Mustard gas exposure causes meibomian gland deficiency in rabbit eye in vivo

Abstract

Purpose : Sulfur mustard (SM) gas exposure to the eye causes severe toxicity to the ocular surface and periocular tissues including the eyelid. Eyelids are important to keep the ocular surface moist, and lubricated, remove foreign bodies, and avoid infections with the help of oils and lipids produced by meibomian glands located in both the eyelids. This study investigated SM toxicity to eyelid tissues focusing on the meibomian glands in rabbit eyes in vivo.

Methods : Eyes of New Zealand White Rabbits were exposed to SM vapor (200 mg-min/m³ for 8min) and subjected to clinical microscopic (slit-lamp, confocal, spectralis, and specular) examinations, fluorescein eye test, Schirmer’s tear test, pachymetry, tonometry, and optical coherence tomography. Rabbits were humanely euthanized at 4 month, and eyelids were collected, for histological, molecular, and cellular analyses.

Results : SM exposure led to moderate-to-severe blepharitis, photophobia, and redness in palpebral and bulbar conjunctiva in a time-dependent manner, in comparison to age-matched naive eyes. Also, an enhanced tear flow (14.1 ± 2.3) was observed. The histopathological examinations revealed that meibomian glands are fewer in number also their size decreased significantly (p<0.001) in comparison to age-matched control.

Conclusions : Ocular SM exposure showed damage to eyelids and altered the size and number of meibomian glands in rabbit eyes in vivo. Additional studies are ongoing.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.