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

Airway stability in sleep apnea: Assessing continuous positive airway pressure efficiency

Obstructive Sleep Apnea Syndrome (OSAS) disrupts millions of lives with its burden of airway obstruction during sleep. Continuous Positive Airway Pressure (CPAP) therapy has been scrutinized for its biomechanical impact on the respiratory tract. This study leverages computational fluid dynamics to investigate CPAP's effects at 9 cm H2O (882.6 Pa) on the computed-tomography-based nasal-to-14-generation full respiratory tract model compared to ambient conditions, focusing on static pressure, airflow velocity, and shear stress. Our findings reveal that CPAP significantly increases static pressure, enhancing airway patency without adverse changes in airflow velocity or harmful shear stress on lung tissue, challenging prior concerns about its safety. Notably, the larynx experiences the highest shear stress due to its narrow anatomy, yet CPAP therapy overall supports airway walls against collapse. This investigation highlights CPAP's critical role in OSAS treatment, offering reassurance about its safety and efficacy. By clarifying CPAP therapy's physiological impacts, our study contributes vital insights for optimizing OSAS management strategies, affirming CPAP's benefit in maintaining open airways with minimal tissue strain.

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

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

Primary open-angle glaucoma in patients with obstructive sleep apnoea in a Colombian population: a cross-sectional study

OBJECTIVE

Determine the prevalence, functional and structural alterations of primary open-angle glaucoma (POAG) in patients with obstructive sleep apnoea (OSA).

DESIGN

Cross-sectional.

SETTING

Tertiary hospital associated with specialised center in ophthalmologic images in Bogota, Colombia.

PARTICIPANTS

150 patients, for a sample of 300 eyes, 64 women (42.7%) and 84 men (57.3%) between 40 and 91 years old with a mean age of 66.8 (±12.1) years.

INTERVENTIONS

Visual acuity, biomicroscopy, intraocular pressure, indirect gonioscopy and direct ophthalmoscopy. Patients classified as glaucoma suspects underwent automated perimetry (AP) and optical coherence tomography of the optic nerve OUTCOME MEASURE: The primary outcomes are the determination of prevalence of glaucoma suspects and POAG in patients with OSA. Secondary outcomes are the description of functional and structural alterations in computerised exams of patients with OSA.

RESULTS

The prevalence of glaucoma suspect was 12.6%, and for POAG was 17.3%. No alterations in the appearance of the optic nerve was seen in 74.6%, focal or diffuse thinning of the neuroretinal rim (16.6%) was the most frequently finding, followed by asymmetry of the disc>0.2 mm (8.6%) (p=0.005). In the AP, 41% showed arcuate, nasal step and paracentral focal defects. The mean retinal nerve fiber layer (RNFL) was normal (>80 µM) in 74% of the mild OSA group, 93.8% of the moderate group and 17.1% of the severe group. Similarly, normal (P5-90) ganglion cell complex (GCC) in 60%, 68% and 75%, respectively. Abnormal results in the mean RNFL was seen in 25.9%, 6.3% and 23.4% of the mild, moderate and severe groups, respectively. In the GCC, 39.7%, 33.3% and 25% of the patients in the aforementioned groups.

CONCLUSION

It was possible to determine the relationship between structural changes in the optic nerve and the severity of OSA. No relationship with any of the other studied variables was identified.

Retinal and Choroidal Effects of Continuous Positive Airway Pressure as Treatment for Sleep Apnea: Results at 12 Months

BACKGROUND

To determine the impacts of continuous positive airway pressure (CPAP) treatment on retinal and choroidal thickness measurement in individuals with obstructive sleep apnea (OSA).

METHODS

Participants were 28 patients with OSA treated with CPAP who were enrolled immediately after diagnosis and graded according to the apnea hypopnea index (AHI) determined in an overnight polysomnography. Inclusion criteria were a new diagnosis of OSA and an indication for CPAP. Participants underwent a full ophthalmologic examination including standard automated perimetry (SAP) and optical coherence tomography (OCT) at the levels peripapillary, macular, and choroidal before CPAP onset, and after three and twelve months of CPAP. The data compared before and after treatment were intraocular pressure, SAP, and the thicknesses peripapillary retinal nerve fiber layer (pRNFL), total retinal (TR), retinal ganglion cell layer (RGCL), inner plexiform layer (IPL), photoreceptor layer (PL), and choroidal.

RESULTS

After 3 months of CPAP, we observed thickening of the pRNFL (in 5/6 subfields) (p < 0.004) and TR (in 5/9 subfields) (p < 0.010). At 12 months, thickening persisted in these layers, this time affecting 2/6 and 2/9 subfields, respectively (p < 0.012 and p < 0.001, respectively). Choroidal thinning was observed at the temporal level at both 3 and 12 months compared to measurements before starting CPAP treatment (p = 0.014 and p = 0.038, respectively). SAP remained unchanged. Intraocular pressure was higher at 12 months than at 3 months (p = 0.001).

CONCLUSIONS

12 months of CPAP avoids retinal thinning and normalizes choroidal thickness in OSA patients.

A Narrative Review of the Association between Obstructive Sleep Apnea and Glaucoma in Adults

BACKGROUND

Obstructive sleep apnea (OSA) is a sleep disorder, primarily of the upper airway, which not only has a significant impact on quality of life but is also associated with various systemic diseases. Several ophthalmological diseases are also associated with OSA, especially glaucoma. The purpose of this review is to take a closer look at the causality and mutual influence.

METHODS

A systematic literature search was conducted using PubMed. A total of 19 studies with 316,178 adult participants were included.

RESULTS

Eleven of the sixteen studies concentrating on the prevalence of glaucoma in patients with OSA showed an association of both entities. One paper found a higher risk for progression of glaucoma in OSA patients. Five of the sixteen included studies failed to show a correlation between OSA and glaucoma. One study out of three surveying specific ophthalmological parameters showed an influence of OSA therapy on retinal nerve fiber layer (RNFL) thinning and vision. One study showed a rise in intraocular pressure (IOP), while two other studies showed no increase under continuous positive airway pressure (CPAP).

CONCLUSIONS

Our findings suggest an association between OSA and glaucoma and, especially, between OSA and thinning of RNFL. CPAP therapy appears to be also suitable for patients with comorbid glaucoma.

Ocular Complications of Obstructive Sleep Apnea

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

Retinal and choroidal thickness measurements in obstructive sleep apnea: impacts of continuous positive airway pressure treatment

PURPOSE

To examine retinal and choroidal thicknesses in individuals with obstructive sleep apnea (OSA) and determine the impacts of continuous positive airway pressure (CPAP) treatment.

METHODS

Prospective follow-up study conducted at a university hospital. 40 patients with OSA, 28 treated with CPAP, and 12 untreated, were enrolled immediately after diagnosis and graded according to the apnea hypopnea index (AHI) determined in an overnight polysomnography. Inclusion criteria were a new diagnosis of OSA and CPAP indicated. Participants underwent a full ophthalmologic examination including optical coherence tomography (OCT) at the peripapillary, macular, and choroidal levels and the same examination 3 months later. Outcome measures were peripapillary retinal nerve fiber layer (RNFL), total retinal (TRT), retinal ganglion cell layer (RGCL), inner plexiform layer (IPL), photoreceptor layer (PL), and choroidal thicknesses.

RESULTS

At 3 months, RGCL thickness was reduced at the inner nasal macula segment in the no-CPAP group (P = 0.016). In + CPAP, increases were produced in RNFL thickness (5/6 segments) and TRT (7/ 9 segments), while choroidal thinning was observed temporally (P = 0.003). At baseline, positive correlation was detected between choroidal thickness and AHI (r = 0.352, P = 0.005) and between IPL thickness (7/9 segments) and AHI (r = 0.414, P < 0.001).

CONCLUSIONS

Initial retinal and choroidal thickening was followed by RGCL thinning over 3 months. In patients receiving CPAP, we observed no thinning of any retinal layer and normalization of choroidal thickness.

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.

Ocular pathology associated with obstructive sleep apnea syndrome

Objective: The purpose of this study was to describe the ophthalmological findings in patients with obstructive sleep apnea syndrome (OSAS). Methods: The study group was made up of 65 patients with OSAS diagnosis and the findings were compared with the ones of the control group (n=39), which comprised patients without OSAS. An observational, analytic study, with a transversal component and a prospective component, was performed. Results: The IOP (intraocular pressure) was similar in both groups (p=0,9786). In the OSAS group, IOP increased with a higher AHI (apnea/ hypopnea index), but not significantly (p=0,057). Similarly, there was no correlation between a higher AHI and the lacrimal secretion in the OSAS group (p=0,3282). However, when we compared control with OSAS patients, we found a significantly higher degree of lacrimal hyposecretion in the latter (p=0,0003). CPAP treatment had no effect on IOP, as initial and final medium IOP were 15.06 and 14.89 respectively (p=0,8327). Regarding lacrimal secretion, it seems that CPAP treatment had an improving effect, as tear production rose from a 9.25 mm medium to 10.45 mm on the Schirmer I test (p=0,0118). Conclusions: Overall, OSAS patients showed similar IOP and glaucoma prevalence as the normal population. However, they had an abnormal tear secretion and a higher prevalence of eyelid laxity (a sign of floppy eyelid syndrome). Abbreviations: OSAS/ SASO = obstructive sleep apnea syndrome, AHI = apnea/ hypopnea index, CPAP = continuous positive airway pressure, FES = floppy eyelid syndrome, TSch/ TSCH = Schirmer test, IOP = intra-ocular pressure, PSG = polysomnography.