EyeWorld India March 2021 Issue

Supplement to EyeWorld Asia-Pacific March 2021 Story of the Epithelium Dr. Naren Shetty discussed the need for studying the healing pattern of epithelium. Just like how bone has its own mechanism for healing, epi- thelium has its own way of healing after refractive surgery. In Dr. Shet- ty’s research, he studied whether artificial intelligence can be used to improve surgery outcomes as well as determining differences in epithelial remodeling between flap and flapless procedures. In order to build an AI model, Dr. Shetty took the epithelial thickness difference pre- and post-operatively, converted these values to Zernike Indices, and incorporated the values into the AI program. With the help of AI, one can see a significant differ- ence between corneal epithelial thick- ness among SMILE, LASIK, manual PRK, and trans PRK procedures. Thus, using AI and machine learning, we can predict and choose the most appropriate refractive surgery pro- cedure for specific types of eyes (i.e. early ectasia or epithelial regression). In early ectasia, AI can help with early detection of post-LASIK ectasia much earlier than without the help of AI. In refractive regression, AI can help predict how the epithelium changes during SMILE procedures. Wound Healing Model in Post SMILE and its Relation to Dry Eyes Dr. Pooja Khamar next discussed how wound healing differs between SMILE and LASIK. Specifically, Dr. Khamar’s research looked at the immediate modulations occurring in the corneal tissue in eyes undergoing either SMILE or LASIK compared to eyes that did not undergo any type of surgery. In this study, the corne- New Advancements in Refractive Surgery: A Fresh Perspective on SMILE in the time of COVID-19 study was performed on donor eyes. What Dr. Khamar found was that different markers including galec- tin-3-binding protein and interleukin-1 receptor antagonist protein regulated inflammation while lactoperoxidase and peroxiredoxin-5 proteins aided in wound healing. With this data, Dr. Khamar concluded that lysozyme C and the other protein markers found in the corneal stroma has inflammato- ry functions and a role in dry eye after refractive surgery. Epigenetics of Healing in SMILE & LASIK & Implications on Post-LASIK Ectasia In the next presentation, Dr. Swam- inathan Sethu began by describing that a surgeon’s precision along with technology and tissue response is necessary for successful refractive surgery. Tissue response, particu- larly, has been the most researched, “ We are already scratching the epigenetic role in modulating post refractive outcome. This is a new field which is going to have a very useful impact. ” Dr. Swaminathan Sethu, India tracellular matrix remodeling in post SMILE procedures. Additionally, there was enhanced cell differentiation and quick restoration of corneal epitheli- um post SMILE surgery compared to LASIK. Dr. Khamar was also interested in whether these results would hold up in patient eyes, since the previous al stroma was extracted 14 hours after surgery, and protein from the stroma was extracted. With quanti- tative proteomic analysis using mass spectrometry, Dr. Khamar found that the lysozyme C enzyme showed less inflammation in SMILE procedures compared to LASIK. There was also better intracellular calcium signaling and homeostasis as well as less ex- Figure 3. SMILE procedures showed less inflammation, better intracellular calcium signaling and homeostasis, less extracellular matrix remodeling, and enhanced wound healing compared to LASIK. Source: Khamar P et al. Exp Eye Res 2020. image @ 1:57:30 Copyright 2021 APACRS. All rights reserved. The views expressed here do not necessarily reflect those of the editor, editorial board, or publisher, and in no way imply endorsement by EyeWorld, Asia-Pacific or APACRS.