LASIK for the Correction of High Hyperopic Astigmatism With Epithelial Thickness Monitoring.

PURPOSE: To evaluate outcomes of high hyperopic LASIK using the MEL 80 excimer laser (Carl Zeiss Meditec, Jena, Germany).

METHODS

Retrospective analysis of 830 consecutive high hyperopic LASIK procedures using the MEL 80 excimer laser and either the VisuMax femtosecond laser (Carl Zeiss Meditec) or zero compression Hansatome microkeratome (Bausch & Lomb, Rochester, NY). Inclusion criteria were attempted hyperopic correction of +4.00 diopters [D] or higher in one axis and corrected distance visual acuity (CDVA) of 20/20 or better. Patients were observed for a minimum of 1 year. Epithelial thickness monitoring by Artemis very high-frequency (VHF) digital ultrasound (ArcScan Inc., Morrison, CO) was used to evaluate potential for further steepening as a re-treatment.

RESULTS

One-year data were available for 785 eyes. Mean attempted spherical equivalent refraction (SEQ) was +4.52 ± 0.84 D (range: +2.00 to +6.96 D) for the primary treatment and mean cylinder was 1.05 ± 0.86 D (range: 0.00 to 5.25 D). Mean age was 50 ± 12 years (range: 18 to 70 years) and 61% were women. Postoperative SEQ was ±0.50 D in 50% and ±1.00 D in 77% of eyes after primary treatment. After re-treatment, 67% of eyes were within ±0.50 D and 89% were within ±1.00 D. Uncorrected distance visual acuity was 20/20 or better in 76% of eyes after final treatment. One line of CDVA was lost in 25% of eyes and two lines were lost in 0.4%. There was a clinically insignificant but statistically significant decrease (P < .05) in contrast sensitivity (CSV-1000) by less than 1 log unit at 3 and 6 cycles per degree (cpd) and by 1 log unit at 12 and 18 cpd. Diurnal fluctuation in refraction was identified in 2 eyes, proven by VHF digital ultrasound to be due to diurnal epithelial remodeling overnight and unrelated to maximum postoperative keratometry induced.

CONCLUSIONS

LASIK for hyperopia by cumulative treatment of up to +8.33 D with the MEL 80 excimer laser was found to satisfy accepted criteria for safety, efficacy, and stability when applying specialized protocols, including epithelial monitoring. [J Refract Surg. 2017;33(5):314-321.].