title: Piggyback intraocular lens implantation to correct myopic pseudophakic refractive error after penetrating keratoplasty.
abstract: OBJECTIVE
  To determine the safety and efficacy of implanting a second intraocular lens (IOL) to correct myopic pseudophakic refractive error after penetrating keratoplasty (PKP).
  
  
  METHODS
  Department of Ophthalmology, Toronto Western Hospital, Toronto, Ontario, Canada.
  
  
  METHODS
  In this retrospective case series, 6 eyes of 6 post-PKP pseudophakic patients had a second piggyback IOL implantation to correct a residual myopic refractive error. The uncorrected visual acuity (UCVA) and the best corrected visual acuity (BCVA) were measured at regular intervals during a 7-month follow-up. Efficacy was determined by the achieved refractive correction and Snellen UCVA measurements. Safety was measured by loss of BCVA and complications (intraoperative and postoperative).
  
  
  RESULTS
  The UCVA improved in all cases. Five patients achieved a BCVA of 20/40 or better postoperatively. Before surgery, the mean spherical equivalent (SE) was -8.08 diopters (D) (range -6.13 to -12.00 D). After surgery, the mean SE was -0.94 D (range -2.38 to +0.25 D). Four patients were within +/-1.50 D of emmetropia. There were no intraoperative or postoperative complications.
  
  
  CONCLUSIONS
  Implanting a piggyback IOL was a safe and effective means of correcting myopic pseudophakic refractive error post PKP.
authors.affiliation: University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Paul
authors.forename: Hall F
authors.initials: HF
authors.lastname: Chew
authors.forename: Neera
authors.initials: N
authors.lastname: Singal
authors.forename: David S
authors.initials: DS
authors.lastname: Rootman
authors.forename: Allan R
authors.initials: AR
authors.lastname: Slomovic
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D015948:Keratoplasty, Penetrating; D019654:Lens Implantation, Intraocular / Q000379:methods*; D008875:Middle Aged; D009216:Myopia / Q000209:etiology / Q000601:surgery*; D011183:Postoperative Complications; D019591:Pseudophakia / Q000209:etiology / Q000601:surgery*; D012029:Refraction, Ocular; D012189:Retrospective Studies; D012449:Safety; D014792:Visual Acuity