Common Ocular Conditions: Recognition and Management
What to know cold
Build a differential framework by compartment. Adnexal: entropion, ectropion, distichiasis, trichiasis, prolapsed gland of the third eyelid (cherry eye). Corneal: ulceration (superficial, deep, descemetocele, perforation), keratoconjunctivitis sicca, keratoconjunctivitis (feline herpes), corneal dystrophy vs degeneration. Intraocular: uveitis (anterior, lens-induced), cataract, glaucoma (primary vs secondary), lens luxation, retinal detachment, and sudden acquired retinal degeneration syndrome (SARDS).
Know hallmark signs: epiphora and blepharospasm with corneal disease; aqueous flare, miosis, hypotony, and ciliary flush with anterior uveitis; a fixed mid-dilated pupil and corneal edema with acute glaucoma; a hyperreflective tapetum and vascular attenuation with retinal degeneration. Know the Schirmer tear test, fluorescein staining, tonometry (normal IOP roughly 10–20 mmHg in dogs), and gonioscopy for glaucoma risk.
Traps
Distinguish uveitis from glaucoma: both can have a red eye and pain, but uveitis is typically hypotonus with miosis, glaucoma is hypertensive with mydriasis. Another trap: a deep corneal ulcer with a negative fluorescein result if the stroma is thin - always assess depth and consider a descemetocele. Do not overlook systemic causes of uveitis (infectious, neoplastic).
Rule of thumb
Red, painful eye: check IOP and stain the cornea first. Worked example: a dog with a cloudy cornea, episcleral injection, IOP 45 mmHg, and a mid-dilated pupil - treat as acute glaucoma (ocular hypotensive therapy, refer), not as uveitis.