Ahmed glaucoma valve implantation with Ologen® Collagen Matrix for the surgical treatment of feline glaucoma

An Ahmed valve implantation with an Ologen® Collagen Matrix (Ologen® CM, Aeon Astron, Leiden, the Netherlands) was performed for the treatment of uncontrolled glaucoma in a cat. This cat was a 5‐year‐old castrated Russian Blue male with a 12‐week history of conjunctival hyperemia and mydriasis of the left eye. During the ophthalmic examination, the intraocular pressure (IOP) oculus sinister (OS) was 52 mmHg, and a narrow iridocorneal angle (ICA) was detected by gonioscopy. Medical treatment with Cosopt® (2% dorzolamide and 0.5% timolol) failed to decrease the IOP. The left eye still had vision, and an Ahmed valve implantation was performed. During the gonioimplantation, Ologen® CM was used to inhibit scar formation around the valve. Following the operation, the IOP was stable at an approximate average of 15 mmHg during the 7‐month follow‐up period, and vision in the left eye was retained without medication. An adequate subconjunctival filtering bleb was formed after 140 days. This is the first case report in which an Ahmed valve gonioimplant with an Ologen® CM has been used for the surgical treatment of glaucoma in a cat.