Customized PRK improves astigmatism after PK

Issue: May 25, 2013

SAN FRANCISCO — Topographically guided PRK was effective in treating irregular astigmatism after penetrating keratoplasty, according to a study presented here.

Perspective from Karl G. Stonecipher, MD

Best corrected visual acuity improved in almost half of all eyes, Simon P. Holland, MD, said at the American Society of Cataract and Refractive Surgery meeting.

Simon P. Holland

"Topographically guided PRK for irregular astigmatism after penetrating keratoplasty using custom topographical neutralization offered promising results with good safety and efficacy," Holland said.

The retrospective case series included 49 eyes that underwent topographically guided PRK after previous PK.

Surface ablation was performed with the Allegretto WaveLight excimer laser (Alcon). The custom topography neutralization technique was used to modify manifest refraction based on refractive changes predicted from plano topographically guided correction.

Uncorrected and corrected distance visual acuity, refraction, keratometry, topography and haze were evaluated at 3, 6 and 12 months after surgery; 39 eyes completed at least 6 months of follow-up.

Study results showed that uncorrected visual acuity improved to 20/40 or better in 18 eyes (46%).

Best corrected visual acuity improved in 16 eyes (42%); eight eyes (21%) gained one line and eight eyes (21%) gained two or more lines. Five eyes (13%) lost one line and three eyes (8%) lost two or more lines.

Postoperative cylinder ranged from 0 D to 6 D. The re-treatment rate was 5.76%, Wade said.

Disclosure: Holland is a member of the speakers bureau for Allergan and Bausch + Lomb and receives research funding from Alcon.

Perspective

Karl G. Stonecipher, MD

With full-thickness penetrating keratoplasty comes the dilemma of what to do when the incision healing is suboptimal. Simon Holland presented us with an option at this year’s ASCRS meeting other than attempts with a variety of styles of contact lens that usually are less optimal options for this patient population. We know that in patients with regular astigmatism, we have multiple options for laser vision correction; however, irregular astigmatism has been less successful with regard to final outcomes for uncorrected or best corrected vision. The take-home message for us from this series is that topography-guided laser vision correction can help many of these patients whose only option my be a repeat PK with the associated surgical risks. This intervention as described by Holland will change how we treat these challenging patients in our day-to-day practice. While at first the results of these initial patients may not impress some, those of us who deal with this patient population understand what a breakthrough this type of treatment is for this difficult presentation.

Karl G. Stonecipher, MD

Clinical assistant professor of ophthalmology, University of North Carolina

Medical director, TLC Vision, Greensboro, N.C.

Medical director, Laser Defined Vision

Disclosures: Stonecipher is a consultant and speaker for Alcon.

American Society of Cataract and Refractive Surgery Meeting

Customized PRK improves astigmatism after PK

Perspective