title: Outcomes of Same-Size Host and Donor Trephine in Deep Anterior Lamellar Keratoplasty for Keratoconus.
abstract: OBJECTIVE
  To evaluate the efficacy of the same-size host and donor trephine on reducing myopic refractive errors for patients with keratoconus when deep anterior lamellar keratoplasty (DALK) was used.
  
  
  METHODS
  Randomized controlled clinical trial.
  
  
  METHODS
  One hundred eighteen eyes of 118 patients with keratoconus were enrolled. Using stratified blocked randomization, eligible eyes were allocated into the same-size trephine group or oversize trephine group. Postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), spherical equivalent (SE), topography data, and eye axial length were compared at each year for 5 years.
  
  
  RESULTS
  The same-size trephine group had comparable UCVA to the oversize trephine group through 5 years after surgery. But the former had better BSCVA than the latter after 3 years of follow-up. At 5 years, mean BSCVA was 0.17 ± 0.10 logMAR in the same-size trephine group vs 0.25 ± 0.13 logMAR in the oversize trephine group (P = .03). The same-size trephine group had lower topographic power than the oversize trephine group after 3 years of follow-up. At 5 years, mean topographic power was 45.30 ± 2.28 diopters (D) in the same-size trephine group vs 46.75 ± 2.60 D in the oversize trephine group (P = .006). Eye axial lengths at 5 years were longer than those preoperatively as well as at 1 year follow-up after surgery in both groups.
  
  
  CONCLUSIONS
  The same-size host and donor trephine could reduce late-stage myopic refractive errors for the patients with keratoconus after DALK. The mechanism may be late-stage axial length increase with time.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. Electronic address: thuang@vip.163.com.
authors.forename: Ting
authors.initials: T
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Ouyang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Qianni
authors.initials: Q
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yunwei
authors.initials: Y
authors.lastname: Hu
mesh_terms: D000328:Adult; D003315:Cornea; D019781:Corneal Topography; D016039:Corneal Transplantation; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D009216:Myopia / Q000517:prevention & control*; D014019:Tissue Donors; D066027:Transplant Recipients; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult