Posters

Very high astigmatism outcomes with PRK and LASIK

Poster Details

First Author: A.Wallerstein CANADA

Co Author(s):    X. Liu   E. Adiguzel   M. Cohen        

Abstract Details

Purpose:

To determine the accuracy, efficacy, safety, and stability of laser vision correction (LVC) for high astigmatism greater than -5 D.

Setting:

Multi-clinic national laser refractive surgery centre

Methods:

Retrospective chart review of eyes with greater than -5 D cylinder. All eyes underwent aspheric PRK or LASIK targeting emmetropia. 6 month or greater postop manifest refraction, UDVA and CDVA were compared to preop measurements. RM-ANOVA with Holms- Sidak post hoc tests and vector analysis (VA) were performed.

Results:

208 eyes, with a preop sphere of 0.82±2.32 D (-6.75 to +5.50D) and cyl of 5.89±0.77D (-5.00 to -7.75D). 88 eyes had a postop of 6+ months, with mean FU 12.9±5.8 months. Achieved postop sphere of +0.08±0.48D ( -1.50 to +1.25D), cyl of -0.67±0.53 D (0 to -2.25D). 46, 73, 98% within ±0.25, ±0.50, ±1.00D. Cumulative UDVA of 20/20, 20/25, 20/40 in 34, 65, 94%, with respective preop CDVA in 48, 82, 98%; efficacy index 0.9±0.2. 2 lines CDVA loss in 1%, 1 line in 5%, no change in 55%, and gain of ≥1 lines in 39%. No loss of >2 lines; safety index of 1.1±0.2. MRSE stable. 30 (14%) had retreat. VA: correction ratio 0.95±0.10, error ratio 0.11±0.08, axis shift -3.2±36.7°. Error of magnitude and axis 0.32±0.62D and -0.44±2.65°.

Conclusions:

LVC for very high astigmatism (greater than -5 D) has excellent accuracy, efficacy, and safety profiles. Vector analysis demonstrated a high degree of precision in treating these highly astigmatic eyes. FINANCIAL INTEREST: NONE