Department of Veterinary Clinical Sciences, Purdue University, Indiana, USA.
Department of Comparative Pathobiology, Purdue University, Indiana, USA.
Equine Vet J. 2021 Nov;53(6):1268-1276. doi: 10.1111/evj.13399. Epub 2021 Jan 19.
Amniotic membrane extract enhances the rate of epithelialisation after corneal ulceration in several species but has not been studied in the equine cornea.
To evaluate the effect of amniotic membrane extract on re-epithelialisation of equine corneal ulcers compared with ulcers treated with antibiotic, antifungal and mydriatic medical therapy alone, and to evaluate equine corneal healing after experimentally induced superficial ulceration.
Masked, randomised, controlled experimental trial.
Superficial, 8 mm corneal ulcers were created bilaterally in each horse. One eye was treated with amniotic membrane extract and the opposite was control. Both eyes were treated with medical therapy. Treatment eyes received amniotic membrane extract, and control eyes received the amniotic membrane extract vehicle. Ulcers were stained with fluorescein and photographed in 12-hour increments until completely healed. Ulcer surface area was determined by analysing photographs with ImageJ. A mixed linear model was used to compare ulcer surface area and hours until healing between treatment groups. A regression model was also used to calculate corneal re-epithelialisation rate over time.
Regardless of therapy, healing occurred in two phases: an initial rapid phase of 0.88 mm /hr (95% CI: 0.81-0.94 mm /hr) for approximately 48-54 hours followed by a second, slow phase of 0.07 mm /hr (95% CI: 0.04-0.09 mm /hr). Most eyes healed within 135.5 ± 48.5 hours. Treatment (amniotic membrane extract vs. control) was not significantly associated with size of ulcers over time (P = .984). Discomfort was minimal to absent in all horses.
Results achieved experimental studies may differ from outcomes in the clinical setting.
There was no significant difference in healing rate with addition of amniotic membrane extract to medical therapy for equine superficial corneal ulcers. A biphasic corneal healing process was observed, with an initial rapid phase followed by a slow phase. Further study will be needed to determine whether amniotic membrane extract will be helpful for infected or malacic equine corneal ulcers.
羊膜提取物可促进多种物种角膜溃疡上皮化，但尚未在马角膜中进行研究。
评估与单独使用抗生素、抗真菌和散瞳药物治疗相比，羊膜提取物对马角膜溃疡再上皮化的影响，并评估实验性诱导的浅层溃疡后马角膜的愈合情况。
双盲、随机、对照实验研究。
在每匹马的双侧创建 8mm 的浅层角膜溃疡。一只眼用羊膜提取物治疗，另一只眼为对照。双眼均接受药物治疗。治疗眼给予羊膜提取物，对照眼给予羊膜提取物载体。用荧光素染色并在 12 小时内增加拍照，直到完全愈合。用 ImageJ 分析照片确定溃疡面积。使用混合线性模型比较治疗组之间的溃疡面积和愈合时间。还使用回归模型计算随时间的角膜再上皮化率。
无论治疗如何，愈合都分为两个阶段：初始快速阶段为 0.88mm/小时（95%CI：0.81-0.94mm/小时），持续约 48-54 小时，然后是第二阶段，缓慢阶段为 0.07mm/小时（95%CI：0.04-0.09mm/小时）。大多数眼睛在 135.5±48.5 小时内愈合。治疗（羊膜提取物与对照）与时间上的溃疡大小无显著相关性（P=0.984）。所有马的不适均轻微至不存在。
实验研究的结果可能与临床环境的结果不同。
在马浅层角膜溃疡的药物治疗中加入羊膜提取物对愈合速度没有显著影响。观察到角膜愈合呈双相，初始快速相后是缓慢相。需要进一步研究以确定羊膜提取物是否对感染或马氏角膜溃疡的马有帮助。
