COMPARISON OF ASTIGMATISM AFTER PENETRATING KERATOPLASTY BY EXPERIENCED CORNEA SURGEONS AND CORNEA FELLOWS

PURPOSE: We compared surgically induced astigmatism after penetrating keratoplasty performed by supervised cornea fellows and experienced co rnea surgeons. METHODS: Data were collected by retrospective chart rev iew of 166 cases (166 eyes) of penetrating keratoplasty: 63 performed by two cornea surgeons and 103 by four cornea fellows. Astigmatism was calculated using scalar and vector methods. Vector analysis was perfo rmed on 109 of 166 eyes. Two techniques were compared: intraoperative keratometry and suture adjustment and the torque-antitorque running su ture technique with no intraoperative keratometry or suture adjustment . RESULTS: Mean surgically induced scalar astigmatism changed from pre operative astigmatism by 3.27 diopters (fellows) and 2.94 diopters (at tending surgeons). In 109 cases surgically induced vector cylinder cha nged from preoperative astigmatism by 4.21 diopters at 98 degrees (fel lows) and 4.25 diopters at 114 degrees (surgeons). Surgically induced vector astigmatism changed from preoperative astigmatism by 4.67 diopt ers at 93 degrees in the first 6 months (fellows) and by 3.79 diopters at 103 degrees in the second 6 months, Analysis of x-axis and y-axis components of the surgically induced vector cylinder showed that the m ajority of the astigmatism was induced in the y-axis and that this dif ference was significant (P < .001) in all comparisons, independent of technique or surgeon group. CONCLUSIONS: Penetrating keratoplasty perf ormed by supervised cornea fellows resulted in similar rates of surgic ally induced vector astigmatism, surface asymmetry, and surface regula rity as that by experienced surgeons. Fellows induced significantly mo re with the rule astigmatism, but this tendency decreased with further training. Penetrating keratoplasty astigmatic outcomes were not signi ficantly different whether or not intraoperative keratometry and sutur e adjustment were utilized. This study supports the concept that incre ased experience with corneal transplantation improves the outcome of p enetrating keratoplasty by using the criterion of postoperative astigm atism as a measure.