Phosphate and electrolyte content of topical steroid drops and potential clinical implications

Mukherjee, S. K.; O’Reilly, Denis St. J.; Cox, Alison; Ramaesh, Kanna

doi:10.1136/bjo.2007.114694

Cited by 2 publications

(1 citation statement)

References 10 publications

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“…The risk apparently increased when such drops are applied in the context of ocular surface disease. 25 We postulate that iatrogenic formation of crystals or crystal-like precipitates cause direct damage to cellular structures, causing corneal toxicity, potentiating epithelial defects. The cases reported in our study share a background of acanthamoeba keratitis, and the localisation of the crystals to the area of de-epithelialisation may reflect a required substrate within exposed stroma.…”

Section: Discussionmentioning

confidence: 99%

New insight into non-healing corneal ulcers: iatrogenic crystals

Livingstone

Stefanowicz

Connolly

et al. 2013

Eye

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Aims To characterise and correlate crystalline precipitations implicated in non-healing corneal ulceration in two patients with a previous history of acanthamoeba keratitis. Materials and methods Persistence of acanthamoeba and secondary bacterial infection was excluded with negative corneal scrapes. Confocal microscopy identified crystal-like deposits within the corneal stroma. To investigate possible precipitating combinations, all concurrent treatments at the time of presentation were mixed in wells, with observation of precipitate formation. Precipitates were observed with phasecontrast microscopy, and subsequently characterised via crystallography techniques and electrospray ionisation mass spectrometry. Results Combinations of dexamethasone 0.1% minims and chlorhexidine gluconate 0.2% formed an amorphous material characterised by electrospray ionisation mass spectrometry as an insoluble chlorhexidine salt. Combinations of chloramphenicol drops and timolol 0.5% formed a crystal identified via X-ray crystallography as santite (K(B 5 O 6 (OH) 4 ).(H 2 O) 2 ). This is a borate mineral identified in nature, arising from thermal springs, but never reported in biological tissues. Clinical improvement was observed following the cessation of the implicated precipitating combinations. Conclusion Our observations suggest iatrogenic precipitate formation, with a potential deleterious effect upon healing. The substrates for these precipitates include several frequently prescribed topical ophthalmic treatments. These findings shed new light on the aetiopathogenesis of nonhealing corneal ulceration, and have broad implications on topical prescribing for this challenging condition.

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Section: Discussionmentioning

confidence: 99%