title: Wavefront-optimized surface retreatments of refractive error following previous laser refractive surgery: a retrospective study.
abstract: BACKGROUND
  Retreatments are sometimes necessary to correct residual or induced refractive errors following refractive surgery. Many different combinations of primary treatment methods and retreatment techniques have been studied, however, few studies have investigated wavefront-optimized (WFO) technology for retreatment following primary refractive surgery. This study aimed to report the outcomes of WFO photorefractive keratectomy (PRK) retreatments of refractive error following previous laser refractive surgery with PRK, laser in situ keratomileusis (LASIK), or laser-assisted subepithelial keratectomy (LASEK).
  
  
  METHODS
  We reviewed records of patients who underwent WFO PRK retreatments using the Allegretto Wave Eye-Q 400 Hz Excimer Laser System (Alcon Surgical) between January 2008 and April 2011 at Walter Reed Army Medical Center and Madigan Army Medical Center. Outcomes were recorded in terms of uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), corrected distance visual acuity (CDVA), and complications at 1 month (M), 3 M, and 6 M post-op.
  
  
  RESULTS
  Seventy-eight patients (120 eyes) underwent WFO PRK retreatment during the study period. Primary surgery was surface ablation in 87 eyes (78 PRK, 9 LASEK) and LASIK in 33 eyes. The mean spherical equivalent before retreatment was -0.79 ± 0.94 D (-3.00 to 1.88 D). UDVA was ≥ 20/20 in 69 eyes (60.0 %) at 1 M, 54 eyes (71.1 %) at 3 M, and 27 eyes (73.0 %) at 6 M follow-up. MRSE was within ±0.50 D of emmetropia in 78 eyes (67.8 %) at 1 M, 59 eyes (77.6 %) at 3 M, and 25 eyes (67.6 %) at 6 M follow-up. CDVA was maintained within ±1 line of pre-op in 113 of 115 eyes (98.3 %) at 1 M, 74 of 76 eyes (97.4 %) at 3 M, and 37 eyes (100 %) at 6 M follow-up.
  
  
  CONCLUSIONS
  Although follow-up was limited beyond 3 M, WFO PRK retreatments in patients with residual refractive error may be a safe and effective procedure. Further studies are necessary to determine the long-term safety and stability of outcomes.
authors: Ophthalmology Service, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20814 USA.
authors: Kevin M
authors: KM
authors: Broderick
authors: Warfighter Refractive Eye Surgery Program and Research Center, Ft. Belvoir, VA USA.
authors: Rose K
authors: RK
authors: Sia
authors: Warfighter Refractive Eye Surgery Program and Research Center, Ft. Belvoir, VA USA.
authors: Denise S
authors: DS
authors: Ryan
authors: Ophthalmology Service, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20814 USA.
authors: Richard D
authors: RD
authors: Stutzman
authors: Ophthalmology Service, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20814 USA.
authors: Michael J
authors: MJ
authors: Mines
authors: Ophthalmology Service, Madigan Army Medical Center, Tacoma, WA USA.
authors: Travis C
authors: TC
authors: Frazier
authors: Ophthalmology Service, Madigan Army Medical Center, Tacoma, WA USA.
authors: Mark F
authors: MF
authors: Torres
authors: The Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD USA.
authors: Kraig S
authors: KS
authors: Bower
keywords: Enhancement; LASEK; LASIK; PRK; Retreatment; Wavefront-optimized