This test is used to diagnose corneal ulcers, where epithelium is absent and the stroma is exposed. However, florescin will not stain ulcers that have re-epilethialised or Descemet’s membrane.
The tiger will need to be sedated unless it is a small cub. The florescin test strip should be wet with sterile water and touched onto the dorsal or ventral bulbar conjunctiva. The eye should then be irrigated with saline to flush excess florescin from the ocular surface. The eye should then be examined (preferably in a darkened room) using a blue UV light. Positive staining indicates a defect in the epithelium and, hence, an ulcer.