the Change of Corneal SurfaCe temperature during SurfaCe refraCtiVe SurgiCal proCedureS performed uSing exCimer laSerS with different repetitiVe frequenCieS

Abstract

Intoduction. refractive surgery is still one of the most frequently performed procedures in ophthalmology. millions of patients every year are operated with surface lasers as well as with deep or lamellar lasers. The operational technique and tools are constantly improving. Aim. To examine the changes in the temperature of the corneal surface during refractive surgery procedures performed using different types of excimer lasers. Material and methods. 150 eyes of 111 patients were included in the study. The corneal surface temperature was measured with a calibrated eBro Tlc730 infrared thermometer (wTw gmBh, germany) before photorefractive keratectomy (prK), after epithelial removal and immediately after finishing the procedure. The average myopic correction was -3.9 ± 1.9 dpt (ranging from -2.5 dpt to -6.5 dpt). The average age of the patients was 25 ± 3.3 years. Results. using anova variance analysis, a statistically significant difference in the change of the temperature was found between different laser platforms. with the post hoc Bonferroni correction, a significant difference between the mel 80 (carl Zeiss meditec, Jena, germany) and the two other analyzed excimer lasers, mel 70 (carl Zeiss meditec, Jena, germany) and wavelight allegretto 400 (alcon wavelight, erlangen, germany), was found. There was no statistically significant difference between the wavelight allegretto and mel 70 excimer lasers. Conclusions. The moderate cooling effect of the different excimer laser platforms might be related to different airflow systems used in the models. it seems that the rise in the surface temperature is not a causative factor of postoperative subepithelial corneal haze when the procedure is performed with lasers using frequencies lower or equal to 400 hz.