Optical coherence tomography angiography and Humphrey visual field in patients with obstructive sleep apnea

Abstract

Study objectives: To determine if obstructive sleep apnea syndrome (OSAS) predisposes patients to glaucoma and macular disease due to vascular compromise by evaluating retinal and optic nerve vasculature and function using optical coherence tomography angiography and Humphrey visual field testing, respectively.

Methods: In this prospective, observational, cross-sectional study 45 patients undergoing polysomnography ordered per standard of care were selected and stratified based on apnea-hypopnea index (AHI). Medical history, visual acuity testing, 24-2 Humphrey visual field, intraocular pressure measurement, and optical coherence tomography angiography studies of the macular and peripapillary retina were obtained. Correlations between polysomnography parameters and imaging data were analyzed.

Results: The radial peripapillary capillary vascular density demonstrated no relationship to AHI (95% confidence interval [CI] [-0.026,0.038]) or severity of OSAS (95% CI: [-0.772, 3.648]) for moderate OSAS compared to mild/normal and (-1.295, 3.1421) for severe compared to mild/normal. Optical coherence tomography angiography superficial parafoveal vascular density (95% CI: [-0.068,0.011], deep parafoveal vascular density (95% CI: [-0.080,0.009]), and foveal avascular zone (95% CI: [-0.001, 0.001]) showed no statistically significant relationship to AHI or OSAS severity after controlling for confounders. Optical coherence tomography retinal nerve fiber layer thickness increased with AHI (P = .014), but there was no statistically significant correlation with OSAS severity with retinal nerve fiber layer thickness (95% CI: [-12.543, 6.792] for moderate comparing to normal and [-2.883, 16.551] for severe comparing to normal). Visual field parameters were unaffected by OSAS (95% CI: mean deviation [-0.21,0.29], pattern standard deviation: [-0.351, 0.121], visual field index: [-0.166, 0.329]). Optical coherence tomography choroidal thickness showed a statistically significant decrease when OSAS was grouped by severity (P = .0092) but did not correlate with AHI (P = .129, 95% CI: [-1.210, 0.095]).

Conclusions: The severity of OSAS did not show a statistically significant effect on parameters associated with glaucoma or macular vascular disease. Larger cohorts may be required to determine the physiologic consequences of OSAS on the macular and optic nerve vasculature, structure, and function.

Citation: Davanian A, Williamson L, Taylor C, et al. Optical coherence tomography angiography and Humphrey visual field in patients with obstructive sleep apnea. J Clin Sleep Med 2022;18(9):2133-2142.

Keywords: OCT-A and sleep apnea; glaucoma in sleep apnea; macular degeneration; normal tension glaucoma and sleep apnea; obstructive sleep apnea and vascular dysregulation; optic neuropathy; vascular density in sleep apnea.

Figure 1. Radial peripapillary capillary vascular density (VD) and retinal nerve fiber layer (RNFL) thickness measurement.

En-face view of the vasculature above the outer plexiform layer (A) and RNFL layer (B). Vasculature in the RNFL layer is considered the radial peripapillary capillaries. (C) and (D) Segmentation from internal limiting membrane to the RNFL. The RNFL is then divided into 8 segments. (E) RNFL thickness reported as the distance shown between the segmentation lines in C and D. (F) Vascular density reported as the number of pixels measured in the corresponding section in B.

Figure 2. Superficial parafoveal vascular density (VD) measurement with segmentation lines outlining the area between the internal limiting membrane (ILM) and inner plexiform layer (IPL) with −9-µm offset.

(A) En face view and (B) segmentation lines. The number of pixels in each of the 4 quadrants is reported. A similar method was used for deep parafoveal vascular density with segmentation lines outlining the area between IPL with a −9 µm offset to the outer plexiform layer (OPL) with a 9 µm offset.

Figure 3. En-face view of the fovea showing automated outline and measurement of the foveal avascular zone.

This was reported as millimeters squared.

Figure 4. Choroidal thickness measurement by enhanced depth imaging optical coherence tomography (EDI-OCT).

The distance shown is reported.

Figure 5. Flowsheet outlining patient participation.

HVF = Humphrey visual field, OCT-A = optical coherence tomography angiography.

Figure 6. Relationship between apnea-hypopnea index (AHI) and radial peripapillary capillary vascular density (RPC VD).

No significant correlation was found and thus our hypothesis was not supported. Additionally, there were no correlations found when coupling AHI score with age, sex, diabetes, or hypertension.