Use of an ophthalmic formulation of megestrol acetate for the treatment of eosinophilic keratitis in cats

Vet Ophthalmol. 2016 Jul;19 Suppl 1:86-90. doi: 10.1111/vop.12371. Epub 2016 Mar 3.


Objective: To evaluate a compounded ophthalmic formulation of 0.5% megestrol acetate to treat eosinophilic keratitis in cats.

Study design: Prospective study.

Animals studied: Seventeen client owned cats with eosinophilic keratitis in one or both eyes.

Methods: Eosinophilic keratitis was confirmed by cytology. At each visit, fluorescein staining and photography were performed. Cats were initially treated q 8-12 h with 0.5% megestrol acetate in an aqueous base. Serum glucose was measured at the first or second reexamination.

Results: Fifteen of 17 (88%) cats had a positive response to treatment, with 6 of 17 (35%) having complete resolution at the first reexamination (2-4 weeks). Two of 17 (12%) cats did not respond to treatment. Most cats required a treatment frequency of once daily to once weekly to maintain remission of disease. No ocular irritation or systemic side effects were noted in any cat.

Conclusions and clinical relevance: The use of an ophthalmic formulation of 0.5% megestrol acetate is a viable option for treating feline eosinophilic keratitis.

Keywords: cat; eosinophilic keratitis; feline; megestrol acetate; proliferative keratitis.

Publication types

  • Clinical Trial

MeSH terms

  • Administration, Ophthalmic
  • Animals
  • Cat Diseases / drug therapy*
  • Cat Diseases / pathology
  • Cats
  • Eosinophils
  • Female
  • Keratitis / drug therapy
  • Keratitis / pathology
  • Keratitis / veterinary*
  • Male
  • Megestrol Acetate / administration & dosage
  • Megestrol Acetate / adverse effects
  • Megestrol Acetate / therapeutic use*
  • Ophthalmic Solutions / adverse effects
  • Ophthalmic Solutions / therapeutic use*
  • Progestins / adverse effects
  • Progestins / therapeutic use*
  • Prospective Studies


  • Ophthalmic Solutions
  • Progestins
  • Megestrol Acetate