Thajunnisa A S, Sainulabdeen Anoop, Dileepkumar K M, Philip Laiju M, Vasudevan V N, Devanand C B
Department of Veterinary Surgery and Radiology, College of Veterinary and Animal Sciences, Kerala Veterinary and Animal Sciences University, Mannuthy, Kerala, India.
Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Kerala Veterinary and Animal Sciences University, Mannuthy, Kerala, India.
Vet World. 2020 Nov;13(11):2401-2410. doi: 10.14202/vetworld.2020.2401-2410. Epub 2020 Nov 11.
Ulcerative corneal lesions are common ocular affections encountered in veterinary ophthalmology, having a higher incidence in dogs with brachycephalic conformation. Prompt and effective diagnosis and repair are necessary to avoid corneal perforation and restore vision. Corneal wound healing is a complex phenomenon often resulting in vision impairment as a consequence of corneal fibrosis and pigmentation. The present study investigated the efficacy of decellularized and gamma-irradiated bovine omentum as an extracellular matrix scaffold in the reconstruction of extensive and full-thickness corneal defects, and the cytotoxic effects of mitomycin-C (MMC) to prevent corneal fibrosis and pigmentation.
Twelve injured corneas of eleven dogs irrespective of breed, age, and sex were randomly divided into Groups I and II, consisting of six corneas each. Under general anesthesia, corneal grafting with decellularized and gamma-irradiated bovine omentum was carried out in Group I, whereas Group II corneas underwent single time intra-operative application of topical MMC for 2 min before corneal grafting with the same material. Epithelialization of cornea and observations including corneal edema, neovascularization, the extent of pigmentation, corneal clarity, and scarring was recorded on days 7, 14, 21, and 60 postoperatively.
All corneas in Group I showed early epithelialization by day 7 compared to Group II where the MMC delayed epithelialization in 50% of the corneas. Visual function scores improved greatly from 0.17±0.17 in Group II on the day of presentation to 1.0±00 by the end of the observation period compared to Group I (from 0.33±0.15 to 0.88±0.11). Although epithelialization and corneal healing were delayed, 50% of the corneas recovered with undetectable corneal scar and melanosis at the end of the observation period in Group II due to the anti-fibrotic effect of MMC.
From the present study, it was concluded that re-epithelialization of the cornea was enhanced by corneal grafting with decellularized bovine omentum, and application of MMC was effective in delaying corneal fibrosis and pigmentation.
溃疡性角膜病变是兽医眼科常见的眼部疾病,在短头畸形犬中发病率较高。及时有效的诊断和修复对于避免角膜穿孔和恢复视力至关重要。角膜伤口愈合是一个复杂的现象,常因角膜纤维化和色素沉着导致视力受损。本研究调查了脱细胞并经γ射线辐照的牛网膜作为细胞外基质支架在重建广泛全层角膜缺损中的疗效,以及丝裂霉素-C(MMC)预防角膜纤维化和色素沉着的细胞毒性作用。
11只犬的12只受伤角膜,不分品种、年龄和性别,随机分为I组和II组,每组6只角膜。在全身麻醉下,I组采用脱细胞并经γ射线辐照的牛网膜进行角膜移植,而II组角膜在使用相同材料进行角膜移植前,术中单次局部应用MMC 2分钟。术后第7、14、21和60天记录角膜上皮化情况以及包括角膜水肿、新生血管形成、色素沉着程度、角膜透明度和瘢痕形成等观察指标。
与II组相比,I组所有角膜在术后第7天显示早期上皮化,II组中50%的角膜MMC延迟了上皮化。与I组(从0.33±0.15提高到0.88±0.11)相比,II组视觉功能评分从就诊当天的0.17±0.17大幅提高到观察期结束时的1.0±0.00。尽管II组上皮化和角膜愈合延迟,但由于MMC的抗纤维化作用,50%的角膜在观察期结束时恢复,角膜瘢痕和黑素沉着不可检测。
从本研究得出结论,脱细胞牛网膜角膜移植可增强角膜的再上皮化,应用MMC可有效延迟角膜纤维化和色素沉着。