Chronic irritation or inflammation in the canine’s eye causes melanin granule deposition into the corneal layer. Pigmentary keratitis also commonly referred to as melanosis may spread to throughout the entire cornea. The pigmentation spreading through the cornea and pupil hinders light entering the eye and can affect your dog’s vision even blindness. Brachycephalic breeds such as boxers, pugs and bulldogs are more prevalent for this condition due to facial characteristics. It is imperative to perform a thorough examination to evaluate what underlying problem is causing the pigmentary keratitis.
Surgical procedures can correct eyelid abnormalities such as entropion (inward) and ectropion (outward) or tumors. Abnormal blink reflexes and keratoconjunctivitis sicca (KCS) causing poor tear production/lubrication leads to chronic inflammation. Other causes like ulceration and glaucoma would be treated by alleviating infection and pressure respectively. Cyclosporin and tacrolimus have been shown to reverse or at least slow corneal pigmentation caused by pannus or KCS. This must be given indefinitely to help with inflammation and tear production. Pharmacy Solutions can make both compounded ophthalmic cyclosporin and tacrolimus to alleviate this condition.
The important distinction in pigmentary keratitis is causation because treating causation will alleviate the underlying issue.
Cyclosporin 1% or 2%- Instill 1-2 drop(s) into affected eye(s) every 12 hours
Tacrolimus 0.02% or 0.03%- Instill 1 drop into affected eye(s) every 12 hours
Caplan, C. Pigmentary keratitis: What you need to know. (2022) Veterinarians.org.
Available at: https://www.veterinarians.org/pigmentary-keratitis/ (Accessed: Oct 31, 2022).