病例18　44歲女性，右眼植物外傷后眼紅痛1個月

CASE 18　A 44-year-old female injuried from plant, red eye and sever pain in the right eye for 1 month

見圖1-29。See Fig. 1-29.

鑒別診斷

Differential Diagnosis

◎ 棘阿米巴性角膜炎：早期癥狀不典型，表現為角膜上皮假樹枝狀潰瘍，上皮及上皮下浸潤，放射狀游走性神經炎。進展期表現為基質潰瘍、環形浸潤、衛星灶、前房積膿。晚期表現為角膜基質化膿或壞死、變薄和穿孔。

◎ Acanthamoeba keratitis: Early signs may be mild and nonspecif ic, including epithelial pseudodendrites, epithelial or subepithelial inf iltrates, and radial keratoneuritis. Later signs include stromal ulcer, ring-shaped inf iltrates, satellite lesions,hypopyon. Advanced signs include stromal suppuration,necrosis, thinning and corneal perforation.

◎ 真菌性角膜炎：角膜潰瘍多呈灰白色羽毛狀或干燥的豆腐渣樣，可有偽足，前房可伴積膿，結膜充血明顯。

◎ Fungal keratitis: The corneal lesion has a white/gray inf iltrate with feathery borders. There might be satellite lesions with hypopyon and conjunctival congestion as well as purulent secretions.

◎ 病毒性角膜炎上皮型：病毒性角膜炎上皮型可表現為上皮樹枝狀潰瘍、地圖狀潰瘍以及邊緣性潰瘍。典型的樹枝狀潰瘍可見樹枝末端膨大。而棘阿米巴性角膜炎的假樹枝狀上皮病變表現不同。

◎ Viral epithelial keratitis: Viral epithelial keratitis usually presents dendritic ulcer, geographic ulcer, and marginal keratitis. Dendritic epithelial keratitis has round spotlike widenings at the endings of the epithelial erosions.Pseudodendritiformic epitheliopathy in acanthamoeba keratitis is differential.

◎ 細菌性角膜炎：主要表現為角膜潰瘍或者角膜膿性浸潤，進展迅速，多伴前房積膿。棘阿米巴性角膜炎多表現為亞急性或者慢性。

◎ Bacterial keratitis: The corneal ulcer or corneal purulent inf iltration is rapidly formed and progressed, usually accompanied by severe hypopyon in the anterior chamber.Acanthamoeba keratitis generally presents the features of subacute or chronic onset and gradual progression.

◎ 表麻藥相關性角膜病變：表現為持續性角膜上皮缺損、角膜潰瘍以及角膜環形浸潤。患者通常有表麻藥濫用史。

◎ Anaesthetic abuse keratopathy: Anaesthetic abuse keratopathy has been characterised by persistent epithelial defects, keratitis ulcer and ring inf iltration of the cornea.The patient had the history of using topical anaesthetics.

病史詢問

Asking History

◎ 疾病發生之前是否有長期角膜接觸鏡配戴史，是否用自來水清洗接觸鏡鏡片以及配戴角膜接觸鏡游泳，有角膜異物及角膜擦傷史。

◎ The history of contact lenses wearing and their cleaning solutions, clean contact lens with tap water, wear contact lens in swimming pool, foreign bodies or minor bruises in cornea.

◎ 是否伴劇烈疼痛。

◎ Accompany with massive pain.

眼部檢查

Examination

◎ 視力下降。

◎ Visual acuity is decreased.

◎ 裂隙燈檢查：早期以角膜上皮假樹枝狀潰瘍及放射狀神經炎為主要表現；進展期為角膜基質潰瘍、環形浸潤、衛星灶、前房積膿；晚期出現角膜基質化膿或壞死、變薄和穿孔。

◎ Slit lamp examination: Early signs include epithelial pseudodendrites and radial keratoneuritis. Later signs include stromal ulcer, ring-shaped inf iltrates, satellite lesions,hypopyon. Advanced signs include stromal suppuration,necrosis, thinning and corneal perforation.

實驗室檢查

Lab

◎ 角膜刮片在表面麻醉后于裂隙燈下進行。滋養體和包囊可以用革蘭氏和吉姆薩染色。

◎ Involved area of cornea can be scraped with a sterile instr ume nt under topical anesthesia at the slit lamp. Acanthamoeba trophozoites and cysts can also be identif ied with the help of Gram and Giemsa.

◎ 阿米巴培養可以用含大腸桿菌的非營養瓊脂。

◎ The culture specimen can then be inoculated into a dish of E. coli plated over non-nutrient agar.

◎ 共聚焦顯微鏡檢查：包囊表現為圓形，雙壁，高密度影像，直徑15~20μm（圖1-30）；滋養體表現為不規則高密度影像，其中心或偏中心可見致密的核，直徑25~40μm（圖 1-31）。

◎ Laser Confocal microscope: The acanthamoeba cyst presentes a round high-contrast particle, 15 to 20 μm in diameter, with a double wall (Fig. 1-30). The trophozoite presentes an irregular high-contrast particle, without an apparent wall, 25 to 40 μm in diameter and with a round conspicuous nucleus (Fig. 1-31).

診斷

Diagnosis

棘阿米巴性角膜炎。

Acanthamoeba keratitis.

治療

Management

◎ 徹底清創。

◎ Extensive epithelial lesion debridement.

◎ 局部抗阿米巴藥：常用0.02%聚六亞甲基雙胍(poly he x amethylene biguanide, PHMB)和 0.02%氯己定二葡萄糖酸鹽。

◎ Topical polyhexamethylene biguanide (PHMB) 0.02%and chlorhexidine diglucoate 0.02% are commonly used biguanides.

◎ 控制疼痛：口服非甾體抗炎藥。

◎ Systematic non-steroid anti-inf lammatory drug.

◎ 對藥物治療欠佳的患者，可行板層 / 穿透性角膜移植術。

◎ In therapy resistant cases, lamellar/penetrating keratoplasty may be applied.

患者教育和預后

Patient Education & Prognosis

◎ 避免自來水清洗鏡片以及配戴角膜接觸鏡游泳。棘阿米巴性角膜炎由于早期易誤診及治療困難，預后差。目前抗棘阿米巴的藥物品種少且特異性不強，如果角膜穿孔須行穿透性角膜移植手術，但復發率較高。

◎ Do not clean contact lens with tap water or wear contact lens in swimming pool. There is often a poor prognosis because of a signif icant delay in diagnosis and frequently a lack of effective medical management. If corneal perforates,penetrating keratoplasty is only effective surgical option,but the risk of recurrence is high.