Abstract
Abstract: :
Purpose: To evaluate the usefulness of patched amniotic membrane (AM), which has been shown to induce downregulation of TGF-beta signaling, not only as an antifibrotic modulator of wound healing but also as a mechanical barrier against infection, in refractory glaucoma patients who had undergone trabeculectomy. Methods: Enrolled in this study were eight refractory glaucoma patients who had suffered severe cornea-related diseases such as penetrating keratoplasty (PKP; 7 eyes), PKP with ocular surface reconstruction (1 eye), and PKP with perforating corneal injury (1 eye). AM obtained at Cesarean section was washed in isotonic sodium chloride solution, cut into 20 x 20 mm pieces, and stored in a deep freezer. For use in surgery, the AM was spontaneously thawed and prepared in balanced salt solution with antibiotics. After regular trabeculectomy (TLE) with adjunctive mitomycin C, four eyes were randomly chosen to receive the newly developed surgical technique (AM-TLE group), comprising a subconjunctival AM patch. AM patch which was placed epithelial side down on the scleral flap, was sutured at the limbal area with 10-0 nylon, and covered with conjunctiva. The other four eyes in the study received the regular TLE procedure only with adjunctive mitomycin C (regular TLE group). Results: Three of the four eyes in the AM-TLE group formed a well-established filtering bleb with no leakage or wall thinning, with no hyperfiltration, stable anterior chamber, and intraocular pressure maintained below 15 mmHg. However, one eye failed to maintain the filtering bleb because of MRSA infection owing to postoperative strong immunosuppressant therapy against corneal graft rejection. Although this case experienced severe bleb infection, the inflammation was localized just outside the AM, and endophthalmitis was not observed. The four eyes without the AM patch, in contrast, all failed to maintain the filtering bleb, and required additional surgery (regular TLE group). The mean observation period for all eyes was 6.8 months. Conclusion: These findings confirm that AM-TLE is effective for treating refractory glaucoma after severe corneal disease. For trabeculectomy, AM is considered to function not only as a mechanical barrier, but also as a biological barrier.
Keywords: 631 wound healing • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • 356 clinical (human) or epidemiologic studies: systems/equipment/techniques