This article is part of Ophthalmology Advisor’s conference coverage from the 2021 meeting of The Association for Research in Vision and Ophthalmology (ARVO), held virtually from May 1 to 7, 2021. The team at Ophthalmology Advisor will be reporting on a variety of the research presented by the eye and vision experts at ARVO. Check back for more from the ARVO 2021 Meeting.
Slit lamp exams are traditionally used to assess the damage caused by alkali chemical burns to the cornea. However, these exams provide poor depth analysis and are obstructed by tissue scarring. Researchers have found that anterior segment optical coherence tomography (AS-OCT) can overcome these limitations. They presented their findings during a poster session at the Association for Research in Vision and Ophthalmology (ARVO) 2021 Annual Meeting.
Following an Institutional Animal Care and Use Committees-approved protocol, acute injury model of alkali burn was performed by applying a 2 mm diameter circle of filter paper soaked in 1.0 M NaOH to the right eye for 30 seconds, while the left eye was treated with phosphate buffered saline 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 9 points on a central cornea slice in ImageJ and OCT angiography (OCT-A) was performed on the images captured by AS-OCT using a custom algorithm.
Investigators found 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, OCT-A showed development of neovascularization from the limbal area toward the center of the cornea. An anterior chamber inflammation also was observed on day 7, with hyper- and hypo-reflective stromal cysts and expansive edemas.
AS-OCT was able to detect edema/swelling, opacification, and neovascularization resulting from alkali burn with high sensitivity. 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 level of corneal scarring. Researchers concluded that AS-OCT can be a valuable complement to standard diagnostic tools for the assessment of corneal alkali injury and wound healing.
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Lin J, Luisi J, Kraft E, et al. Anterior segment optical coherence tomography (AS-OCT) for the assessment of corneal alkali injury. Poster presented at: Association for Research in Vision and Ophthalmology (ARVO) 2021 annual meeting; May 1-7; Virtual. Abstract 3536987.