Limbal Subconjunctival Abscess - A Rare Late Complication Of Acanthamoeba Keratitis

Published 2022 - 40th Congress of the ESCRS

Reference: PP17.09 | Type: Case report | DOI: 10.82333/ryc2-tz56

Authors: Daniel Sibley* ¹ , Laura de Benito-Llopis ²

¹Cornea and external eye diseases,Moorfields,NHS,United Kingdom, ²Cornea and external eye diseases,Moorfields,London,United Kingdom

Acanthamoeba keratitis (AK) is a rare form of infectious keratitis with variable prognosis even in those with early diagnosis and treatment. We report a previously undocumented complication - sub conjunctival limbal abscess, as a rare late complication and a treatment strategy

Moorfields Eye Hospital, London, UK

42-year-old contact lens wearer presented with pain, redness and photophobia in the right eye. Examination showed diffuse corneal epitheliopathy with mild anterior stromal haze. Confocal microscopy revealed cysts in the epithelium and anterior stroma. Initial treatment was hourly polyhexamethylene biguanide (PHMB) 0.06% and moxifloxacin 0.5% 4/day. Cultures and polymerase chain reaction (PCR) samples taken at presentation were both positive for Acanthamoeba.

Dexamethasone 0.1% was initiated after three weeks. They had a relapsing-remitting course. Despite continuous PHMB four months into treatment three raised limbal lesions developed associated with lid swelling. Repeat confocal microscopy showed cysts of various morphologies and an inflammatory response throughout the stroma. Aspiration was performed in clinic using an aseptic non touch technique with a 30G needle. The aspirate was culture and PCR positive for Acanthamoeba. Treatment was changed to chlorhexadine 0.2% hourly then tapering. A week later the limbal granulomas were diffuse and had resolved within two weeks.

The abscesses reoccurred with diffuse scleritis five months later. Repeat aspiration was performed and treatment changed to propamidine 0.1% 4/day, chlorhexadine 0.2% 6/day, topical voriconazole 1% 4/day and oral voriconazole 400mg 2/day for 1 day then 200mg twice a day for 1 month. The lesions resolved to leave sectorial scleromalacia. There have been no recurrences in 4 months.

AK is a rare condition that presents diagnostic and treatment conundrums. In this case we have shown a previously undocumented late complication of AK – subconjunctival abscesses. This differs from sclerokeratitis, a late complication associated with poor outcomes, requiring prolonged systemic immunosuppression. Previous case reports have demonstrated extra-ocular spread following immunosuppression leading to loss of the eye. This highlights the need to exclude an infectious cause prior to starting immunosuppression. The case we have described emphases this further and documents limbal abscesses as a manifestation of infectious scleritis. Changing to systemic anti-amoeba treatment and drainage of the lesions resulted in resolution.