Pinna Antonio, Porcu Tiziana, Boscia Francesco, Cano Antonella, Erre Giuseppe, Mattana Antonella
*Department of Surgical, Microsurgical, and Medical Sciences, Ophthalmology Unit, University of Sassari, Sassari, Italy; †Azienda Opedaliero-Universitaria di Sassari, Unità Operativa di Oculistica, Sassari, Italy; and ‡Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
Cornea. 2017 Jul;36(7):785-790. doi: 10.1097/ICO.0000000000001226.
To describe the diagnostic and clinical features and treatment results in 43 consecutive patients with microbiologically proven free-living amoebae (FLA) keratitis.
In this hospital-based, prospective case series, corneal scrapings from 43 patients with presumed amoebic keratitis were plated on nonnutrient agar. Amoebic isolates were identified morphologically and by the polymerase chain reaction. All patients with culture-proven FLA keratitis were treated with polyhexamethylene biguanide (PHMB) 0.02% eye drops.
Forty-three corneal scrapings from 43 patients were found to be culture positive for FLA; 41 (95%) were from contact lens wearers and 2 (5%) were from noncontact lens wearers. Microscopic examination identified 4 Acanthamoeba spp, 24 Hartmannella spp, 12 vahlkampfiid amoebae, and 3 mixed infections with Hartmannella/vahlkampfiid amoebae. Morphological results were confirmed by the polymerase chain reaction. Patients with Acanthamoeba, Hartmannella, and vahlkampfiid keratitis had indistinguishable clinical features. In 38 eyes with keratitis at an early stage, treatment with PHMB 0.02% eye drops was fully successful. In 5 patients with advanced keratitis, topical PHMB 0.02% controlled the infection, but all of them developed a central corneal scar with visual deterioration.
Acanthamoeba is not the only cause of amoebic keratitis, because this condition may also be caused by other FLA, such as Hartmannella and vahlkampfiid amoebae. This finding is epidemiologically interesting, suggesting a possible different geographical prevalence of the different FLA responsible for keratitis. Early diagnosis and proper antiamoebic treatment are crucial to yielding a cure.
描述43例经微生物学证实的自由生活阿米巴（FLA）角膜炎患者的诊断、临床特征及治疗结果。
在这个基于医院的前瞻性病例系列研究中，将43例疑似阿米巴角膜炎患者的角膜刮片接种于无营养琼脂上。通过形态学和聚合酶链反应鉴定阿米巴分离株。所有经培养证实为FLA角膜炎的患者均使用0.02%的聚六亚甲基双胍（PHMB）滴眼液进行治疗。
43例患者的43份角膜刮片培养出FLA阳性；41例（95%）来自隐形眼镜佩戴者，2例（5%）来自非隐形眼镜佩戴者。显微镜检查鉴定出4株棘阿米巴属、24株哈特曼氏阿米巴属、12株瓦氏阿米巴属，以及3例哈特曼氏阿米巴属/瓦氏阿米巴属混合感染。聚合酶链反应证实了形态学结果。棘阿米巴属、哈特曼氏阿米巴属和瓦氏阿米巴属角膜炎患者的临床特征无明显差异。在38例早期角膜炎患者中，使用0.02%的PHMB滴眼液治疗完全成功。在5例晚期角膜炎患者中，局部使用0.02%的PHMB控制了感染，但所有患者均出现中央角膜瘢痕并伴有视力下降。
棘阿米巴不是阿米巴角膜炎的唯一病因，因为这种疾病也可能由其他FLA引起，如哈特曼氏阿米巴属和瓦氏阿米巴属。这一发现具有流行病学意义，提示导致角膜炎的不同FLA可能存在不同的地理分布。早期诊断和适当的抗阿米巴治疗对于治愈至关重要。
