Ward Mathew S, Hastings Jordan P, Shmunes Kathryn M, Ronquillo Yasmyne, Hoopes Phillip C, Moshirfar Majid
Riverwoods Eye Center, Provo, UT, USA.
California Northstate University College of Medicine, Elk Grove, CA, USA.
Am J Ophthalmol Case Rep. 2021 Dec 16;25:101243. doi: 10.1016/j.ajoc.2021.101243. eCollection 2022 Mar.
To describe an atypical case of acanthamoeba keratitis with positive in vivo confocal microscopy in a non-contact lens user who presented with signs and symptoms suggestive of central toxic keratopathy.
The patient presented with bilateral, though sequential, decreased visual acuity with mild pain. Examination showed stromal haze with corneal flattening and thinning without epithelial defects. Optical coherence tonometry of the right eye revealed an inverse dome-shaped appearance of the opacity and in-vivo confocal imaging showed double-walled cysts consistent with acanthamoeba. Corneal haze, stromal loss, resolved and visual acuity improved over time.
Acanthamoeba is a rare cause of infectious keratitis that is most often associated with contact lens wear in developed countries. Typically, it presents with a unilateral decrease in visual acuity, photophobia, watering, and pain that is out of proportion to slit lamp examination findings. However, many atypical presentations have been reported in the literature. Consequently, it may be misdiagnosed, especially early in the course of the disease. This delay in diagnosis can lead to progressive ulceration and visual impairment. In addition, cyst formation can make eradication with anti-amoebic treatment especially difficult.Central toxic keratopathy is a non-inflammatory clinical syndrome of unknown etiology that is most often associated with excimer laser ablation, though other associated causes have been reported. It is characterized by a central or paracentral opacity with corneal stromal loss and resultant hyperopic shift. The opacification and stromal loss mostly resolve over the course of months with an improvement in visual acuity. This report may help physicians broaden their differential and correctly diagnose atypical presentations of amoebic infection.
描述一例非隐形眼镜使用者患棘阿米巴角膜炎的非典型病例，该病例在共聚焦显微镜检查下呈阳性，患者表现出提示中央毒性角膜病变的症状和体征。
患者出现双侧视力下降，虽为先后出现，但伴有轻度疼痛。检查显示角膜基质混浊，角膜扁平且变薄，无上皮缺损。右眼光学相干眼压测量显示混浊呈倒穹顶状外观，共聚焦显微镜成像显示与棘阿米巴一致的双壁囊肿。随着时间推移，角膜混浊、基质丢失得到缓解，视力改善。
棘阿米巴是感染性角膜炎的罕见病因，在发达国家最常与隐形眼镜佩戴相关。通常，其表现为单眼视力下降、畏光、流泪和疼痛，且疼痛程度与裂隙灯检查结果不成比例。然而，文献中已报道了许多非典型表现。因此，该病可能被误诊，尤其是在疾病早期。诊断延迟可导致进行性溃疡和视力损害。此外，囊肿形成会使抗阿米巴治疗的根除尤其困难。中央毒性角膜病变是一种病因不明的非炎症性临床综合征，最常与准分子激光消融相关，不过也有其他相关病因的报道。其特征为中央或旁中央混浊，伴有角膜基质丢失及由此导致的远视性移位。混浊和基质丢失大多在数月内消退，视力改善。本报告可能有助于医生拓宽鉴别诊断范围，并正确诊断阿米巴感染的非典型表现。
