LONG-TERM RESULTS OF IMPLANTATION OF HYDROXYAPATITE AS EYE-BALL REPLACEMENT
A. Norda, H.-W. Meyer-Rüsenberg
Ever since its first implantation as eye-ball replacement in 1985, hydroxyapatite has been one of the most widely used implants in the USA. In Europe there has been only a slow increase in the use of this material. Since October 1993, 200 patients have received a hydroxyapatite implantation at our hospital, either after enucleation or evisceration, or as a replacement. In the spring of 1997, 52 patients underwent a follow-up examination at our hospital. The everage postoperative follow-up period was 23 (12-41) months. The aim of the study was to collect data about subjective tolerance, the prominence of the implant in comparsion to the natural eye, the lid-closure and lid position, the depth of the sulcus, and also the measurable motility of the implantation with and without the artificial eye. All findings were documented by one examiner using a slit lamp. The measurement of motility was carried out using modified Keestenbaum eye-glasses. The prominence of the implant was measured using Hertel exophthalometry. The subjective tolerance was considered good by ¾% of patients. The remaining patients reported either discharge or dryness. Three patients complained of inadequate motility and one of persistent pain. In the comparison of position and prominence of the artificial eye 8 patients achieved complete equalisation. In most cases (80%) there was a slight undercorrection of 2mm. 20% of cases had incomplete lid-closure, mainly after secondary operations. As regards defective lid position, 8 patients had a ptosis, 6 an ectropium, and there was one case of entropium. The lid-crease of the upper lid was preserved in only 32 cases, i. e. depending on it still being there prior to surgery. Changes in conjunctiva stretched from muciferous secretion to follicular squamous hyperplasia. With reference to the method of implantation, far superior motility was observed in primary implantations. Statistically significant motility differences could not be shown respective comparison of mucle attachment (all 6 eye-muscles as opposed to only the 4 straight eye muscles) because of the small number of cases. In the collective examined, hydroxyapatite was proved to be a generally well-tolerated orbital implant with few postoperative complications and good motility. Primary well-tolerated orbital implant with few postoperative complications and good motility. Primary implantation with attachment of all six eye muscles gave the best results. However, the cosmetic end results are largely dependent on preoperative conditions.
St. Josefs Hospital, Hagen