Longitudinal Assessment of Alkali Injury on Mouse Cornea Using Anterior Segment Optical Coherence Tomography

Chemical burns due to alkalis cause extensive damage to the ocular surface leading to blindness. Assessment of ocular burn could be challenging due to severe opacity, inflammation, and angiogenesis. Anterior segment optical coherence tomography (AS-OCT) and OCT angiography (OCTA) may provide fast, non-invasive deep tissue visualization of pathology with high sensitivity in conjunction with slit-lamp analysis.

C57-BL/6J mice were anesthetized with ketamine/dexmedetomidine, and corneal alkali burn was induced (n = 6) by placing filter paper soaked in 1-M sodium hydroxide for 30 seconds on the right eye while the left eye was kept as control. Longitudinal imaging was done with AS-OCT/OCTA and fluorescein angiography at various time intervals for 14 days.

AS-OCT showed characteristic pathological changes in alkali-burned eyes with high sensitivity. Although OCT/OCTA showed three-dimensional and cross-sectional views of the anterior chamber and angiogenesis, fluorescein angiography showed nascent vessels with active leakage. Corneal swelling progressively increased by 125.26% on day 12 with a high prevalence of epithelial bullae, stromal cysts, stromal splitting, and Descemet's membrane detachment. Neovascularization was noted as early as day 4 in the burned eyes by both methods. Severe corneal opacity and anterior chamber inflammation were also detected by AS-OCT/OCTA.

AS-OCT/OCTA is a promising, noninvasive, high-resolution imaging modality that can provide both qualitative and quantitative information regarding deep tissue pathology at a structural level.

Noninvasive AS-OCT/OCTA and fluorescein methods show promise in clinical pathology evaluation for ocular injury management and prognostic indications, as the early presence of Descemet's membrane detachment and corneal swelling appears to be correlated with the severity and localization of corneal neovascularization.