Topographic stability after hyperopic LASIK.

PURPOSE

To analyze and compare time-dependent topographic changes after hyperopic LASIK.

METHODS

Sixty-six consecutive eyes of 37 patients treated for hyperopic astigmatism with the SCHWIND ESIRIS excimer laser with follow-up of > or = 3 months were retrospectively evaluated. In all cases, standard examinations and 3-, 12-, and 36-month topographic analyses with a Keratron topographer (Optikon 2000 SpA) were performed. Topographic changes in Maloney index, simulated keratometry (sim K), and keratometry (K) readings at 3, 5, and 7 mm were evaluated.

RESULTS

Postoperatively, 92% of eyes were within +/- 0.50 diopters (D) manifest refraction after 3-month follow-up, compared with 83% after 12 months, and 72% after 36 months. No significant regression between the 3-month and 1-year follow-up as well as 1 to 3 years postoperatively was noted. Evaluation of mean regression (increasing hyperopia) between 3 and 36 months postoperatively resulted in a Maloney index of 0.016 D/month, regression of 0.013 D/month for the sim K readings, and regression of 0.010 D/month, < 0.001 D/month, and 0.004 D/month for the 3-, 5-, and 7-mm zones, respectively. Refractive stability was comparable to the Maloney index and sim K index stability.

CONCLUSIONS

Topography can be used as an objective method to analyze regression after treatment of hyperopia. This method allows differentiation as to whether there is regression, topographic change, or latent hyperopia, which becomes manifest after a certain time period. Following hyperopic LASIK with the SCHWIND ESIRIS laser, no topographic regression between 3- and 36-month follow-up could be observed.