Acanthamoeba Keratitis: A Single-Institution Series of Four Cases With Literature Review

Abstract

Acanthamoeba species are free-living protozoa found pervasively in water and soil, which can cause infections of the central nervous system, skin, and eye. Amoebic keratitis (AK) is a vision-threatening, often chronic infection that is associated with the use of soft contact lenses due to corneal microtrauma and improper cleaning and storage. Although AK infections are rare, they cause significant morbidity including vision loss due to the diagnostic and therapeutic challenges they pose.The clinical course is determined by the organism's inherent pathogenicity, delay of diagnosis, and the paucity of data on effective therapeutic regimens. The case series and review of literature that follows examine current latest best practices in AK diagnosis including in vivo confocal microscopy (IVCM) and therapeutic interventions including miltefosine.

Diagnosing and monitoring the characteristics of Acanthamoeba keratitis using slit scanning and laser scanning in vivo confocal microscopy

“…A further study used IVCM in three of their four patients diagnosed with AK, which showed worsening symptoms despite treatment. In these three cases, IVCM demonstrated cysts which had migrated deeper into the cornea, and a deep anterior lamellar keratoplasty was necessary in all three cases 63 …”

“…A total of 13 studies reported the use of IVCM to track AK during and/or after treatment 9,30,34,39,42,46–48,53,55,59,63,64 . Two described the appearance of cysts and trophozoites following treatment 34,42 .…”

“…A total of 13 studies reported the use of IVCM to track AK during and/or after treatment. 9,30,34,39,42,[46][47][48]53,55,59,63,64 Two described the appearance of cysts and trophozoites following treatment. 34,42 Bourcier et al observed that cysts were still present 6 weeks after treatment and these were round or ovoid structures 5-15 μm long.…”

“…In these three cases, IVCM demonstrated cysts which had migrated deeper into the cornea, and a deep anterior lamellar keratoplasty was necessary in all three cases. 63 Presence or absence of cysts or trophozoites following treatment…”

A Review Article: Clean Water Contamination as a Risk Factor for Acanthamoeba Keratitis

“…One of the pathogens that can cause keratitis in coastal communities with the majority of work as divers and fishermen is Acanthamoeba spp. Acanthamoeba parasites can cause progressive infection of the cornea 8 . The main risk factor for Acanthamoeba (KA) is the use of contact lenses while swimming or diving.…”