British Journal of Ophthalmology 1996;80:849-853 849 Br J Ophthalmol: first published as 10.1136/bjo.80.9.849 on 1 September 1996. Downloaded from LETTERS TO THE EDITOR

Acanthamoeba keratitis: first recorded Table 1 Drug sensitivity ofAcanthamoeba the clinical features in this case were not espe- case from a Palestinian patient with isolatefrom cornea cially reminiscent of those generally recorded trachoma for such an amoebal infection.9 Minimum amoebicidal Traumatic injury is likely to predispose the concentration (fuglml) Keratitis due to Acanthamoeba is a potentially then compromised cornea to Acanthamoeba infection. For the contact lens wearer, there is sight threatening condition if unrecognised, or Drug Trophozoites Cysts if inappropriate medical therapy is used.' The now irrefutable evidence to demonstrate that the protozoa are derived from contaminated infection is being recognised worldwide.'A It Chlorhexidine 1.6 1.6 is often associated in Europe and in the USA Polyhexamethylene tap water,'0 which is used as part of the clean- with contact lens wear; elsewhere, particularly biguanide 3.2 6.3 ing disinfection procedures for the lenses and in the tropics, it occurs most often in rural Alexidine 6.3 6.3 associated paraphernalia. communities and can be associated with Propamidine 6.3 25.0 The observations from this case indicate trauma and mud splashing.5 Pentamidine 12.5 50.0 that chronic trachomatous disease may also Hexamidine 6.3 25.0 compromise the corneal surface such as to We present here the first recorded isolation Neomycin 12.5 50.0 of Acanthamoeba in a Palestinian patient with facilitate invasion by Acanthamoeba, and that keratitis, not associated with either contact this should be considered where other predis- lens wear or the patient's recollection of not used initially because of local unavailabil- posing factors cannot be readily identified. trauma. The patient suffered from previous ity of the diamidine. Neomycin was likewise Further, the clinical appearance ofthe Acanth- trachoma (Fig 1). Herbert's pits were clearly unavailable as a single agent. The treatment amoeba infection, as in this case, may not be observable at the superior limbus, although brought about a rapid improvement in the typical. there was no evidence of trichiasis. appearance of the cornea. The patient was A PYOT discharged 4 days later, having been taught StJohn's Ophthalmic Hospital, CASE REPORT the procedure for self administration of the Jerusalem 97200, Israel A 65-year-old female UNRWA refugee pre- antiprotozoal chemotherapy. J HAY sented with a 2 day history of diminished The corneal samples were incubated in a D SEAL vision (counting fingers) in the right eye. The defined medium.8 After 1 week at 32°C there Tennent Institute of Ophthalmology, cornea was hazy and a small (2 mm) central was prolific growth ofAcanthamoeba. No bac- Western Infirmary, Glasgow GlI 6NT teria or were isolated. abscess was present. Fundal examination fungi Drug sensitivity Correspondence to: Dr J Hay. revealed an old central retinal vein occlusion. tests were performed6 (Table 1). Accepted for publication 6 May 1996 Initial treatment was topical cephalothin Two weeks later, the patient was readmitted with ocular There was marked corneal (10%) and topical gentamicin (1.5%) both 2 pain. 1 Kirkness CM, Hay J, Seal DV, Aitken D. hourly, and topical homatropine (2%). Local oedema secondary to rubeotic glaucoma, the Acanthamoeba keratitis. Ophthal Clin N Am microbiology laboratory investigations proved pressure being 55 mm Hg. Initially the 1994;7:605-16. pressure was reasonably well controlled with 2 Seal DV, Hay J, Kirkness CM. Acanthamoeba unhelpful. The condition improved and she keratitis and contact lens wear: the need for a was discharged after 4 days. oral acetazolamine (250 mg, four times daily) global strategy for prevention of corneal infec- On first review, 1 week later, there was a and topical Timolol (0.5%, twice daily). tion. Community Eye Health 1995;8:4-5. There was considerable fluctuation over the 3 Mohamed Kamel AG, Norazah A. First case of significant improvement. Treatment was Acanthamoeba keratitis in Malaysia. Trans Roy

following 5 weeks, however, and vision http://bjo.bmj.com/ changed to chloramphenicol (0.5%) ointment Soc Trop Med Hyg 1995;89:652. and topical Liquifilm three times daily. The dropped to no perception of light. Ultimately, 4 Hay J, Seal DV. Acanthamoeba keratitis, contact patient re-presented 6 weeks later with a 3 day pressure reduction and comfort were achieved lenses, and the potential health implications of through use of cyclotherapy. By this time, global marketing. Trans Roy Soc Trop Med Hyg history of severe pain; vision had decreased to 1996;90:33 1. light perception. There was an elevated Brolene had been received from Glasgow. At 5 Thomas PA. Acanthamoeba keratitis. Ind J Med central lesion with surrounding ring abscess. this point there was no perceptable progres- Microbiol 1995;13:51-3. sion of the ring abscess, but the rubeotic glau- 6 Hay J, Kirkness CM, Seal DV, Wright P. Drug The intraocular pressure was 35 mm Hg. A resistance and Acanthamoeba keratitis; the stromal biopsy was performed the following coma remained problematic. After 4 weeks the quest for alternative antiprotozoal chemo- day and the tissues forwarded to the Tennent discharge later, patient therapy. Eye 1994;8:555-63. on September 26, 2021 by guest. Protected copyright. Institute in Glasgow, for microbiological attended clinic intermittently. She was not 7 Seal D, Hay J, Kirkness C, Morrell A, Booth A, altogether compliant with the fairly demand- Tullo A, et al. Successful medical therapy of analysis. Acanthamoeba keratitis with topical chlorhexi- Meanwhile, with a high index of clinical ing schedule required for self administration dine and propamidine. Eye (in press). suspicion of Acanthamoeba infection of the of the chlorhexidine-Brolene therapy. The 8 Byers TJ, Akins RA, Maynard BJ, Lefken RA, cornea, novel therapy with chlorhexidine corneal infection, however, appeared to be Martin SM. Rapid growth of Acanthamoeba in well controlled using this combination. Two defined medium: association of encystment by (0.02%, 2 hourly) was instituted, in combina- glucose-acetate starvation. J Protozool 1980;27: tion with topical dexamethasone (0.1%, four months later, the patient re-presented with an 216-9. times daily), atropine (1%, twice daily), and area of central corneal staining and hypopyon. 9 Bacon AS, Dart JKG, Ficker LA, Matheson MM, A deep corneal scrape was performed but rig- Wright P. Acanthamoeba keratitis the value of topical Polycidin (polymyxin B, neomycin, early diagnosis. Ophthalmology 1993;100:1238- gramidicin). The combination of chlorhexi- orous microbiological examination failed to 43. dine digluconate and propamidine isethionate reveal any organisms, including Acan- 10 Ledee DR, Hay J, Byers TJ, Seal DV, Kirkness thamoeba. The patient was, however, treated CM. Acanthamoeba griffini. Molecular charac- (as Brolene), known to be effective against terization of a new corneal pathogen. Invest Acanthamoeba both in vitro and in vivo,6 7 was with topical chlorhexidine (0.02%, 2 hourly), Brolene (2 hourly), dexamethasone (0.1%, Ophthalmol Vis Sci 1996;37:544-50 four times daily), and chloramphenicol oint- ment (twice daily). Within 4 days, there was resolution and the patient was once again dis- charged. There has been no subsequent recur- Cytomegalovirus retinitis associated rence of the ocular disease. with long term oral corticosteroid use COMMENT EDrroR,-We examined a patient with a small Antibiotic therapy alone was unsuccessful for area of peripheral retinitis in her left eye. She treatment of the keratitis in this case, resolu- had been using oral corticosteroids continu- tion being accomplished only when a combi- ously for 17 years for asthma. Despite nation of a cationic antiseptic (chlorhexidine) treatment with intravenous acyclovir and laser and an aromatic diamidine (propamidine photocoagulation the lesion recurred and isethionate) was used. It was considered resembled cytomegalovirus (CMV) retinitis. Figure 1 Appearance of cornea 1 week after fortunate that corneal scrapings were for- CMV DNA was detected in the aqueous biopsy, showing Herbert's pits and warded to a centre with expertise in cultiva- humour using the polymerase chain reaction. Acanthamoeba keratitis. tion and identification ofAcanthamoeba, since She was HIV negative with normal T cell