title: Two-year results of conductive keratoplasty for the correction of low to moderate hyperopia.
abstract: OBJECTIVE
  To evaluate the 2-year postoperative safety, efficacy, predictability, and stability results of conductive keratoplasty (CK) to correct low to moderate hyperopia.
  
  
  METHODS
  Department of Ophthalmology, Stanford University Medical Center, Stanford, California, USA.
  
  
  METHODS
  In a prospective nonrandomized noncontrolled trial, 25 eyes of 14 patients with +0.75 to +3.00 diopters (D) of hyperopia and </=0.75 D of cylinder were treated with CK. Low-energy, radio-frequency current was applied to the peripheral corneal stroma through a probe inserted at 8 to 32 treatment spots. An early nomogram was used in 2 eyes, and a current nomogram was used in 23 eyes; the intended refraction was plano. The 23 eyes treated with the current nomogram were analyzed for efficacy, predictability, and stability. All 25 eyes were included in the safety and patient-satisfaction analyses.
  
  
  RESULTS
  Preoperatively, the mean manifest refraction spherical equivalent (MRSE) in the 23 current-nomogram eyes was +1.55 D. At 2 years, the uncorrected visual acuity was 20/20 or better in 64% of eyes and 20/40 or better in 95%. The MRSE was within +/-0.50 D in 64% of eyes, within +/-1.00 D in 91%, and within +/-2.00 D in 100%. No eye lost more than 1 line of best spectacle-corrected visual acuity or had an induced cylinder greater than 0.75 D. The mean MRSE of the cohort with all follow-ups was +0.48 D, which reflected a 29% regression from the intended plano and 43% regression from the 1-month postoperative overcorrection. The rate of regression appeared to be low and decreasing, +0.024 D per month between 12 and 24 months. A patient survey revealed improved quality of vision and a high level of satisfaction.
  
  
  CONCLUSIONS
  Conductive keratoplasty appeared to be safe, effective, and predictable for correcting low to moderate hyperopia. Mild hyperopic regression was observed; however, the rate of regression indicated by the mean change in MRSE per month was low and decreased over the 2-year follow-up. Longer follow-up may be necessary to further characterize the refractive stability of CK.
authors.affiliation: Department of Ophthalmology, Stanford University Medical Center, Stanford, CA 94305, USA.
authors.forename: Danny Y
authors.initials: DY
authors.lastname: Lin
authors.forename: Edward E
authors.initials: EE
authors.lastname: Manche
mesh_terms: D000368:Aged; D003319:Corneal Stroma / Q000503:physiopathology / Q000601:surgery*; D004564:Electrocoagulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000601:surgery*; D007429:Intraocular Pressure / Q000502:physiology; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011183:Postoperative Complications; D011446:Prospective Studies; D011846:Radio Waves; D012029:Refraction, Ocular / Q000502:physiology; D012449:Safety; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology