This content from the 2020 ASCRS Virtual Annual Meeting is only available to ASCRS members. To log in, click the teal "Login" button in the upper right-hand corner of this page.
To report on visual results, patient reported outcomes, flap thickness precision in eyes undergoing elliptical thin-flap LASIK (sub-Bowman keratomileusis; SBK) with a temporally hinged ,120° side-cut angles.
A prospective pilot study to evaluate preoperative and postoperative tests included best spectacle-corrected visual acuity, uncorrected visual acuity (UCVA). Patients completed subjective questionnaires at each visit. Patients were evaluated before surgery and 1 day, 1 week, 2 weeks and 1 month after surgery. In all cases customized WaveLight® EX500 Excimer Laser followed thin flap creation by OCT guided FEMTO LDV Z8 (Ziemer Ophthalmic Systems Port, Switzerland). A pain questionnaire was conducted at 1 day, 2 day and 1 week postoperatively. Target flap thickness varied 85μm in 45 eyes, 90 μm in 7 eyes, and 100 μm in 10 eyes.
The mean preoperative spherical refraction was diopters -4.8 D and the mean cylinder was -0.73 D for all eyes. At one day UCVA of 20/20 or better achieved in 44 eyes. Standardized flap parameters were programmed for each procedure. Intra-operative OCT (Ziemer Z8 LDV) for flap visualization. Heidelberg Optical Coherence Tomography used to measure the post-operative flap thickness. Achieved flap thickness were measured to be very close to intended flap thickness in all cases. All values within 95% confidence limit. All patients were highly satisfied with the procedure. No adverse events reported. No intra- or postoperative complications reported.
Thin-flap LASIK created by FEMTO LDV Z8 is considered to offer advantages of both surface and flap technique with biomechanical stability, painless and leading to earlier visual recovery. The additional customization of the OCT guidance can help the surgeon to visualize the epithelium and plan targeted Sub-bowman flaps of 80-90 µm effectively.