Abstract
Purpose :
There is limited prospective information comparing retreatment with LASIK to retreatment with PRK following previous keratorefractive surgery. This study prospectively evaluates whether LASIK or PRK retreatment yields superior results over a long follow-up period.
Methods :
In this prospective study, 28 eyes of 23 patients status post prior LASIK or PRK surgery underwent retreatment with wavefront-guided LASIK (n=10) or wavefront-guided PRK (n=18) for residual refractive error using the AMO VISX S4 CustomVue IR excimer laser. Safety, efficacy, predictability, and wavefront outcomes were evaluated.
Results :
At last follow-up, both LASIK and PRK retreatment resulted in similar improvement in visual acuity with mean ± standard deviation (SD) uncorrected distance visual acuity (UDVA) of -0.08 ± 0.10 logMAR and -0.04 ± 0.17 logMAR in the LASIK and PRK groups respectively (p=0.44). 20% (n=2) of LASIK eyes and 27.8% (n=5) of PRK eyes gained one or more lines of best-corrected distance visual acuity (CDVA), while 10% (n=1) and 16.7% (n=3) of eyes lost lines of CDVA, respectively. 100% (n=10) of LASIK eyes and 88.9% (n=16) of PRK eyes were within ± 0.50 diopter of emmetropia with a corresponding mean ± SD spherical equivalent of -0.075 ± 0.25 and -0.090 ± 0.44 in the two groups (p=0.91). Wavefront analyses revealed a similar reduction in total higher-order aberrations in the LASIK and PRK groups from a mean ± SD preoperative RMS error of 0.50 ± 0.17 and 0.54 ± 0.19 to postoperative values of 0.465 ± 0.17 and 0.45 ± 0.22 respectively (p=0.56). Furthermore there was no significant difference in coma (p=0.42), trefoil (p=0.53), or spherical aberration (p=0.51) between the LASIK and PRK groups.
Conclusions :
Wavefront-guided LASIK and wavefront-guided PRK following prior keratorefractive surgery demonstrate similar safety, efficacy, and predictability. Furthermore postoperative higher-order aberrations appear to be comparable between the two treatment groups.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.