Acanthamoeba keratitis challenges a case report

Abstract

Acanthamoeba keratitis is a rare, chronic, mainly contact lens-related infection caused by a free-living amoeba found ubiquitously in water and soil.
A case of a 9-year-old child, who presented to our clinic with painful, red left eye, associated with photophobia, and decreased visual acuity, wais reported. The clinical examination revealed a discoid opacity inferiorly bounded by a dense, gray infiltrate. The progressive nature of the corneal infiltrate, the epithelial defect, and the lack of response to treatment was highly suggestive for Acanthamoeba keratitis.
The distinctiveness of this case was the presence of Acanthamoeba keratitis in a child without a history of trauma or contact lens usage, the lack of an appropriate diagnosis and management of this vision-threatening infection.

Full text

40
Romanian Journal of Ophthalmology, Volume 60, Issue 1, January-March 2016. pp:40-42
CASE REPORT
Romanian Society of Ophthalmology
© 2016
Acanthamoeba keratitis challenges
a case report
Stan Cristina* **, Vlăduţiu Cristina* **, Popovici Mihaela* **
*Ophthalmology Clinic, County Clinical Emergency Hospital of Cluj-Napoca, Cluj, Romania
**”Iuliu Haţieganu” University of Medicine and Pharmacy, Cluj-Napoca, Cluj, Romania
Correspondence to: Stan Cristina, MD,
Ophthalmology Clinic, County Clinical Emergency Hospital of Cluj-Napoca
3-5 Clinicilor Street, zip code 400006, Cluj-Napoca, Cluj, Romania,
Mobile phone: +40 745 617 453, Fax: +40264 430 719, E-mail: cristtrif1959@yahoo.com
Accepted: January 25, 2016
Abstract
Acanthamoeba keratitis is a rare, chronic, mainly contact lens-related infection caused by
a free-living amoeba found ubiquitously in water and soil.
A case of a 9-year-old child, who presented to our clinic with painful, red left eye, associated
with photophobia, and decreased visual acuity, wais reported. The clinical examination
 

was highly suggestive for Acanthamoeba keratitis.
The distinctiveness of this case was the presence of Acanthamoeba keratitis in a child
without a history of trauma or contact lens usage, the lack of an appropriate diagnosis and
management of this vision-threatening infection.
Keywords:
Introduction
Acanthamoeba keratitis is a sight-
threatening infection caused by a free-living,
pathogenic amoeba. It causes a progressive
ulcerative keratitis, which is not replying to the
common antimicrobial therapy and is frequently
misdiagnosed for stromal herpes keratitis [1].
Acanthamoeba is naturally found in air, soil,
and water and is relatively resistant to normal
levels of chlorine in tap water [2]. It exists in two
forms: as an invasive, trophozoite stage and as a
latent, cystic stage [3].
The earliest evidence of acanthamoeba
infection is the diffuse, irregular edema, which
occurs at the epithelial level and may lead to a
dendritiform ulceration, which is often mistaken
for herpes simplex virus keratitis [1]. There
are certain clinical features that may prompt
   

be paracentral with clear central cornea in early
disease. Unbearable pain is pathognomonic and
       
untreated, the amoeba invades all layers of the
cornea, determining a ring abscess, which may
ultimately end with a corneal perforation [3].
Diagnosis is made upon the direct
visualization of the Acanthamoeba by confocal
microscopy. Cysts appear as round, double-
    
cysts could be visible with regular Giemsa,
Gram’s, ink-potassium hydroxide stains or the


41
Romanian Society of Ophthalmology
© 2016
Romanian Journal of Ophthalmology 2016;60(1): 40-42

Acanthamoeba can be grown on a bed of E. Coli
plated on a non-nutrient agar. Other investigations
include PCR or corneal biopsy [4].
The typical treatment consists of hourly,
around-the-clock, topical applications of

0.02% and chlorhexidine - CHX 0.02%), and

combination. Debridement of affected epithelium
may aid eye drop penetration. Antifungals such
 
Antibacterial treatment for co-infection may
be advised if the clinical picture encourages it.


has been attained. Penetrating Keratoplasty
       
poor visual acuity after scarring or imminent
perforation [5].
Case report
A 9 year-old child presented to our clinic
with painful, red left eye, photophobia, tearing
and decreased visual acuity. Three weeks prior
to the presentation to our clinic, the patient
began to develop cloudy vision, photophobia, and
increasingly exquisite pain in the left eye. The
symptoms worsened despite topical antibiotic

had been unsuccessfully treated with acyclovir,
ibuprofen, topical antibiotic, and mydriatic for
presumed herpes simplex virus keratitis. The
medical history highlighted a possible corneal
abrasion due to intense scratching and the use of
tap water to wash the eyes.
The best-corrected visual acuity was 5/ 5
in the right eye and hand-motion vision in the
left eye. A right eye slit lamp examination was
normal, while a left eye slit lamp examination
showed a marked ciliary injection and diffuse
corneal edema. The central part of the cornea was
involved with a discoid opacity bounded inferiorly
       
examination of the anterior chamber impossible.
There was an epithelial defect overlying that area
   

Fig. 1 Left eye ciliary injection, central discoid opacity
with epithelial defect
According to this picture, the treatment
with local mydriatics, corneal reepithelialization
     
The patient received various antimicrobial

    
ointment and systemic ceftriaxone, cefuroxime,
gentamicin, acyclovir. Intravenous dexamethasone
       

administered. A therapeutic bandage contact lens
was applied to relieve the pain but it was borne
away due to the distress and purulent secretion.
The patient received autologous platelet-rich
plasma eye drops along with standard medical
treatment. Direct bacteriological examination of
conjunctival secretion was negative for bacteria
or fungi.
Along hospitalization, the evolution was
     
a translucent crescent formed at the edge of the
    
The Acanthamoeba keratitis was highly suspected
due to the progressive nature of the corneal
       
response to treatment.
A confocal microscopy examination was
performed in the Ophthalmology Department of
University of Debrecen and revealed characteristic
cyst-like structures in and on the surface of the
    

Since the standard treatment is currently
unavailable in Romania, the parents transported

where she received the appropriate care.

42
Romanian Journal of Ophthalmology 2016;60(1): 40-42
Romanian Society of Ophthalmology
© 2016
Discussions
    
early stages and the diverse morphological
manifestations could often postpone
Acanthamoeba keratitis diagnosis. Due to deep
    
the infection is often confounded with herpes
simplex stromal keratitis [4]. The clinical aspect
of the ulceration and the progressive nature of
      
Acanthamoeba keratitis.
Intense ocular pain due to infection
    
Acanthamoeba keratitis [1]. Despite the anti-
     
therapeutic bandage contact lens and the sharp
ocular pain emphasizes this evidence.
In cases of keratitis in children,
acanthamoeba should be regarded even
without the history of contact lens usage [6].
Acanthamoeba infection was most probably the
consequence of the intense eye scratching during
a keratitis episode and the contamination from
tap water the parents reported.
This case was a true challenge for
several reasons. The management of keratitis
was particularly complicated by the poor
cooperation during the examinations and the
lack of information prior to the presentation.
Moreover, the lack of appropriate diagnosis tools
and medical therapy in Romania, led to a failure
regarding the diagnosis and management of this
sight threatening infection, resistant to most
ocular antibiotics.
References
1. Yanoff M, Duker JS. Cornea and Ocular Surface Diseases.

2. -
usual Case of Acanthamoeba polyphaga and Pseudo-
monas aeruginosa Keratitis in a Contact Lens Wearer
from Gauteng, South Africa. J Clin Microbiol. 2000 Feb;

3. -
tis. Albert & Jakobiec's Principles & Practice of Ophthal-

4. Krachmer J. Corneal infections, Cornea Fundamentals,
Diagnosis and Management, 2010, Elsevier, 1026-1027.
5. 

6. Demirci G, Ay GM, Karabas LV, Altintas O, Tamer GS,
       
without a history of contact lens usage. Cornea. 2006;
