CORNEAL ASTIGMATISM AFTER PTERYGINMEXCISI ON AND PHOTOTHERAPEUTIC KERATECTOMY WITH THE EXCIMER-LASER (193 NM)

Background Phototherapeutic keratectomy with the excimer laser is a su itable procedure for corneal smoothing after pterygium excision. In th is study the effect of postoperative excimer laser smoothing on induce d and absolute astigmatism after pterygium surgery was investigated. M aterials and Methods 60 of 53 eyes underwent pterygium surgery using a bare sclera technique. In addition 30 of the treated eyes underwent p ostoperative phototherapeutic keratectomy of the wound region with the excimer laser. Astigmatism was measured preoperatively and postoperat ively after 6 months up to four years. Results Absolute astigmatism of patients treated with excimer laser decreased significantly from 1.38 +/- 0.83 D pre operative to 0.35 +/- 0.32 D postoperative (p < 0.0001 ). In this group mean induced astigmatism was 1.37 +/- 0.93 D. There w as no correlation between the induced astigmatism and the number of ex cimer pulses applied (r = 0.0287; p = 0.905). Absolute astigmatism of the control group decreased from 1.10 +/- 0.85 D to 0.72 +/- 0.56 D (p < 0.05). There were no significant differences between the excimer- a nd the control group concerning preoperative astigmatism. Postoperativ e absolute astigmatism of the excimer group was significantly lower th an absolute astigmatism of the control group (p < 0.0001). Mean induce d astigmatism of the control group was 1.15 +/- 0.95 D and not signifi cantly different from the excimer treated group (p = 0.2654). Conclusi on Phototherapeutic keratectomy with an excimer laser for corneal smoo thing after pterygium excision reduces astigmatism significantly.