Macular choroidal thickness measurements in patients with obstructive sleep apnea syndrome

Evaluation of Choroidal Thickness and Retinal Vessel Density with Serum HIF-1α and TNF-α Level in Patients with OSAS

PURPOSE

To reveal changes in choroidal thickness, retinal vessel density, and serum HIF-1α and TNF-α levels in obstructive sleep apnea syndrome (OSAS) and their correlation.

METHODS

This prospective case-control study included 118 patients divided into mild-to-moderate OSAS (n = 40), severe OSAS (n = 39), and a control group (n = 39). Choroidal thickness was evaluated with OCT, vessel density with OCTA, AHI index with polysomnography, and serum HIF-1α and TNF-α levels were analyzed using the enzyme-linked immunosorbent assay.

RESULTS

The serum HIF-1α values of the participants in the mild-moderate OSAS and severe OSAS groups were [893.25(406.7-2068) and 1027(453-2527), respectively], and were both significantly higher than the control group [(521.5(231.6-2741))] (p < 0.001). Serum TNF-α levels did not differ significantly between the groups (p = 0.051).). Subfoveal choroidal thickness (SFCT) values of the severe OSAS groups were significantly lower than the control group (p < 0.05). The superficial and deep capillary plexus vascular density (SVD and DVD) values of the severe OSAS group were lower than the control group (p < 0.05). Serum HIF-1α and TNF-α levels of all participants were negatively correlated with both their SVD values (p < 0.05, r: -0.220 and p < 0.05, r: -0.252, respectively) and their DVD values (p < 0.001, r: -0.324 and p = 0.001, r: -0.299, respectively).

CONCLUSIONS

Increased serum levels of inflammatory mediators (HIF-1α ve TNF-α) in OSAS cause a decrease in SFCT, SVD, and DVD, which is an indication of systemic vascular damage. Further research on developing treatment strategies to modulate TNF-α ve HIF-1α may help recede vascular morbidity in OSAS patients.

Obsructive sleep apnea syndrome: is it a risk factor for ocular surface disease and ocular comorbidities?

PURPOSE

To investigate the accompanying ocular findings in patients with obstructive sleep apnea syndrome (OSAS) and evaluate the susceptibility to ophthalmological diseases.

MATERIALS AND METHODS

In this cross-sectional study, qualifying study subjects were patients who had been diagnosed with severe OSAS (apnea/hypopnea index (AHI > 30/h), n = 31), and control subjects (n = 30) who had an AHI index of < 5 (as normal). General ophthalmological examination, eyelid laxity measurements, corneal topography, visual field, retinal nerve fiber layer parameters, dry eye tests were performed on the patients.

RESULTS

It was observed that the two groups had similar characteristics in terms of gender, age, presence of hypertension, diabetes, and body mass index. According to eyelid laxity measurements, the incidence of loose eyelids was higher in the OSAS patient group. Choroidal thickness was thinner in the study group than in the control group. Schirmer test and tear break-up time were significantly lower in the study group than in the control group. The percentage of meibomian gland loss in meibography and the ocular surface disease index score for symptoms was significantly higher in the study group than in the control group.

CONCLUSION

In this study, we found significant changes in ocular surface parameters, eyelid laxity, choroidal thickness, and visual field indices in OSAS patients. Dry eye syndrome might be related eyelid laxity and inflammation in OSAS patients. Early diagnosis and follow-up of ocular diseases in OSAS, which affect the quality of life and visual prognosis in advanced ages, are important.

Effect of obstructive sleep apnoea syndrome and continuous positive airway pressure treatment on choroidal structure

OBJECTIVES

To evaluate the effect of obstructive sleep apnoea syndrome (OSAS) and continuous positive airway pressure (CPAP) therapy on choroidal structural changes and choroidal vascularity index (CVI) in patients with OSAS.

METHODS

Choroidal structural changes in patients with OSAS immediately after diagnosis and 12 months after CPAP treatment were evaluated and compared with healthy controls. The choroidal images on enhanced depth imaging optical coherence tomography (EDI-OCT) were binarized into luminal area (LA) and stromal area (SA) using the ImageJ software. CVI was calculated as the ratio of LA to total choroid area (TCA). The correlations between the results of polysomnography (PSG) and choroidal parameters were evaluated.

RESULTS

A total of 48 eyes of 48 patients (22 patients with OSAS, and 26 controls) were included. The mean age of the patients was 47.21 ± 8.82 (range, 30-63) years. The mean CVI values were 68.10 ± 1.80% in the OSAS group before CPAP therapy, and 69.22 ± 1.40% in the control group (p < 0.05). After 12 months of regular CPAP therapy, the mean CVI value increased significantly to 69.15 ± 1.77%, and SA decreased significantly from 0.51 ± 0.07 mm2 to 0.48 ± 0.07 mm2 in the OSAS group (p < 0.05). No statistically significant correlation was found between the results of PSG and choroidal structural parameters.

CONCLUSION

According to our results, OSAS was associated with increased stromal oedema in the choroid, which improved after 12 months of regular CPAP therapy. CVI can be an important parameter for the follow-up of patients with OSAS.

EVALUATİON OF THE EFFECT OF OBSTRUCTİVE SLEEP APNEA SYNDROME ON RETİNAL MİCROVASCULARİTY BY OPTİCAL COHERENCE TOMOGRAPHY ANGİOGRAPHY

PURPOSE

Using optical coherence tomography angiography (OCTA), we sought to determine whether there are retinal microvascular changes in patients with obstructive sleep apnea syndrome (OSAS).

METHOD

The study included 56 patients diagnosed with OSAS by polysomnography [21 patients with mild OSAS (group 1), 14 with moderate OSAS (group 2) and 21 with severe OSAS (group 3)], and 26 healthy individuals as a control group (group 4). The vascular densities of the superficial capillary plexus and deep capillary plexus of the retinal segmentations, together with the foveal avascular zone (FAZ) width, were measured for all participants, using OCTA.

RESULT

Compared with the control group, vascular densitiy in whole image of superficial capillary plexus were found to be significantly lower in group 2. In addition, vascular densitiy in fovea region of superficial capillary plexus was significantly lower in group 1 than the control group. In deep capillary plexus, vascular densitiy of whole image, superior hemi and nasal regions were found to be significantly lower in group 2 and group 3 compared with the control group. Parafoveal region in group 3 had significantly lower vascular densities than the controls. A significantly larger FAZ was also found in group 1 and group 3 in the deep capillary plexus, compared with the controls.

CONCLUSION

We detected smaller vascular densities in both the superficial capillary plexus and deep capillary plexus and a larger deep capillary plexus FAZ in OSAS patients. Therefore, OCTA may be useful as a non-invasive method to understand the systemic effects of OSAS.

The Effect of Obstructive Sleep Apnea Treatment and Severity on Choroidal Thickness in Patients With Central Serous Chorioretinopathy

Purpose:

This work aimed to analyze the association of obstructive sleep apnea (OSA) with choroidal thickness (CT) in patients with central serous chorioretinopathy (CSC).

Methods:

We identified patients in the Stanford Research Repository with a diagnosis of CSC and OSA. Age- and sex-matched controls with either CSC or OSA only were also identified. CT was measured at 5 points (subfoveal, and 1500 and 3000 µm nasal and temporal) by 2 graders. In addition to OSA treatment and severity, we also investigated the association of Oxygen Desaturation Index and nocturnal oxygen saturation nadir with subfoveal CT (SFCT).

Results:

A total of 57 patients and 72 eyes met the study inclusion criteria. The mean SFCT was significantly different across the 3 groups: OSA-only was the thinnest, followed by CSC with OSA, and CSC-only was the thickest (194.2 μm, 295.1 μm, and 357.8 μm, respectively, P < .001). SFCT was thicker in CSC with OSA compared with those with only OSA ( P < .05). OSA treatment status and OSA severity did not show a significant difference in SFCT in multivariable modeling. Nocturnal oxygen saturation nadir was positively associated with SFCT, but this did not reach significance..

Conclusions:

SFCT is significantly different in patients with OSA alone, CSC with OSA, and CSC alone. While OSA treatment status did not demonstrate a significant difference in SFCT in this study, future studies should evaluate patients for OSA in patients known to have CSC and atypically thin CT to further investigate the novel metrics leveraged in this study.

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.

Comparison of the choroidal structural components and choroidal vascularity index between patients with obstructive sleep apnea syndrome and healthy controls

AIM

To compare the choroidal structural components and choroidal vascularity index (CVI) between patients with obstructive sleep apnea syndrome (OSAS) and healthy controls.

METHODS

The choroidal images of the eyes of patients with OSAS and healthy controls, which were obtained by using enhanced depth imaging optical coherence tomography (EDI-OCT), were binarized into luminal area (LA) and stromal area (SA) using the ImageJ software. CVI was calculated as the ratio of LA to the total choroid area (TCA). The CVI, LA, SA, and TCA measurements were compared between the groups.

RESULTS

Seventy-one eyes of 57 patients, 33 eyes of 27 patients with OSAS and 38 eyes of 30 healthy individuals, were included. The mean age of all patients was 46.77±9.75 (range, 30-67) years. There was no statistically significant difference for age, sex, axial length (AL) or the side of the eyes between the groups (p>0.05). The mean body mass index (BMI) of the patients was significantly higher in the OSAS group (p<0.05). The mean CVI value was 68.33±1.81% in the OSAS group and 69.21±1.27% in the control group (p<0.05). There was no statistically significant difference for the mean values of LA, SA, and TCA between the groups (p>0.05). No significant correlation was found between the polysomnography test results and the choroidal measurements (p>0.05).

CONCLUSION

In our study, CVI was found to be lower in patients with OSAS than in the healthy controls. Further studies with larger sample sizes are required to evaluate the role of CVI in OSAS.

Obstructive sleep apnea and the retina: a review

CITATION

This review's objective was to synthesize the literature on the repercussions of obstructive sleep apnea (OSA) in the retinal vascular system. Two independent investigators conducted a search using the MEDLINE/PubMed database using the following terms: sleep apnea syndrome, obstructive sleep apnea, retina, vascular tortuosity, central serous chorioretinopathy, diabetes mellitus, and subfoveal choroidal thickness. Patients with OSA present increased vascular tortuosity compared with patients without OSA, decreased parafoveal and peripapillary vessel density, and increased retinal vein occlusion incidence. In central serous chorioretinopathy patients and patients who are poor responders to intravitreal anti-VEGF (-vascular endothelial growth factor) treatment for macular edema, OSA is more frequent. Macular choroidal thickness alterations are controversial, and OSA may worsen diabetic maculopathy, thus being a risk factor for diabetic retinopathy, proliferative diabetic retinopathy, and macular edema. OSA is a prevalent syndrome with many systemic vascular changes. The retina and choroid are the most affected ocular structures, with primarily vascular changes. New noninvasive technologies such as optical coherence tomography and optical coherence tomography angiography could help to better understand retinal structures and help clarify the ophthalmological repercussions of OSA.

CITATION

Nakayama LF, Tempaku PF, Bergamo VC, et al. Obstructive sleep apnea and the retina: a review. J Clin Sleep Med. 2021;17(9):1947-1952.

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.

Exploring the Biopsychosocial Pathways Shared by Obstructive Sleep Apnea (OSA) and Central Serous Chorioretinopathy (CSC): A Literature Overview

This study addressed the following question: “Is it possible to highlight the link between obstructive sleep apnea (OSA) and central serous chorioretinopathy (CSC) through common biopsychosocial pathogenetic pathways?”. The study was conducted through electronic searches of the PubMed, Web of Science, and Scopus databases. All relevant selected human research studies published from January 2003 to December 2020 were included. The scientific literature search was performed through repeated use of the words “OSA” and/or “acute/chronic CSC” paired with “biomedical/biopsychosocial illness model”, “psychopathology”, “stress”, “personality characteristics”, “functional diseases”, “comorbidity”, and “quality of life” in different combinations. Our literature search identified 213 reports, of which 54 articles were ultimately reviewed in this paper. Taken together, the results indicate that there is a cross-link between OSA and CSC that can be classified among biopsychological disorders in which various major biological variables integrate with psychological-functional and sociological variables; many of these variables appear in both diseases. This concept can have important implications for improving patients’ quality of life, thus providing the necessary strategies to cope with challenging life events even through nonpharmacological approaches.

Evaluation of retinal vessel density and foveal avascular zone measurements in patients with obstructive sleep apnea syndrome

PURPOSE

To compare retinal capillary plexus vessel densities, choroidal thickness, optic disc vessel densities and foveal avascular zone measurements between normal subjects and subjects with obstructive sleep apnea syndrome (OSAS) using spectral-domain OCT angiography (OCTA).

METHODS

Forty eyes of patients with overall OSAS, 20 eyes of patients with mild-moderate OSAS, 20 eyes of patients with severe OSAS on polysomnography and 21 controls were evaluated with the RTVue-XR Avanti OCTA (Optovue, Inc., Fremont, CA). Superficial and deep retinal capillary plexus vessel densities, choroidal thickness and foveal avascular zone (FAZ) parameters (area, diameter, acircularity index of the FAZ, foveal density-300) were measured for all subjects.

RESULTS

Superficial capillary plexus vessel densities of the groups were similar. Deep capillary plexus (DCP) vessel densities of all three OSAS groups decreased in the parafoveal region (< 0.001). In the perifoveal region, DCP vessel densities were decreased in the Overall OSAS group (p = 0.023) and in the Severe OSAS group (p = 0.021), whereas it was similar in the Mild-moderate OSAS group. Choroidal thickness decreased in all three OSAS groups (p < 0.001). All FAZ measurements and foveal density-300 measurements were similar compared to the control group.

CONCLUSION

Our findings indicate that in severe OSAS patients, deep parafoveal, perifoveal vascular densities decrease and the choroid layer becomes thinner. When evaluating a patient with OSAS, it should be kept in mind that there may be eye involvement due to the disease.

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.

Evaluation of choroidal thickness measurements in patients with marked nasal septal deviation

Introduction

Chronic upper airway obstruction due to marked nasal septal deviation may cause chronic hypoxia. It may change the balance of the sympathetic-parasympathetic system and may affect blood flow in the choroid.

Objective

To assess choroidal thickness measurements of patients with marked nasal septal deviation.

Methods

The patients who had nasal obstruction symptoms diagnosed with marked nasal septal deviation by anterior rhinoscopy and nasal endoscopy and scheduled for septoplasty were included in the study. The control group consisted of age, sex and body mass index-matched healthy individuals. The choroidal measurements at the central fovea and 1000 μm away from the fovea in the nasal and temporal regions were performed using enhanced depth imaging optical coherence tomography.

Results

In the study group, 52 eyes of 26 patients with a mean age of 26.34 ± 8.14 years were examined. In the control group, 52 eyes of 28 healthy individuals with a mean age of 26.69 ± 7.84 years were examined. There was no statistically significant difference in terms of choroidal thickness measurements between the groups (p > 0.05).

Conclusion

Our results suggest that marked nasal septal deviation may not lead to significant hypoxia and sympathetic activation, resulting in deterioration of the choroidal blood flow and consequent choroidal thickening.

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.

Evaluation of choroidal thickness in children with adenoid hypertrophy

OBJECTIVE

To assess choroidal thickness in children with adenoid hypertrophy versus normal controls using enhanced depth imaging optical coherence tomography (EDI-OCT).

METHODS

Twenty-six children (left and right eyes, total 52 eyes), which were scheduled to adenoidectomy with severe adenoid hypertrophy and 26 age, sex and body mass index-matched healthy subjects (left and right eyes, total 52 eyes) were included in the study. Choroidal thicknesses (CT) were evaluated using enhanced depth imaging optical coherence tomography. The CT measurement was taken at the fovea and 1000 μ away from the fovea in the nasal and temporal regions. The macular retinal thickness was also measured.

RESULTS

There was no statistically significant difference in the CT of all regions between the groups (p > 0.05). No statistically significant difference was found between two groups in terms of macular choroidal thickness (p > 0.05).

CONCLUSION

These results revealed that severe adenoid hypertrophy did not cause a significant effect on choroidal thickness. Short-term exposure to obstructive symptoms in children and preserved sympathetic-parasympathetic balance may explain this result.

Choroidal thickness measurements in children with isolated growth hormone deficiency

PurposeThe aim of this study was to determine the choroidal thickness measurement values in cases with isolated growth hormone deficiency (IGHD), to compare them with the healthy control group by using enhanced depth imaging optical coherence tomography (EDI-OCT), and to evaluate the effect of growth hormone (GH) treatment on choroid.Patients and methodsIn this study, 23 cases who were diagnosed with IGHD as a study group and 46 healthy subjects as a control group were included. All patients and controls underwent a complete ophthalmologic examination, including an examination with EDI-OCT. Choroidal thickness (CT) was measured at the fovea and at 1000 μm intervals from the foveal center in both temporal and nasal directions.ResultsThe mean subfoveal choroidal thickness (SFCT) was 329.04±88.49 μm in the cases with IGHD and 365.35±50.48 μm in the control group (P=0.033). The mean CT at temporal 1 and 2 mm were thinner in the IGHD group than that of control group (P=0.033 and P=0.043, respectively). Nasal quadrant measurements were also found to be thinner in the IGHD cases than that of control group, but the difference was not statistically significant. We found a significant positive correlation between pubertal staging and SFCT (r_s=0.607, P=0.006). There was no statistically significant difference in CT values of the study group between before and 12 months after GH treatment (P>0.05).ConclusionThis study shows patients with IGHD has a thinner CT when compared with healthy pediatric cases. GH treatment seems to be not associated with the choroidal development.

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

PURPOSE

To evaluate peripapillary choroidal thickness (PPCT), central macular choroidal thickness (CMCT), and retinal nerve fiber layer (RNFL) thickness in untreated patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

This prospective, randomized, and comparative study was conducted in a university ophthalmology clinic. 106 eyes of 106 patients with OSAHS and 44 eyes of 44 healthy individuals were evaluated in this study. Only right eyes were evaluated. The patients with OSAHS were divided into three groups as mild (group 1), moderate (group 2), and severe (group 3) according to apnea-hypopnea index. The PPCT, CMCT, and RNFL measurements were performed by using spectral domain optical coherence tomography with enhanced depth imaging technique. The main parameters assessed were PPCT-Temporal, PPCT-Superior, PPCT-Nasal, PPCT-Inferior quadrants, CMCT, and RNFL thicknesses.

RESULTS

The PPCT of all quadrants was significantly thicker in the control group compared with the moderate and severe subgroups of OSAHS (p < 0.05). The PPCT-Superior and PPCT-Temporal were significantly thinner in the mild subgroup compared with the control group (p = 0.003 and p = 0.028, respectively). There was no difference between the control and mild groups regarding the RNFL thicknesses except nasal RNFL and inferotemporal RNFL which are thinner in the mild group. The RNFL thicknesses of all quadrants were significantly thicker in the control group compared with moderate and severe subgroups (p < 0.05). The CMCT was significantly thicker in the control group compared with all subgroups of OSAHS (p < 0.05).

CONCLUSIONS

In OSAHS patients, PPCT, CMCT, and RNFL were significantly thinner compared with the control group. These results may explain why OSAHS patients are prone to normotensive glaucoma.

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.

Changes in the choroidal thickness in reproductive-aged women with iron-deficiency anemia

BACKGROUND

The aim of this study was to investigate the potential significance of the central macular thickness (foveal thickness-FT) and choroidal thickness (CT) in the eyes of patients with iron-deficiency anemia, the most common form of the anemia, via enhanced-depth imaging optical coherence tomography (EDI-OCT). We also investigated whether such changes might serve as an early indicator of underlying hematological disease.

METHODS

This prospective clinical study compared 96 female patients with iron-deficiency anemia and 60 healthy female control subjects. The macular and choroidal thicknesses in the temporal and nasal subfoveal areas were measured using enhanced-depth imaging optical coherence tomography (EDI-OCT) at 500 and 1500 microns and in five different regions (FCT, T1500, T500, N500, and N1500).

RESULTS

The mean ages of the patients and healthy controls were 34.08 ± 10.39 years and 32.29 ± 8.28 years, respectively (P =0.232). There were no significant changes in macular thickness between the groups (225.58 ± 19.76 vs. 222.45 ± 13.51, P =0.2). The choroidal thickness was significantly reduced in the patient group relative to the controls at all measured points (foveal choroidal thickness, P = 0.042; nasal-500 microns, P = 0.033; temporal-500 microns, P = 0.033; and temporal-1500 microns, P = 0.019). At some points, the choroidal thickness findings correlated with the hemoglobin values (temporal-500 microns, r = -0.287, P = 0.001; nasal-500 microns, r = -0.287, P = 0.005; nasal-1500 microns, r = -0.245, P = 0.016; and temporal-1500 microns, r = -0.280, P = 0.06).

CONCLUSIONS

Patients with iron-deficiency anemia had a significantly reduced choroidal thickness.