title: Contact lens manipulation of corneal topography after penetrating keratoplasty: a preliminary study.
abstract: We conducted a preliminary retrospective study of five eyes that had undergone penetrating keratoplasty (PK) to determine if rigid gas permeable (RGP) contact lenses could be used as splints or molds to improve postoperative corneal topography. RGP lenses were fit 3-6 months (mean: 4.1 months) after PK and 3-4 months (mean: 1.8 months) after removal of the 10-0 nylon suture. Lenses were fit to attain a contact lens resting position centered on the corneal graft. After 4 to 8 months (mean: 6.2 months) of contact lens wear, analysis of corneal topography showed a decrease in simulated keratometry cylinder from 4.7 +/- 0.6 D (mean +/- 1 standard deviation) to 1.8 +/- 0.8 D (P = 0.02) and an improvement in anterior corneal surface regularity (surface regularity index: initial = 1.40 +/- 0.2; final = 1.0 +/- 0.2; P = 0.04). Three eyes were fit with a well-centered RGP lens; two eyes were fit with lenses that rode off-center. Increased irregular astigmatism in the two eyes with decentered contact lenses suggests the importance of centering RGP lenses with respect to corneal grafts. The best corrected spectacle visual acuity either improved or remained unchanged in four of five eyes after contact lens wear. One eye demonstrated a decrease in best corrected spectacle acuity by one Snellen line after 3 months of lens wear. Further clinical studies are needed to determine the potential of postoperative use of RGP lenses to improve corneal surface regularity, to decrease astigmatism, and to optimize visual results.
authors.affiliation: Lions Eye Research Laboratories, Louisiana State University Medical Center School of Medicine, New Orleans.
authors.forename: S E
authors.initials: SE
authors.lastname: Wilson
authors.forename: R S
authors.initials: RS
authors.lastname: Friedman
authors.forename: S D
authors.initials: SD
authors.lastname: Klyce
mesh_terms: D001251:Astigmatism / Q000517:prevention & control*; D003261:Contact Lenses; D003315:Cornea / Q000033:anatomy & histology*; D003316:Corneal Diseases / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015948:Keratoplasty, Penetrating; D011182:Postoperative Care; D012189:Retrospective Studies; D014792:Visual Acuity