Retinal vascular manifestations of obstructive sleep apnea

Risk factors in developing retinal vein occlusion in subject with obstructive sleep apnea

BACKGROUND

Patients with obstructive sleep apnea (OSA) have a higher risk of developing vascular diseases. In this study, we evaluated the clinical profile of patients with OSA who develop retinal vein occlusion (RVO) compared with a population of OSA patients without RVO.

METHODS

We analyzed patients with OSA diagnosed with RVO (21 cases; mean of age 61 years. range 44-87 years. 67% men), belonging to a large cohort of people with long-term follow-up for RVO (up to 12 years). We compared them with 21 patients with OSA, without RVO, matched by age and gender, selected from the Sleep Unit Registry (control group).

RESULTS

There were no differences in the prevalence of arterial hypertension (AHT) or Diabetes mellitus (DM), but the RVO patients presented a higher diastolic blood pressure compared to controls (87.6±12.6 mmHg vs. 77.9±10.1 mmHg respectively). The polygraphic parameters were similar in both groups. The Apnea-Hypopnea Index (IHA) similar in both groups (30.4±20.9 RVO vs. 33.7±22.1 controls). In addition, RVO patients had a less favorable lipid profile, with higher total cholesterol (218±52 mg/dL vs. 179±41 mg/dL), higher LDL cholesterol (139±47 mg/dL vs. 107±32 mg/dL) and higher atherogenic indices: LDL/HDL (2.78±0.95 RVO vs. 2.03±0.67 controls) and total cholesterol/HDL (4.37±1.08 vs. 3.45±0.84). Among the cases, 81% had peripheral RVO (superior temporal branch in 20 out of 21 cases) and 19% had central RVO. A percentage of 62% of the cases received intravitreal antiangiogenic therapy and dexamethasone implants and 33% received argon laser photocoagulation.

CONCLUSIONS

Poor control of cardiovascular risk factors, particularly dyslipidemias, in patients with OSA may lead to the development of this ocular complication.

Sleep-disordered breathing is related to retinal vein occlusion: A meta-analysis

BACKGROUND

Previous studies suggest that sleep-disordered breathing (SDB) may be a potential risk factor of retinal vein occlusion (RVO). We conducted a meta-analysis to systematically explore the relationship between RVO and SDB.

METHODS

Observational studies assessing the relationship between SDB and RVO were retrieved by searches of electronic databases including the PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Wan Fang databases from database inception to August 9, 2023. In consideration of intra-study heterogeneity, a random-effects model was adopted to combine the results.

RESULTS

Seven studies (1 retrospective cohort and 6 case-control studies) were included in this meta-analysis, and among 36,628 adults included in those studies, 6452 (17.6%) had SDB. The combined results indicated that SDB was associated with RVO [risk ratio (RR): 1.92, 95% confidence interval (CI): 1.60-2.30, P < .001] with no significant heterogeneity (I2 = 0%). Subgroup analyses showed consistent relationships between SDB and any RVO (RR: 1.73, 95% CI: 1.13-2.28, P < .001), central RVO (RR: 2.20, 95% CI: 1.57-3.08, P < .001), and branch RVO (RR: 1.85, 95% CI: 1.15-2.99, P = .01). Moreover, the relationship was consistent among patients with mild (RR: 1.82, 95% CI: 1.32-2.53, P < .001), moderate (RR: 2.17, 95% CI: 1.65-2.85, P < .001), and severe SDB (RR: 2.66, 95% CI: 1.96-3.62, P < .001). The association was consistent in studies that adjusted for age and sex (RR: 2.17, 95% CI: 1.50-3.13, P < .001), and in studies with additional adjustment for comorbidities (RR: 1.78, 95% CI: 1.42-2.25, P < .001).

CONCLUSION

SDB is associated with RVO in adults.

Role of sleep-disordered breathing in age-related macular degeneration

AIMS

To examine the association between obstructive sleep apnoea (OSA) and age-related macular degeneration (AMD), and the subphenotype of AMD with reticular pseudodrusen (RPD).

METHODS

Case-control study with 351 participants (211 AMD and 140 controls) using the Epworth Sleepiness Scale (ESS) and the STOP-BANG Questionnaire (SBQ) validated sleep questionnaires. Participant risk of having moderate-to-severe OSA was determined using a binary risk scale based on the ESS and SBQ combined and an ordinal risk scale based on the SBQ. A prior diagnosis of OSA and whether receiving assisted breathing treatment was also ascertained. Retinal imaging allowed AMD and RPD determination.

RESULTS

Higher risk of moderate-to-severe OSA according to the binary and ordinal scales was not associated with the presence of AMD (p≥0.519) nor AMD with RPD (p≥0.551). Per point increase in ESS or SBQ questionnaire score was also not associated with AMD nor AMD with RPD (p≥0.252). However, being on assisted breathing treatment for diagnosed OSA was significantly associated with a higher likelihood of having AMD with RPD, but not all AMD, (OR 3.70; p=0.042 and OR 2.70; p=0.149, respectively), when compared with those without diagnosed OSA on treatment.

CONCLUSIONS

Formally diagnosed OSA undergoing treatment, increased the likelihood of having AMD with RPD, but not overall AMD compared with those who were not undergoing treatment. Risk-based OSA questionnaires showed no difference in risk for all AMD or AMD with RPD. Future research, using formal sleep studies could further explore the potential role of nocturnal hypoxia in AMD.

Ocular manifestations of common pulmonary diseases: a narrative review

Several pulmonary disorders can cause ocular involvement. Understanding these manifestations is critical for early diagnosis and treatment. Hence, we set out to examine the most common ocular manifestations of asthma, chronic obstructive pulmonary disease (COPD), sarcoidosis, obstructive sleep apnea (OSA), and lung cancer. Allergic keratoconjunctivitis and dry eye are two ocular manifestations of bronchial asthma. The inhaled corticosteroids used to treat asthma can cause cataract formation. COPD is associated with ocular microvascular changes as a result of chronic hypoxia and systemic inflammation spillover into the eyes. Its clinical significance, however, is unknown. Ocular involvement is common in sarcoidosis, occurring in 20% of cases of pulmonary sarcoidosis. It can affect nearly any anatomical structure of the eye. Obstructive sleep apnea has been linked to floppy eye syndrome, glaucoma, non-arteritic anterior ischemic optic neuropathy, keratoconus, retinal vein occlusion, and central serous retinopathy, according to research. However, while an association has been established, causality has yet to be established. The effect of positive airway pressure (PAP) therapy used to treat OSA on the aforementioned ocular conditions is unknown. PAP therapy can cause eye irritation and dryness. Lung cancer can affect the eyes through direct nerve invasion, ocular metastasis, or as part of a paraneoplastic syndrome. The goal of this narrative review is to raise awareness about the link between ocular and pulmonary disorders in order to aid in the early detection and treatment of these conditions.

Retinal vascular fractal dimension measurements in patients with obstructive sleep apnea syndrome: a retrospective case-control study

STUDY OBJECTIVES

We performed a case-control study to investigate the correlation between the apnea-hypopnea index (AHI) and the retinal vascular fractal dimension (FD).

METHODS

We selected 527 individuals who underwent polysomnography during health checkups at the Huadong Sanatorium from January to December 2021 as the study population, of whom 468 were included and 59 were excluded. All participants underwent a detailed health examination, including medical history assessment, physical examination, assessment of lifestyle factors, fundus photography, and laboratory examinations. The retinal vasculature was quantitatively assessed using Singapore I Vessel Assessment (SIVA) software. The relationship between the AHI and the retinal vessel quantitative was examined by multiple linear regression analyses and restricted cubic spline.

RESULTS

Among the 468 studied individuals, the average age was 51.51 (43-58) years, with 369 (78.85%) men and 99 (21.15%) women. According to the AHI indicator, 355 individuals were diagnosed with obstructive sleep apnea (OSA) syndrome, with an average AHI of 17.00 (9.200-30.130) events/h; 113 individuals were classified as controls, with an average AHI of 2.13 (0.88-3.63) events/h. In multiple linear regression, following varying degrees of adjustment for confounding factors, FD was reduced by 0.013 (P = .012; 95% confidence interval [CI]: -0.024 to -0.003), FD arteriole (FDa) was reduced by 0.013 (P = .019; 95% CI: -0.024 to -0.002), and FD venule (FDv) was reduced by 0.014 (P = .08; 95% CI: -0.024 to -0.004) in the high-AHI group compared with the low-AHI group. All tests for trend P values were < .05. The restricted cubic spline in the overall OSA population and the individuals without diabetes revealed a U-shaped pattern of decreasing, then increasing, FD, FDa, and FDv with a rising AHI. In the OSA individual with diabetes, FD, FDa, and FDv gradually decreased with increasing AHI.

CONCLUSIONS

The FD is associated with AHI in OSA individuals. The link between AHI and FD varied for OSA individuals with and without diabetes.

CITATION

Wang J, Chen T, Qi X, Li Y, Yang X, Meng X. Retinal vascular fractal dimension measurements in patients with obstructive sleep apnea syndrome: a retrospective case-control study. J Clin Sleep Med. 2023;19(3):479-490.

Influence of continuous positive airway pressure on lipid profiles of obstructive sleep apnea: A systematic review and meta-analysis

BACKGROUND

To investigate the influence of continuous positive airway pressure (CPAP) on lipid profiles of the patients with obstructive sleep apnea (OSA) in this meta-analysis.

METHODS

Relevant studies reporting the correlation between CPAP and lipid profiles of OSA patients were searched in Pubmed, Cochrane Library and Embase before January 1, 2021. Data of eligible studies were extracted and analyzed using the fixed-effect or random-effect model. Standard mean difference (SMD) and 95% confidence interval (95% CI) were calculated to assess such influence. Subgroup analysis based on CPAP duration was further performed. STATA 12.0 was used in this meta-analysis.

RESULTS

A total of 12 independent randomized controlled studies involved 1129 OSA patients were recruited in this meta-analysis. The analyzed lipid profiles included total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and high density lipoprotein (HDL). CPAP was not correlated to TC (SMD = -0.07, 95% CI = -0.33 to 0.19), TG (SMD = -0.01, 95% CI = -0.19 to 0.17), LDL (SMD = -0.01, 95% CI = -0.23 to 0.21) and HDL (SMD = 0.10, 95% CI = -0.03 to 0.22) in OSA patients. Moreover, CPAP duration (=12 weeks; >12 weeks; <12 weeks) also did not influence lipid profiles of OSA patients as well.

CONCLUSIONS

Regardless of the treatment in CPAP duration, it doses does not influence lipid profiles of OSA patients, including TC, TG, LDL and HDL. The results are inconsistent with previous findings, which should be further validated in the multi-center, long-term randomized controlled trials.

Sleep medicine: Practice, challenges and new frontiers

Sleep medicine is an ambitious cross-disciplinary challenge, requiring the mutual integration between complementary specialists in order to build a solid framework. Although knowledge in the sleep field is growing impressively thanks to technical and brain imaging support and through detailed clinic-epidemiologic observations, several topics are still dominated by outdated paradigms. In this review we explore the main novelties and gaps in the field of sleep medicine, assess the commonest sleep disturbances, provide advices for routine clinical practice and offer alternative insights and perspectives on the future of sleep research.

Peripheral retinal neovascularization in a patient with obstructive sleep apnea

Purpose

Observations

Conclusions and Importance

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Disruption of Circadian Rhythm Genes in Obstructive Sleep Apnea Patients-Possible Mechanisms Involved and Clinical Implication

Obstructive sleep apnea (OSA) is a chronic condition characterized by recurrent pauses in breathing caused by the collapse of the upper airways, which results in intermittent hypoxia and arousals during the night. The disorder is associated with a vast number of comorbidities affecting different systems, including cardiovascular, metabolic, psychiatric, and neurological complications. Due to abnormal sleep architecture, OSA patients are at high risk of circadian clock disruption, as has been reported in several recent studies. The circadian clock affects almost all daily behavioral patterns, as well as a plethora of physiological processes, and might be one of the key factors contributing to OSA complications. An intricate interaction between the circadian clock and hypoxia may further affect these processes, which has a strong foundation on the molecular level. Recent studies revealed an interaction between hypoxia-inducible factor 1 (HIF-1), a key regulator of oxygen metabolism, and elements of circadian clocks. This relationship has a strong base in the structure of involved elements, as HIF-1 as well as PER, CLOCK, and BMAL, belong to the same Per-Arnt-Sim domain family. Therefore, this review summarizes the available knowledge on the molecular mechanism of circadian clock disruption and its influence on the development and progression of OSA comorbidities.

Association Between Obstructive Sleep Apnea and Diabetic Macular Edema in Patients with Type 2 Diabetes

PURPOSE

To evaluate the relationship between obstructive sleep apnea (OSA) and diabetic macular edema (DME) and the effect of OSA on refractory DME in patients with type 2 diabetes (T2DM).

DESIGN

Retrospective clinical cohort study.

METHODS

A population-based study was conducted at Chang Gung Memorial Hospital from March 1, 2009, to March 1, 2020. Among 14,152 patients who had undergone polysomnography (PSG) and whose data were registered on the sleep center's PSG database, 121 patients (242 eyes) with T2DM were enrolled according to the International Classification of Diseases, Ninth Revision (ICD-9) code 3620 for diabetic retinopathy (DR). Patients with a secondary cause of macular edema and those lacking medical records were excluded. All patients with T2DM enrolled in our study received both optical coherence tomography (OCT) and PSG. The prevalence of severe (apnea-hypopnea index [AHI] ≥30) and nonsevere (AHI <30) OSA was compared between patients with and without DME and refractory DME.

RESULTS

In total, 102 eyes (54 patients) were divided into groups of 40 eyes with DME or 62 eyes without DME. Severe OSA (odds ratio, 7.36; 95% confidence interval [CI]: 1.32-40.96; P = .023) was significantly associated with DME. Refractory DME was significantly more frequent in patients with severe OSA (27%) than in those with nonsevere OSA (0%; P = .009). Cox proportional hazards regression analysis revealed that OSA (hazard ratio, 2.97; CI, 1.08-8.16; P = .034) independently increased the DME risk after adjustment for age, sex, glycohemoglobin level, hypertension, and hypercholesterolemia.

CONCLUSIONS

Severe OSA is a risk factor for DME and is associated with having refractory DME.