title: Refractive and visual outcomes of penetrating keratoplasty versus deep anterior lamellar keratoplasty with hydrodissection for treatment of keratoconus.
abstract: OBJECTIVE
  To compare refractive and visual outcomes of penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK) with hydrodissection for keratoconus.
  
  
  METHODS
  A review of medical records was performed to identify 69 subjects (77 eyes) who had undergone keratoplasty by a single surgeon. Inclusion criteria were as follows: no episodes of rejection, no adverse events or complications intraoperatively or postoperatively, a fairly normal rate of epithelialization within 2 weeks, and suture removal after 11 months. Eyes were categorized according to the procedure: 47 had undergone DALK with hydrodissection (DALK group) and 30 had undergone PKP (PKP group). A between-group comparison was performed.
  
  
  RESULTS
  Before suture removal, there was no statistical difference between groups in best-corrected visual acuity (BCVA) or refraction at 6 months (P > 0.05, all cases). The mean BCVA was 0.18 logarithm of the minimum angle of resolution for both groups at 12 months (just after suture removal) and 24 months postoperatively. The mean postoperative mean refractive spherical equivalents at 12 months and 2 years were -4.11 ± 3.4 diopters (D) and -4.68 ± 2.9 D, respectively, for the DALK group and -1.7 ± 2.7 D and -1.1 ± 3.6 D, respectively, for the PKP group. The DALK group was statistically more myopic at 12 and 24 months (P > 0.05, both cases). The mean refractive cylinders at 12 months and 2 years were 2.88 ± 1.60 D and 3.18 ± 1.70 D, respectively, for the DALK group and 2.80 ± 1.6 D and 3.80 ± 1.80 D, respectively, for the PKP group. The differences between groups were not statistically significant (P > 0.05, all comparisons).
  
  
  CONCLUSIONS
  Long-term BCVA, mean refractive spherical equivalent, and mean refractive cylinder after DALK with hydrodissection were similar to those after PKP.
authors.affiliation: Cornea and Refractive Surgery Unit, Magrabi Eye and Ear Center, Jeddah, Saudi Arabia.
authors.forename: Ashraf F
authors.initials: AF
authors.lastname: Amayem
authors.forename: Islam M
authors.initials: IM
authors.lastname: Hamdi
authors.forename: Momen M
authors.initials: MM
authors.lastname: Hamdi
mesh_terms: D000293:Adolescent; D000328:Adult; D016039:Corneal Transplantation / Q000379:methods*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D015948:Keratoplasty, Penetrating; D008297:Male; D042282:Microdissection / Q000379:methods*; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult