Abstract
Purpose :
To investigate the effectiveness of a new treatment algorithm to reduce post-operative induction of spherical aberration for myopic LASIK surgeries.
Methods :
A new algorithm has been developed to reduce the induction of spherical aberration observed in LASIK surgeries. The process was postulated as a linear filtering operation to the cornea after the ablation and during the healing process. An optimization algorithm was employed to yield an optimized mathematical kernel that can be applied to develop modified ablation shapes. A clinical trial (STAR-114-SARA) was designed to test the effectiveness of the new algorithm. 26 myopic patients were recruited in Bogota, Columbia to participate in the study. The study was prospective, paired-eye randomized, single-center, contralateral study with the study eye treated with the new algorithm and the control eye treated with CustomVue®. The pre-operative MRSE ranges from -4 D to -12 D, with astigmatism up to 8 D. The patients’ ages range from 20 to 48. Post-operative refractions, acuities, OCT, subjective questionnaire, and high order aberration were collected in 1-day, 1-week, 1-month, and 3-month after surgery.
Results :
The primary spherical aberration and secondary spherical aberration of both the study eyes and the control eyes were examined, together with other major HOA terms, such as coma and secondary astigmatism, over a 6 mm diameter and a 5 mm diameter, respectively. Over time, there is an increase of spherical aberration. However, the amount of spherical aberration at the same time point for the study eye is statistically significantly smaller than the control eye, both at 6 mm diameter and 5 mm diameter, indicating effectiveness of the new algorithm over previous treatments. At 6 mm diameter, the spherical aberration at 3-month post-op has a mean of 0.2 um for the study eyes and 0.26 um for the control eyes. The difference becomes more prominent at a smaller diameter. At 5 mm diameter, the spherical aberration at 3-month post-op has a mean of 0.02 um for the study eyes and 0.06 um for the control eyes. As for the visual acuities, there is no statistically significant difference between the two groups as expected, for both uncorrected and best-corrected acuities.
Conclusions :
The study shows the effectiveness of the new algorithm to reduce the induction of spherical aberration for myopic LASIK surgeries.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.