In veterinary medicine we see many different eye conditions. Here is a list with a summary of what each one involves.
A scratch on the cornea is commonly referred to as a corneal ulcer. There are numerous causes from cat scratches, foreign items stuck under the third eyelid, to being hit or poked in the eye with an object. To determine if the cornea is scratched, we numb the eye with Proparacaine, then add fluorescein stain to the eye. A defect in the cornea will collect the stain and glow green making it easier to locate. A minor ulcer can be healed with antibiotic eye drops. More severe cases may need harvest serum which is derived from the patients own blood. The cells in the serum help to heal the cornea faster. A grid keratotomy, a procedure to remove inappropriately healing corneal tissue to allow it to heal properly, may also be needed. Ulcers tend to develop and worsen quickly and should be addressed promptly.
“Cherry Eye” is a term used for a prolapsed third eyelid or nictitating membrane. The third eyelid is located on the inner corner of each eye. It serves as an additional layer of protection and the accompanying gland provides about 50% of the eye’s lubrication. Mild cases are characterized by small, pink tissue that comes and goes occasionally while severe cases may cover a large portion of the eye consistently. Treatment usually requires surgical repair. If the gland is damaged beyond repair it will need to be removed, which can lead it a condition called “dry eye”.
Entropion & Ectropion
Entropion refers to a defect in the eyelid where it is turned inward, causing the hair and lashes to rub against the eyeball. Patients with this condition can often have non-healing corneal ulcers given the constant irritation. Ectropion is the opposite condition where the eyelid is turned outward causing a gap between the eyeball and eyelid. Patients can easily collect foreign objects in this gap or get the eyelid caught on things (barbwire, toenails, etc). Both conditions require surgical repair.
Keratoconjunctivitis sicca (KCS), commonly referred to as “Dry Eye”, is an inflammatory condition that causes inadequate tear production. Tears are important to lubricate the eyes and flush away debris. Some causes include immune diseases, canine distemper, hypothyroidism, or side effects of medications. Treatment includes lubricating the eyes and addressing the underlying cause. If left untreated the irritation can lead to painful, non-healing ulcers.
Nuclear sclerosis refers to the condition where the lens inside the eye hardens. The lens is supposed to be clear allowing light in. When hardened is become cloudy or opaque. The pet is not blind, but has slightly diminished site, especially in low light. There is no treatment or prevention for this condition.
A cataract is an opacity or imperfection of the lens that obscures vision. It can vary from a small portion to the entire lens. The condition can be hereditary or brought on by diseases such as diabetes or overexposure to UV light. Drops can be prescribed to delay progression and surgery can be done to replace the lens.
The eyeball is filled with fluid called aqueous humor. This nutrient and oxygen rich fluid supports the eye structures. The intra-ocular pressure (IOP) remains constant if the production and drainage are equal. If the drainage is inadequate, the excess fluid causes the IOP to increase, this condition is called Glaucoma. Inflammation, dislocation or damage of the lens, tumors, or intra-ocular bleeding can be causes. Increased pressure causes damage to the structures of the eye. Treatment of the underlying condition is key as well as pain control and medications that decrease fluid production and promote drainage. Severe cases may require the eye to be removed, also called enucleation.
If you pet is having eye issues, please call us at 444-5797 to schedule an appointment.