Abstract
Purpose :
Corneal incisions created during cataract surgery include full thickness incisions (FTIs) used to access the anterior chamber and partial thickness incisions (PTIs) used to correct corneal astigmatism. Laser-generated corneal incisions demonstrate increased accuracy, predictability and reproducibility compared to standard, manual incisions. This study assessed the accuracy of partial thickness corneal incisions constructed in the porcine eye model by an integrated femtosecond laser phacoemulsification system (ALLY System, LENSAR, Orlando, FL).
Methods :
Paired corneal PTIs, 180° apart, were generated on 36 porcine eyes at 3 incision depth modes and 3 arc lengths (30°, 60°, and 90°). The 3 incision depth modes were Fixed Depth, Fixed Residual Stroma and Percentage Depth. Incision depths were measured with a Fourier Domain OCT system. Incision arc lengths captured from the laser system and from a laboratory microscope were analyzed using a MATLAB algorithm.
Results :
For Fixed Depth PTIs, the mean achieved depths were 407µm ± 30µm and 628µm ± 30µm for intended depths of 400µm and 600µm, respectively. In the Fixed Residual Stroma group, the mean achieved residuals were 181µm ± 23µm and 276µm ± 33µm for intended residual depths of 150µm and 250µm, respectively. For the Fixed Percentage Depths group, the mean achieved percentages were 75% ± 4% and 86% ± 4% for intended percentage depths of 75% and 85%, respectively. Arc lengths measured from microscope images for intended arc lengths of 30°, 60° and 90°, were 30.20° ± 0.44°, 60.32° ± 0.56° and 89.56° ± 0.28°. Similarly, arc lengths measured from laser system images were 30.38° ± 0.54°, 60.19° ± 0.61° and 89.55° ± 0.34°, for intended corresponding arc lengths of 30°, 60° and 90°.
Conclusions :
The LENSAR ALLY System constructs accurate, predictable, and reproducible PTIs at selected parameters and incision modes. Additionally, incision arc length measurements are consistent between images acquired by the laser system during the procedure and images acquired via microscopy after laser treatment. The consistency and regularity associated with the PTIs created using the ALLY system may help minimize the incidence of undesirable refractive surprises, thus providing an advantage compared to manual PTIs.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.