Results of transverse keratotomies for astigmatism after penetrating keratoplasty : a retrospective study of 48 consecutive cases

BACKGROUND: High astigmatism is still a common complication of penetrating keratoplasty which often limits the final corrected visual acuity. Surgical correction of high astigmatism persistent after suture removal remains rather controversial. In our present study, we used the technique of transverse keratotomies for the surgical correction of high astigmatism following penetrating keratoplasty because of its simplicity and corrective potential. METHODS: We present a retrospective clinical study based on the results of 48 consecutive transverse keratotomy procedures performed on the graft. Three eyes were operated on twice, for a total of 51 procedures. The astigmatism had to be stable for at least 6 months after suture removal, with poor corrected visual acuity with spectacles or contact lenses. The operative protocol (number of incisions, optical zone size) was decided based on the degree of astigmatism. The mean post-operative observation period was 5.11 +/- 3.93 months (range, 1 to 24 months). RESULTS: The mean preoperative cylinder was 8.96 +/- 2.22 diopters and 4.91 +/- 1.79 D postoperatively. The mean cylindrical change was 4.51 +/- 2.77 D. The spherical equivalent remained unchanged in most cases. In a majority of cases, the corrected visual acuity for distance and near vision was improved. No cases of persistent graft edema caused by immunologic rejection or endothelial failure were observed. Moreover, in no case was there worsening of the best corrected visual acuity. CONCLUSIONS: The technique of transverse incisions in the graft to correct or reduce high postkeratoplasty astigmatism is simple, efficient, and relatively safe. The main problem was poor predictability.