Impact Of Varied Spot And Track Distances And Pulse Energies Within The Same Total Energy On Keratorefractive Lenticule Extraction Using A Novel 2 Mhz Femtosecond Laser
Published 2024 - 42nd Congress of the ESCRS
Reference: FP20.03 | Type: Free paper | DOI: 10.82333/hrzs-j126
Authors: David Sung Yong Kang* 1 , Samuel Arba-Mosquera 2 , Kangyoon Kim 1 , Byunghoon Chung 1 , Tae-im Kim 3
1Eyereum Eye Clinic,Seoul,Korea, Republic Of, 2Research & Development,SCHWIND Eye-Tech-Solutions GmbH,Kleinostheim,Germany, 3Department of Ophthalmology,Yonsei University College of Medicine,Seoul,Korea, Republic Of;POSTECH Biotechnology Center,Pohang University of Science and Technology,Pohang,Korea, Republic Of
Purpose
To assess the initial two-month postoperative results following keratorefractive lenticule extraction (KLEX) utilizing the VisuMax 800 femtosecond laser device (Carl Zeiss, Meditec AG), incorporating different combinations of spot and track distances and pulse energies within same total energy delivery.
Setting
Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea.
Methods
This study involved 1000 eyes of 500 patients who underwent keratorefractive lenticule extraction (KLEX) using the VisuMax 800 femtosecond laser system to correct compound myopia. Treatments involved applying low-energy levels of laser pulse (sub-100 nj). One eye of each patient received pulse lasers with symmetric spacings, while the contralateral eye was treated with asymmetric spacings. Preoperative and postoperative evaluations at 1 day, 1 to 2 weeks, and 1 to 2 months included measurements of visual acuity, subjective refraction, and corneal higher-order aberrations. Comparative analyses were conducted between groups treated with a spectrum of spot and track spacings and pulse energies.
Results
Baseline characteristics showed no differences between groups (p > 0.05). The 1-week postoperative UDVA (logMAR) for groups with pulse energies of 85 nj, 90 nj, 95 nj, and 100 nj were -0.045±0.05, -0.047±0.06, -0.038±0.06, and -0.031±0.06, respectively (p < 0.001). The symmetric and asymmetric spacing group had UDVA of -0.030±0.06 and -0.047±0.04, respectively, at 1 week postoperatively. The induced SA (RMS) for groups with pulse energies of 85 nj, 90 nj, 95 nj, and 100 nj were -0.034±0.129, 0.016±0.120, 0.028±0.127, and 0.039±0.118, respectively. The symmetric and asymmetric spacing group had SA values of 0.028±0.132 and 0.017±0.130, respectively, at 1 week postoperatively.
Conclusions
Low levels of laser pulse energy and asymmetric spot and track spacing contributed to early visual rehabilitation after KLEX using the VisuMax 800 femtosecond laser for treatment of myopia.