Retinal and choroidal thickness evaluation by SD-OCT in adults with obstructive sleep apnea-hypopnea syndrome (OSAS)

Retinal microvascular phenotypes can track small vessel disease burden and CPAP treatment effectiveness in obstructive sleep apnea

Optical coherence tomography angiography (OCT-A) retinal imaging enables in vivo visualization of the retinal microvasculature that is developmentally related to the brain and can offer insight on cerebrovascular health. We investigated retinal phenotypes and neuroimaging markers of small vessel disease (SVD) in individuals with obstructive sleep apnoea (OSA). We enrolled 44 participants (mean age 50.1 ± SD 9.1 years) and performed OCT-A imaging before and after continuous positive airway pressure (CPAP) therapy. Pre-treatment analyses using a generalized estimating equations model adjusted for relevant covariates, revealed perivascular spaces (PVS) volume in basal ganglia associated with greater foveal vessel density (fVD) (p-value < 0.001), and smaller foveal avascular zone area (p-value = 0.01), whereas PVS count in centrum semiovale associated with lower retinal vessel radius (p-value = 0.02) and higher vessel tortuosity (p-value = 0.01). A reduction in retinal vessel radius was also observed with increased OSA severity (p-value = 0.05). Post-treatment analyses showed greater CPAP usage was associated with a decrease in fVD (p-value = 0.02), and increased retinal vessel radius (p-value = 0.01). The findings demonstrate for the first time the potential use of OCT-A to monitor CPAP treatment and its possible impact on both retinal and brain vascular health.

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.

Oxidative stress and optical coherence tomography angiography evaluation of choriocapillaris and retinal vessel density in children with obstructive sleep apnea

OBJECTIVES

To investigate the vascular networks of the retina and choroid using optical coherence tomography angiography (OCTA) to identify early biomarkers of obstructive sleep apnea (OSA) severity and to evaluate correlations with blood levels of oxidative stress.

STUDY DESIGN

Patients with OSA were diagnosed based on video-polysomnography (PSG) and blood samples were collected to evaluate oxidative stress markers: total antioxidant status (TAS), biological antioxidant potential (BAP) test, Diacron reactive oxygen metabolites (d-ROMs) test. The eyes of children with OSA were evaluated and compared with eyes of healthy age-matched children. OCTA imaging was carried out to evaluate the choroidal and retinal vascular network density indices.

RESULTS

A total of 31 children with OSA were recruited and compared with 10 healthy children. Choriocapillaris flow area decreased (p = 0.006) and superficial capillary plexus vessel density increased (p=0.01) with increasing severity of OSA. Children with OSA showed significant differences in TAS and d-ROMs test when compared to normal pediatric values (p<0.05). In calculating the correlations between PSG, oxidative stress, and OCTA variables, there was a negative correlation between choriocapillaris flow area and apnea hypopnea index (AHI) (p = 0.02, r2 -0.5) and between choriocapillaris flow area and the d-ROMs test (p 0.03; r2 0.5).

CONCLUSIONS

The severity of OSA was associated with the choroidal and retinal capillary vascular networks. The correlation of the choriocapillaris flow area with AHI and the d-ROMs test indicates the connection of the choroidal microvasculature with the number of obstructive apnea and hypopnea events and oxidative stress.

Influence of high altitude on choroid thickness, retinal thickness, and myopia: A cross-sectional study comparing adolescents in Shanghai and Tibet

PURPOSE

This study aimed to explore the influence of high altitude on myopia, macular choroidal thickness (mCT), and macular retinal thickness (mRT) in adolescents.

METHODS

Two schools, one in Shanghai (at sea level) and one in Shigatse, Tibet (more than 4000 m above sea level), were selected. Refractive error was measured by an autorefractor instrument and subjective refraction, and mCT and mRT were measured at three concentric circles by optical coherence tomography. Student's t -test, Chi-square test, and multiple linear regression analyses were used to analyze the data.

RESULTS

A total of 1114 participants (657 and 457 in Shanghai and Tibet, respectively) were enrolled in this cross-sectional study. The average age of the participants was 18.81 ± 1.10 years, and 44.34% were males. The spherical equivalent (SE) of adolescents in Shanghai was significantly lower than that of adolescents in Tibet (-4.14 ± 2.37 D and -2.12 ± 1.87 D, P < 0.01). The prevalence of myopia and high myopia among adolescents in Shanghai (94.52%, 19.48%) was significantly higher than those among adolescents in Tibet (44.74%, 2.41%) ( P < 0.01). The mCT of Tibetan adolescents was significantly thicker than that of Shanghai adolescents (295.80 ± 62.46 μm and 218.71 ± 61.42 μm, P < 0.01), especially the central mCT. The mRT of Tibetan adolescents was also thicker than that of Shanghai adolescents (301.42 ± 23.26 μm and 281.04 ± 12.24 μm, P < 0.01).

CONCLUSIONS

Compared with Shanghai adolescents, the choroid of Tibet adolescents is thicker, and the myopia prevalence is lower. It is speculated that increased altitude is associated with the thickening of mCT and a low myopia prevalence.

Investigation of the optic disc and retinal microvasculature by optical coherence tomography angiography in children with asthma

PURPOSE

To assess the optic disc and retinal microvasculature by optical coherence tomography angiography (OCTA) in asthmatic children.

MATERIALS AND METHODS

Thirty asthmatic children (asthma group) and 30 control age- and sex-matched healthy controls (control group) were included in this cross-sectional study. The asthma group was then divided into two subgroups according to the presence of inhaled steroid use. Demographic findings were noted. Retinal nerve fiber layer (RNFL) thickness and vessel density in different sections of the retina and optic nerve head were analyzed by OCTA.

RESULTS

RNFL thickness for temporal quadrants and flow area for outer retina levels were significantly lower in the asthma group than the control group (72.58 ± 10.99 μm vs 77.73 ± 9.73μm, P = 0.015, and 0.60 ± 0.31mm2 vs. 0.72 ± 0.31mm2, P = 0.047, respectively). However, inside disc vascular densities were significantly higher in the asthma group when compared to controls (55.16% ± 3.71% vs. 52.08% ± 3.79%, P < 0.001). Inside disc vascular densities were also significantly higher, and RNFL thickness for temporal quadrants was significantly lower in the asthmatic patients without steroid use subgroup when compared to others (P < 0.001, P = 0.012, respectively).

CONCLUSION

Lower values of temporal quadrant RNFL, and flow area for outer retina, but higher levels of inside disc vascular density seem to be associated with asthmatic children. OCTA findings in asthmatic children appear to be regardless of inhaled steroid use.

Functional and Anatomical Outcomes of Anti-Vascular Endothelial Growth Factor Treatment for Exudative Age-Related Macular Degeneration with or without Obstructive Sleep Apnea

(1) To investigate the functional and anatomical outcomes of anti-vascular endothelial growth factor (anti-VEGF) treatment in patients with exudative age-related macular degeneration (AMD) with or without obstructive sleep apnea (OSA); (2) In total, 65 patients with AMD with or without OSA who received three consecutive doses of intravitreal anti-VEGF injections were enrolled. The primary outcomes-best-corrected visual acuity (BCVA) and central macular thickness (CMT)-were assessed at 1 and 3 months. Moreover, morphological changes observed through optical coherence tomography were analyzed; (3) In total, 15 of the 65 patients had OSA and were included in the OSA group; the remaining 50 patients were included in the non-OSA (control) group. At 1 and 3 months after treatment, BCVA and CMT had improved but did not differ significantly between the groups. More patients in the OSA group demonstrated subretinal fluid (SRF) resorption at 3 months after treatment than in the non-OSA group (p = 0.009). Changes in other imaging biomarkers, such as intraretinal cysts, retinal pigment epithelium detachment, hyperreflective dots, and ellipsoid zone disruptions, did not differ significantly between the groups; (4) Our results suggest that the BCVA and CMT outcomes 3 months after anti-VEGF treatment are similar between patients with and without OSA. Moreover, patients with OSA may exhibit superior SRF resorption. A large-scale prospective study is mandatory to evaluate the association between SRF resorption and visual outcomes in AMD patients with OSA.

Evaluation of acute effects of pulmonary involvement and hypoxia on retina and choroid in coronavirus disease 2019: An optic coherence tomography study

PURPOSE

We investigated the acute subclinical choroidal and retinal changes caused by Coronavirus Disease 2019 (COVID-19) in patients with and without pulmonary involvement, using spectral domain optic coherence tomography.

METHODS

This prospective case-control study included COVID-19 patients: 50 with pulmonary involvement and 118 with non-pulmonary involvement. All patients were examined 1 month after recovering from COVID-19. The changes were followed using optic coherence tomography parameters such as choroidal and macular thickness and retinal nerve fibre layer and ganglion cell complex measurements.

RESULTS

All choroidal thicknesses in the pulmonary involvement group were lower than in the non-pulmonary involvement group and the subfoveal choroidal thickness differed significantly (p=0.036). Although there were no significant differences between the central and average macular thicknesses in the two groups, they were slightly thicker in the pulmonary involvement group (p=0.152 and p=0.180, respectively). A significant decrease was detected in the pulmonary involvement group in all ganglion cell complex segments, except for the outer nasal inferior segment (p<0.05). In addition, a thinning tendency was observed in all retinal nerve fibre layer quadrants in the pulmonary involvement group compared to the non-pulmonary involvement group.

CONCLUSION

In COVID-19 patients with pulmonary involvement, subclinical choroidal and retinal changes may occur due to hypoxia and ischemia in the acute period. These patients may be predisposed to ischemic retinal and optic nerve diseases in the future. Therefore, COVID-19 patients with pulmonary involvement should be followed for ophthalmological diseases.

Decreased Peripapillary and Macular Vascular Densities in Patients with Moderate/Severe Obstructive Sleep Apnea/Hypopnea Syndrome

PURPOSE

To compare peripapillary and macular vascular densities (PVDs and MVDs) between patients with obstructive sleep apnea/hypopnea syndrome (OSA) and control subjects with symptoms of sleep-related breathing disorders only by swept-source optical coherence tomography angiography (OCTA).

PARTICIPANTS AND METHODS

In this prospective study, 192 participants underwent a full-night polysomnography to determine OSA severity and subsequently received OCTA measurements as well as AngioTool software analysis.

RESULTS

A total of 146 patients with OSA (51 mild, 43 moderate, 52 severe) and 24 control subjects (apnea/hypopnea index, AHI <5) were enrolled. PVDs and MVDs in the superficial and choroidal layers were significantly different among the four groups. When participants with simple snoring/mild OSA (AHI <15) were grouped together and compared with moderate/severe OSA (AHI ≥15), PVDs were significantly lower for the latter group in the superficial layer (p = 0.0003), deep layer (p = 0.004), and choroidal layer (p = 0.003). MVDs were also lower for the moderate/severe OSA group in the superficial (p = 0.012) and choroidal layer (p = 0.004). Negative correlations were identified between AHI and PVDs in the superficial layer (ρ = -0.257, p = 0.0007), deep layer (ρ = -0.197, p = 0.0102) and choroidal layer (ρ = -0.220, p = 0.0039) and between AHI and MVDs in the superficial layer (ρ = -0.199, p = 0.0094) and choroid layer (ρ = -0.186, p = 0.0152).

CONCLUSION

PVDs and MVDs were significantly lower in patients with moderate/severe OSA as compared to subjects with simple snoring/mild OSA. Furthermore, decreased PVDs and MVDs significantly correlated with OSA severity.

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.

Evaluation of Optical Coherence Tomography Findings and Choroidal Thickness in Beta-Thalassemia Major Patients Using Chelation Therapy

Objectives

This study aims to analyze the posterior segment of the eye in children with thalassemia major (TM) treated with chelation therapy.

Methods

Forty-four patients diagnosed with TM and 44 age- and gender-matched participants without systemic diseases were included in this cross-sectional comparative study. A complete ophthalmologic examination, including visual acuity and fundus examination, was performed on all participants. The study and control groups' optic coherence tomography (OCT) evaluation was performed with a spectral domain featured OCT device. Central macular thickness (CMT), macular volume, ganglion cell complex (GCC) thickness, retinal nerve fiber layer (RNFL) thickness, subfoveal choroidal thickness (CT), CT at 1 mm temporal to the fovea, CT at 1 mm nasal to the fovea, CT at the 1 mm temporal to the optic nerve head, and CT at the 1 mm nasal to the optic nerve head were compared between the study and control groups.

Results

The mean ages for the study group and for the control group were 15.2±6.2 and 14.2±4.9 years, respectively. The mean subfoveal CT was 287.73±47.04 µm in the TM group and 312.66±39.95 µm in the control group (p=0.014). CT at the nasal to the fovea and temporal to the optic nerve head was thinner in the TM group than in the healthy group. The mean CMT, macular volume, GCC thickness, and RNFL thickness of the study and the control groups were similar. No significant difference was found between the patients with and without deferoxamine therapy concerning macular thickness, GCC thickness, and macular and peripapillary CT.

Conclusion

Our results suggested that subfoveal, perifoveal, and peripapillary CTs were significantly thinner in children with TM than the control group. The use of deferoxamine did not cause a further reduction in CT.

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.

The effect of positive airway pressure therapy on intraocular pressure and retina in severe obstructive apnea syndrome

To identify and compare changes in intraocular pressure (IOP), macular, and peripapillary retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) measurements before and after 3 months of positive airway pressure (PAP) therapy in patients with severe obstructive sleep apnea syndrome (OSAS). Twenty-five patients diagnosed with severe OSAS in the neurology sleep outpatient clinic were included in the study. Ophthalmologic examinations were performed at the time of diagnosis and after 3 months of PAP therapy. Statistical analysis of comparisons of pre-treatment and post-treatment measurements of IOP and OCT was performed. Before the PAP therapy, the correlations between central corneal thickness (CCT), body mass index (BMI), OCT, IOP, and sleep parameters were statistically analyzed. Compared to the pre-treatment measurements at the time of diagnosis, post-treatment measurements showed insignificant decrease in IOP, significant increase in mean macular thickness and significant thinning in superior nasal RNFL. There was no correlation found between pre-treatment measurements including IOP, OCT, CCT, BMI, and sleep parameters. The effect of intermittent hypoxia and hypercapnia on the IOP and macula may be reversible in severe OSAS patients receiving 3 months of PAP therapy, but the reversibility of the neurodegenerative effects of OSAS on RNFL with this treatment seems controversial. OCT can be considered to be a promising technique for monitoring disease progression under PAP therapy in patients with severe OSAS.

Assessment of the Effectiveness of Obstructive Sleep Apnea Treatment Using Optical Coherence Tomography to Evaluate Retinal Findings

Retinal findings may change in patients with obstructive sleep apnea syndrome (OSAS). The present study aims to evaluate several retinal findings, such as macula layer thickness, the peripapillary retinal nerve fiber layer, and the optic nerve head in patients with OSAS, using optical coherence tomography (OCT); it also aims to monitor the result of several types of treatment of OSAS with OCT. A prospective comparative study was designed. Patients were recruited at a Sleep Unit of a University Hospital and underwent comprehensive ophthalmological examinations. Following exclusion criteria, fifty-two patients with OSAS were finally included. Patients were examined by OCT twice: once before treatment, and again after six months of treatment. In mild–moderate patients, where retinal swelling had been demonstrated, retinal thicknesses decreased [fovea (p = 0.026), as did inner ring macula (p = 0.007), outer ring macula (p = 0.015), and macular volume (p = 0.015)]. In severe patients, where retinal atrophy had been observed, retinal thickness increased [fovea (p < 0.001)]. No statistically significant differences in efficacy between treatments were demonstrated. In conclusion, OCT can evaluate the retina in patients with OSAS and help to monitor results after treatment. In severe OSAS, retinal thickness increased six months after treatment.

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.

Is there any connection between choroidal thickness and obesity?

Obesity is a health-threatening and epidemic medical condition that can affect individuals of different ages and is potentially associated with an increased risk of systemic and ocular disorders. Despite the well-documented adverse effects of obesity on different parts of the body vasculature, less published data are available concerning obesity-related consequences on the ocular vasculature. As the human choroid is a highly vascularized tissue, its morphology and function might be altered in obese individuals. The micro-structural changes within the choroid could also trigger development of subsequent functional abnormalities of the eye. Previous population-based studies have asserted an association between obesity and choroidal thickness; however, they reported conflicting patterns of association between obesity and changes in choroidal thickness. Therefore, to enhance our understanding of the changes in choroidal morphology secondary to obesity, we reviewed studies describing the micro-structural consequences of obesity on the choroidal thickness profile and its underlying physiological and anatomical basis. This review includes all original publications related to the association between choroidal thickness and obesity published until mid-2021 that were indexed in PubMed, Google Scholar, ScienceDirect, or Scopus.

Choroidal vascularity index in obstructive sleep apnea syndrome

BACKGROUND

There is growing evidence supporting an association between obstructive sleep apnea syndrome (OSAS) and systemic vascular disorders. However, the data on choroidal microvasculature are limited. In recent years, choroidal thickness (CT) and choroidal vascularity index (CVI) have been of considerable interest as objective markers of choroidal vascularity. We hypothesized that the imbalance of vascular regulation in OSAS may adversely affect the CT and CVI and may help to assess the vascular risk in these patients.

PURPOSE

This study aimed to evaluate the choroidal morphology in patients with OSAS.

MATERIALS AND METHODS

Patients with moderate OSAS were included to this study. The subfoveal, nasal, and temporal CT were calculated. The choroidal area (CA) was binarized to the luminal area (LA) and stromal area (SA) using ImageJ software. The CVI was calculated as the proportion of the LA to the total CA.

RESULTS

Of 40 eyes of 40 patients, the mean subfoveal CT was significantly decreased in the OSAS group in comparison to the controls (p = 0.032). The mean CA, LA, and SA were decreased in the OSAS group compared with the controls, but the differences did not reach a statistical significance (p = 0.132, p = 0.104, and p = 0.184, respectively). The CVI was not significantly changed in patients with OSAS (p = 1.000).

CONCLUSION

Unlike CT, there were no significant differences in choroidal structural parameters and CVI in patients with OSAS.

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.

Choroidal vascularity index and choroidal thickness changes in patients with allergic asthma

BACKGROUND

This study aimed to investigate whether the choroidal vascularity index (CVI), choroidal thickness (ChT), and retinal nerve fiber thickness (RNFL) of patients with allergic asthma change compared to the healthy control group.

METHODS

This cross-sectional, observational study comprised 59 eyes of 59 patients with allergic asthma (Group 1) and 50 eyes of 50 age and sex-matched healthy volunteers as a control group (Group 2). CVI was measured by binarization of images obtained from choroidal enhanced depth imaging (EDI) mode optic coherence tomography. CVI was defined as the ratio of the choroidal luminal area to the total circumscribed choroidal area. ChT was measured manually at 3 points, subfoveal and 1000 microns nasal and temporal to the fovea (SFCT, N1000, and T1000 respectively). RNFL measurements were subdivided as global, nasal, temporal, superonasal, superotemporal, inferonasal, and inferotemporal quadrants.

RESULTS

Subfoveal CVI and ChT were significantly lower in asthma patients (p:0,043 and p: 0.034, respectively). N1000 and T1000 ChT and RNFL thicknesses were lower in asthma patients compared to the control group, though no significant difference was found between them (p> 0.05).

CONCLUSION

Our findings suggest that asthma patients have choroidal structural changes. In the literature, there are not enough studies regarding the effects of asthma on ocular parameters.

Choroidal and retinal thickness variations in anaemia and anaemic retinopathy

Anemia is the most common hematological disorder noted in the people of the Indian subcontinent. Hemodynamic changes following anemia on the retina and choroid are not frequently studied. The aim of the study was to analyse the subfoveal retinal (CRT) and choroidal (SFCT) thickness changes in patients with anemia. In this retrospective, comparative study, patients who were diagnosed with primary anemia and had a fundus examination by a retinal specialist were included. Patients were divided into 3 groups: Group 1: Patients with anemic retinopathy; Group 2: Patients with anemia without retinopathy; Group 3: Normal healthy controls. One hundred and ninety-seven eyes of 197 subjects (group 1 - 38 eyes, group 2 - 90 eyes; group 3 - 69 eyes) met the inclusion criteria. Mean CRT was 269 ± 117µm, 258 ± 99.7µm and 201 ± 19.2µm and SFCT was 303 ± 68.4µm, 303 ± 50.1µm and 275 ± 38.9µm in groups 1, 2 and 3 respectively. Low haemoglobin corelated negatively with retinal (r = -0.362; p = <0.001) and choroidal (r = -0.294; p = <0.001) thickening and reduced visual acuity (r = -0.157; p = 0.03). In conclusion, patients with anemia have a thicker retina and choroid compared to normal healthy controls.

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.

Reversibility of retinochoroidal vascular alteration in patients with obstructive sleep apnea after continuous positive air pressure and surgical intervention

Purpose

The aim of this work was to study various retinochoroidal parameters in patients with obstructive sleep apnea syndrome (OSAS) and the effect of interventions on these parameters at 6 months follow-up.

Methods

A total of 36 patients were recruited prospectively from the otorhinolaryngology clinics of a large tertiary center between September 2018 to March 2020. The subjects were divided into three groups depending upon intervention chosen for OSAS: Group A (surgery, i.e., uvulopalatopharyngoplasty), group B (medical therapy, i.e., continuous positive air pressure) and group C (no intervention). Various retinochoroidal parameters which were studied included retinal thickness (RT), choroidal thickness (CT), choroidal vascularity index (CVI), arteriovenous ratio (AVR), capillary density index (CDI) in superficial and deep retina, at baseline and 6 months of follow-up after the intervention.

Results

In group A, CT increased significantly at 6 months (332.76 ± 86.41 um) compared to baseline (306.28 ± 78.19) (P = 0.0004). Similarly, CDI at both superficial and deep capillary plexus increased significantly at 6 months (superficial CDI: 0.65 ± 0.04, deep CDI: 0.38 ± 0.01) compared to baseline (superficial CDI: 0.62 ± 0.03, deep CDI: 0.36 ± 0.02) (P = 0.004 and 0.002 respectively). In group B, CT increased significantly at 6 months (361.38 ± 78.63 um) compared to baseline (324.21 ± 76.97 um) (P = 0.008). Also, CVI showed a significant decrease at 6 months (65.74 ± 1.84%) compared to baseline (67.36 ± 1.57%) (P = 0.019). In group C, all except CDI in deep capillary plexus showed a significant decrease at 6 months (0.35 ± 0.01) compared to baseline (0.36 ± 0.02) (P = 0.003).

Conclusion

OSAS alters various retinochoroidal parameters and timely intervention in patients with OSAS can prevent these alterations. Also, these retinochoroidal parameters could serve as one of the markers to monitor the disease progression.

Association Between Sleep Apnea Risk Score and Retinal Microvasculature Using Optical Coherence Tomography Angiography

PURPOSE

To investigate the retinal vessel changes at peripapillary and parafoveal regions using optical coherence tomography angiography in patients with varying obstructive sleep apnea syndrome (OSAS) risk, identified by the STOP-BANG questionnaire.

DESIGN

Prospective, hospital-based cross-sectional study.

METHODS

Participants were divided into 3 groups based on the OSAS risk score. Flow areas and vessel densities were calculated at peripapillary and parafoveal regions using optical coherence tomography angiography. Microvasculature changes between the 3 groups and correlation between OSAS risk score and vascular changes were calculated.

RESULTS

Six hundred and six eyes of 303 patients were included in groups 1 (n = 96), 2 (n = 135), and 3 (n = 72). In patients with high OSAS risk, an increase in flow areas (P = .011) and vessel densities (P = .002) in superficial capillary plexus was noted. In contrast, flow areas (P = .003) and vessel densities (P < .000) in deep capillary plexus were reduced. Positive correlation was noted between sleep scores and vessel densities in superficial capillary plexus (P = .04). Negative correlation was noted between sleep scores and flow areas (P = .003) and vessel densities (P ≤ .001) in deep capillary plexus.

CONCLUSION

The sleep apnea questionnaire is an easy method of identifying the disease severity stage, but polysomnography still remains the definitive gold standard. Optical coherence tomography angiography shows some associations with disease severity, but it cannot be used unambiguously to distinguish the severity of sleep apnea.

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.

RETRACTED ARTICLE: Evaluation of macular thickness and visual pathways using optic coherence tomography and pattern visual evoked potential in different clinical stages of obstructive sleep apnea syndrome

AIM

The present study aimed to investigate and compare possible changes in amplitude and latency of pattern visual evoked potentials (PVEP) and thickness of quadrants of the macula (TQM) using optic coherence tomography (OCT).

MATERIALS AND METHODS

According to polysomnography examinations, 30 mild, 30 severe, 30 controls were included in the study after approval from the ethics committee.

RESULTS

No significant difference was found in age and gender between the groups (p = 0.184 and p = 0.954). Significant difference was found between external and internal superior TQM, mean thickness of ganglion cell layer in comparison of all three groups (p = 0.011, p = 0.047, p = 0.030). In comparison between severe OSAS and control groups, significant difference was found in internal nasal, internal superior and external superior TQM (p = 0.048, p = 0.033, p = 0.014) while no significant difference was found TQM in comparison between the mild OSAS and control groups. In comparison between the group of severe OSAS and controls, significant increase was found in P100 as well as N145 latencies whereas only P100 latency was found to increase when mild OSAS was compared with controls. No significant correlation was found between TQM and PVEP parameters in mild and severe OSAS patients.

DISCUSSION

Latency and amplitude of PVEP altered in OSAS because edema and inflammation was remarkable in mild as well as severe stages of the disease. Furthermore, thinning in the macula was observed only in severe stages of the disease, explained with level of atrophy and exposure to extended hypoxia.

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.

The Effects of Surgical Treatment on Retina-Choroidal Findings in Patients With Obstructive Sleep Apnea Syndrome

BACKGROUND AND OBJECTIVE

The purpose of this study was to determine the effect of surgical treatment on ocular findings in obstructive sleep apnea syndrome (OSAS).

PATIENTS AND METHODS

The authors studied 34 eyes of 34 newly diagnosed OSAS patients. The sleep study was performed before and 6 months after expansion sphincter pharyngoplasty (ESP). Retinal nerve fiber layer (RNFL), choroidal thickness (CT), and retinal arteriolar caliber (RAC) analyses were performed using spectral-domain optical coherence tomography. Intraocular pressure (IOP) and ocular pulse amplitude were performed using the Pascal dynamic contour tonometer.

RESULTS

The preoperative and postoperative Apnea Hypopnea Index scores and average oxygen saturation values were significantly different (P = .0001 and P = .001, respectively). There was no significant difference between the preoperative and postoperative RNFL thicknesses (P > .05). The preoperative subfoveal, nasal, temporal CT, and IOP were significantly different from the postoperative measurements (P = .006, P = .05, P = .036, and P = .0001, respectively).

CONCLUSIONS

ESP had a significant influence on CT and IOP in patients with OSAS, maintaining a decrease in CT and IOP 6 months after surgery. The determination of these ocular findings may be useful to show the positive effects of ESP. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:35-42.].

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.

Evaluation of effects of positive airway pressure treatment on retinal fiber thickness and visual pathways using optic coherence tomography and visual evoked potentials in the patients with severe obstructive sleep apnea syndrome

INTRODUCTION

Hypoxia during sleep in obstructive sleep apnea syndrome (OSAS) increases intracranial pressure, decreases cerebral perfusion pressure, and alters vascular supply to the optic nerve. Pattern visual evoked potential (pVEP) has revealed that it causes alterations in the optic nerve, and optic coherence tomography has shown that it causes alterations in the retinal and macular layers.

OBJECTIVES

To detect and compare possible alterations in macula and peripapillary retinal nerve fiber thickness (pRNFL) using OCT and in the optic nerve pathways using pVEP before and after positive airway pressure (PAP) in the patients with severe OSAS.

MATERIALS AND METHODS

Thirty patients who were diagnosed as having severe OSAS in the neurology-sleep outpatient clinic and 30 healthy control subjects were included in the study. Ophthalmic examinations were performed prior to (month 0) and after (month 6) PAP treatment, and pVEP (peak time [PT] and amplitude) and OCT parameters (peripapillary retinal-macular layers) were compared.

RESULTS

In the comparison between the severe OSAS (before treatment) and control groups, thinning was found in pRNFL (average, nasal, inferior) and in the macular layers (external and internal superior quadrants) (p < 0.05). pVEP investigation revealed increased PT in P100 and N145 waves and decreased amplitude of N75-P100 waves. In the comparisons before and after PAP treatment, a decrease in PT of N75 and P100 waves and increase in N75-P100 amplitudes were found. In the pRNFL, significant thickening was found in the layers with thinning before treatment, whereas no significant thickening was found in macular layers, except for the fovea.

DISCUSSION

It was shown that PAP treatment in patients with severe OSAS prevents hypoxia without causing alterations in intraocular pressure and thus reduces inflammation and causes thickening in the pRNFL and macular layers.

Retinal, choroidal and optic disc analysis in patients with Graves' disease with or without orbitopathy

PURPOSE

To compare optic disc, retinal and choroidal measurements in patients with Graves' disease with or without orbitopathy, and healthy controls.

METHODS

Optical coherence tomography and Heidelberg retinal tomography were performed in 40 patients with Graves' orbitopathy (GO), 40 subjects with Graves's disease (GD) with no sign of orbitopathy and 40 healthy controls. Degree of exophthalmos, ocular alignment, clinical activity score (CAS), choroidal thickness, retinal thickness, ganglion cell layer (GCL) thickness, disc area, cup area, rim area, cup/disc area ratio, linear cup/disc ratio and mean peripapillary retinal nerve fibre layer thickness were analysed.

RESULTS

GO patients and healthy controls significantly differ regarding mean central retinal thickness (275 ± 19 µm and 285 ± 20 µm, P = 0.017); mean central GCL thickness (14.87 ± 3.0 µm and 17.92 ± 5.02 µm, P = 0.001); mean disc area (2.00 ± 0.44 mm² and 1.72 ± 0.37 mm², P = 0.003); mean cup area (0.53 ± 0.52 mm² and 0.31 ± 0.20 mm², P = 0.003); cup/disc area ratio (0.22 ± 0.10 and 0.17 ± 0.08, P = 0.010); and linear cup/disc ratio (0.47 ± 0.15 and 0.40 ± 0.13, respectively, P = 0.011). No difference was found between patients without orbitopathy and healthy controls. No significant difference was found regarding the choroidal thickness between the three groups. There was no statistically significant relationship between retinal thickness, ganglion cell layer thickness, mean disc area, mean cup area, cup/disc area ratio, linear cup/disc ratio, CAS, exophthalmometric value and ocular alignment.

CONCLUSION

GO patients showed significant changes in foveal and GCL thickness, and optic nerve head morphology suggesting a possible influence of the orbital inflammatory process.

Insomnia Might Influence the Thickness of Choroid, Retinal Nerve Fiber and Inner Plexiform Layer

Sleep may play a fundamental role in retinal regulation and the degree of retinal variables. However, no clinical study has investigated optical coherence tomography (OCT) parameters in patients with primary insomnia. All participants were evaluated with the insomnia severity index (ISI) and the Pittsburgh sleep quality index (PSQI). The retinal nerve fiber layer (RNFL), ganglion cell layer (GC), inner plexiform layer (IPL), macula and choroidal (CH) thickness were compared between 52 drug-naïve patients with primary insomnia and 45 age-gender-BMI-smoke status matched healthy controls (HC). The patients with primary insomnia differed from the HC regarding RNFL-Global (p = 0.024) and RNFL-Nasal inferior (p = 0.010); IPL-Temporal (p < 0.001), IPL-Nasal (p < 0.001); CH-Global (p < 0.001), CH-Temporal (p = 0.004), CH-Nasal (p < 0.001), and CH-Fovea (p = 0.019). ISI correlated with RNFL-Global and RNFL-Nasal inferior. The regression analysis revealed that ISI was the significant predictor for the thickness of RNFL- Nasal inferior (p = 0.020), RNFL-Global (p = 0.031), and CH-Nasal (p = 0.035) in patients with primary insomnia. Sleep disorders are seen commonly in patients with psychiatric, including ocular diseases. Adjusting the effect of insomnia can help to clarify the consistency in findings of OCT.

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 1000μm 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.

To Evaluate the Effect of Chronic Obstructive Pulmonary Disease on Retinal and Choroidal Thicknesses Measured by Optical Coherence Tomography

Purpose

To evaluate the retinal and choroidal thicknesses in patients with chronic obstructive pulmonary disease using optical coherence tomography.

Methods

The study included 26 patients with chronic obstructive pulmonary disease (COPD) and 26 age-matched healthy control groups. Detailed ocular examinations were performed on all participants. Cirrus EDI-OCT (enhanced depth imaging-optical coherence tomography) was used for choroidal thickness measurements with frame enhancement software. The subfoveal area was used for choroidal thickness measurements.

Results

The patients with the chronic obstructive pulmonary disease had an average 239.13 ± 57.77 μm subfoveal choroidal thickness, and the control group had an average 285.02 ± 25 μm subfoveal choroidal thickness. The subfoveal choroidal thickness measurements revealed a statistically significant difference between patients and the control group (p < 0.05). There were no statistically significant differences between patients and control group regarding mean macular thickness, central macular thickness, and GCIPL (ganglion cell-inner plexiform layer) thickness. Also, there was no statistically significant difference between patients and control group regarding mean, superior, nasal, inferior, and temporal RNFL (retinal nerve fiber layer) thicknesses.

Conclusion

Chronic hypoxemia seems to cause decreased choroidal thickness in patients with chronic obstructive pulmonary disease.

Short-term variations of optic coherence tomography findings in mild and severe chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the short-term changes in subfoveal choroidal thickness (SFCT), ganglion cell complex (GCC) analysis, and retinal nerve fiber length (RNFL) of patients with chronic obstructive pulmonary disease (COPD) in a 3-month follow-up.

MATERIALS AND METHODS

Forty-eight patients with COPD (96 eyes) and 40 control subjects (80 eyes) were enrolled in our study. COPD patients were grouped according to disease severity as Group 1 (mild-moderate) and Group 2 (advanced). GCC, RNFL, and SFCT analysis by Cirrus SD-OCT were obtained for all eyes, in two consecutive examinations with a 3-month interval.

RESULTS

SFCT in Group 2 was lower than Group 1 and control group in the initial and 3rd month examination (p < 0.001, respectively). Inferior RNFL in Group 2 were lower than control group in the initial and 3rd month examination (p = 0.002, p < 0.001, respectively) Temporal RNFL were lower in Group 2 than Group 1 in 3rd month examination (p = 0.009). Average, superior, superotemporal, inferior, and inferonasal GCC analyses of the Group 2 were lower than control group both in the initial and 3rd month examination (p = 0.001, p < 0.001, respectively) SFCT, average, and superior GCC of Group 2 were significantly reduced during the 3-month follow-up (p < 0.001).

CONCLUSION

Hypoxia is thought to be the underlying mechanism in COPD, which may influence retinal and choroidal OCT parameters. Decrease in blood flow of optic nerve head, increased vascular resistance, and reduced blood flow in choroid may affect the visual ability in these patients, which should be kept in mind during their follow-up.

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.

Ocular morphological changes in patients with restless legs syndrome analyzed by optical coherence tomography

BACKGROUND

Two leading hypotheses for restless legs syndrome (RLS) pathophysiology are dopaminergic dysfunction and sympathetic overactivity. Ocular changes occur with both dopaminergic and sympathetic pathologies, and thus may provide unique insights into the pathophysiology of RLS.

METHODS

Thirty-five patients with RLS and 35 healthy individuals were enrolled in the study. Peripapillary retinal nerve fiber layer (RNFL), macular, and choroidal thicknesses were measured by optical coherence tomography (OCT).

RESULTS

There were no statistically significant differences between the two groups regarding RNFL and macular thicknesses. The subfoveal, temporal and nasal choroidal thicknesses were significantly thinner in patients with RLS compared with normal subjects (p < 0.05).

CONCLUSION

Thinning of the choroid is linked to sympathetic overactivity. Our results provide further evidence for sympathetic overactivity in the pathogenesis of RLS.

Choroid thickness profile in patients with lupus nephritis

BACKGROUND

Choroidopathy is a rare manifestation of systemic lupus erythematosus (SLE). This entity is associated with active phases of severe SLE and it is frequently accompanied by acute kidney failure, central nervous system involvement and coagulopathy.

PURPOSE

To evaluate the choroid thickness of patients with lupus nephritis (LN) without choroidopathy, and to compare this with that of age-matched SLE patients without LN and healthy control subjects.

STUDY DESIGN

Cross-sectional case control study.

MATERIAL AND METHODS

Fifteen women with LN in remission phase (study group), 15 women with SLE in remission without LN (SLE control group), and 15 healthy women (healthy control group), without ocular diseases or significant refractive error, were recruited. Full ophthalmological examination and a macular optical coherence tomography in enhanced depth imaging mode were performed. The choroid thickness was measured at nine macular points and six lines of mean choroidal thickness were determined. A comparative analysis between the three groups was performed using the one-way ANOVA test and the paired t-test. The choroid thickness of patients under corticotherapy was also compared to that of patients without corticotherapy. Additionally, the correlation between choroid thickness and disease duration was evaluated using the Pearson analysis.

RESULTS

The mean macular choroidal thickness was 295.73 ± 67.62 μm in the study group, 233.34 ± 41.01 µm in the SLE control group, and 240.98 ± 37.93 μm in the control group ( p = 0.00006 and p = 0.0003, respectively). Additionally, the choroid thickness was significantly thicker than in the SLE and healthy control groups at the foveal ( p = 0.004 and p < 0.000), nasal ( p < 0.000 and p = 0.001), superior ( p = 0.002 and p < 0.000) and inferior ( p < 0.000 and p = 0.001) mean lines. The choroidal thickness in this group was not associated with the duration of the disease. The subgroup of patients with LN under corticotherapy did not reveal a significantly different choroidal thickness.

CONCLUSION

This study suggests a relationship between LN and choroidal changes, which may represent an increased risk for choroidopathy in these patients. Choroid thickening was not related with the duration of the disease. This thickening may be correlated with histopathological changes similar to those occurring in kidney glomeruli.

The role of optical coherence tomography in therapeutics and conditions, which primarily have systemic manifestations: a narrative review

Optical coherence tomography is designed to evaluate in vivo qualitative and quantitative changes of the anterior segment, optic nerve and the retina. Initial applications of this technology were confined mainly to ophthalmic diseases. However recently, numerous studies have evaluated its use in systemic conditions and in therapeutics where, optic nerve and retinal architecture can be assessed to monitor progression of systemic conditions and its response to treatment. This is a narrative review aimed at evaluating the debate surrounding the role of spectral domain optical coherence tomography, in systemic conditions where optic nerve affection can be measured and be used in the diagnosis, monitoring and assessment of treatment effect as a non-invasive, quick, novel technique.

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.

The relation between retrobulbar blood flow and posterior ocular changes measured using spectral-domain optical coherence tomography in patients with obstructive sleep apnea syndrome

PURPOSE

To investigate the effect of posterior ocular hemodynamics on the retinal nerve fiber layer (RNFL), choroid thickness (CT) and central macular thickness (CMT) in patients with obstructive sleep apnea syndrome (OSAS) and to reveal the association with glaucomatous optic neuropathy.

METHODS

The research was planned as a prospective, randomized study. The ophthalmic, retinal and posterior ciliary artery pulsatile index (PI) and resistive index (RI) were measured by colored Doppler sonography. RNFL thickness, CMT and CT were then measured by spectral-domain optical coherence tomography.

RESULTS

Sixty subjects were divided into four groups-mild, moderate and severe OSAS and a control group. There were 16 subjects in the control group, 14 in the mild OSAS group, 15 in the moderate OSAS group and 15 in the severe OSAS group. Ophthalmic artery and central retinal artery PI and RI values of the OSAS patients did not show statistically significant difference than those of the control group, but posterior ciliary artery (PCA) PI and RI values were significantly higher. In addition, mean, superior and inferior RNFL thickness values were significantly lower than those in the control group. Moreover, the glaucoma prevalence of the OSAS patients in this study was 6.8% and all of these patients were in the severe OSAS group.

CONCLUSION

PI and RI values of the PCA, which supplies the optic nerve, show a linear increase as the apnea hypoxia index values in OSAS. As the grade of OSAS improves, this situation leads to a more serious ischemic optic neuropathy. Furthermore, the prevalence of glaucoma in this study is found to be higher in the severe OSAS group.

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.

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 evaluation in paediatric patients with adenotonsillar hypertrophy

OBJECTIVE

To investigate choroidal thickness using enhanced-depth imaging optical coherence tomography in paediatric patients with adenotonsillar hypertrophy, with comparison to healthy children, three months after adenotonsillectomy.

METHODS

The patients were assigned to three groups: an adenotonsillar hypertrophy group, an adenotonsillectomy group and a healthy control group. In all groups, subfoveal, temporal and nasal choroidal thickness measurements were taken.

RESULTS

In the subfoveal, temporal and nasal regions, choroidal tissue was found to be significantly thinner in adenotonsillar hypertrophy children than healthy children (p = 0.012, p = 0.027 and p = 0.020). The subfoveal and temporal choroidal thickness measurements of adenotonsillar hypertrophy group cases were significantly decreased compared to those in the adenotonsillectomy group (p = 0.038 and p = 0.048).

CONCLUSION

There was a significant association between decreased choroidal thickness and adenotonsillar hypertrophy. Adenotonsillar hypertrophy may play an important role in decreased choroidal thickness.

CORRELATION BETWEEN SUBFOVEAL CHOROIDAL THICKNESS AND FOVEAL THICKNESS IN THALASSEMIC PATIENTS

PURPOSE

To assess the impact of two iron chelation modalities in thalassemic patients on foveal and subfoveal choroidal thickness.

METHODS

The study included 60 β-thalassemia major patients. They included 30 patients on oral deferasirox after a period of subcutaneous deferoxamine (Group 2) and 30 patients on subcutaneous deferoxamine (Group 3). Thirty age- and sex-matched healthy children were included as a control group (Group 1). All participants underwent a complete ophthalmologic evaluation and Spectral Domain Optical Coherence Tomography.

RESULTS

Age, gender, intraocular pressure, best-corrected visual acuity, and refraction were not statistically different between the three studied groups. Ferritin level, pretransfusion hemoglobin, serum iron, and duration of thalassemia were not statistically different between the two thalassemic groups. Foveal thickness in Group 1 (225.15 ± 17.35 μm) was statistically higher than in Group 2 (210.53 ± 21.73 μm) (P < 0.001) and Group 3 (200.15 ± 7.34 μm) (P < 0.001). It was statistically higher in Group 2 than in Group 3 (P = 0.001). Subfoveal choroidal thickness in Group 1 (279.70 ± 32.54 μm) was statistically higher than in Group 2 (255.80 ± 19.20 μm) (P < 0.001) and Group 3 (248.28 ± 20.43 μm) (P < 0.001). It was statistically higher in Group 2 than in Group 3 (P < 0.05).

CONCLUSION

Thalassemic patients can develop a significant decrease in foveal thickness because of the inevitable use of chelation therapy. Deferoxamine as a chelating agent can affect foveal thickness more than the oral form (deferasirox).

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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