Excimer laser versus diamond fraise. Short-term results of two different methods for corneal smoothing in the treatment of pterygia

Background: The treatment of pterygia often results in irregular astigmatis m. Corneal smoothing at the end of surgery plays a major role in the develo pment of astigmatism. The aim of our study was to compare the efficiency of corneal smoothing performed by phototherapeutic keratectomy compared with the conventional method performed by a diamond fraise. The effect of postop erative excimer laser smoothing on refraction, visual acuity and irregular astigmatism was investigated. Patients and Methods: 32 eyes underwent pterygium excision using a standard ized surgical procedure. In addition 9 eyes underwent postoperative phototh erapeutic keratectomy of the wound region with an excimer laser, 23 eyes we re treated with a diamond fraise for corneal smoothing. The postoperative e xamination was performed 7, 14 and 30 days after surgery. Corneal topograph y was performed by a computer-assisted video-keratoscope (TMS-1). The resul ts were evaluated by the Fourier transform analysis. Results: Both methods showed similar results concerning refraction and visu al acuity postoperatively. Preoperatively all patients had an irregular fla ttening of the corneal topography in the area of the pterygium. Postoperati vely a small irregular flattening was left in eyes treated with a diamond f raise. In the excimer laser treated group a steepening in the corneal topog raphy could be observed. Conclusions: The phototherapeutic keratectomy with excimer laser in the tre atment of pterygia suggests to be a gentle alternative creating a smooth wo und surface. Despite of this advantage the treatment with the excimer laser effects a remarkable increase in administration and expense.