[Corneal astigmatism after pterygium excision and subsequent phototherapeutic keratectomy with the excimer laser (193 rm)].

BACKGROUND

Phototherapeutic keratectomy with the excimer laser is a suitable procedure for corneal smoothing after pterygium excision. In this study the effect of postoperative excimer laser smoothing on induced and absolute astigmatism after pterygium surgery was investigated.

MATERIALS AND METHODS

60 of 53 eyes underwent pterygium surgery using a bare sclera technique. In addition 30 of the treated eyes underwent postoperative phototherapeutic keratectomy of the wound region with the excimer laser. Astigmatism was measured preoperatively and postoperatively after 6 months up to four years.

RESULTS

Absolute astigmatism of patients treated with excimer laser decreased significantly from 1.38 +/- 0.83 D preoperative to 0.35 +/- 0.32 D postoperative (p < 0.0001). In this group mean induced astigmatism was 1.37 +/- 0.93 D. There was no correlation between the induced astigmatism and the number of excimer 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- and the control group concerning preoperative astigmatism. Postoperative absolute astigmatism of the excimer group was significantly lower than absolute astigmatism of the control group (p < 0.0001). Mean induced astigmatism of the control group was 1.15 +/- 0.95 D and not significantly different from the excimer treated group (p = 0.2654).

CONCLUSION

Phototherapeutic keratectomy with an excimer laser for corneal smoothing after pterygium excision reduces astigmatism significantly.