非结核分枝杆菌性角膜炎的诊断与治疗

目的 探讨角膜异物外伤后非结核分枝杆菌性角膜炎的临床特点、诊断及治疗.方法 回顾性系列病例研究.分析2007年3月至2008年1月期间南通大学附属医院诊治的12例(12只眼)非结核分枝杆萧性角膜炎患者的临床和实验室资料,包括病史、临床表现、实验室检查、诊断和治疗经过以及预后情况.主要的实验诊断方法包括角膜病灶刮取物的微生物培养、抗酸染色、聚合酶链式反应、病变角膜的组织病理及电镜检查.治疗方法包括局部和全身应用抗生素、5%碘酊病灶烧灼清创以及角膜移植.患者的平均年龄、病程采用算术平均数法计算.结果 本组11例为同一基层医院角膜金属异物摘除术后群发感染,另1例发生于芦苇刺伤角膜后.较特征性的体征包括角膜基质灰蓝色或灰白色结晶样、多灶性浸润,可伴有溃疡形成、后弹力层放射状改变等.12例微生物培养均为快速生长型非结核分枝杆菌(5例鉴定为龟分枝杆菌脓肿亚型),8例聚合酶链式反应检查7例细菌阳性,3例电镜检查均见吞噬了细长杆状或短粗型的分枝杆菌的门细胞和坏死组织.10例经局部和全身应用多种抗生素(阿米卡星、利福平、氧氟沙星、加替沙星、环丙沙星、阿奇霉素等)以及5%碘酊病灶烧灼清创2～5个月治愈,2例药物治疗6个月无明显疗效经板层或穿透性角膜移植治愈.结论 非结核分枝杆菌性角膜炎是一种少见的机会性感染,可在角膜异物摘除术后群发流行,诊断困难,易被误诊为真菌性角膜炎,可经细菌培养、抗酸染色明确诊断.该病病程长,药物治疗反应慢,大多数患者可经抗生素控制,顽固性病例需角膜移植治愈.

The diagnosis and treatment of rapidly growing non-tuberculous mycobacterial keratitis

Objective To study the clinical features, diagnosis and treatment of non-tuberculous mycobacterial keratitis (NTMK). Methods It was retrospective case series study. Twelve eyes in 12 patients with NTMK following corneal foreign body trauma in 2007 were studied retrospectively including the case histories, clinical findings, laboratory examinations, diagnosis, treatment and prognosis. The main laboratory examination included corneal scrapings by culturing, polymerase chain reaction (PCR) and transmission electron microscopy (TEM), corneal lesions by histopathologic examinations and TEM. The patients received local and systemic antibiotics therapy, lesion cleaning followed by cauterization with tincture of iodine (5%) and (or) keratoplasty. Results All cases had a history of corneal trauma, there was corneal metallic foreign body removal at one hospital in 11 cases, corneal reed trauma in 1 case. The characteristic signs involved grayish-blue crystalloid keratopathy, multifocal infiltrates, satellites,radiatiform changes in the Descement's membrane. The results of laboratory examinations of the scrapings of the cornea infection were as follows: all cultures (12/12) were positive for rapidly growing mycobacteria, and isolates from 5 patients were all diagnosed as mycobacterium chelonae subspecies abscess; acid-fast staining revealed positive bacilli in all the 4 patients ; seven of 8 patients were positive for bacterium by PCR. Transmission electron microscopy in all the 3 specimens showed many slender red-shaped or short coarse-shaped bacteria which were phagocytized by monocytes, and some necrotic tissue. Infections in 10 eyes were resolved by combined treatment regimen including a combination of antimicrobial agents (amikacin, rifampin, gatifloxation, ciprofloxacin, azithromycin and/or ofloxacin, etc. ) and local lesion cleaning followed by cauterization with 5% tincture of iodine within 2-5 months; two cases resolved by keratoplasty which poorly responded to antibiotic therapy for 6 months. Conclusions NTMK is a rare, recalcitrant opportunistic infection which can occur in an epidemic fashion following corneal foreign body trauma. The diagnosis of NTMK is difficult, and may easily be misdiagnosed as fungal keratitis. Acid-fast staining, TEM, especially bacterial culture can help to obtain definitive diagnosis. NTMK has a long response period to medical management. The majority of patients can be cured by local and systemic antibiotics therapy, and the recalcitrant infections could be resolved by keratoplasty.