Kate E Leahy1,2, Michele C Madigan3,4, Maria Sarris5, Stephanie L Watson3,5, Peter McCluskey3, Andrew Jr White1,3,4,6. 1. Department of Ophthalmology, Westmead Hospital, Sydney, New South Wales, Australia. 2. Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia. 3. Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia. 4. School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia. 5. School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia. 6. Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia.
Abstract
IMPORTANCE: Transient corneal endothelial changes are routinely noted on slit-lamp examination immediately following selective laser trabeculoplasty (SLT). BACKGROUND: To determine the mechanism of transient corneal endothelial changes observed following SLT. DESIGN: University laboratory-based observational study. SAMPLES: Ten corneas from six human cadaveric donors. METHODS: Corneas were treated with SLT, direct laser or peroxide, or used as controls. Haematoxylin and eosin staining and immunolabelling for zonula occludens-1 (ZO-1) and beta-catenin were performed. MAIN OUTCOME MEASURES: Histological appearance; ZO-1 and beta-catenin immunostaining. RESULTS: There were no differences in histological features between SLT-treated and control corneas. Corneas treated with SLT or peroxide showed reduced and less regular ZO-1 immunofluorescence along cell membranes compared with ZO-1 expression in controls. These changes were generalized across the endothelium. There was no effect on the ZO-1 immunostaining after direct laser. There was no difference in beta-catenin immunostaining patterns between control, SLT and peroxide-treated corneas. CONCLUSIONS AND RELEVANCE: Altered ZO-1 immunostaining may represent disassembly of tight junctions between corneal endothelial cells. The similarity of our findings between SLT-treated and peroxide-treated corneas suggests that both conditions trigger changes at the level of endothelial tight junctions, perhaps triggered by liberation of free radicals as previously proposed.
IMPORTANCE: Transient corneal endothelial changes are routinely noted on slit-lamp examination immediately following selective laser trabeculoplasty (SLT). BACKGROUND: To determine the mechanism of transient corneal endothelial changes observed following SLT. DESIGN: University laboratory-based observational study. SAMPLES: Ten corneas from six human cadaveric donors. METHODS: Corneas were treated with SLT, direct laser or peroxide, or used as controls. Haematoxylin and eosin staining and immunolabelling for zonula occludens-1 (ZO-1) and beta-catenin were performed. MAIN OUTCOME MEASURES: Histological appearance; ZO-1 and beta-catenin immunostaining. RESULTS: There were no differences in histological features between SLT-treated and control corneas. Corneas treated with SLT or peroxide showed reduced and less regular ZO-1 immunofluorescence along cell membranes compared with ZO-1 expression in controls. These changes were generalized across the endothelium. There was no effect on the ZO-1 immunostaining after direct laser. There was no difference in beta-catenin immunostaining patterns between control, SLT and peroxide-treated corneas. CONCLUSIONS AND RELEVANCE: Altered ZO-1 immunostaining may represent disassembly of tight junctions between corneal endothelial cells. The similarity of our findings between SLT-treated and peroxide-treated corneas suggests that both conditions trigger changes at the level of endothelial tight junctions, perhaps triggered by liberation of free radicals as previously proposed.
Authors: Raul E Ruiz-Lozano; Jimena Alamillo-Velazquez; Gustavo Ortiz-Morales; Lucas A Garza-Garza; Manuel E Quiroga-Garza; Carlos Alvarez-Guzman; Alejandro Rodriguez-Garcia Journal: Int Ophthalmol Date: 2022-08-13 Impact factor: 2.029