What are distichia in the context of veterinary ophthalmology?

Distichia refers to a condition in which there are abnormal or additional eyelashes that grow from the Meibomian gland openings in the eyelid margin. This condition can lead to discomfort, irritation, and potentially corneal damage as these abnormal cilia may touch the globe of the eye, creating persistent irritation. The Meibomian glands, which are located within the eyelids, are responsible for producing the oily component of the tear film, but when eyelashes grow from these glands, they can cause significant ocular issues.

The other options describe different conditions that do not pertain to distichia. Abnormal blood vessels in the eye refer to conditions like conjunctival or corneal neovascularization, excessive tear production pertains to conditions like epiphora, and growth of conjunctival tissue could indicate a conjunctival hyperplasia or a similar condition. These descriptions do not accurately represent the characteristics or implications of distichia within veterinary ophthalmology.