| Glaucoma is a common eye disease causing blindness in canine. Trabeculectomy is a surgical procedure indicated for the treatment of canine glaucoma, however, surgery leads to excess proliferation of fibrous tissues that are inevitable for the recurrence of glaucoma. Amniotic membrane has anti- inflammatory, anti-angiogenesis properties and prevents from postoperative fibrous tissues hyperplasia is recently established treatment of glaucoma in human patients. Mitomycin has been widely used in clinical medicine for the treatment of glaucoma because it is an anti- metabolic drug that inhibits DNA replication. It has strong toxicity to the fibroblasts and hence limits the generation of fibrous tissue after glaucoma surgery. The practiced surgical methods result postoperative complications. There is an utmost need to have the best efficacious method to treat canine glaucoma.In the present study, the compound of carbomer solution was injected into anterior chamber of both eyes at baseline of twelve healthy male and female dogs that developed the glaucoma model after 7 days. The twelve bilateral induced glaucoma dogs randomly assigned into four different treatment groups ensuring that two eyes of a same dog receive different surgical methods to have 6 model eyes for every method. We compared the following four surgical methods to evaluate the clinical efficacy for the treatment glaucoma in dogs:(a) Common trabeculectomy(C T group);(b) Trabeculectomy combined with amniotic membrane(AM group), transplant amniotic membrane under scleral and subconjunctival flap;(c) Trabeculectomy combined with mitomycin(MMC group), trabeculectomy plus mitomycin under the scleral and conjunctival flap and;(d) trabeculectomy combined with mitomycin and amniotic membrane(AM + MMC group), trabeculectomy plus amniotic membrane and plus mitomycin under the scleral and conjunctival flap.The intraocular pressures(IOP) were measured at baseline and at 7, 14, 21, 28, 35, 42, 49, 56 and 63 days after surgery. The operated dogs were observed minutely for filtering bleb, tissue healing and count the numbers of the fibroblasts in surgical area and postsurgical complications throughout the study period. All the experimental dogs were euthanized at 63 days. The eye tissues were harvested, stored properly and processed further for histopathological examination.The results of present study showed that the IOP of all treatment groups were significantly lower at 14 days, afterward gradually increased. Compared to baseline, the CT and AM groups resulted significantly higher(P < 0.05) IOP at 49 and 42 days respectively. Likewise, MMC group showed significantly lower(P < 0.05) IOP both at 21 and 28 days, however AM + MMC group showed significantly lower(P < 0.05) IOP at 21 days. The IOP of AM and MMC groups were significantly lower(P < 0.05) at 14, 21, 28, 35 days and 14,21,28,35,42,49,56, 63 days respectively as compared to CT group. Similarly, AM + MMC group revealed significantly lower(P < 0.05) IOP at 35,42,49,56, 63 days as compared with AM group, while it showed highly significant difference(P = 0.027) at 14 days than that of MMC group.The obvious filtering blebs were observed at D14 in all groups. The filtering bleb scores of CT, MMC, the both AM and AM+MMC groups were significantly lower(P < 0.05) at 35, 42 and 49 days respectively in comparison with 14 days. The filtering bleb scores of AM and MMC groups at D35-42 and D14-49 respectively, showed significantly(P < 0.05) higher score than C T group. Similarly, the filtering bleb scores of AM+MMC group significantly higher(P < 0.05) as compared to AM group at 14,21,28,35,42,49 and 56 days, but did not show significant difference(P > 0.05) with MMC group at all- time points.The postoperative complications were 33.3%, 33.3%, 16.6% and 0% observed in group C T, MMC, AM and AM + MMC respectively. The fibrous tissue hyperplasia was observed clearly in sub-conjunctival area of CT and AM group, but fibroblasts number did not show any difference(P = 0.337) in groups. There were no obvious fibrous tissue hyperplasia and non significant number of fibroblasts observed(P = 0.275) in MMC and AM + MMC groups. However, fibroblasts numbers in MMC and AM + MMC groups were significantly lower(P < 0.05) than that of C T and AM groups, but MMC group showed fiber degradation in the scleral flaps.Based on findings of present study, the trabeculectomy combined with amniotic membrane revealed superior at 14,21,28 and 35 days than conventional trabeculectomy method for treatment of glaucoma in dogs. IOP remained lower and the filtering bleb retained longer in trabeculectomy combined with mitomycin group but in 2 eyes complications were noticed. In one eye, conjunctival wound was not healed well and in the second eye, the IOP remained lower than normal.It can be concluded that trabecular resection combined with mitomycin and amniotic membrane can be used for the treatment of canine glaucoma patients because this method maintained stable IOP, follicular formation, less proliferation of fibrous tissue, and no complications throughout the postoperative period. |
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