advertisement
Abstract #19184 Published in IGR 3-1
Ultrasound biomicroscopy and intraocular-pressure-lowering mechanisms of deep sclerectomy with reticulated hyaluronic acid implant
Marchini G; Marraffa M; Brunelli C; Morbio R; Bonomi LJournal of Cataract and Refractive Surgery 2001; 27: 507-517
PURPOSE: To evaluate the anatomical characteristics and intraocular pressure (IOP) lowering mechanisms of deep sclerectomy with reticulated hyaluronic acid implant (DS with RHAI) using ultrasound biomicroscopy (UBM). METHODS: Thirty patients with primary open-angle glaucoma not controlled by medical therapy had DS with RHAI in one eye. A complete ocular examination and UBM study were performed one, three, six, and 12 months postoperatively, and thereafter at six-monthly intervals. Eleven parameters were evaluated, the most important of which were IOP, surgical success in lowering IOP to 21 mmHg or less with or without additional medical therapy, UBM appearance of the site of DS with RHAI, size of the decompression space, presence of a filtering bleb and supraciliary hypoechoic area, and scleral reflectivity around the decompression space. RESULTS: After a mean follow-up of 11.4 ± 4.7 months (SD), the mean percentage reduction in IOP compared to preoperatively was 38% (from 26 ± 4.5 to 16.2 ± 3.8 mmHg; p = 0.0001). Twenty-four patients (80%) had an IOP of less than 21 mmHg; however, seven of these eyes (23%) required additional IOP-lowering medical therapy. The operation failed in six patients (20%), despite additional therapy. UBM revealed a reduction in the size of the decompression space from six months postoperatively, and its disappearance in two cases. The difference in size at the last follow-up and at one month postoperatively (maximum length 2.41 ± 1.02 mm versus 3.53 ± 0.51 mm) was significant (p = 0.0001). At the last examination, a filtering bleb was present in 18 patients (60%), a supraciliary hypoechoic area in 18 (60%), and hyporeflectivity of the scleral tissue around the decompression space in 14 (47%). These three UBM characteristics were detected singly and in various combinations. The simultaneous presence of all three characteristics in the same eye correlated significantly with a higher surgical success rate (p = 0.004). CONCLUSIONS: UBM showed that filtering bleb formation was frequent in eyes having DS with RHAI, but that it was not the only surgically induced IOP-lowering mechanism. Increased uveoscleral and transscleral filtration may be equally important.
Dr G. Marchini, Eye Clinic, Department of Neurological and Vision Sciences, University of Verona, Verona, Italy
Classification:
12.8.3 Non-perforating (Part of: 12 Surgical treatment > 12.8 Filtering surgery)