EyeWorld Asia-Pacific June 2023 Issue

diagnosing infectious disease in ophthalmology care. “Why do we want novel approaches in diagnostics?” Dr. Prajna asked during the symposium Updates on Infectious Keratitis. “One important thing to know is that different fungi respond to different antifungals.” Thus, surgeons should know how to differentiate fungi. “If you show photographs to clinicians, they will correctly distinguish bacterial from fungal etiology 66% of the time,” he explained. With AI, computer vision models (such as MobileNet or DenseNet) can achieve superhuman performance in identifying the underlying infectious cause of microbiologically-positive corneal ulcers when compared to the ability of experienced cornea specialists. Another new diagnostic tool is the SmartProbe, which rapidly evaluates corneal scrapes from patients as an alternative to using a Gram stain. Two activatable peptide-based fluorescent imaging probes that have been previously developed for pulmonary applications are BAC One (reports on presence of bacterial or fungal microbes) and BAC Two (reports presence of gram-negative bacteria). “Initially, you may be thinking we require a fluorescent microscope for diagnostics. But, we just published a paper in which we designed a cost-effective fluorescent instrument costing around $10 USD, which can be used as point-of-care testing,” Dr. Prajna said. He next described another tool in which isothermal amplification is combined with CRISPR, a family of DNA sequences, to produce an assay (RID MyC) to detect fungal nucleic acids. Advantages of this technique include rapid turnaround time, improved specificity, and accessible reporting formats such as lateral flow strips and fluorescent readouts. The RID MyC assay costs only USD$6 and boasts a 93.6% sensitivity and 91.1 specificity, whereas the cost of PCR remains US$25 with a range of 70-98% sensitivity and 56-95% specificity. The excitement of these new advancements in diagnostics could be felt by all in the room. “I will leave you with one message,” Dr. Prajna said. “The way we get a finding from microbiology in the future is going to be completely different from what we are getting today.” Allogenic cell therapy approval among highlights in corneal innovation session Less than 3 months after the first-ever regulatory approval for an allogenic cell therapy to treat corneal endothelial disease, Shigeru Kinoshita, MD, PhD, spoke to attendees at the 35th APACRS Singapore What’s New in Cornea session about the approval that meant so much to him personally. Two main concepts of regenerative medicine products are being studied: what Prof. Kinoshita calls “pseudo-regenerative medicine,” which is the sustained release of cytokines by regenerative medicine products, and “true” regenerative medicine, which is the restoration of tissue structure and function by regeneration medicine products. Prof. Kinoshita is studying the latter, and told attendees that cultivated human corneal endothelial cells (HCEC) are heterogenous. Published studies by his group have shown the superiority of mature differentiated cultured HCEC injection therapy. “Cell injection therapy is going to be the treatment for endothelial cell failure in the future,” he said, adding that restoring corneal endothelial health to patients by innovating with cell therapy “has been my life’s work.” To date, more than 130 patients worldwide have been treated with the therapy, Vyznova (Aurion Biotech). Similarly, Gerd U. Auffarth, MD, said endothelial keratoplasty (EK) comprises 60% of the corneal tissue replacement market. Endoart, an artificial corneal endothelial implant, was originally developed to decrease corneal edema by preventing aqueous humour from entering the cornea. The implant works in two stages: first, a gas bubble creates surface tension that holds the implant in place and then natural healing promotes adhesion protein to adhere to the implant’s surface. A total of 123 patients have up to 4-year follow-up data available, the longest follow-up being 9 years. “There have been no device-related complications, and we have shown long-term safety,” he said, with one patient up to 9 years who “still has a clear cornea.” In general, Dr. Auffarth said the surgical implantation “is easier than conventional Descemet’s membrane endothelial keratoplasty,” the implant is “very forgiving” in terms of intraoperative handling, there have been no observations of material degradation, patients do not require immunosuppression therapy, corneal swelling is effectively reduced, and “pain from bullous keratopathy resolves.” Other key attributes, he said, is that there are no waiting lists for human tissue for patients, and the overall procedure is at a lower cost than traditional EK surgery. NEXUS CoNNECtiNg EvEryoNE & EvErythiNg

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