Comparison of Visual and Refractive Outcomes of Keratorefractive Lenticule Extraction for Compound Myopic Astigmatism Between VisuMax and VISUMAX 800

Abstract

Purpose: To evaluate the visual outcomes of keratorefractive lenticule extraction using a new version of a femtosecond laser platform with semi-automated cyclotorsion compensation in comparison to the previous generation without cyclotorsion control.

Methods: This was an ambispective study of consecutive eyes treated by SMILE with the VisuMax and VISUMAX 800 femtosecond lasers at the Uma Eye clinic, Chennai, India between June 2022 and July 2023. Inclusion criteria were myopia up to -10 D and astigmatism between 1.5 D and 5 D. Data was retrospectively collected from patients that underwent SMILE using the VisuMax without cyclotorsion compensation and prospectively collected from patients undergoing SMILE using the VISUMAX 800 with Oculign and Centralign software aids.

Results: Data was collected from a total of 220 eyes that underwent routine SMILE; 115 eyes with VisuMax (VM500 group) and 105 eyes with VISUMAX 800 (VM800 group). The mean attempted spherical equivalent was -4.82±2.16 D in the VM500 group and -4.80±2.24 in the VM800 group. At the 3-month postoperative visit, 94% of eyes in the VM500 group and 98% of eyes in the VM800 group had an UDVA of 20/20 or better. Accuracy of the SEQ showed that 71% of eyes were within ±0.50 D and 100% were within ±1.00 D of target in the VM500 group and 96% of eyes were within ±0.50 D and 100% were within ±1.00 D of target in the VM800 group. There were no reported cases of suction loss or any other intraoperative complication in either group.

Conclusion: SMILE with the VisuMax and VISUMAX 800 provided excellent visual and refractive outcomes for subjects with myopic astigmatism. The VISUMAX 800, using Oculign and Centralign aids, demonstrated better accuracy when correcting cylinder greater than 2 D compared to the VisuMax without using manual cyclotorsion compensation.

Keywords: VISUMAX 800; astigmatism; small-incision lenticule extraction.

Figure 1

Standard graphs for reporting refractive surgery showing the 3-month postoperative outcomes after small-incision lenticule extraction using the VisuMax 500 femtosecond laser. (A) Cumulative Snellen visual acuity (20/× or better) comparing postoperative (postop) uncorrected distance visual acuity (UDVA) with preoperative (preop) corrected distance visual acuity (CDVA). (B) Comparison of pre operative CDVA with post operative UDVA. (C) Change in corrected distance visual acuity (CDVA) compared to preoperative. (D) Attempted versus achieved spherical equivalent of refraction. (E) Spherical equivalent refractive accuracy. (F) Stability of post op spherical equivalent of refraction. (G) Distribution of refractive astigmatism pre and post op. (H): Comparison of Target induced astigmatism with surgically induced astigmatism. (I) Distribution of angle of error of refractive astigmatism.

Figure 2

Standard graphs for reporting refractive surgery showing the 3-month postoperative outcomes after small-incision lenticule extraction using the VISUMAX 800 femtosecond laser. (A) Cumulative Snellen visual acuity (20/× or better) comparing postoperative (postop) uncorrected distance visual acuity (UDVA) with preoperative (preop) corrected distance visual acuity (CDVA). (B) Comparison of pre operative CDVA with post operative UDVA. (C) Change in corrected distance visual acuity (CDVA) compared to preoperative. (D) Attempted versus achieved spherical equivalent refraction. (E) Spherical equivalent refractive accuracy. (F) Stability of post op spherical equivalent of refraction. (G) Distribution of refractive astigmatism pre and post op. (H) Comparison of Target induced astigmatism with surgically induced astigmatism. (I) Distribution of angle of error of refractive astigmatism.

Figure 3

Vector analysis of refractive cylinder showing target induced astigmatism (TIA), surgically induced astigmatism (SIA), difference vector (DV), and correction index (CI) after small-incision lenticule extraction using the VisuMax 500 femtosecond laser.

Figure 4

Vector analysis of refractive cylinder showing target induced astigmatism (TIA), surgically induced astigmatism (SIA), difference vector (DV), and correction index (CI) after small-incision lenticule extraction using the VISUMAX 800 femtosecond laser.