Dendrite-like anterior stromal keratitis coinfected with Acanthamoeba and Pseudomonas in an orthokeratology contact lens wearer

Abstract

Acanthamoeba species can cause a keratitis misdiagnosed as herpes keratitis or fungal keratitis. We report an unusual dendrite-like anterior stromal keratitis coinfected with Acanthamoeba and Pseudomonas aeruginosa in an orthokeratology contact lens wearer in Taiwan. Topical 1% voriconazole and 0.5% levofloxacin were prescribed because besides Acanthamoeba keratitis, fungal keratitis was also highly suspected initially. Topical 0.02% chlorhexidine was added after the culture of the scraped cornea showed positive results of Acanthamoeba and P. aeruginosa . The lesion subsided using this triple combination therapy for 1 week. Both Acanthamoeba and P. aeruginosa are potentially devastating causes of infectious keratitis. Our case highlights the importance of considering the possibility of a concurrent infection and atypical presentation in cases with contact lens-related keratitis. The use of topical levofloxacin combined with voriconazole should be considered as the first-line treatment in such patients.

Case Series: Unusual Presentation of Acanthamoeba Coinfection in the Cornea

“…Initial presentation for most of the cases involving Acanthamoeba coinfection with P. aeruginosa is most often changes occurring in the later stages, such as ring infiltrates or deep central stromal infiltrate. Only one case (Table 1) presented with anterior stromal infiltrates with a final best-corrected visual acuity of up to 20/20 1 . A previous case report indicated that a late-stage change of corneal ulcer morphology may also be a poor prognostic factor for vision outcome in Acanthamoeba keratitis coinfection 9 .…”

“…In this cases series, perineuritis was observed in case 1, whereas epitheliitis was observed in case 2. Perineuritis and epitheliitis are known presentations in early Acanthamoeba keratitis infection, but these two presentations are relatively unusual in Acanthamoeba keratitis coinfection 1,4–7,9 . Perineuritis, a typical characteristic of Acanthamoeba keratitis, was also reported in contact lens–related microbial keratitis caused by P. aeruginosa 12 .…”

“…Whereas the patient described in case 1 wore orthokeratology lens, the patient described in case 2 reported no contact lens use and no trauma but had a history of exposure to muddy water. The use of contact lenses appears to be a strong risk factor for Acanthamoeba coinfection with P. aeruginosa 1,4–7 Table 1. showed five cases of concurrent P. aeruginosa and Acanthamoeba infection.…”

“…Acanthamoeba keratitis is a severe and vision-threatening disease of the cornea, which is caused by the free-living, ubiquitous protozoa Acanthamoeba. 1,2 The main risk factors include wearing contact lenses, exposure to contaminated water or tap water, and damage of the corneal surface 3 . Diagnosis of this disease tends to be challenging and can often be delayed 3 .…”

Atypical presentation of acanthamoeba keratitis resembling central toxic keratopathy

“… 38 A rare and unusual dendrite-like anterior stromal keratitis has been reported from coinfection with Acanthamoeba and Pseudomonas aeruginosa in a contact lens wearer. 39 …”