NR 2/2012 ART. 41
With written permission by SAGE Publications LTD.
The oryginal version of this paper has been published in Journal of Feline Medicine and Surgery May 2011, 13 (5), 333-346 , doi 10.1016/j.jfms2011.03.010, URL http:/intl-jfm.sagepub.com
Answers, case notes 1:
1a). A mild mucopurulent ocular discharge is associated with superficial corneal neovascularisation extending towards multiple areas of discrete white proliferative lesions that appear to be raised from the ocular surface.
1b). The clinical appearance is characteristic of eosinophilic keratitis. Diagnosis can be confirmed by corneal cytology, which should show a mixed inflammatory response including eosinophils.
1c). Eosinophilic keratitis is usually responsive to topical corticosteroids. However, use of corticosteroids in FHV-1 infected cats carries a high risk (70%) of viral reactivation.2 Treatment options in this case include topical corticosteroids in combination with topical antivirals, or systemic megoestrol acetate.
Answers, case notes 2:
2a). Figure ii shows a mucoid ocular discharge with green staining due to application of topical fluorescein. The reflection from the tear film reflex on the ocular surface is disrupted and a faint brown discolouration to the cornea is evident. Figure iii reveals a relatively large but apparently superficial corneal ulcer surrounded by diffuse corneal oedema, consistent with epithelial under-running. The central part of the ulcer is faintly brown in colour.
2b). The brown discolouration of the corneal stroma is diagnostic of early corneal sequestrum formation. This is associated with an under-run superficial corneal ulcer. It is likely that recurrent or chronic corneal ulceration has predisposed to the formation of a corneal sequestrum.
2c). The presence of a corneal sequestrum means that the overlying corneal ulcer is unlikely to heal without surgical intervention. Surgical treatment would involve gentle debridement of the underrun epithelium followed by superficial keratectomy to remove the corneal sequestrum. This procedure should be performed under an operating microscope, and additional grafting procedures (eg conjunctival pedicle grafting) may be required following superficial keratectomy.
Although the cat has previously been tested negative for FHV-1, the ophthalmic history and the environmental association with a known FHV-1 carrier raise the suspicion that this cat is chronically infected with and maybe currently affected by FHV-1. Repeat PCR testing may be indicated, or a therapeutic trial with antiviral medications could be considered