Peripapillary Choroidal Thickness and Retinal Nerve Fiber Layer in Untreated Patients with Obstructive Sleep Apnea-Hypopnea Syndrome: A Case-Control Study

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.

Differential effects of obstructive sleep apnea on the corneal subbasal nerve plexus and retinal nerve fiber layer

Purpose

Obstructive sleep apnea (OSA) is an established independent risk factor for peripheral neuropathy. Macro and microvascular changes have been documented in OSA, including high levels of potent vasoconstrictors. In diabetes, vasoconstriction has been identified as an underlying risk factor for corneal neuropathy. This study sought to establish a potential relationship between OSA and corneal nerve morphology and sensitivity, and to determine whether changes in corneal nerves may be reflective of OSA severity.

Design

Single center cross-sectional study.

Methods

Sixty-seven patients were stratified into two groups: those with OSA and healthy controls. Groups were matched for age, sex, race, smoking, and dry eye status. Outcome measures included serologies, a dilated fundus exam, dry eye testing, anthropometric parameters, corneal sensitivity, subbasal nerve plexus morphology, retinal nerve fiber layer (RNFL) thickness, and the use of questionnaires to assess symptoms of dry eye disease, risk of OSA, and continuous positive airway pressure (CPAP) compliance.

Results

No significant differences were observed in corneal nerve morphology, sensitivity, or the number of dendritic cells. In the OSA test group, RNFL thinning was noted in the superior and inferior regions of the optic disc and peripapillary region. A greater proportion of participants in the OSA group required a subsequent evaluation for glaucoma than in the control. In those with OSA, an increase in the apnea hypopnea index was associated with an increase in optic nerve cupping.

Conclusions

OSA does not exert a robust effect on corneal nerves. OSA is however, associated with thinning of the RNFL. Participants with glaucomatous optic nerve changes and risk factors for OSA should be examined as uncontrolled OSA may exacerbate glaucoma progression.

Diurnal changes of retinal microvascular circulation and RNFL thickness measured by optical coherence tomography angiography in patients with obstructive sleep apnea-hypopnea

PURPOSE

To evaluate capillaries perfusion and retinal nerve fiber layer (RNFL) thickness diurnal changes of macular/optic disc regions among participants with or without obstructive sleep apnea-hypopnea (OSA) using spectral-domain optical coherence tomography angiography (OCTA).

METHODS

In this study, we enrolled a cohort of 35 participants including 14 patients with mild-to-moderate OSA, 12 patients with severe OSA, and 9 healthy individuals. All participants had Berlin questionnaire filled. At 20:00 and 6:30, right before and after the polysomnography examination, a comprehensive ocular examination was conducted. The systemic and ocular clinical characteristics were collected, and OCTA scans were performed repeatedly. Blood flow and RNFL thickness parameters were then exported using built-in software and analyzed accordingly.

RESULTS

After sleep, the overall vessel density (VD) variables, especially macular and choriocapillaris VDs, were relatively comparative and stable. One exception was the RPC vessel density at the inside-disc region with a decreasing trend in the mild-to-moderate group (p=0.023). RNFL changes before and after sleep in the nasal-inferior and peripapillary region were statistically significant (p=0.003; p=0.043) among three groups. And multiple testing correction verified the significant difference in diurnal changes between the mild-to-moderate group and the control group in pairwise comparisons (p=0.006; p=0.02).

CONCLUSIONS

The changes of imperceptible blood flow and RNFL thickness overnight around optic disc areas could be observed in OSA patients. Despite physiological fluctuations, aberrant diurnal changes might be useful for identifying a decrease in micro-environmental stability associated with the development of various ocular diseases such as glaucoma. Other VD variables, especially macular and choriocapillaris VDs, are relatively stable in eyes of patients having OSA with different severity.

Choroidal Thickness Profile in Chorioretinal Diseases: Beyond the Macula

Enhanced depth imaging optical coherence tomography (EDI-OCT) and swept-source OCT (SS-OCT) have emerged as essential diagnostic tools in the study and management of various chorioretinal diseases. Evidence from early clinical studies using EDI-OCT and SS-OCT indicates that choroidal dysfunction plays a major role in the pathogenesis of chorioretinal diseases. Measurement of choroidal thickness (CT) has already become a major research and clinical method, and CT is considered as an indicator of choroidal status in a variety of ophthalmic diseases. Recently, CT measurement has also been proposed as a non-invasive marker for the early detection and monitoring of various systemic diseases. Among the several possible CT measurement locations, subfoveal CT has rapidly become a reliable parameter for measuring CT in healthy and diseased eyes. Moreover, recent advancements in OCT technology have enabled faster and wider imaging of the posterior part of the eye, allowing the various changes in CT as measured outside the macula to be shown accordingly. In this review, we first provide an overview of the results of clinical studies that have analyzed the healthy macular choroid and that in various chorioretinal diseases, and then summarize the current understanding of the choroid outside the macula. We also examine the CT profile as an index that encompasses both within and outside of the macula. Furthermore, we describe the clinical applications of ultrawide OCT, which enables visualization of the far periphery, and discuss the prospects for the development of more reliable choroidal parameters that can better reflect the choroid's characteristics.

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.

Retinochoroidal vascular plexuses in patients with iron deficiency anaemia

Clinical relevance: Optical coherence tomography angiography (OCT-A) may enable the identification of alteration in the retinochoroidal microvasculature in patients with iron deficiency anaemia.Background: To investigate the presence of macular microvascular alterations in females with IDA by using OCT-A.Methods: This is a cross-sectional comparative study. Forty patients with IDA and 35 age-matched healthy women underwent a complete ophthalmologic examination and OCT-A imaging. Foveal avascular zone parameters and the vessel density in the superficial (SCP) and deep capillary plexus (DCP) were calculated using automated software. All measurements were compared between groups. Correlations between the OCT-A metrics and haematological laboratory parameters were evaluated.Results: Compared to healthy subjects, IDA patients revealed significantly decreased vessel density of the SCP in all parafoveal quadrants (p < 0.05). In contrast, vessel density analysis in DCP has shown no statistically significant difference in all parafoveal quadrants (p > 0.05). Although foveal vessel density in both SCP and DCP were higher in the IDA group, only the foveal vessel density in DCP was significantly higher than controls (p = 0.001). The mean values of the foveal avascular zone area and perimeter and choriocapillaris flow area were significantly lower in the IDA group (p < 0.05). The parafoveal vessel density in SCP, foveal avascular zone area, and choriocapillaris flow area were positively correlated with haematological parameters including haemoglobin, haematocrit, mean corpuscular haemoglobin, and mean corpuscular volume (p < 0.01).Conclusion: Patients with IDA had decreased parafoveal vessel density in the SCP, but not the DCP. Foveal avascular zone metrics and choriocapillaris flow area measurements were significantly lower in IDA.

Quantitative evaluation of retinal microvascular circulation in patients with obstructive sleep apnea-hypopnea using optical coherence tomography angiography

PURPOSE

To compare capillaries perfusion in macular areas at different layers and peripapillary region in radial peripapillary capillaries (RPC) between healthy subjects and subjects with obstructive sleep apnea-hypopnea (OSA) using spectral-domain optical coherence tomography angiography (OCTA).

METHODS

Totally 16 eyes with mild-to-moderate OSA, 14 eyes with severe OSA and 22 control eyes were enrolled in this study. Every subject filled out the Berlin questionnaire and received a comprehensive ocular and physical examination. The clinical characteristics were collected, OCT and OCTA scans using OCTA RT XR Avanti (AngioVue software, Optovue Inc., Fremont, CA, USA) were performed and analyzed.

RESULTS

Compared to the control group, the severe group had significantly higher VD in parafovea and perifoveal regions (p = 0.031; p = 0.029) at the level of deep capillary plexus (DCP), whereas the mild-to-moderate group had a significantly lower VD in the peripapillary region on RPC network in disc areas (p = 0.013).

CONCLUSIONS

Blood flow changes in macular areas might first appear at the DCP layer in OSA patients. Reduced VD in the peripapillary region at the RPC layer might be associated with OSA and cause subsequent RNFL changes.

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.

ASSOCIATION OF OBSTRUCTIVE SLEEP APNEA WITH CENTRAL SEROUS CHORIORETINOPATHY AND CHOROIDAL THICKNESS: A Systematic Review and Meta-Analysis

PURPOSE

Obstructive sleep apnea (OSA) has been associated with an array of ocular disorders. This systematic review aims to investigate the association of OSA with central serous chorioretinopathy (CSCR) and subfoveal choroidal thickness changes on enhanced depth imaging optical coherence tomography.

METHODS

Systematic review and meta-analysis of all articles published up to November 2017 examining rate of OSA in patients with CSCR versus controls or examining subfoveal choroidal thickness measurements on enhanced depth imaging optical coherence tomography in patients with OSA versus controls. Pooled odds ratios and weighted mean difference with 95% confidence intervals (CIs) were calculated.

RESULTS

For the CSCR/OSA analysis, 7,238 patients (1,479 with CSCR and 5,759 controls) from 6 studies were eligible. For the choroidal thickness/OSA analysis, 778 eyes of 778 patients (514 with OSA and 264 controls) from 9 studies were eligible. Patients with CSCR had a 1.56 increased odds of having OSA than controls (odds ratio, 1.56; 95% CI, 1.16-2.10). There was no statistically significant difference in choroidal thickness between mild OSA subjects and controls (weighted mean difference = -3.17; 95% CI, -19.10 to 12.76). Patients with moderate OSA (weighted mean difference = -24.14; 95% CI, -42.16 to -6.12) and severe OSA (weighted mean difference = -51.19; 95% CI, -99.30 to -3.08) had thinner choroidal thickness measurements than controls.

CONCLUSION

In summary, our results suggest that patients with CSCR are more likely to have OSA, and that moderate/severe OSA is associated with smaller subfoveal choroidal measurements on enhanced depth imaging optical coherence tomography.