Lower ablation temperatures produce less corneal damage, better acuity, study suggests

ROME — Eyes that underwent PRK with a solid-state laser had faster visual recovery and less corneal haze than eyes that underwent PRK with an excimer laser, according to Paolo Garimoldi, MD. He noted that these differences correlated with lower intraoperative corneal temperatures during ablation with the solid-state laser than with the excimer

At the winter meeting of the European Society of Cataract and Refractive Surgeons, Dr. Garimoldi presented results in 64 eyes of 34 patients treated with PRK for myopia or myopic astigmatism. He said 31 eyes were treated with conventional laser and 33 were treated with a solid-state laser. Corneal temperature was measured with a thermal camera during ablation.

All corneas were examined with confocal microscopy before and immediately after surgery. Follow-up was at 1, 3, 6, 9 and 12 months, Dr. Garimoldi said. He calculated haze thickness and haze reflectivity, graded at slit-lamp examination, and compared them between the two procedures.

Corneal temperatures increased an average of 5.3° C in eyes undergoing PRK with the conventional excimer laser, but increased only 0.8° C in eyes undergoing PRK with the solid-state laser, he said.

The mean haze reflectivity and mean haze thickness were higher in the eyes treated with the standard laser, he said. Dr. Garimoldi said haze was higher in eyes treated with the excimer laser especially in the first 3 months, but the haze tended to decrease over time.