title: Comparison of refractive changes after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus.
abstract: OBJECTIVE
  To compare refractive changes occurring after deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PKP) in patients with keratoconus.
  
  
  METHODS
  We retrospectively reviewed the medical records of 57 patients with keratoconus who received DALK (19 eyes of 19 patients) or PKP (38 eyes of 38 patients) before and after surgery between January 1996 and January 2008, in an effort to evaluate the surgical results and clinical courses. The principal outcome measures were as follows: preoperative and postoperative uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest refraction, and corneal topography including anterior chamber depth (ACD).
  
  
  RESULTS
  We noted no significant difference between the DALK and PKP groups in terms of postoperative UCVA, BCVA, astigmatism, or donor-recipient graft size disparities. For the PKP and DALK groups, the mean postoperative spheres were -1.64 D and -4.29 D at 6 months (P = 0.01) and -2.73 D and -4.22 D at 12 months, respectively (P = 0.04). Postoperative mean central corneal powers (3.0/5.0 mm zone) were 45.01/45.03 D and 46.94/47.84 D, respectively (P = 0.04 and P = 0.02). ACD after surgery was 3.25 and 3.37 mm at the final follow-up, respectively (P = 0.02).
  
  
  CONCLUSIONS
  Although DALK is a safe alternative in cases of keratoconus, the DALK group evidenced significantly higher myopia than did the PKP group, which was related to steeper central corneal power and deeper ACD.
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kuk-Hyoe
authors.initials: KH
authors.lastname: Kim
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Choi
authors.forename: Kyeon
authors.initials: K
authors.lastname: Ahn
authors.forename: Eui-Sang
authors.initials: ES
authors.lastname: Chung
authors.forename: Tae-Young
authors.initials: TY
authors.lastname: Chung
mesh_terms: D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000209:etiology / Q000503:physiopathology; D002648:Child; D003315:Cornea / Q000503:physiopathology; D019781:Corneal Topography; D016039:Corneal Transplantation / Q000379:methods*; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000209:etiology / Q000503:physiopathology; D011184:Postoperative Period; D012029:Refraction, Ocular; D014792:Visual Acuity; D055815:Young Adult