Chronic Effects of e-Cigarette Aerosol Inhalation on Macular Perfusion Assessed Using OCT Angiography

Abstract

Purpose: To determine whether there are significant differences in the microvasculature and central retinal thickness (CRT) between e-cigarette users (user group) and age-matched nonusers (control group) using optical coherence tomography angiography (OCTA). Methods: In this prospective cross-sectional observational study, OCTA images were acquired of 52 eyes of 26 users and 25 eyes of 25 age-matched nonusers. Daily e-cigarette users with no ocular history were identified from provider information in the electronic medical record. A custom algorithm was used to calculate the foveal avascular zone (FAZ), vessel area density (VAD), and vessel length density (VLD). OCT software was used to calculate the foveal, superior, inferior, nasal, and temporal CRT. Generalized estimating equations using the Z-statistic were used to determine how the FAZ, VAD, VLD, and CRT parameters varied between groups and to assess the differential contribution of descriptive data in the user group. Results: No statistically significant difference was found between the user group and control group in the FAZ, superficial vascular complex (SVC) VAD, SVC VLD, or deep vascular complex (DVC) VAD. A statistically significant difference was found for DVC VLD ( P = .002), with the user group having a slightly higher VLD on average. Superior, temporal, and inferior inner macular thicknesses were significantly thinner in the user group ( P = .038, P = .012, and P = .035, respectively). Conclusions: Significant negative differences were found in CRT measures but not in retinal microvasculature parameters between e-cigarette users and nonusers. Decreased inferior, temporal, and superior inner macular thickness in e-cigarette users may show an early chronic structural effect that warrants further assessment of retinal effects as this population ages and continues to use e-cigarettes.