PubMed · 7239823
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R H Rengstorff. 1981. Postwear refractive changed.. https://pubmed.ncbi.nlm.nih.gov/7239823/
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Since January 1992 planned extracapsular cataract extraction (ECCE) is performed routinely with the no-stitch technique at our clinic. To minimize surgically induced astigmatism further, modified wound constructions for planned ECCE with on 1.1-mm tunnel width were evaluated. The follow-up time was up to 3 years postoperatively. For 250 eyes wound closure was performed prospectively either sutureless (n = 70), with a single perpendicular suture (n = 100) or cross sutures (n = 40) at the 12 o'clock position or sutureless in the temporal position (n = 40). The complication rate was 4% (filtering bleb, iris prolapse or transient hypotonia). There were no wound ruptures, but once endophthalmitis was observed. Late mean astigmatism after up to 3 years follow-up for vertical incision was 2.05 +/- 1.16 D (1.01 +/- 0.96 D preoperatively) for sutureless wound closure, 1.63 +/- 1.08 D (0.86 +/- 0.95 D) for perpendicular and 1.76 +/- 0.88 D (0.73 +/- 0.55 D) for cross-sutures. A temporal incision resulted in 0.78 +/- 0.52 D (1.0 +/- 0.69 D) of astigmatism and was only performed on eyes with against the rule astigmatism preoperatively. Surgically induced astigmatism was stabilized early. For with the rule astigmatism preoperatively, a 12 o'clock incision with a perpendicular single suture is recommended and for against the rule astigmatism, a temporal incision.
Scleral tunnel incision at the 12 o'clock-position for no-stitch cataract surgery can increase preexisting against-the-rule astigmatism by flattening the vertical corneal meridian. An oblique axis can change by operative induction. We investigated, in a prospective study, whether reduction of such a preoperative astigmatism could be induced by locating the tunnel incision on the steeper meridian. Eighteen eyes with senile cataract and against-the-rule or oblique astigmatism of at least 0.7 diopters were operated with a standardized 5 x 6 mm scleral tunnel incision and a 6 mm PMMA posterior chamber lens. We evaluated the astigmatism with a videokeratoscopy TMS-I preoperatively and about 6 months after the surgery. The mean corneal astigmatism was 1.8 diopters pre- and 1.5 diopters postoperatively. A reduction of keratometric astigmatism was reached in 72% of cases; 17% remained unchanged. The surgically induced astigmatism calculated by Jaffer's and Clayman's vector analysis was 0.68 diopters. The technique of scleral tunnel incision with lateral or oblique approach can reduce a preexisting against-the-rule or oblique astigmatism.
PURPOSE: We compared surgically induced astigmatism after penetrating keratoplasty performed by supervised cornea fellows and experienced cornea surgeons. METHODS: Data were collected by retrospective chart review 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 performed on 109 of 166 eyes. Two techniques were compared: intraoperative keratometry and suture adjustment and the torque-antitorque running suture technique with no intraoperative keratometry or suture adjustment. RESULTS: Mean surgically induced scalar astigmatism changed from preoperative astigmatism by 3.27 diopters (fellows) and 2.94 diopters (attending surgeons). In 109 cases, surgically induced vector cylinder changed from peroperative astigmatism by 4.21 diopters at 98 degrees (fellows) and 4.25 diopters at 114 degrees (surgeons). Surgically induced vector astigmatism changed from preoperative astigmatism by 4.67 diopters 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 majority of the astigmatism was induced in the y-axis and that this difference was significant (P < .001) in all comparisons, independent of technique or surgeon group. CONCLUSIONS: Penetrating keratoplasty performed by supervised cornea fellows resulted in similar rates of surgically induced vector astigmatism, surface asymmetry, and surface regularity as that by experienced surgeons. Fellows induced significantly more with-the-rule astigmatism, but this tendency decreased with further training. Penetrating keratoplasty astigmatic outcomes were not significantly different whether or not intraopertive keratometry and suture adjustment were utilized. This study supports the concept that increased experience with corneal transplantation improves the outcome of penetrating keratoplasty by using the criterion of postoperative astigmatism as a measures.