Barzilai University Medical Center

72 Research Day 2020 Barzilai University Medical Center 50 RE-TREATMENT BY FLAP RELIFT VERSUS SURFACE ABLATION AFTER MYOPIC LASER IN SITU KERATOMILEUSIS Kaiserman I 1 , Mimouni M 2 , Rabina G 3 , Hecht I 4 . 1 Department of Ophthalmology, Barzilai University Medical Center, Ashkelon, Israel. Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 2 Department of Ophthalmology, Rambam Health Care Campus, Affiliated to the Bruce and Ruth Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel. 3 Division of Ophthalmology, Sourasky Medical Center, Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. 4 Department of Ophthalmology, Assaf Harofeh Medical Center, Affiliated to the Sackler School of Medicine, Tel Aviv University, Israel. Background Regression of refractive treatment after LASIK can occur in 5-10% of the cases. Re-treatment is usually possible and can be done either by lifting the LASIK flap or by surface ablation. Hypothesis Re-lifting the LASIK flap has different complications than re-treatment by surface ablation. Objectives To compare clinical outcomes of patients undergoing first re-treatment by flap re-lift with those re-treated by surface ablation. Methods This is a retrospective cohort analysis of consecutive patients who underwent myopic LASIK and required re-treatment between January 2007 and December 2016. Cases re-treated by flap re-lift were propensity score matched with cases re-treated by surface ablation, and clinical outcomes were compared. One eye from each patient was included. Results A total of 1,234 out of 21,191 cases required re-treatment after myopic LASIK during the follow-up period. Surface ablation was performed in 75% of cases and re-lift in 25%. Patients re-treated by surface ablation were more commonly male (61.8% vs. 48.1%, P < 0.001), were younger (33.2 ± 7.8 vs. 35.2 ± 10 years, P = 0.005), and had thinner corneas (483 ± 46 vs. 502 ± 43 μm, P < 0.001). Cases re-treated by surface ablation had a worse safety index (0.98 ± 0.12 vs. 1.02 ± 0.17, P = 0.049), yet better predictability (0.14 ± 0.6 vs. 0.35 ± 0.5 diopters of deviation, P = 0.009), a similar efficacy index (0.92 ± 0.2 vs. 0.93 ± 0.3, P = 0.814), higher rates of haze (5.8% vs. 0.5%, P = 0.002), and a lower risk for epithelial ingrowth (0.5% vs. 8.2%, P < 0.001). Conclusions Re-treatment after myopic LASIK with surface ablation resulted in worse safety and higher rates of haze, yet more predictable outcomes and reduced ingrowth rates, compared with re-treatment with flap relift.