Refractive Stability after LASIK-Xtra for Hyperopia and Astigmatism

Abstract

Purpose : Laser in situ keratomileusis (LASIK) is the most frequent refractive surgical procedure. Inaccuracy and regression are limitations of concern in patients with astigmatic and hyperopic refractive errors. It is hypothesized that the addition of partial corneal collagen crosslinking (CxL) to the LASIK procedure (LASIK-Xtra) enhances refractive stability.
We report the long-term outcomes, stability, safety, accuracy and efficacy in a case series of hyperopia and astigmatism treated with LASIK-Xtra.

Methods : We included 33 eyes of patients with hyperopia and/or astigmatism that underwent LASIK-Xtra in the Refractive Surgery Clinic of our Ophthalmology Department at our University Hospital. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction and automated keratometry were recorded before surgery and during follow-up at 1, 3, 6 and 12 months.

Results : Mean age was 30 (range 18 to 50) years. Preoperative manifest refraction (Mean ± standard deviation) in diopters (D) was sphere (Sph): +3.62±2.27, cylinder (Cyl): -2.79±1.82, spherical equivalent (SE): +1.44±2.66. All eyes showed refractive stability and no regression from month-1 to month-12 in SE (from -0.37±0.35D to-0.22±0.79D), Sph (+0.10±0.04D to +0.34±0.84D) and Cyl (-0.90±0.80D to -1.12±0.90D). Keratometric stability was attained from month-3 (44.53±2.91D) until the last visit (44.22±3.13D). At month-12, 15% (n=3) of the eyes had a loss of 1 or more Snellen lines of preoperative CDVA, and 15% (n=3) of the eyes gained 1 or more Snellen lines (Safety); 83% of the eyes were within 1.00D from the SE target (Accuracy). At 1-year of follow-up, 20% of the eyes had an UDVA > 20/20, 45% > 20/25 and 80% > 20/30 (Efficacy).

Conclusions : This refractive procedure demonstrated to be safe, accurate and efficient, according to a sample of eyes with hyperopia and astigmatism. Our results suggest that LASIK-Xtra achieves refractive stability from the first month postoperatively until at least a year after the procedure, probably preventing regression. Further studies with longer follow-up periods and control groups are required.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.