New method of microwave thermokeratoplasty to correct myopia in 33 eyes: one-year results.

PURPOSE

To assess the safety, predictability, and stability of a new microwave thermokeratoplasty procedure to correct myopia.

SETTING

Cornea and refractive surgery subspecialty.

DESIGN

Prospective clinical trial.

METHOD

Thermokeratoplasty was performed in myopic eyes at a single center in Turkey from June 2009 to June 2010. The attempted corrections ranged from -1.25 to -5.75 diopters (D). The main outcome measures were changes in logMAR uncorrected distance visual acuity (UDVA) and in keratometry (K) values.

RESULTS

The procedure was performed in 33 eyes (patients aged 20 to 45 years). The mean preoperative logMAR UDVA (0.76 ± 0.24 [SD]) significantly improved to 0.19 ± 0.20 at 1 month, postoperatively. By 3 months, the mean UDVA had markedly regressed to 0.59 ± 0.29; however, the residual improvement remained statistically significant. At 12 months, the mean logMAR UDVA was 0.72 ± 0.26. The mean K values were 43.9 ± 1.36 D preoperatively, 41.25 ± 2.63 D at 1 month, 43.4 ± 1.69 D at 3 months, and 44.1 ± 1.09 D at 12 months. The mean endothelial cell density was 2836 ± 342 cells/mm(2) preoperatively and were statistically unchanged 12 months postoperatively (2732 ± 353 cell/mm(2)). No patient lost lines of corrected distance visual acuity by 12 months postoperatively.

CONCLUSIONS

The new thermokeratoplasty procedure produced the desired reduction in myopia and improvement in postoperative UDVA 1 month postoperatively without significant side effects. However, early and complete regression shows the need for further development of this technique.

FINANCIAL DISCLOSURE

Drs. Yilmaz and Marshall are paid consultants to Avedro, Inc., and Dr. Muller is president and CEO of Avedro, Inc. No other author has a financial or proprietary interest in any material or method mentioned.