title: Potential acuity meter for predicting postoperative visual acuity in penetrating keratoplasty. A new method using a hard contact lens.
abstract: An irregular corneal surface degrades the optical transmission and limits the effectiveness of the potential acuity meter (PAM) in predicting post-keratoplasty visual acuity. The authors investigated the efficacy of using a temporarily placed hard contact lens to neutralize surface irregularities in conjunction with the PAM in predicting post-keratoplasty visual acuity. A prospective evaluation was performed on 40 keratoplasty patients with a mean follow-up of 10.4 months. Of 27 patients with corneas clear enough to permit them to read letters on the PAM chart, 17 (63%) had very accurately predicted visual acuities by this new method, compared to only eight patients (30%) with the PAM alone. Three patients had predicted visions better than final vision, but this was due to a concurrent cataract in two cases and chronic cystoid macular edema (CME) in the third case. This study indicates that temporarily placing a hard contact lens for use with the PAM can increase its accuracy in predicting final visual acuity after penetrating keratoplasty.
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003261:Contact Lenses; D016039:Corneal Transplantation; D005260:Female; D006801:Humans; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014787:Vision Tests / Q000295:instrumentation / Q000379:methods; D014792:Visual Acuity