title: A new technique for rigid gas permeable contact lens fitting following penetrating keratoplasty.
abstract: OBJECTIVE
  To evaluate a new, rigid gas permeable contact lens fitting technique following penetrating keratoplasty.
  
  
  METHODS
  For the correction of postoperative anisometropia or astigmatism, a rigid gas permeable, tetra-curve contact lens with an overall diameter of 12.0 mm and a back optic zone diameter of 8.5 mm was fitted in 36 eyes of 33 patients, 7 months after penetrating keratoplasty. The contact lens back optic zone radius was selected using the videokeratography values over the elevated edges of the transplant wound (with the sutures in place). Graft clarity, visual outcome, and corneal topography were evaluated up to 3 years after surgery at intervals of 6 months.
  
  
  RESULTS
  Throughout the follow-up period (range 6-36, mean 19.3+/-sd 11.8 months), all grafts remained clear. Mean contact lens daily wearing time averaged 13.6 (+/- sd 4.7) hours. Mean best-corrected visual acuity improved from +0.36 (+/- sd 0.18) LogMAR with spectacles to +0.11 (+/- sd 0.11) LogMAR with contact lenses (p < 0.0001). One patient was excluded from the study due to a lack of motivation and one had an adverse reaction to the stitches.
  
  
  CONCLUSIONS
  To improve the visual performance following penetrating keratoplasty, the described fitting technique, guided by videokeratography, eased selection of the back optic zone radius of the initial trial lens. The large diameter contact lenses with a tetra-curve design were well tolerated in all patients for more than 13 hours daily.
authors.affiliation: Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, The Netherlands. f.eggink@ohk.azn.nl
authors.forename: F A
authors.initials: FA
authors.lastname: Eggink
authors.forename: R M
authors.initials: RM
authors.lastname: Nuijts
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015858:Anisometropia / Q000209:etiology / Q000628:therapy*; D001251:Astigmatism / Q000209:etiology / Q000628:therapy*; D003261:Contact Lenses; D003316:Corneal Diseases / Q000601:surgery; D019781:Corneal Topography; D005139:Eyeglasses; D006085:Graft Survival; D006801:Humans; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D017755:Prosthesis Fitting / Q000379:methods; D012029:Refraction, Ocular; D014792:Visual Acuity