neck circumference, and male Gender (STOP-Bang) questionnaire and categorized as low risk (<3) or intermediate/higher risk (≥3). We used multivariable logistic regression models to evaluate the relationship between risk of OSA and glaucoma adjusted for key variables, and further stratified for subtype and ethnicity.

RESULTS

Of the 3126 participants (mean age: 63.1±9.6 y; 52.5% female), 134 (4.3%) had glaucoma, comprising 86 (2.8%) POAG, 22 (0.7%) PACG and 26 (0.8%) secondary glaucomas, and 1182 (37.8%) had an intermediate/higher risk of OSA. Compared with individuals with a low risk of OSA, individuals with intermediate/higher risk had 50% greater odds of having glaucoma (odds ratio: 1.55, 95% confidence interval: 1.03-2.33; P =0.035). We observed a nonsignificant increase in likelihood of having POAG in those with intermediate/higher risk of OSA compared with those with low risk. The OSA-glaucoma relationship was modified by ethnicity, with Malays with intermediate/higher risk of OSA having a 2-fold risk of having any glaucoma (odds ratio: 2.01, 95% confidence interval: 1.12-3.59 P =0.019); while the same elevated risk was not observed for Indians.

CONCLUSIONS

Intermediate or high risk of OSA is associated with 50% higher odds of having glaucoma in our Singaporean population, with a 2-fold higher risk of glaucoma observed in Malays (but not Indians); however a conformational sleep study is needed.

Exploring the Association Between Resilience and Quality of Life Among Glaucoma Patients: Sleep Disturbance as a Mediating Factor

BACKGROUND

Patients with glaucoma may experience many symptoms such as blindness, which seriously affect their quality of life (QoL). Resilience is playing a vital role in enhancing the QoL and well-being of patients with chronic diseases. In addition, sleep disturbance is common in patients with glaucoma, leading to a decline in their QoL. However, there is a dearth of research on whether sleep disturbance plays a mediating role between resilience and QoL among glaucoma patients.

OBJECTIVE

The aim of this study is to explore the role of sleep disturbance in the relationship between resilience and QoL among glaucoma patients.

METHODS

From July to December 2019, a cross-sectional survey was conducted on 215 glaucoma patients in an ophthalmic hospital in Liaoning Province. Hierarchical multiple regression (HMR) analyses and structural equation modeling (SEM) were conducted to examine the factors related to QoL and to test the hypothesis that sleep disturbance mediates the relationship between resilience and QoL among glaucoma patients.

RESULTS

The average QoL score among glaucoma patients was 43.85 ± 14.97 as reported by the Glaucoma Quality of Life-15 (GQL-15) scale, where a higher scores indicating a poorer QoL. Resilience was found to be linked with a lower QoL score (P < 0.01), while sleep disturbance was associated with a higher QoL score (P < 0.01). When sleep disturbance was included in the model as partial mediator, the path coefficients for the association between resilience and QoL score was significantly decreased (a*b = -0.1, BCa95% CI: -0.154∼-0.045).

CONCLUSION

Findings of this study reflected that QoL among glaucoma patients in China was poor. Resilience was found to be an important positive factor, which could result in the improvement of QoL. Furthermore, sleep disturbance mediated the relationship between resilience and QoL among patients with glaucoma, thereby reducing the positive impact of resilience on QoL in glaucoma patients. Efforts to improve QoL among glaucoma patients may benefit from interventions that enhance the levels of resilience and promote healthy sleep.

Retinal microcirculation characteristics in obstructive sleep apnea/hypopnea syndrome evaluated by OCT-angiography: a literature review

PURPOSE

The retina may provide a window to estimate systemic vascular status; therefore, there has been interest in identifying microcirculation characteristics that possibly reflect hypoxic alterations in obstructive sleep apnea/hypopnea syndrome (OSAS). Emerging evidence has suggested that retinal microvasculature investigation holds the potential to characterize the pathophysiology involved in ocular manifestations of OSAS. The advent of optical coherence tomography angiography (OCT-A) has attracted significant attention as this technique offers detailed analysis of the retinal capillary plexus.

METHODS

A detailed literature search was performed in PubMed database until December 2021. We identified and reviewed all papers referring to the alterations of the retinal capillary plexus in OSAS using OCT-A.

RESULTS

A comprehensive update indicates that microcirculation alterations of the retinal capillary plexus utilizing OCT-A may differ with severity of OSAS and imply the potential underlying pathophysiology of ocular manifestations. The reviewed series have revealed variability concerning microvasculature characteristics at the macular and the peripapillary area. Further studies are warranted to establish the OCT-A parameters as biomarkers regarding the evaluation of OSAS in clinical practice.

CONCLUSION

Retinal capillary plexus characteristics as seen on OCT-A reflect microvasculature alterations, potentially leading to concomitant ocular comorbidity in the context of OSAS. The reviewed literature may confirm the diagnostic and prognostic value of OCT-A in the assessment of the pathophysiology of ocular manifestations in OSAS and highlight unmet needs to be addressed by future research.

Is Genetic Risk for Sleep Apnea Causally Linked With Glaucoma Susceptibility?

Purpose

Observational studies have suggested that individuals with pre-existing sleep apnea (SA) have up to double the risk of developing glaucoma than individuals without SA. Understanding risk factors for glaucoma is important to assist with well-structured screening, early intervention, and efficient allocation of specialist consultation. The objective of this study is therefore to use genetic data to determine whether SA is a causal risk factor for glaucoma.

Methods

Two-sample Mendelian randomization (MR) analyses were performed to assess the association between genetically predicted SA and glaucoma susceptibility using genome-wide association study (GWAS) of 25,062 SA cases, 313,372 controls derived from 23andMe and summary data from a glaucoma GWAS meta-analysis (20,582 cases, 119,318 controls), including individuals of European descent, mainly from the UK Biobank.

Results

Inverse variance weighted regression of genetic susceptibility for SA on risk of glaucoma revealed no strong evidence for an association between SA and glaucoma (OR = 0.95, 95% confidence intervals = 0.84–1.07), results were consistent across all MR predictors.

Conclusions

We found little genetic evidence supporting a causal association between SA and glaucoma. Our results refute the possibility of a large effect (glaucoma OR > 1.5 per doubling of odds on SA) between SA and glaucoma.

Prospective evaluation of the comorbidity of obstructive sleep apnea in patients with glaucoma

STUDY OBJECTIVES

This study aimed to identify prospectively the correlation between obstructive sleep apnea (OSA) severity, ocular microcirculation changes, and visual function changes in patients with glaucoma.

METHODS

We prospectively enrolled patients with glaucoma who were willing to undergo overnight polysomnography. The enrolled patients were further divided into normal tension glaucoma, high-tension glaucoma, and control. Visual field progression was analyzed using sequential standard automated perimetry. Peripapillary and macular vessel density were assessed through optical coherence tomography angiography (OCT-angiography). The associations between polysomnography parameters, OCT-angiography parameters, and visual field progression were analyzed.

RESULTS

A total of 22 patients with normal tension glaucoma, 30 patients with high-tension glaucoma, and 24 control patients were enrolled. Through regression analysis, glaucoma was found to be an independent predictor of moderate-to-severe OSA (P = .035); furthermore, moderate-to-severe OSA was significantly associated with visual field progression (P = .008 in the high-tension glaucoma subgroup and P = .008 in the overall glaucoma). Additionally, OSA severity was negatively correlated with the ganglion cell complex thinning rate in the normal tension glaucoma subgroup.

CONCLUSIONS

Presence of glaucoma increased the risk of moderate-to-severe OSA compared with the control group. OSA severity was related to visual field deterioration in patients with glaucoma and further associated with structural progression in the normal tension glaucoma subgroup. Careful monitoring of the comorbid OSA status of patients with glaucoma is essential to prevent disease progression.

CITATION

Chan Y-H, Chuang L-H, Yu C-C, et al. Prospective evaluation of the comorbidity of obstructive sleep apnea in patients with glaucoma. J Clin Sleep Med. 2022;18(1):47-56.

Sleep apnea and eye diseases: evidence of association and potential pathogenic mechanisms

Eye diseases are an important group of increasingly prevalent disorders that contribute very significantly to disability and represent a considerable health burden. Some data suggest that several of these diseases may be associated with sleep-disordered breathing, mainly obstructive sleep apnea (OSA), due to intermediate mechanisms, such as intermittent hypoxia or sleep fragmentation. The aims of this systematic review were to identify and critically evaluate the current evidence supporting the existence of a possible relationship between OSA and the more relevant eye diseases as well as to evaluate the potential pathogenic mechanisms. There is a body of largely low-level evidence for the association of OSA with glaucoma, nonarteritic ischemic optic neuropathy, central serous chorioretinopathy, and diabetic retinopathy. Meta-analysis of available case-control studies shows that OSA increases the risk of glaucoma (pooled odds ratio: 1.50; 95% confidence interval: 1.25 to 1.80; P < .001), nonarteritic ischemic optic neuropathy (3.62; 1.94 to 6.76; P < .001), and diabetic retinopathy (1.57; 1.09 to 2.27; P = .02). Moreover, several pathogenic pathways have been identified, mainly related to hypoxic damage, mechanical stress, systemic inflammation, oxidative stress, sympathetic tone, and endothelial dysfunction. In contrast, information about the effect of apnea-hypopnea suppression on the development and progression of eye damage is either nonexistent or of a very low level of evidence. In conclusion, OSA has emerged as an additional potential risk factor for many eye diseases, although their link is weak and contradictory, so further examination is required.

CITATION

García-Sánchez A, Villalaín I, Asencio M, García J, García-Rio F. Sleep apnea and eye diseases: evidence of association and potential pathogenic mechanisms. J Clin Sleep Med. 2022;18(1):265-278.

Pathophysiology of the comorbidity of glaucoma with obstructive sleep apnea: A postulation

Glaucoma is a serious and progressive optic neuropathy, the exact pathophysiology of which is still poorly understood. Furthermore, glaucoma exhibits significant comorbidity with obstructive sleep apnea (OSA) that warrants an in-depth study in view of highly probable beneficial and far-reaching clinical implications. In this brief paper, the authors have studied the existing theories in an attempt to explain the comorbidity and its underlying pathophysiology. From the ensuing evidence, the role of connective tissue strength has emerged as a major factor and which appears to play a pivotal role not only in the development of glaucoma but also in the underlying pathophysiology of its enigmatic comorbidity with OSA. Understanding the pathophysiology of the comorbidity can stimulate newer therapeutic strategies targeted toward strengthening of connective tissues that may at least retard if not arrest the progression of glaucomatous changes and their complications.

Ocular Complications of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), the most common form of sleep-disordered breathing, is characterized by repetitive episodes of paused breathing during sleep, which in turn induces transient nocturnal hypoxia and hypercapnia. The high prevalence of OSA and its associated health consequences place a heavy burden on the healthcare system. In particular, the consequent episodic oxygenic desaturation/reoxygenation series and arousals from sleep in patients with OSA have the potential to trigger oxidative stress, elevated systemic inflammatory responses, and autonomic dysfunction with sympathetic activation. Given these adverse side-effects, OSA is highly correlated to many eye diseases that are common in everyday ophthalmic practices. Some of these ocular consequences are reversible, but they may permanently threaten a patient’s vision if not treated appropriately. Here, this article seeks to review the ocular consequences and potential pathophysiologic associations in patients with OSA. Understanding these OSA-related eye diseases may help clinicians provide comprehensive care to their patients.

The Associations of Obstructive Sleep Apnea and Eye Disorders: Potential Insights into Pathogenesis and Treatment

Purpose of Review

Obstructive sleep apnea (OSA) patients are at significantly increased risks for cardiovascular and cerebrovascular morbidities. Recently, there has been heightened interest in the association of OSA with numerous ocular diseases and possible improvement of these conditions with the initiation of OSA treatment. We reviewed the current evidence with an emphasis on the overlapping pathogeneses of both diseases.

Recent Findings

Currently available literature points to a substantial association of OSA with ocular diseases, ranging from those involving the eyelid to optic neuropathies and retinal vascular diseases. Since the retina is one of the highest oxygen-consuming tissues in the body, the intermittent hypoxia and hypercapnia ensuing in OSA can have deleterious effects on ocular function and health. Tissue hypoxia, autonomic dysfunction, microvascular dysfunction, and inflammation all play important roles in the pathogenesis of both OSA and ocular diseases. Whether OSA treatment is capable of reversing the course of associated ocular diseases remains to be determined. It is anticipated that future therapeutic approaches will target the common underlying pathophysiologic mechanisms and promote favorable effects on the treatment of known associated ocular diseases.

Summary

Emerging evidence supports the association of ocular diseases with untreated OSA. Future studies focusing on whether therapeutic approaches targeting the common pathophysiologic mechanisms will be beneficial for the course of both diseases are warranted.

A Narrative Review of Cerebellar Malfunctions and Sleep Disturbances

Cerebellar malfunctions significantly impact the regulation of the sleep–wakefulness transition. The possible mechanism for this effect is still unknown. Evidence on the role of cerebellar processing in the sleep–wake cycle is derived mainly from animal studies, and clinical management of the sleep–wake cycle is also challenging. The purpose of this review is to investigate the role of cerebellar activity during normal sleep and the association between cerebellar dysfunction and sleep disorders. Large-scale, multicenter trials are still needed to confirm these findings and provide early identification and intervention strategies to improve cerebellar function and the sleep quality of patients.

Associations of sleep apnoea with glaucoma and age-related macular degeneration: an analysis in the United Kingdom Biobank and the Canadian Longitudinal Study on Aging

BACKGROUND

Sleep apnoea, a common sleep-disordered breathing condition, is characterised by upper airway collapse during sleep resulting in transient hypoxia, hypoperfusion of the optic nerve, and spike in intracranial pressure. Previous studies have reported conflicting findings on the association of sleep apnoea with glaucoma, and there are limited reports on the link between sleep apnoea and age-related macular degeneration (AMD).

METHODS

Middle-aged and older participants from the longitudinal United Kingdom (UK) Biobank (n = 502,505) and the Canadian Longitudinal Study on Aging (CLSA; n = 24,073) were included in this analysis. Participants in the UK Biobank and the CLSA were followed for 8 and 3 years, respectively. Participants with diagnosed glaucoma or AMD at baseline were excluded from the analysis. In the UK Biobank, sleep apnoea and incident cases of glaucoma and AMD were identified through hospital inpatient admission, primary care records, and self-reported data. Multivariable Cox proportional hazards models were used to explore associations of sleep apnoea with incidence of glaucoma or AMD.

RESULTS

During the 8-year follow-up in the UK Biobank, glaucoma incidence rates per 1000 person-years were 2.46 and 1.59 for participants with and without sleep apnoea, and the AMD incidence rates per 1000 person-years were 2.27 and 1.42 for participants with and without sleep apnoea, respectively. Multivariable adjusted hazard ratios of glaucoma and AMD risk for sleep apnoea were 1.33 (95% confidence interval [CI] 1.10-1.60, P = 0.003) and 1.39 (95% CI 1.15-1.68, P <  0.001) relative to participants without sleep apnoea. In the CLSA cohort, disease information was collected through in-person interview questionnaires. During the 3-year follow-up, glaucoma incidence rates per 1000 person-years for those with and without sleep apnoea were 9.31 and 6.97, and the AMD incidence rates per 1000 person-years were 8.44 and 6.67, respectively. In the CLSA, similar associations were identified, with glaucoma and AMD odds ratios of 1.43 (95% CI 1.13-1.79) and 1.39 (95% CI 1.08-1.77), respectively, in participants with sleep apnoea compared to those without sleep apnoea (both P <  0.001).

CONCLUSIONS

In two large-scale prospective cohort studies, sleep apnoea is associated with a higher risk of both glaucoma and AMD. These findings indicate that patients with sleep apnoea might benefit from regular ophthalmologic examinations.

Clinical study of atherosclerotic plaque in the carotid artery and lower extremities in patients with obstructive sleep apnea-hypopnea syndrome

OBJECTIVE

The present study aimed to explore the relationship between young and middle-aged patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and atherosclerotic plaque of the carotid artery and lower extremities.

METHODS

A total of 110 patients diagnosed with OSAHS by polysomnography in the researchers' hospital from September 2018 to September 2019 were selected as the research objects. The enrolled patients were divided into a mild group (36 cases), a moderate group (38 cases), and a severe group (36 cases). Another 36 healthy subjects were set up as the non-OSAHS group. All the selected subjects were examined by color Doppler ultrasound of the carotid artery and lower extremity arteries.

RESULTS

The detection rate of atherosclerotic plaque of the carotid artery and/or lower extremities in patients with OSAHS was significantly higher than that in the non-OSAHS group (P < 0.05), and the incidence of plaque tended to increase along with an increase in the degree of OSAHS.

CONCLUSION

The findings indicate that OSAHS might be an independent influencing factor for atherosclerosis.

Association of obstructive sleep apnea/hypopnea syndrome with glaucomatous optic neuropathy and ocular blood flow

The present study aimed to investigate the prevalence of glaucomatous optic neuropathy in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). In total, 83 subjects (45 cases of severe OSAHS and 38 controls) underwent polysomnographic assessment and were evaluated for the severity of the disease using the Apnea-Hypopnea index. A detailed ophthalmologic exam was then performed, including measurement of the intraocular pressure (IOP) with a Goldmann applanation tonometer and Pascal dynamic contour tonometer (DCT), recording of the ocular pulse amplitude measured by the Pascal DCT, standard automated perimetry and retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness evaluation using optical coherence tomography. Ocular blood flow was assessed using color Doppler imaging (CDI) and ophthalmic artery indices were evaluated, including peak systolic blood velocity, end diastolic blood velocity and resistivity index (RI). There was a significant difference in the mean IOP between controls (11.03±3.85 mmHg) and cases of severe OSAHS (18.06±3.39 mmHg) when the IOP was measured by DCT (P<0.0001), but not with the Goldmann applanation tonometer (IOP, 13.97±2.85 mmHg for controls and 14.89±3.21 mmHg for cases of severe OSAHS; P=0.0877). Significant negative correlations were observed between RNFL thickness and RI (P=0.0011) in cases of severe OSAHS, as well as between GCC thickness and RI (P<0.008) in all subjects. Furthermore, a negative correlation between RI and RNFL thickness in severe cases of OSAHS suggested a hemodynamically induced vulnerability of RNFL in OSAHS. The correlation between RI and GCC thickness in all subjects suggested that impaired perfusion, more prominent in OSAHS, leads to structural changes. Therefore, cases of severe OSAHS should be monitored for changes in RNFL and GCC thickness, as well as CDI findings. Furthermore, patients with increased ophthalmic artery RIs should be monitored for changes in the GCC, regardless of the etiology of the RI increase.

Ganglion cell layer thickening in patients suffering from Obstructive Sleep Apnea-Hypopnea syndrome with long Mean Apnea-Hypopnea Duration during sleep

PURPOSE

To study the effects of mean apnea-hypopnea duration (MAD), a useful indicator of blood oxygenation, on peripapillary retinal nerve fiber layer (RNFL), macular ganglion cell to inner plexiform layer (GC-IPL) and macular retinal thickness in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

Sixty-five patients recently diagnosed with OSAHS and 35 healthy individuals were enrolled in this cross-sectional study. OSAHS patients were divided according to their MAD values into group 1 with 16 participants (MAD:10-15.5 s), group 2 with 17 participants (MAD:15.5-19 s), group 3 with 17 participants (MAD:19-30 s) and group 4 with 15 participants (MAD > 30 s). The average and sectorial values of RNFL, GC-IPL and retinal thickness were measured by SS-OCT (DRI OCT Triton, Topcon). Intraocular pressure was recorded by Goldmann Applanation and Pascal Dynamic Contour Tonometer (DCT-IOP).

RESULTS

The average RNFL and retinal thickness values were higher in group 4, but did not reach statistical significance. With the exception of the central 1 mm at the fovea, GC-IPL was always thickened in group 4, and significant differences were evident when its average value was compared with group 2 (p = 0.03), its superior and inferior-nasal values were compared with group 2 (p = 0.02, p = 0.006, respectively) and group 3 (p = 0.01, p = 0.02, respectively), its superior-temporal value was compared with group 3 (p = 0.003) and the control group (p = 0.03), and its superior-nasal value was compared with group 2 (p = 0.03), group 3 (p = 0.001) and the control group (p = 0.03). DCT-IOP was significantly positively correlated with the duration of sleep in which oxygen saturation (SaO₂ ) was decreased under 90% (r = 0.359, p = 0.01).

CONCLUSION

We report a novel observation of GC-IPL thickening in OSAHS patients experiencing long MAD, a parameter which incorporates the severity of breathing events during sleep. Higher DCT-IOP was noted with advancing hypoxemia.

Optic Disc Measures in Obstructive Sleep Apnea: A Community-based Study of Middle-aged and Older Adults

PRéCIS:: This study found an association between thinner superotemporal retinal nerve fiber layer (RNFL) and obstructive sleep apnea (OSA). However, the lack of association of sleep apnea with other disc measures does not support a link with glaucoma.

AIM

Previous findings on the link between OSA and increased glaucoma risk have been inconsistent. In a community-based study of middle-aged and older adults, we explored for differences in optic disc measures that may resemble preclinical glaucomatous changes in relation to OSA status and severity.

METHODS

A total of 865 participants (46 to 67 y; 45% male) underwent an at-home sleep study during which their apnea-hypopnea index (AHI) and sleep oxygen saturation level were measured. Participants were determined to have no OSA (AHI<5 events/h), mild (AHI 5 to 15), moderate (AHI 16 to 30), or severe OSA (AHI>30). At a 6-year follow-up visit, the optic discs of both eyes were imaged using spectral domain optic coherence tomography to measure the Bruch membrane opening-minimum rim widths and RNFL thicknesses.

RESULTS

On the basis of the AHI, 411 participants (48%) had OSA, of whom 92 (11% of total sample) and 26 (3%) had moderate and severe OSA, respectively. In the multivariate analysis, participants with severe OSA had thinner RNFL superotemporally than those without OSA or with mild OSA (P<0.001 and 0.001, respectively). In addition, superotemporal RNFL was inversely associated with AHI (P=0.004) and sleep time with oxygen saturation level <90% (P=0.005). There was no association between OSA measures and Bruch membrane opening-minimum rim widths.

CONCLUSIONS

Our findings do not provide strong evidence of a link between measures of OSA and the optic disc. However, the association between increased OSA severity and thinner superotemporal RNFL has been reported consistently in previous studies and thus warrants further evaluation.

Links between obstructive sleep apnea and glaucoma neurodegeneration

In the last few years, the possible link between obstructive sleep apnea (OSAS) and glaucoma, has attracted the interest of many scientists, especially in those forms of primary open angle glaucoma (POAG) and normal tension glaucoma (NTG), in which a progression of the disease occurs, even though intraocular pressure (IOP) is in the range of normality. The increased prevalence of POAG or NTG in patients affected by OSAS, and vice versa, has stimulated interest in the pathogenetic mechanisms that could trigger these two diseases. Hypoxia generated by apnea/hypopnea cycles has been identified as the main cause of many changes in the vascular and neurological systems, which alter the functioning not only of the optic nerve, but also of the whole organism. However, many other factors could be involved, like mechanical factors, obesity, hormonal imbalance and other sleep disorders. Furthermore, the demonstration of typical glaucomatous or glaucoma-like changes in the anatomy or function of the optic nerve and retinal nerve fiber layer by sensitive specific and diagnostic methods, such as perimetry, optical coherence tomography (OCT), optical coherence tomography angiography (OCTA) and electrophysiological exams keeps interest high for this field of study. For this reason, further investigations, hopefully a source of stronger scientific evidences, are needed.

Obstructive Sleep Apnea in Patients With Primary-open Angle Glaucoma: No Role for a Screening Program

PRéCIS:: In this study, we found a high prevalence of obstructive sleep apnea (OSA) among patients with primary open-angle glaucoma (POAG) but this was not different (nor was OSA more severe) to matched people without glaucoma.

RATIONALE

It has been proposed that OSA might be a contributing factor in the development of POAG and by extension that there could be a role for screening people with POAG for OSA.

OBJECTIVES

To assess whether the prevalence of OSA among patients with POAG is different from that in people without glaucoma and to examine for associations between apnea-hypopnea index (AHI) and markers of functional and structural changes in POAG.

METHODS

Unselected POAG patients and control subjects were consecutively recruited in a single center. A comprehensive ocular assessment and nocturnal multichannel cardiorespiratory monitoring were performed.

RESULTS

Data from 395 participants, 235 POAG patients, and 160 controls were analyzed. The prevalence of OSA was 58% [95% confidence interval (CI), 52-65] in POAG patients and 54% (95% CI, 47-62) in controls, with 22% (95% CI, 16-27) of POAG patients and 16% (95% CI, 11-22) of controls diagnosed with moderate or severe OSA. A total of 160 POAG participants were matched to the controls using propensity score matching. There was no significant difference in OSA prevalence between the matched groups (P=0.91 for AHI≥5 and P=0.66 for AHI≥15). The AHI was not associated with the severity of visual field defect or retinal nerve fiber layer thinning after adjustment for confounders.

CONCLUSIONS

This study confirms a high prevalence of OSA among patients with POAG which is, however, not higher than in people without glaucoma matched for known OSA risk factors. Our results do not support screening for OSA in patients with POAG.

Is "normal tension glaucoma" glaucoma?

Primary open angle glaucoma (POAG) represents a distinct disease entity with elevated intraocular pressure (IOP) as the main risk factor, even though the reasons for why the IOP is elevated remains to be elucidated. It is considered that normal tension glaucoma (NTG) is a subtype of POAG, comprising a special form of glaucomatous neurodegeneration or glaucomatous optic neuropathy (GON) almost exactly the same as that seen in POAG, but the IOP, as named, remains in the statistically normal range. Actually the disease entity of NTG has been a profound confusion and it is difficult to be accurately conceptualized. One of the reasons is that the IOP is closely linked to the occurrence of GON in POAG but not in NTG, and for the latter, it seems that GON is secondary to a number of local or systemic disorders. In recent years, increasing evidences suggest that NTG or IOP independent GON is a non-glaucomatous disease with different disease entities from POAG and with more diverse and complex etiologies. Here we hypothesized that NTG, at least for those with recognizable primary diseases, is not a glaucomatous disease; instead, it represents a group of disorders with GON as a characteristic clinical feature or phenotype.

Investigation of the Presence of Glaucoma in Patients with Obstructive Sleep Apnea Syndrome Using and Not Using Continuous Positive Airway Pressure Treatment

Objectives:

To evaluate the frequency of glaucoma in patients with obstructive sleep apnea syndrome (OSAS) using and not using continuous positive airway pressure treatment.

Materials and Methods:

This prospective study included 59 patients diagnosed with OSAS based on the Apnea-Hypopnea Index (AHI). OSAS patients were divided into 3 groups according to their AHI scores: 5-15 was considered mild (19 patients), 16-30 was considered moderate (16 patients), and >30 (24 patients) was considered severe. Twenty-eight (47.5%) of the OSAS patients had been using continuous positive airway pressure treatment. The control group included 19 healthy subjects. Retinal nerve fiber layer and ganglion cell complex (GCC) thickness analyses were performed.

Results:

Average GCC thickness in left eyes was significantly lower in the mild OSAS group than in the control group (p=0.013). The GCC was significantly thinner in the inferior and inferonasal sectors of both eyes in the mild OSAS group compared to the control group (p=0.029, p=0.022, p=0.037, and p=0.019 respectively). Minimum GCC thickness in the left eyes of all OSAS groups was significantly lower than in the control group (p<0.05).

Conclusion:

In OSAS patients, there may be changes in retinal nerve fiber layer and ganglion cell complex thickness before alterations in the visual field emerge.

Prevalence and Predictors of Ocular Complications in Obstructive Sleep Apnea Patients: A Cross-sectional Case-control Study

Purpose:

This study sought to identify the magnitude and the possible risk factors of ocular complications in patients with Obstructive Sleep Apnea (OSA).

Methods:

A hospital-based cross-sectional study with a nested case-control design was conducted. Qualifying study subjects were patients who had been diagnosed with moderate to severe OSA (AHI index of ≥ 5, n=80), and control subjects (n=20) who had an AHI index of ≤ 5 (“normal”). Study participants were recruited from Mansoura University Hospital’s Sleep Disorders Clinic in Mansoura, Egypt.Selected subjects were assessed for ocular complications at Mansoura Univerity Hospital Ophthalmic Center, (Mansoura), Egypt. An ophthalmic history was recorded, and opthalmic testing was carried out. The testing included unaided visual acuity measurement, refraction, best-corrected visual acuity measurement, slit lamp bio-microscopic evaluation of the anterior segment and anterior segment photography, dilated fundus examination, intraocular pressure measurement, fundus photo, and fluorescein angiography, and visual field assessment. Various tests of OSA symptoms were also monitored, including the AHI, lowest oxygen concentrations and desaturation index plus the overall severity index. .

Results:

It was found that OSA patients n=28 (35%), n=24 (30%), n=4 (5%) had senile cataract, normal tension glaucoma, and retinal ischemia, respectively, with an overall prevalence of 45%. Additionally, the OSA group had seven times greater risk (OR=7.36, 95%CI: 1.6-33.86) of vision-threatening disorders compared to the controls. OSA patients were observed to be at a greater risk of senile cataract 28 (35%), normal tension glaucoma 24 (30%), retinal ischemia 4 (5%) and conjunctival hyperemia and dry eye (OR=3.77, 95%CI: 1.02-13.95, OR=4.36, 95%CI: 1.26-17.08). Also, multivariate logistic regression analysis testing showed that the lowest oxygen saturation index was the only significant predictor negatively associated with vision-threatening disorders (OR=0.84, 95%CI: 0.75-0.93).

Conclusion:

The risk of vision-threatening and non-threatening ocular disorders is higher among OSA cases. The lowest oxygen saturation index was the only significant predictor of vision-threatening disorders. These findings support the recommendation that a full ophthalmic examination should be carried out on patients with confirmed OSA.

Associations between Optic Disc Measures and Obstructive Sleep Apnea in Young Adults

PURPOSE

Obstructive sleep apnea (OSA) is linked to increased glaucoma risk in middle-aged and older adults. However, little is known about associations between OSA and glaucoma-related optic disc parameters in young adults. We explored associations between overnight polysomnography-derived measures of OSA and the optic disc in young adults.

DESIGN

Cross-sectional cohort study.

PARTICIPANTS

Eight hundred forty-eight adults 19 to 22 years of age.

METHODS

Participants underwent an ophthalmic examination that included OCT imaging of the optic disc and measurements of intraocular pressure, axial length, and refractive error. Participants then underwent an overnight polysomnography study that obtained measurements of apnea-hypopnea index (AHI), peripheral oxygen saturation level, and number of cortical arousals from sleep. Based on the AHI results, participants were grouped into no OSA (AHI < 5 events/hour), mild OSA (AHI ≥ 5 and <15 events/hour), moderate OSA (AHI ≥ 15 and <30 events/hour), or severe OSA (AHI ≥ 30 events/hour).

MAIN OUTCOME MEASURES

Neuroretinal rim area, horizontal and vertical widths, and peripapillary retinal nerve fiber layer (RNFL) thickness.

RESULTS

The median AHI result across the study cohort was 2.2 events per hour (interquartile range, 1.0-4.4 events/hour). Based on the AHI results, 178 participants (21.0%) demonstrated OSA: 150 with mild OSA, 26 with moderate OSA, and 2 with severe OSA. In the unadjusted analyses, participants with OSA on average showed thinner peripapillary RNFL at the inferotemporal (P = 0.026) and superotemporal (P = 0.008) segments compared with those without OSA. Additionally, higher AHI results were associated with thinner RNFL superotemporally (P = 0.007). These findings remained significant after adjusting for gender, body mass index, ethnicity, and potential ocular confounders. There were no significant differences in optic disc measures between groups of OSA severity.

CONCLUSIONS

Obstructive sleep apnea may be associated with preclinical thinning of the peripapillary RNFL in young adults. This suggests that an increased glaucoma risk already may be present in individuals with OSA since young adulthood. Long-term follow-up of this cohort will allow further optic disc changes in relationship to polysomnography parameters to be documented and associations with future glaucoma diagnosis to be explored.

Correlation between structural progression in glaucoma and obstructive sleep apnea

BACKGROUND/OBJECTIVES

To investigate the correlation between obstructive sleep apnea (OSA) severity and the structural and functional progression in patients with glaucoma.

SUBJECTS/METHODS

This retrospective comparative cohort study included subjects from the polysomnography database in Chang Gung Memorial Hospital between June 1, 2009, and June 1, 2017, by identifying patients who had received diagnoses of primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), or glaucoma suspect. Patients with follow-up time of <3 years and/or <3 consecutive reliable optical coherence tomography (OCT) or visual field (VF) tests were excluded. Progression of overall peripapillary retinal nerve fiber layer (RNFL) thickness on OCT scans and VF mean deviation (MD) or VF index (VFI) were determined through linear regression trend analysis.

RESULTS

Thirty-two patients were included. There was a trend to higher percentage of progression on RNFL thickness and VF in higher OSAS severity. After stratifying patients to no OSA/mild OSA (group 1) and moderate/severe OSA (group 2), group 2 exhibited a significantly higher percentage of RNFL thickness progression than did group 1 (64.7% vs 26.7%, P = 0.042). Multivariate Cox regression analysis showed that severe OSA had an 8.448-fold higher risk of RNFL thickness progression after age, sex, diabetes mellitus, hypertension, hyperlipidemia, and body mass index adjustment (95% confidence interval, 1.464-48.752, P = 0.017).

CONCLUSIONS

Severe OSA is significantly correlated with a higher risk of structural deterioration in patients with glaucoma.

Posterior segment assessment in patients with obstructive sleep apnea syndrome

PURPOSE

The present study aimed to evaluate the lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD), subfoveal and parafoveal choroidal thicknesses, peripapillary choroidal thickness (PCT), and retina nerve fiber layer (RNFL) thickness in patients with obstructive sleep apnea syndrome (OSAS) using spectral domain optical coherence tomography (SD-OCT).

METHODS

This single-center, case-control study included 45 OSAS patients and 43 age-and sex-matched healthy controls. Only the right eyes of the patients and controls were included. Each participant underwent a comprehensive ophthalmic assessment including slit lamp examination (biomicroscopy), stereoscopic fundus examination, and intraocular pressure (IOP) measurement. The SD-OCT measurements were also performed in both patients and controls.

RESULTS

The mean ages of the patients (females, 55.6%) and controls (females, 51.2%) were 50.09 ± 9.7 years and 50.30 ± 4.2 years, respectively. The groups were similar in terms of age and gender. Evaluation of the study parameters revealed that there were no significant differences between the OSAS patients and controls regarding IOP, RNFL thickness, subfoveal and parafoveal choroidal thicknesses, and PCT. A significant difference was found between the OSAS patients and controls regarding LCT but not regarding LCD. The mean LCT values were 213.38 ± 30.7 μm and 300.49 ± 42.6 μm for the OSAS patients and controls, respectively (p ˂ 0.001).

CONCLUSIONS

The results of the present study indicated that the lamina cribrosa was significantly thinner in the OSAS patients than in the controls. In our opinion, this finding should be supported by large-scale studies and the reason underlying the thinning of the lamina cribrosa in OSAS patients should be investigated physiopathologically.

Holistic Management of Obstructive Sleep Apnea: Translating Academic Research to Patient Care

A holistic approach is pertinent in managing obstructive sleep apnea (OSA). It goes beyond integrated multidisciplinary assessment and management in the hospital setting. Although clinicians should be aware of different treatment modalities and adjunctive measures, proactive management of OSA is as important. The future of OSA management lies in identifying patients at risk of developing OSA and developing strategy to prevent OSA from taking root. It involves active screening of patients with OSA and treating them and identifying patients with OSA with high risk of preventable serious morbidity and death and intervening early to prevent these from happening.

Normal-tension glaucoma: Pathogenesis and genetics

Normal-tension glaucoma (NTG) is a multifactorial optic neuropathy which, similar to open-angle glaucomas, is characterized by progressive retinal ganglion cell death and glaucomatous visual field loss. The major distinction of NTG from open-angle glaucomas is that the intraocular pressure (IOP) does not exceed the normal range. Missing the major risk factor and target of therapy, the elevated IOP, NTG poses a clinical challenge. Several insightful reviews have been published on the pathophysiology of NTG describing the possible underlying mechanisms. The current literature available also suggests that a significant percentage of patients with NTG (as high as 21%) have a family history of glaucoma, indicating a genetic predisposition to the disease. These facts strengthen the indication that NTG remains an enigmatic process. The aim of this review was to summarize the vascular, mechanical and genetic components considered to be responsible for NTG development and to discuss the mechanisms through which they are involved in the pathogenesis of NTG.

Adenotonsillectomy outcomes regarding bone age and osteocalcin in treatment of obstructive sleep apnea syndrome in children

BACKGROUND

To investigate the effect of adenotonsillectomy (AT) on bone development, quality of life and polysomnography evaluation in children with obstructive sleep apnea syndrome (OSA).

METHODS

Preoperative and postoperative (6 months) physical examination, PSG, bone age (BA) and osteocalcin (OC) evaluation were performed on the selected OSA children (n=92) and the healthy children (n=87). The OSA children were also scored based on the OSA 18-item questionnaire. A two-year follow-up was conducted to evaluate BA and OC changes.

RESULTS

After AT, 81 (88.04%) OSA children recovered completely, eight (8.70%) achieved remarkable improvements, and three (3.26%) achieved moderate improvements. In the OSA children, postoperative OSA 18-item score and the scores of the five domains were significantly higher than preoperative ones. Compared with the preoperative, body mass index (BMI), weight for age Z-sores, height for age Z-sores, weight for height Z-sores and BMI Z-score in the OSA group 6 months after the operation were significantly increased, but no significant difference was detected between the OSA and the control group. The changes of BA and chronological age in the OSA group were significantly different from those in the control group. Two years after AT, BA between the two groups was no longer significantly different. Preoperative serum OC in the OSA group was lower than that in the control group, but increased to normal levels 6 months after AT. Correlation analysis showed serum OC levels were negatively correlated with apnea hyponea index, obstructive apnea index, arousal index, and lowest oxygen saturation.

CONCLUSIONS

After AT, bone growth and development in children with OSA recovered gradually, and the serum OC levels decreased to the normal level. Therefore, preventive measures and positive treatments should be applied to minimize the negative effects of OSA in children.

Ophthalmic Diseases in Patients With Obstructive Sleep Apnea

Symptomatic obstructive sleep apnea (OSA) affects 2% of women and 4% of men, but the prevalence of asymptomatic OSA is significantly higher. Several ophthalmic conditions are associated with OSA, including floppy eyelid syndrome, glaucoma, nonarteritic anterior ischemic optic neuropathy, papilledema, keratoconus, and central serous chorioretinopathy. The purpose of this review is to provide primary care physicians with a general knowledge of the signs, symptoms, and management of the ophthalmic diseases associated with OSA.

Macular Retinal Ganglion Cell Layer Thickness Is Not Reduced in Patients with Obstructive Sleep Apnea

PURPOSE

To evaluate macular ganglion cell layer (GCL) and ganglion cell-inner plexiform layer (GCIPL) thicknesses in patients with obstructive sleep apnea (OSA) syndrome.

METHODS

73 OSA patients and 67 age-matched controls were consecutively and prospectively enrolled. All participants underwent at least one reliable standard automated perimetry (SAP) and were imaged with spectral-domain optical coherence tomography (OCT) using two different devices. The OCT parameters were compared between groups, and Pearson correlations between main indices of SAP and OCT parameters were calculated.

RESULTS

The pattern standard deviation of SAP was higher in the OSA group (p = 0.001). Mean GCIPL thickness was 82.99 ± 10.30 and 80.78 ± 12.15 µm in the control and OSA groups, respectively (p = 0.25), and GCL thickness was 44.93 ± 11.42 µm in the control group and 48.81 ± 10.85 µm in OSA individuals (p = 0.47). Pearson correlations between the GCIPL-GCL measurements and the main indices of SAP were not significant.

CONCLUSIONS

Neither GCIPL nor GCL thickness were reduced in OSA subjects compared with healthy individuals. Retinal sensitivity evaluated with SAP was however decreased in OSA patients.

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.

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.

Update on the Prevalence, Etiology, Diagnosis, and Monitoring of Normal-Tension Glaucoma

Glaucoma is a leading cause of blindness worldwide. Normal-tension glaucoma (NTG) is a type of open-angle glaucoma with intraocular pressure measurements always 21 mm Hg or less. A controversy surrounding NTG is the question of whether it should be regarded as a disease within the spectrum of primary open-angle glaucoma or as a distinctive disease entity. Nonetheless, NTG does have distinctive features compared with primary open-angle glaucoma: intraocular pressure-independent risk factors for development of NTG, characteristic patterns of structural and functional damage, and a unique disease course. This review provides an overview and update on the current issues surrounding the prevalence, etiology, diagnosis, and monitoring of NTG.

Advance in the pathogenesis and treatment of normal-tension glaucoma

Normal-tension glaucoma (NTG) is a multifactorial disease where mechanical stresses and vascular alterations to the optic nerve head probably represent the key pathogenic moments. Although intraocular pressure (IOP) plays a crucial role in the retinal ganglion cell loss, the IOP reduction does not necessarily reduces the disease progression. Therefore, several IOP-independent factors such as glutamate toxicity, oxidative stress, autoimmunity, and vascular dysregulation have been considered in the pathogenesis of NTG. Numerous evidences documented an impairment of the ocular blood flow, involved both in the onset and progression of the disease. The IOP reduction remains the main strategy to reduce the damage progression in NTG. Recently, new treatment strategies have been proposed to improve the control of the disease. Neuroprotection is a rapidly expanding area of research, which represents a promising tool. In the present review, we summarize the recent scientific advancements in the pathogenesis and treatment of NTG.