Rohit Shetty1,2, Nimisha Rajiv Kumar3,4, Natasha Pahuja1, Rashmi Deshmukh1, KrishnaPoojita Vunnava1, Valsala Gopalakrishnan Abilash4, Abhijit Sinha Roy5, Arkasubhra Ghosh2,3. 1. Cornea and Refractive Surgery Division, Narayana Nethralaya, Bangalore, India. 2. Singapore Eye Research Institute, Singapore. 3. GROW Research Laboratory, Narayana Nethralaya Foundation, Bangalore, India. 4. Department of Biomedical Sciences, School of Bio Sciences and Technology, VIT University, Vellore, India. 5. Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation, Bangalore, India.
Abstract
PURPOSE: To evaluate the correlation of visual and keratometry outcomes after corneal cross-linking (CXL) in patients with keratoconus with cone epithelium-specific gene expression levels. METHODS: Corneal epithelium was obtained from 35 eyes that underwent accelerated CXL (KXLII, 9 mW/cm for 10 min). Using corneal topography, epithelium over the cone and periphery was obtained separately from each subject. The ratio of gene expression for lysyl oxidase (LOX), matrix metalloproteinase 9 (MMP9), bone morphogenic protein 7, tissue inhibitor of metalloproteinase 1, collagen, type I, alpha 1, and collagen, type IV, alpha 1 (COL IVA1) from the cone and peripheral cornea was correlated with the outcome of cross-linking surgery. Patients were assessed for visual acuity, keratometry, refraction, and corneal densitometry before and 6 months after surgery. Based on the change in corneal flattening indicated by ΔKmax, the outcomes were classified as a higher response or lower response. RESULTS: Reduction in keratometric indices correlated with improved spherical equivalent after CXL. Preoperative levels of cone-specific LOX expression in cases with a higher response were significant (P = 0.001). COL IVA1, bone morphogenic protein 7, and tissue inhibitor of metalloproteinase 1 gene expressions were reduced in the cones of the subjects with a lower response. MMP9 levels were relatively lower in cases with a higher response compared with those with a lower response. CONCLUSIONS: Our study demonstrates that preoperative levels of molecular factors such as LOX, MMP9, and COL IVA1 aid in understanding CXL outcomes at the tissue level.
PURPOSE: To evaluate the correlation of visual and keratometry outcomes after corneal cross-linking (CXL) in patients with keratoconus with cone epithelium-specific gene expression levels. METHODS: Corneal epithelium was obtained from 35 eyes that underwent accelerated CXL (KXLII, 9 mW/cm for 10 min). Using corneal topography, epithelium over the cone and periphery was obtained separately from each subject. The ratio of gene expression for lysyl oxidase (LOX), matrix metalloproteinase 9 (MMP9), bone morphogenic protein 7, tissue inhibitor of metalloproteinase 1, collagen, type I, alpha 1, and collagen, type IV, alpha 1 (COL IVA1) from the cone and peripheral cornea was correlated with the outcome of cross-linking surgery. Patients were assessed for visual acuity, keratometry, refraction, and corneal densitometry before and 6 months after surgery. Based on the change in corneal flattening indicated by ΔKmax, the outcomes were classified as a higher response or lower response. RESULTS: Reduction in keratometric indices correlated with improved spherical equivalent after CXL. Preoperative levels of cone-specific LOX expression in cases with a higher response were significant (P = 0.001). COL IVA1, bone morphogenic protein 7, and tissue inhibitor of metalloproteinase 1 gene expressions were reduced in the cones of the subjects with a lower response. MMP9 levels were relatively lower in cases with a higher response compared with those with a lower response. CONCLUSIONS: Our study demonstrates that preoperative levels of molecular factors such as LOX, MMP9, and COL IVA1 aid in understanding CXL outcomes at the tissue level.
Authors: Fiona C Simpson; Mohammed Mirazul Islam; Oleksiy Buznyk; Elle Edin; Marc Groleau; Monika Kozak-Ljunggren; Federica M Magrelli; Dina B AbuSamra; Pablo Argüeso; James Chodosh; Aneta Liszka; Per Fagerholm; May Griffith Journal: Front Bioeng Biotechnol Date: 2022-06-13