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 Table of Contents  
Year : 2019  |  Volume : 9  |  Issue : 2  |  Page : 131-133

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

Department of Ophthalmology, Taipei Veterans General Hospital; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan

Date of Submission27-Nov-2017
Date of Acceptance25-Feb-2018
Date of Web Publication31-May-2019

Correspondence Address:
Dr. Chih-Chien Hsu
Department of Ophthalmology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shih-Pai Road, Taipei 112
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/tjo.tjo_114_17

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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.

Keywords: Acanthamoeba keratitis, coinfection, levofloxacin, orthokeratology, Pseudomonas

How to cite this article:
Hsu CC. Dendrite-like anterior stromal keratitis coinfected with Acanthamoeba and Pseudomonas in an orthokeratology contact lens wearer. Taiwan J Ophthalmol 2019;9:131-3

How to cite this URL:
Hsu CC. Dendrite-like anterior stromal keratitis coinfected with Acanthamoeba and Pseudomonas in an orthokeratology contact lens wearer. Taiwan J Ophthalmol [serial online] 2019 [cited 2021 Sep 21];9:131-3. Available from: https://www.e-tjo.org/text.asp?2019/9/2/131/232966

  Introduction Top

Acanthamoeba keratitis (AK) is a severe but unusual infectious disease of the cornea. The pathogen, Acanthamoeba, is a free-living cyst-forming protozoan that is distributed in diverse environments including air, soil, dust, and water. The active form of Acanthamoeba is trophozoite which has an amoeboid shape with pseudopodia, phagocytoses any encountered small sized particle and feeds on keratocytes in the cornea. The cystic form can survive in a difficult environment, and an effective treatment of AK needs cysticidal drugs.[1] Unlike AK, Pseudomonas aeruginosa keratitis usually progresses rapidly and presents with significant suppurative stromal infiltrate and mucopurulent exudate. It is thought that AK can develop in eyes with advanced bacterial keratitis. Coinfections with other microorganisms have been reported in patients with culture-proven AK.[2],[3],[4],[5] Herein, we report a case of dendrite-like anterior stromal keratitis coinfected with Acanthamoeba and P. aeruginosa, who was an orthokeratology contact lens wearer in Taiwan.

  Case Report Top

A 20-year-old male orthokeratology contact lens wearer presented complaining of eye pain and redness in the right eye for 2 days. The patient reported that he had worn orthokeratology contact lens continuously for 30 h. After he removed the contact lens, photophobia of the right eye was noted. He went to a clinic where topical 0.25% chloramphenicol eye drops and 0.5% erythromycin eye ointment were prescribed. He went to our clinics due to the symptoms progressed 1 day later. The slit-lamp examination showed a paracentral dendrite-like anterior stromal infiltration with feathery border. There is a partial epithelial defect at the central part of the lesion [Figure 1]. Besides AK, fungal keratitis was highly suspected and topical 0.5% levofloxacin and 1% voriconazole each hour were prescribed first. The culture of the scraped corneal tissue was positive for P. aeruginosa and Acanthamoeba 3 days and 6 days later, respectively. The lesion subsided in a week after adding topical chlorhexidine 0.02% each hour [Figure 2]. Except paracentral faint corneal scar, the patient had final best-corrected visual acuity 20/20 in both eyes in 1-month follow-up.
Figure 1: Dendrite-like anterior stromal infiltration with feathery border was found at the paracentral cornea. The black arrow indicated the site with epithelial defect

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Figure 2: The cornea became silent and fibrosis after 1-week treatment

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  Discussion Top

Biguanides (i.e., polyhexamethylene biguanide and chlorhexidine) and diamidines (i.e., propamidine and hexamidine) are currently available and most often used antiamoebic agents offering both trophozoicidal and cysticidal effects. Recently, an in vitro study shows that voriconazole, an antifungal agent, has good cysticidal effect against Acanthamoeba.[6] Another study even believes that topical voriconazole has better corneal and anterior chamber penetration and lower cellular toxicity on the cornea than topical chlorhexidine.[7] It may be the first drug of choice of atypical AK that presents like fungal keratitis when the culture result cannot be reached.

Endosymbiont bacteria has been known to exist in Acanthamoeba hosts and influence Acanthamoeba virulence, AK clinical features, and susceptibility to antiamoebic drugs.[2],[8] Iovieno et al. found Acanthamoeba hosting bacterial endosymbionts in half of AK patients. Half of AK patients with endosymbiont belonged to the genus Pseudomonas. Previously, it was assumed that P. aeruginosa and Acanthamoeba were mutually exclusive ocular pathogens.[9] However, in vitro studies have showed that Pseudomonas can increase the resistance of Acanthamoeba to contact lens disinfecting solutions and create a biofilm on contact lens surface enhancing Acanthamoeba retention.[10] The presence of the endosymbiont may modify Acanthamoeba phenotype making the protozoa more pathogenic or resistant to therapy.[11] Changes in gene expression and protein profiles have also been observed resulting from the amoeba/bacteria interaction in Hartmannella.[12] Nakagawa et al. found that the presence of bacteria is essential and a critical number of bacteria is required for the development of AK. The time of coexistence with bacteria may also be an important determinant of the severity of AK.[13] Besides, cases of contact lens-related microbial keratitis caused by P. aeruginosa which presented with perineural infiltrates, a typical characteristic of AK, were also reported.[14] It is thus reasonable to use topical levofloxacin in suspected AK patients before the acquirement of culture result. In our case, topical levofloxacin and voriconazole were chosen as the first line treatment. We added topical chlorhexidine after the culture results showed P. aeruginosa and Acanthamoeba. Ortillés et al. found that combined chlorhexidine, voriconazole, and ciprofloxacin showed the greatest amoebicidal activity in vitro although monotherapy may still have its effects.[15] The lesion in our case subsided in 1 week after the adding of topical chlorhexidine.

  Conclusion Top

Both P. aeruginosa and Acanthamoeba 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. Topical voriconazole should be considered as the first-line treatment for patients with AK suspected of fungal keratitis. The use of topical levofloxacin cannot only control Pseudomonas but also help to treat Acanthamoeba in such patients who are already under antiamoebic treatments.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.


The authors would like to thank Shih-I Li for supporting the laboratory diagnosis of Acanthamoeba keratitis.

Financial support and sponsorship


Conflicts of interest

The authors declare that there are no conflicts of interests of this paper.

  References Top

Illingworth CD, Cook SD. Acanthamoeba keratitis. Surv Ophthalmol 1998;42:493-508.  Back to cited text no. 1
Iovieno A, Ledee DR, Miller D, Alfonso EC. Detection of bacterial endosymbionts in clinical Acanthamoeba isolates. Ophthalmology 2010;117:445-52, 452.e1-3.  Back to cited text no. 2
Hong J, Ji J, Xu J, Cao W, Liu Z, Sun X, et al. An unusual case of Acanthamoeba polyphaga and Pseudomonas aeruginosa keratitis. Diagn Pathol 2014;9:105.  Back to cited text no. 3
Dini LA, Cockinos C, Frean JA, Niszl IA, Markus MB. Unusual case of Acanthamoeba polyphaga and Pseudomonas aeruginosa keratitis in a contact lens wearer from Gauteng, South Africa. J Clin Microbiol 2000;38:826-9.  Back to cited text no. 4
Sharma R, Jhanji V, Satpathy G, Sharma N, Khokhar S, Agarwal T, et al. Coinfection with Acanthamoeba and Pseudomonas in contact lens-associated keratitis. Optom Vis Sci 2013;90:e53-5.  Back to cited text no. 5
Iovieno A, Miller D, Ledee DR, Alfonso EC. Cysticidal activity of antifungals against different genotypes of Acanthamoeba. Antimicrob Agents Chemother 2014;58:5626-8.  Back to cited text no. 6
Martín-Navarro CM, López-Arencibia A, Arnalich-Montiel F, Valladares B, Piñero JE, Lorenzo-Morales J, et al. Evaluation of the in vitro activity of commercially available moxifloxacin and voriconazole eye-drops against clinical strains of Acanthamoeba. Graefes Arch Clin Exp Ophthalmol 2013;251:2111-7.  Back to cited text no. 7
Yu HS, Jeong HJ, Hong YC, Seol SY, Chung DI, Kong HH, et al. Natural occurrence of mycobacterium as an endosymbiont of Acanthamoeba isolated from a contact lens storage case. Korean J Parasitol 2007;45:11-8.  Back to cited text no. 8
Qureshi MN, Perez AA 2nd, Madayag RM, Bottone EJ. Inhibition of Acanthamoeba species by Pseudomonas aeruginosa: Rationale for their selective exclusion in corneal ulcers and contact lens care systems. J Clin Microbiol 1993;31:1908-10.  Back to cited text no. 9
Cengiz AM, Harmis N, Stapleton F. Co-incubation of Acanthamoeba castellanii with strains of Pseudomonas aeruginosa alters the survival of amoeba. Clin Exp Ophthalmol 2000;28:191-3.  Back to cited text no. 10
Fritsche TR, Sobek D, Gautom RK. Enhancement of in vitro cytopathogenicity by Acanthamoeba spp. Following acquisition of bacterial endosymbionts. FEMS Microbiol Lett 1998;166:231-6.  Back to cited text no. 11
abu Kwaik Y, Fields BS, Engleberg NC. Protein expression by the protozoan hartmannella vermiformis upon contact with its bacterial parasite Legionella pneumophila. Infect Immun 1994;62:1860-6.  Back to cited text no. 12
Nakagawa H, Hattori T, Koike N, Ehara T, Narimatsu A, Kumakura S, et al. Number of bacteria and time of coincubation with bacteria required for the development of Acanthamoeba keratitis. Cornea 2017;36:353-7.  Back to cited text no. 13
Robbie SJ, Vega FA, Tint NL, Hau S, Allan B. Perineural infiltrates in Pseudomonas keratitis. J Cataract Refract Surg 2013;39:1764-7.  Back to cited text no. 14
Ortillés Á, Belloc J, Rubio E, Fernández MT, Benito M, Cristóbal JÁ, et al. In vitro development of an effective treatment for Acanthamoeba keratitis. Int J Antimicrob Agents 2017;50:325-33.  Back to cited text no. 15


  [Figure 1], [Figure 2]

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