This study investigated the efficacy of photorefractive keratectomy (PRK) with mitomycin-C (MMC) on patients with consecutive hyperopia who had undergone prior radial keratotomy (RK). It confirms that PRK for consecutive hyperopia is a safe and effective procedure, with favorable results during short- to medium-term follow-up.
It was a prospective, nonrandomized, noncomparative case series including 22 hyperopic patients (35 eyes) ranging in age from 36 to 61 years with a history of RK. Two patients had undergone hyperopic LASIK after RK. Exclusion criteria included unstable refraction.
Epithelial removal was performed manually in the central 9 mm of the cornea. PRK was performed with the Alcon LADARVision 4000 Excimer Laser System, with treatments ranging from 8.4 to 8.9 mm, consisting of a central optical zone of 6.5 mm surrounded by a transitional zone. A 9-mm corneal well was then placed over the ablation area and a single topical application of MMC 0.02% applied for 60 seconds. The surface was then irrigated and a bandage contact lens placed along with instillation of eyedrops. Postoperatively, patients were given a single dose of the oral NSAID, lumiracoxib, as well as topical moxifloxacin, dexamethasone and artificial tears four times a day for one month. Patients were examined postoperatively for up to 18 months. However, follow-up was a mean of 9.6 months, with only 40 percent of eyes seen at the 12-month visit and fewer (22.8 percent) at 18 months.
Preoperative spherical equivalent (SE) ranged from +0.38 to +7.75 D (mean +3.36), although the highest refractive error treated was +6.00 D in one eye. Postoperative mean SE was -0.32 D at one month, +0.47 D at three months, +0.47 D at six months, +0.27 D at 12 months and -0.11 D at 18 months. There were no statistically significant differences in SE between the 3-, 6-, 12-, and 18-month visits. Uncorrected visual acuity was 20/30 or better in 37.2 percent of eyes at one month and 78.6 percent of eyes at 12 months. At that time, 14 percent of the eyes had lost up to one line of Snellen BSCVA due to excessive irregular astigmatism. However, no patients had developed corneal haze, and endothelial cell count had not significantly changed.
A ONE Current Insight article I've written provides a more extensive discussion of laser vision correction following RK.
Dr. Pandit receives lecture fees from Vistakon Pharmaceuticals, LLC.