This dog has an old problem (note healed third eyelid margin laceration), but has also become acutely painful OD in the past few days. Medications have not alleviated his clinical signs.
What is your diagnosis? What would you recommend?
He has a large descemetocele, the deepest variety of corneal ulcer. There is surrounding corneal edema and vascularization from the limbus indicating a degree of chronicity. The yellow-tan material visualized within the ventral anterior chamber is hypopyon and indicates severe reflex anterior uveitis.
Referral to a board certified veterinary ophthalmologist should be strongly encouraged for this unstable eye, which could rupture at any moment. Surgical intervention in the form of corneoconjunctival transposition or conjunctival grafting will almost certainly be recommended.