research digest
LASIK Outcomes: Comparison of Two Keratome Models

An article published in the July issue of Investigative Ophthalmology & Visual Science and presented at the 2005 ARVO Conference in Ft. Lauderdale, Fla. focused on the comparison of a laser keratome to a mechanical micorkeratome.

This study was conducted at the McGill Laser Center, Medical University of South Carolina, Charleston, S.C. The study included 15 bilateral myopic patients undergoing bilateral, customized LASIK ablation. One eye of each patient was randomized to IntraLase (Irvine, Calif.) and the fellow eye to Amadeus (Advanced Medical Optics, Santa Ana, Calif.).

Visual acuity, subjective questionnaire, contrast sensitivity, corneal sensation, basic secretion test, as well as wavefront and ocular surface staining were measured preoperatively, and at 1 and 3 months postoperatively. The flap diameter, hinge size and flap thickness were measured intraoperatively.

Investigators found that overall the accuracy of treatment at 1 month with the Amadeus was >65%, where the IntraLase was >60% at ±0.25 D. The Amadeus and IntraLase were both 100% at ±0.5 D. The subjective questionnaire that was used during the study showed that week 1 postoperatively vision fluctuation was more likely with the IntraLase, and clarity of vision was more likely with the Amadeus. The questionnaire also found dry eye was likely with the IntraLase and not occurring with
the Amadeus.

Ophthalmology Management asked Kerry Solomon, M.D., a lead investigator of the study, to discuss the finding. "They are both good devices and they both create excellent flaps," he said. "What's unique about this study is that it was contralateral, which gives patients something to base a comparison on."

Fourth Generation Flouroquinolones After Penetrating Keratoplasty

An article published in the October issue of Cornea discussed the comparison of the effects of moxifloxacin and gatifloxacin on corneal reepithelialization after penetrating keratoplasty.

In this single-center, open-label, prospective study, 46 consecutive patients requiring penetrating keratoplasty were alternately assigned to receive either postoperative moxifloxacin 0.5% or gatifloxacin 0.3%. The primary outcome measure was the area of the epithelial defect measured by slit-lamp evaluation during the postoperative period.

Investigators found the mean area of the epithelial defect was similar in both treatment groups at baseline (P=0.104), but it was significantly larger in the moxifloxacin group than the gatifloxacin group at day 4 and day 7. At every follow-up visit after day 4, there were more eyes with complete reepithelialization of the corneal graft in the gatifloxacin group than in the moxifloxacin group (statistically significant at days 7 and 14).

The results suggest that the postoperative use of gatifloxacin in corneal transplant patients may allow the early stages of corneal graft reepithelialization to proceed more quickly than does treatment with moxifloxacin.

The Tube vs. Trabeculectomy Study

A study published in August 2005 issue of the American Journal of Ophthalmology focused on the comparison, safety and efficacy of nonvalved tube shunt surgery to trabeculectomy with mitomycin C in patients with previous intraocular surgery.

This multicenter clinical trial randomized 212 patients to undergo placement of a 350-mm2 Baerveldt glaucoma implant or trabeculectomy with mitomycin C (0.4 mg/mL for 4 minutes). IOP, complication rates, visual acuity, visual field, quality of life, reoperations of glaucoma and need for supplemental medical therapy were also measured.

Investigators found baseline IOP was 25.3±5.3 mm Hg (mean±SD). There were no significant differences in the demographic and ocular characteristics between the two treatment groups.