Abstract
Purpose :
Alkali chemical burns to the cornea can ultimately lead to blindness. Slit lamp exam is traditionally used to assess damage to guide management; however, it is limited by poor depth analysis and obstruction by tissue scarring. Anterior segment optical coherence tomography (AS-OCT) is a non-invasive, high-resolution imaging modality that can potentially be used to overcome these limitations and provide fast, depth-resolved evaluation of corneal wound healing and remodeling.
Methods :
Following an IACUC-approved protocol, acute injury model of alkali burn was performed by applying a 2 mm diameter circle of filter paper soaked in 1.0M NaOH to the right eye for 30 seconds, while the left eye was treated with PBS as a control. AS-OCT was performed on the cornea and iris simultaneously, before and after the chemical burn, as well as at 7 and 14 days following the burn. Corneal thickness of each eye was measured at nine points on a central cornea slice in ImageJ and OCT angiography (OCTA) was performed on the images captured by AS-OCT using a custom algorithm.
Results :
We determined that alkali burns result in increased corneal thickness immediately post-injury (+70.33%), peaking on day 7 (+105.02%) and regressing slightly on day 14 (+101.95%). AS-OCT observed epithelial bullae and corneal opacity by day 7, and Descemet’s membrane detachment by day 14. In addition, beginning on day 7, OCTA showed development of neovascularization from the limbal area towards the center of the cornea. An anterior chamber inflammation was also noted, with hyper- and hypo- reflective stromal cysts, as well as expansive edemas, on day 7.
Conclusions :
AS-OCT was able to, with high sensitivity, detect edema/swelling, opacification, and neovascularization resulting from alkali burn. It also provided cross-sectional information for non-invasively exploring angiogenesis and tissue remodeling, as well as 3D visualization of the anterior chamber and corneal layers, regardless of the amount of corneal scarring. AS-OCT can be a valuable adjunct to standard diagnostic tools for the assessment of corneal alkali injury and wound healing.
This is a 2021 ARVO Annual Meeting abstract.