[Normal tension glaucoma, sleep apnea syndrome and nasal continuous positive airway pressure therapy--case report with a review of literature]

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.

Association of obstructive sleep apnea/hypopnea syndrome with glaucomatous optic neuropathy and ocular blood flow

The present study aimed to investigate the prevalence of glaucomatous optic neuropathy in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). In total, 83 subjects (45 cases of severe OSAHS and 38 controls) underwent polysomnographic assessment and were evaluated for the severity of the disease using the Apnea-Hypopnea index. A detailed ophthalmologic exam was then performed, including measurement of the intraocular pressure (IOP) with a Goldmann applanation tonometer and Pascal dynamic contour tonometer (DCT), recording of the ocular pulse amplitude measured by the Pascal DCT, standard automated perimetry and retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness evaluation using optical coherence tomography. Ocular blood flow was assessed using color Doppler imaging (CDI) and ophthalmic artery indices were evaluated, including peak systolic blood velocity, end diastolic blood velocity and resistivity index (RI). There was a significant difference in the mean IOP between controls (11.03±3.85 mmHg) and cases of severe OSAHS (18.06±3.39 mmHg) when the IOP was measured by DCT (P<0.0001), but not with the Goldmann applanation tonometer (IOP, 13.97±2.85 mmHg for controls and 14.89±3.21 mmHg for cases of severe OSAHS; P=0.0877). Significant negative correlations were observed between RNFL thickness and RI (P=0.0011) in cases of severe OSAHS, as well as between GCC thickness and RI (P<0.008) in all subjects. Furthermore, a negative correlation between RI and RNFL thickness in severe cases of OSAHS suggested a hemodynamically induced vulnerability of RNFL in OSAHS. The correlation between RI and GCC thickness in all subjects suggested that impaired perfusion, more prominent in OSAHS, leads to structural changes. Therefore, cases of severe OSAHS should be monitored for changes in RNFL and GCC thickness, as well as CDI findings. Furthermore, patients with increased ophthalmic artery RIs should be monitored for changes in the GCC, regardless of the etiology of the RI increase.

Long-term Effect of Continuous Positive Air Pressure Therapy on Intraocular Pressure in Patients with Primary Open-angle Glaucoma with Obstructive Sleep Apnea

PURPOSE

Prevalence of glaucoma is higher in obstructive sleep apnea (OSA) patients. The gold standard technique to treat OSA is continuous positive airway pressure (CPAP) therapy. The influence of long-term CPAP therapy on intraocular pressure (IOP), blood pressure, ocular perfusion pressure (OPP), and glaucoma progression in primary open-angle glaucoma (POAG) patients was evaluated.

DESIGN

Prospective study.

MATERIALS AND METHODS

In this study, we enrolled 12 eyes from six POAG patients aged >35 years, with newly diagnosed OSA and with indication for CPAP therapy. The CPAP was performed for 12 months. We monitored the IOP every 3 months. Visual field was determined at baseline and 12 months.

RESULTS

The mean IOP after CPAP therapy for 12 months was significantly higher than the mean baseline IOP (average IOP 3 months before CPAP therapy) (19.08 ± 3.47 vs 17.83 ± 2.88 mm Hg; p = 0.006). The IOP rising rate was 0.69 ± 0.47/years (p = 0.138) before CPAP therapy and increased to 1.13 ± 0.47/years (p = 0.016) after CPAP therapy. The OPP after 12 months of CPAP was significantly lower than the baseline (42.21 ± 5.29 vs 45.24 ± 7.09 mm Hg; p = 0.06). Results showed that the pattern standard deviation (PSD) value of 24-2 short wavelength automated perimetry (SWAP) visual field was reduced from 5.34 ± 3.92 to 4.77 ± 3.73 (p = 0.025). Antiglaucoma medication was administered to a patient due to increased IOP without glaucoma progression evidence.

CONCLUSION

The POAG and OSA patients demonstrated significant IOP rising after CPAP therapy but did not show progression of glaucomatous damage. Mean deviation (MD), PSD, and visual field index (VFI) were not significantly different after CPAP therapy.

PRÉCIS

Prospective study of POAG and OSA patients demonstrated significant IOP rising after CPAP therapy for a year. The study did not show progression of glaucomatous damage.

HOW TO CITE THIS ARTICLE

Hirunpatravong P, Kasemsup T, Ayudhya WN, et al. Long-term Effect of Continuous Positive Air Pressure Therapy on Intraocular Pressure in Patients with Primary Open-angle Glaucoma with Obstructive Sleep Apnea. J Curr Glaucoma Pract 2019;13(3):94-98.

Ocular Manifestations of Obstructive Sleep Apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) incurs a host of systemic side effects. The eyes are particularly susceptible to both mechanical and vascular sequelae of the disease. This paper outlines the ocular manifestations of sleep apnea. The authors hope to increase awareness of the ocular complications of this common disorder and increase communication and co-management between eye-care providers and sleep specialists alike.

METHODS

Data were collected from PubMed and the Brown University Library Collection.

RESULTS

Twenty-two papers were included in this review to address floppy eyelid syndrome, nonarteritic anterior ischemic optic neuropathy, central serous retinopathy, retinal vein occlusion, and glaucoma. We used three meta-analyses and several cross-sectional cohort and case-control studies that investigate the aforementioned conditions and their associations with OSA.

CONCLUSIONS

Hypoxia induced by nightly cessation of breathing increases patients' risk of coronary artery disease, heart failure, stroke, and other conditions. As with many maladies detrimental to vascular health, obstructive sleep apnea affects the eye and ocular adnexa. This paper summarizes the current evidence implicating OSA in these ocular maladies and highlights their proposed mechanisms. The authors describe ocular pathology which sleep specialists may encounter. We encourage more aggressive attention to ocular symptoms in patients with sleep apnea to prevent vision-threatening complications. Further research should investigate how sleep apnea treatment affects these ocular findings and identify which sleep apnea patients are most prone to developing ocular pathology.

The interaction between intracranial pressure, intraocular pressure and lamina cribrosal compression in glaucoma

This review examines some of the biomechanical consequences associated with the opposing intraocular and intracranial forces. These forces compress the lamina cribrosa and are a potential source of glaucomatous pathology. A difference between them creates a displacement force on the lamina cribrosa. Increasing intraocular pressure and/or decreasing intracranial pressure will increase the trans-lamina cribrosa pressure difference and the risk of its posterior displacement, canal expansion and the formation of pathological cupping. Both intraocular pressure and intracranial pressure can be elevated during a Valsalva manoeuvre with associated increases in both anterior and posterior lamina cribrosa loading as well as its compression. Any resulting thinning of or damage to the lamina cribrosa and/or retinal ganglion cell axons and/or astrocyte and glial cells attached to the matrix of the lamina cribrosa and/or reduction in blood flow to the lamina cribrosa may contribute to glaucomatous neuropathy. Thinning of the lamina cribrosa reduces its stiffness and increases the risk of its posterior displacement. Optic nerve head posterior displacement warrants medical or surgical lowering of intraocular pressure; however, compared to intraocular pressure, the trans-lamina cribrosa pressure difference may be more important in pressure-related pathology of the optic nerve head region. Similarly important could be increased compression loading of the lamina cribrosa. Reducing participation in activities which elevate intraocular and intracranial pressure will decrease lamina cribrosa compression exposure and may contribute to glaucoma management and may have prognostic significance for glaucoma suspects.

Effects of Use of a Continuous Positive Airway Pressure Device on Glaucoma

Background

The aim of this study was to investigate the prevalence of glaucoma in obstructive sleep apnea syndrome (OSAS) and to determine the efficacy of the equipment used in the treatment of this disease.

Material/Methods

In this cross-sectional study, 38 patients with OSAS used the continuous positive airway pressure (CPAP) device (Group 1) and 32 patients with OSAS refused CPAP device (Group 2). Thirty-six patients did not have OSAS (Group 3).

Results

Patient age, gender, height, weight, and neck circumference did not differ among groups (p>0.05); and the apnea-hypopnea index (AHI) and respiratory disturbance index (RDI) values did not differ between Groups 1 and 2 (p>0.05). Vision and pachymetric values did not differ among groups (p>0.05). The IOP was significantly higher in Group 2 than in Group 1 (p<0.05) but did not differ between Groups 1 and 3 (p>0.05). The fundus C/D ratio was significantly higher (p<0.05) in Group 2 than in the other groups but did not differ between Groups 1 and 3 (p>0.05). In Group 1, 2, and 3, 5.2%, 12.5%, and 0%, respectively, of patients had glaucoma.

Conclusions

OSAS should be considered a significant risk factor for glaucoma. Eye tests may help to identify individuals with undiagnosed OSAS, and such testing of patients with diagnosed OSAS may allow early detection of glaucoma and referral of such patients for CPAP therapy to prevent development of complications.

The eye and sleep apnea

Several eye disorders have been found in association with obstructive sleep apnea (OSA). This paper reviews the current state of knowledge of eye disorders associated with OSA. OSA is associated with a number of eye disorders including floppy eyelid syndrome (FES), optic neuropathy, glaucoma, non-arteritic anterior ischemic optic neuropathy and papilledema secondary to raised intracranial pressure. FES patients have a very high incidence of OSA and a causal relationship may exist, but amongst patients with OSA, FES is uncommon but commoner than in the general population. Treatment of OSA may help floppy eyelid syndrome, halt progression of associated glaucoma or optic neuropathy, and reduce intracranial pressure in patients with associated papilledema. Sleep apnea patients should be asked about ocular symptoms and appropriately examined or referred for assessment as some of the associated eye disorders may permanently impair vision. Ophthalmologists should be aware of the association of sleep apnea with these eye disorders and consider referral to a sleep physician for investigation and possible treatment.

The eye and sleep

BACKGROUND

Sleep-associated disorders of the eye are increasingly recognized. Disordered sleep has also been found in some blind patients.

METHODS

Review of the current state of knowledge of sleep-related eye disorders and blindness-related sleep disorders.

RESULTS

Incomplete eyelid closure during sleep (lagophthalmos) may be physiological but in some patients can cause significant symptoms. Nocturnal lagophthalmos may be a limiting factor in the surgical repair of some eyelid and orbital disorders. Normal eyelid closure has also been linked to the development of a number of ocular surface disorders. Sleep disorders are common, and obstructive sleep apnoea (OSA) the commonest. OSA is associated with a number of serious systemic diseases and also several eye disorders including floppy eyelid syndrome, optic neuropathy, glaucoma, anterior ischaemic optic neuropathy and papilloedema secondary to raised intracranial pressure. Treatment of OSA may help floppy eyelid syndrome, halt progression of associated glaucoma, and reduce intracranial pressure in patients with associated papilloedema. The diagnosis of OSA can only be made with formal sleep studies, but asking a small number of appropriate questions will help screen those patients who should be referred for sleep studies. Some blind patients have disordered sleep patterns due to disruption of the retinal input into the hypothalamic-pineal melatonin secreting apparatus. This can be alleviated by oral administration of melatonin.

CONCLUSIONS

Ophthalmologists should be aware of sleep-associated eye disorders and refer appropriate patients for formal sleep studies. Sleep abnormalities in blind patients should be enquired about and patients offered assessment and treatment by a sleep physician.