Abstract
Purpose :
Sleep apnea has been proposed as a risk factor for normal and high tension glaucomatous optic neuropathy, but little is known about the underlying pathophysiology. We hypothesize that the pathophysiologic manifestations of sleep apnea cause compromise of the retinal peripapillary capillaries (RPC) resulting in decreased vascular density with secondary retinal nerve fiber layer (RNFL) thickness and loss of ganglion cells and atrophy.
Methods :
We are performing a prospective observational clinical study of 100 patients undergoing polysomnography as part of their standard of care. These patients undergo visual acuity, intraocular pressure (IOP), medical and ocular history questionnaire, 24-2 Humphrey visual field, spectral domain optical coherence tomography (OCT), OCT-Enhanced Choroidal Depth (EDI) and OCT-Angiography (OCT-A) of the macula and RNFL. Patients without sleep apnea will serve as our control group; initial results, herein, are compared to literature derived means of macular and RPC vessel density using a one-tailed t-test.
Results :
Six (N=6) patients and Twelve (N=12) eyes have been evaluated to date. The male to female ratio is 1:1. Age ranges from 48-72 years. Three patients have known diabetes and hypertension currently undergoing treatment. No patients had a prior or new diagnosis of glaucoma. All patients demonstrated sleep apnea with mean apnea-hypopnea index of 46.9 (Range=6.3 to 109.1). Mean RPC vessel density was significantly lower than historical normal controls based on comparative analysis of published literature (54.2%, Range=46.9 to 58.6%, compared to 64.5%, t=-10.31, p<0.01). Mean internal limiting membrane to retinal pigment epithelium (ILM-RPE) macular vessel density was also decreased compared to historical based normal controls (46.6%, Range=37.7 to 49.1%, compared to 54.4%, t=-7.8, p<0.01).
Conclusions :
Patients with sleep apnea thus far demonstrate reduced macular vessel density and RPC density. Our study will investigate whether sleep-disordered breathing compromises the retinal vasculature, particularly the RPC, as a primary retinal insult resulting in glaucomatous appearing optic neuropathy.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.