Eyelid agenesis is a congenital disorder in which the eyelid doesn’t form properly during development within the womb. The cause of the condition is unknown, but it is speculated to be either genetic, viral or environmental. While rare, it is the most common congenital eyelid disorder found in cats. It may be partial (coloboma) or complete, it usually affects both eyes (bilateral), and one kitten or several within a litter may be born with the condition. Certain breeds such as Burmese and Persians are at greater risk of being born with this condition.
The function of the eyelid is to protect the eye from drying out and trauma. The lower portion of the eyelid has the eyelashes, which point away from the face, however with agenesis, due to the absence or of an eyelid margin, the remaining skin around the eye has fur, which can rub against the delicate cornea (trichiasis). Without the full eyelid, the eye is exposed to debris from the environment, rubbing, tears will not be able to properly spread across the eyeball, all of which leads to pain, discomfort, and damage.
The lateral (side) portion of the eyelid is most commonly affected, although the entire eyelid can be missing. The extent of the deformity can range from barely perceivable to a complete lack of upper eyelid.
Due to constant exposure common symptoms that commonly occur in cats with agenesis include:
Your veterinarian will perform a complete physical examination of your cat (or kitten) and obtain a medical history from you. Often it is easy for him to diagnose agenesis. He will need to carry out a complete and thorough ophthalmologic exam.
Corneal ulcers are common in cats with agenesis, large ulcers can be seen with the naked eye, however, your veterinarian may use a fluorescein stain, which is a harmless orange dye to see small ulcers. This is placed in the eye and will show up corneal erosion.
Treatment depends on the severity of the condition and may include:
Cryoepilation to freeze the hair follicles in mild cases.
Artificial tear ointment may be necessary to keep the eyes moist.
Reconstruction surgery. This involves removing a portion of skin from the lip and mouth area and creating a new upper eyelid margin. This procedure would be performed by a specialist veterinary ophthalmologist.
Antibiotics to treat corneal ulcers.
Removal of the eye may be necessary for some cats.
Do not breed with cats who have produced kittens with this condition.