Eyeworld

105 September 2016 EW REFRACTIVE Conclusion: BRI quantifies changes in BL following SMILE and is depen- dent on refractive error. BRI is sig- nificantly altered in FFKC, indicating morphological changes may occur before topographic manifestations. In keratoconus BRI can be used as a screening tool for FFKC and high- lights the importance of the BL in keratorefractive practice. Dr. Desai: In this paper, the authors present a model by which the increase in roughness in Bowman's layer seen after keratorefractive procedures, such as LASIK and SMILE, may be quantified. With the use of a best fit curve float model, a Bowman's roughness index (BRI) can quantify micro-distortions in the cornea on high-resolution OCT. I found even more interesting the finding that BRI is statistically reduced in forme fruste keratoconus and even further in frank keratoconus, suggesting that such quantifiable morphological changes precede topographical changes in these disease states and may be used as an early diagnostic screening criteria. EW Editors' note: Dr. Desai is director of cornea, cataract, and refractive surgery at the Eye Institute of West Florida, Tampa Bay, and co-medical director of the Lions Eye Bank and Institute for Transplant Research. He has no finan- cial interests related to his comments. Contact information Desai: desaivision@hotmail.com Purpose: To study and quantify the impact of changes in Bowman's layer (BL) in keratoconus and small incision lenticule extraction (SMILE) surgery using Bowman's roughness index (BRI) and assess the effect of these changes on clinical parameters. Methods: High resolution SD-OCT was used to scan corneas of subjects of keratoconus and those under- going SMILE before and at 1 day, 1 week, and 1 month after surgery. This index (BRI) for area under undulations was calculated with in-house software. The anterior edge of the BL was segmented from OCT images. After segmentation, a third order polynomial was curve fit to the segmented pixels of the BL edge. The area between the micro-distor- tions and curve fit was evaluated. Visual acuity, refraction, and biome- chanics were evaluated. BRI was cal- culated for normals and in different grades of keratoconus. Results: In SMILE, BRI was found to have significant change (P<0.001) toward varying time points, which was maximum at 1 week and then decreased in a month and beyond. Correlation was also found between refractive error and BRI. In keratoco- nus, mean BRI was 2.15, 1.87, and 1.7 mm 2 in normal, FFKC, and KC eyes, respectively (p=0.001). BRI had an area under the ROC curve of 0.7 and sensitivity of 93.3% for detec- tion of FFKC. appeared to have minimal change in best corrected vision, endothelial cell density, and manifest refraction at the 18M postoperative time point. Complications were manageable with all subjects returning to near visual baseline by 6M post-explant. Dr. Desai: Just prior to FDA approval in June 2016, Drs. Koch and Steinert pre- sented data on the unique corneal inlay Raindrop, which approaches presbyopia from an entirely different direction. Whereas the first approved corneal in- lay, KAMRA (AcuFocus, Irvine, Califor- nia), works on the principle of creating a small aperture pinhole effect to extend depth of field, the Raindrop hydrogel inlay works by creating a hyperprolate corneal topography with optics similar to a multifocal IOL. When implanted in the non-dominant eye, there appears to be excellent long-term preservation of distance visual acuity with enhanced intermediate and near vision. While 5% of patients in the clinical trial required explantation, the safety data presented revealed that corneal topogra- phy and visual acuity returned to pre- operative baseline. Such data predicted FDA approval just months after it was presented at the ASCRS•ASOA Sympo- sium & Congress. Bowman roughness index: New index to quantify Bowman's lay- er changes in keratorefractive practice and procedures Rushad Shroff, MD, Rohit Shetty, DNB, FRCS, Kalyani Deshpande, MD, Natasha Pahuja, DOMS, Rashmi Sharad Deshmukh, MBBS, MS, Aarti Agrawal, MD Clinical impact after implanta- tion of non-refractive transpar- ent corneal inlay: U.S. IDE clinical trial update Douglas Koch, MD, Roger Steinert, MD Purpose: To evaluate the change in safety parameters from baseline to 18M postop in subjects implanted with the Raindrop Near Vision Inlay (ReVision Optics, Lake Forest, Cali- fornia). Post-explant visual recovery will also be evaluated in complicated cases. Methods: In an FDA-monitored clinical trial, emmetropic presbyopes were implanted with the Raindrop inlay in their non-dominant eye to correct for presbyopia. Safety param- eters including corrected distance visual acuity (CDVA), refractive stability, and endothelial cell density (ECD) were evaluated at 18M postop compared to baseline. Adverse events and post-explant visual re- covery are reported. Results: At 18M (n=351), CDVA was 20/25 or better in 99% of the inlay eyes with 0% of subjects losing more than two lines from baseline. Refractive stability was achieved by 3M with greater than 98% of subjects within 1.0 D MRSE from 3M to 18M postoperatively. No subjects lost more than 10% of ECD, and 97% had less than 5% ECD loss from baseline. Explants were performed in 4% of eyes, with CDVA in all subjects returning to 20/25 or better by 6M after removal. Conclusion: Subjects implanted with the Raindrop Near Vision Inlay Refractive

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