Department of Ophthalmology, Tokyo Medical University, Shinjuku City, Japan.
Department of Microbiology, Tokyo Medical University, Shinjuku City, Japan.
Sci Rep. 2019 Sep 6;9(1):12821. doi: 10.1038/s41598-019-49128-7.
The role of topical corticosteroids in management of Acanthamoeba keratitis (AK) remains controversial. Using a rabbit AK model, we investigated whether corticosteroid use is a risk factor of AK. Acanthamoeba (1 × 10/ml) was incubated with two densities of P. aeruginosa (PA; high-PA: 1 × 10/ml, low-PA: 3 × 10/ml) before corneal inoculation. Rabbit corneas were inoculated with Acanthamoeba alone or Acanthamoeba plus PA and administered levofloxacin and betamethasone sodium phosphate (BSP) eye drops for 5 or 7 days. Infected rabbit eyes were evaluated for clinical score and Acanthamoeba by histological examination. Acanthamoeba alone and BSP treatment did not produce keratitis. Corneas inoculated with Acanthamoeba plus low-PA treated immediately with levofloxacin and BSP remained clear with few infiltrates. Corneas inoculated with Acanthamoeba plus low-PA treated with levofloxacin immediately and BSP 12 h later developed severe keratitis. Corneas inoculated with Acanthamoeba plus high-PA treated immediately with levofloxacin and BSP also developed severe keratitis. Acanthamoebae were detected by PAS staining in corneas inoculated with Acanthamoeba plus high-PA treated with levofloxacin and BSP. Topical corticosteroids have the potential to aggravate AK when cornea is infected by Acanthamoeba with a critical number of bacteria or when corticosteroids are given after infection has established by Acanthamoeba with small number of bacteria.
局部皮质类固醇在棘阿米巴角膜炎（AK）治疗中的作用仍存在争议。我们使用兔 AK 模型，研究皮质类固醇的使用是否是 AK 的一个危险因素。将棘阿米巴（1×10/ml）与两种密度的铜绿假单胞菌（PA；高 PA：1×10/ml，低 PA：3×10/ml）孵育后，进行角膜接种。兔角膜单独接种棘阿米巴或棘阿米巴加 PA，并用左氧氟沙星和磷酸倍他米松钠（BSP）滴眼剂治疗 5 或 7 天。用临床评分和组织学检查评估感染兔眼的棘阿米巴情况。单独的棘阿米巴和 BSP 治疗不会引起角膜炎。立即用左氧氟沙星和 BSP 治疗接种低 PA 的棘阿米巴的角膜仍保持清晰，仅有少量浸润。立即用左氧氟沙星和 BSP 治疗接种低 PA 的棘阿米巴，然后 12 小时后用 BSP 治疗的角膜会发生严重的角膜炎。立即用左氧氟沙星和 BSP 治疗接种高 PA 的棘阿米巴的角膜也会发生严重的角膜炎。用 PAS 染色在接种高 PA 的棘阿米巴并用左氧氟沙星和 BSP 治疗的角膜中检测到棘阿米巴。当角膜被大量细菌感染的棘阿米巴或当小数量细菌的棘阿米巴感染后给予皮质类固醇时，局部皮质类固醇有加重 AK 的潜力。
