title: Regression of effect over long-term follow-up of conductive keratoplasty to correct mild to moderate hyperopia.
abstract: OBJECTIVE
  To evaluate the long-term efficacy and stability of conductive keratoplasty (CK) for low to moderate hyperopia.
  
  
  METHODS
  Department of Ophthalmology, Stanford University School of Medicine, Stanford, California, USA.
  
  
  METHODS
  In this prospective nonrandomized noncontrolled clinical trial, performed as part of a U.S. Food and Drug Administration pivotal trial, patients with +0.75 to +3.00 diopters (D) of hyperopia and 0.75 D or less cylinder were initially treated with CK. The postoperative uncorrected and corrected Snellen visual acuities and refractions over time were evaluated. The main outcome measures were differences in refraction and uncorrected visual acuity postoperatively.
  
  
  RESULTS
  Nine patients (16 eyes) of a subset of 14 consecutive patients (25 eyes) originally enrolled between 1999 and 2000 were available for long-term follow-up. Preoperatively, the mean manifest refraction spherical equivalent (MRSE) in the subset with long-term follow-up was +1.45 D. Postoperatively, the mean MRSE was +0.295 D. at 23 months, regressing to +1.00 D at 48 months and +1.394 D at the final follow-up (mean 73 months), indicating significant regression of effect. No eye lost more than 1 line of corrected Snellen visual acuity as a result of CK. The rate of regression was linear and calculated at +0.0184 D per month after 6 months postoperatively. Keratometric regression appeared to be similar to MRSE regression.
  
  
  CONCLUSIONS
  Conductive keratoplasty led to significant regression of refractive and keratometric effects over extended follow-up. Patients should be counseled that this refractive procedure is not permanent.
authors.affiliation: Department of Ophthalmology, Stanford University School of Medicine, Stanford, California 94305, USA.
authors.forename: Jason S
authors.initials: JS
authors.lastname: Ehrlich
authors.forename: Edward E
authors.initials: EE
authors.lastname: Manche
mesh_terms: D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000378:metabolism / Q000503:physiopathology*; D004564:Electrocoagulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011846:Radio Waves; D012029:Refraction, Ocular / Q000502:physiology*; D013997:Time Factors; D014792:Visual Acuity / Q000502:physiology*
chemical_list: D003094:Collagen