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Tarek Shaarawy

Publications and source records attributed to Tarek Shaarawy.

9 recordsLinked to original sources
PubMed2006

Outflow mechanisms after deep sclerectomy with two different designs of collagen implant in an animal model.

BACKGROUND: To study experimentally two different shapes of collagen implants (CI) used in deep sclerectomy (DS). The ability to promote drainage vessels, outflow mechanisms, success rates, and biodegradability, were studied prospectively in an animal model. MATERIALS AND METHODS: DS was performed in 20 eyes of ten rabbits. Each rabbit randomly received a cylindrical CI in one eye, while the other eye received a flat CI. Intraocular pressure (IOP) measurement, ultrasound biomicroscopy (UBM) examination of DS site and simultaneous fluorescein and indocyanin green anterior-segment angiography were performed preoperatively, at 1 and 2 weeks, 1, 2, 3, 6 and 9 months for each eye. At the end of the follow-up period, outflow facility (OF) was measured and histological examinations of the filtration site were performed. RESULTS: In the cylindrical implant group, IOP significantly dropped from a mean pre-operative value of 14.8+/-2.2 mmHg to a mean postoperative values of 10.9+/-3.3, 12.5+/-2.2, 11.8+/-2.6, 11.2+/-2.3, 10.7+/-1.9, 14.0+/- 3.2, 12.6+/-2.4 mmHg at 1, 2 weeks, and 1, 2, 3, 6, and 9 months, respectively. In the flat CI group, IOP significantly dropped from a mean preoperative value of 14.1+/-1.8 mmHg to a mean postoperative values of 10.4+/-2.7, 12.7+/-1.9, 12.5+/-3.2, 11.2+/-1.6, 11.6+/-1.8, 11.5+/-2.3, 11.0+/-2.2 mmHg at 1, 2 weeks, and at 1, 2, 3, 6, and 9 months, respectively. UBM images showed a gradual resorption of both type of CI during the first 3 months, and angiographies showed progressive growth of drainage vessels around the filtration site in both groups. The mean OF 9 months postoperatively for the cylindrical CI was 0.53 (SD +/- 0.23) ml/ min per mmHg and was 0.56 (SD+/-0.17) ml/min per mmHg for the flat CI (P=0.6). Histological examination revealed excellent biocompatibilty and a high density of drainage vessels in the sclera around the operative site in both groups. CONCLUSION: Using IOP and OF measurements, UBM, angiography, and histology, we were able to compare two types of CI used as space maintainer in DS. Both CIs showed efficient IOP lowering effect and outflow facility increase, possibly explained by stimulation of drainage vessels growth. Both implants showed excellent biocompatibility. The flat CI showed a slight tendency towards better overall performances.

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PubMed2006

Comparing polymethylmethacrylate implant with collagen implant in deep sclerectomy: a randomized controlled trial.

PURPOSE: To compare the intraocular pressure (IOP) lowering effect and safety of a new rigid, nonabsorbable polymethylmethacrylate implant (PMMA) with the commercially available cylindrical collagen implant used in deep sclerectomy procedure. INTERVENTION: Nonpenetrating deep sclerectomy was performed on all patients. Patients were randomly assigned to receive either a PMMA implant or a collagen implant. METHODS: The trial involved 60 patients (60 eyes) with medically uncontrolled primary and secondary open-angle glaucoma who were randomized to receive either a PMMA implant (30 eyes) or the collagen implant (30 eyes). The patients were examined before and after the operation 1 day before surgery and at day 1; weeks 1, 2 and 3; and months 1, 2, 3, 6, 9, 12, 18, 24, and 30. At each visit, the following examinations were performed: slit lamp examination, tonometry, visual acuity, and fundoscopy. RESULTS: The mean follow-up period was 20.4 (SD 12.4) months (PMMA) and 15.1 (SD 7.7) months (collagen) (P=NS). The mean preoperative IOP was 21.4 (SD 7.1) mm Hg (PMMA) and 21.0 mm Hg (SD 5.4) (collagen). The mean postoperative IOP was 7.4 (SD 4.5) mm Hg (PMMA) and 5.4 (SD 4.4) mm Hg (collagen) at day 1 (P=NS), 15.7 (SD 5.0) mm Hg (PMMA) and 14.7 (SD 5.0) mm Hg (collagen) at month 1 (P=NS), and 13.8 (SD 4.8) mm Hg (PMMA) and 13.3 (SD 2.4) mm Hg (collagen) at month 12 (P=NS). Seven patients had perforations of the trabeculo-Descemet membrane and were excluded from the analysis. At the last follow-up visit, 42% of PMMA patients and 44% of collagen patients achieved an IOP of 21 mm Hg or less without medication (P=NS). The number of medications was reduced from 2.4 (SD 1.0) to 0.6 (SD 0.6) (P<0.001) in the PMMA group, and from 2.4 (SD 1.1) to 0.7 (SD 0.8) (P<0.001) in the collagen group. There were no significant differences between the 2 groups in postoperative and transient complications. CONCLUSIONS: The new PMMA implant offered success and complication rates equal to those of the collagen implant. The new PMMA implant could serve as a low-cost alternative to the collagen implant and render the use of deep sclerectomy with an implant affordable for settings with limited financial resources.

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PubMed2004

Long-term results of deep sclerectomy with collagen implant.

PURPOSE: To study prospectively the success rate and complications of deep sclerectomy with collagen implant (DSCI). SETTING: Glaucoma Unit, Department of Ophthalmology, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland. METHODS: This nonrandomized prospective trial comprised 105 eyes of 105 patients with medically uncontrolled primary and secondary open-angle glaucoma. Visual acuity, intraocular pressure (IOP), and slitlamp examinations were performed before surgery and after surgery at 1 and 7 days, and 1, 3, 6, 9, 12, 18, 24, 30, 36, 48, 54, 60, 66, 72, 78, 84, 90, and 96 months. Visual field examinations were repeated every 6 months. RESULTS: Mean follow-up period was 64 months +/- 26.6 (SD). Mean preoperative IOP was 26.8 +/- 7.7 mm Hg, and mean postoperative IOP was 5.2 +/- 3.35 mm Hg at day 1 and 12 +/- 3 mm Hg at month 78. At 96 months, the qualified success rate (ie, patients who achieved IOP <21 mm Hg with and without medication) was 91%, and the complete success rate (ie, IOP <21 mm Hg without medication) was 57%. At 96 months, 34% of patients had an IOP <21 mm Hg with medication. Fifty-one patients (49%) achieved an IOP < or =15 mm Hg without medication. Neodymium:YAG goniopuncture was performed in 54 patients (51%); mean time of goniopuncture performance was 21 months, and mean IOP before goniopuncture was 20 mm Hg, dropping to 11 mm Hg after goniopuncture. No shallow or flat anterior chamber, endophthalmitis, or surgery-induced cataract was observed. However, 26 patients (25%) showed a progression of preexisting senile cataract (mean time 26 months; range 18 to 37 months). Injections of 5-fluorouracil were administered to 25 patients (23%) who underwent DSCI to salvage encysted blebs. Mean number of medications per patient was reduced from 2.3 +/- 0.7 to 0.5 +/- 0.7 (signed rank P<.0001). CONCLUSION: Deep sclerectomy with collagen implant appears to provide stable and reasonable control of IOP at long-term follow-up with few immediate postoperative complications.

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PubMed2002

Deep sclerectomy with collagen implant in one eye compared with trabeculectomy in the other eye of the same patient.

PURPOSE: To study the efficacy and safety of deep sclerectomy with collagen implant in one eye versus trabeculectomy in the other eye of the same patient. METHODS: The authors conducted a nonrandomized prospective trial of 20 patients with medically uncontrolled primary and secondary open-angle glaucoma. Patients with bilateral medically uncontrolled glaucoma who had previously undergone trabeculectomy in one eye were selected for the study, and a deep sclerectomy with collagen implant was performed in the second medically uncontrolled glaucomatous eye. Trabeculectomy was studied retrospectively whereas deep sclerectomy with collagen implant was studied prospectively. Visual acuity, intraocular pressure, and slit-lamp examinations were performed before and after surgery, at 1 and 7 days, and at 1, 3, 6, 9, 12, 18, and 24 months. Visual fields were repeated every 6 months. RESULTS: The mean follow-up period for both groups was 24.3 +/- 19.1 months. The mean intraocular pressure at 24 months was 13.9 +/- 4.5 mm Hg for deep sclerectomy with collagen implant and 12.9 +/- 4.8 mm Hg for trabeculectomy. At 24 months, IOP was reduced by 39.7% in the deep sclerectomy with collagen implant group (13.8 mm Hg vs. 22.9 mm Hg), and by 55.9% in the trabeculectomy group (12.9 mm Hg vs. 29.3 mm Hg). Forty percent of the deep sclerectomy with collagen implant eyes and 45% of the trabeculectomy eyes achieved a pressure of less than 21 mm Hg without treatment (complete success rate). The deep sclerectomy with collagen implant group showed 50% less hyphema and choroidal detachment than the trabeculectomy group. CONCLUSIONS: Deep sclerectomy with collagen implant is another surgical treatment option in the management of glaucoma, showing pressure results comparable with trabeculectomy but with a lower rate of early postoperative complications.

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