A cataract refers to an opacity within the lens due to altered cellular metabolism.  Cataracts can occur for multiple reasons including genetics, Diabetes mellitus, senility (old age), trauma, nutritional deficiency, electric shock, and more.  Very small cataracts are insignificant in animals and will not cause a noticeable problem.  However, as a cataract advances it has the potential to cause issues such as inflammation as the lens swells and the proteins leak into the eye (lens-induced uveitis), glaucoma (elevated eye pressure), retinal detachment, and blindness.  The only way to restore vision in an eye that has become blind due to cataract is surgical removal of the lens.  When evaluating the animal eye as a potential surgical candidate, the veterinary ophthalmologist will evaluate the status of the cataract and associated inflammation, the position of the lens, the status of the retina and cornea and the anatomy of the iridocorneal angle and vitreous.

Eyelid growths can be common especially in older dogs. Eyelid masses usually enlarge with time resulting in structural and functional changes to the eyelids and irritation to the ocular surface (cornea).  Most are benign, but in a small percentage of cases eyelid masses can be malignant and appropriate diagnosis can determine whether further systemic treatment is needed. Due to the potential for irritation, growth, and discomfort, surgical removal of eyelid masses is often indicated.  Small masses can sometimes be removed with local anesthetic, while large masses require general anesthesia.  After removal, eyelid masses should be submitted for biopsy in order to obtain a definitive diagnosis and to determine if additional therapy is necessary.

Corneal Endothelial Degeneration (CED) is a degenerative condition in dogs that affects the clarity of the cornea. This age-related disease can result in blindness and severe ocular pain from secondary complications.  The cornea is the clear window at the front of the eye. It is a very delicate structure which is less than a millimeter thick. Endothelial cells are located at the most inner layer of the cornea and contain tiny “pumps” that are responsible for maintaining a proper fluid balance in the corneal tissues. This function is critical to ensuring that the cornea remains transparent for vision.  Unfortunately treatment options for CED are limited, but identification and appropriate diagnosis early in the course of the disease, and early medical or surgical intervention can help your pet avoid ocular discomfort and slow, delay, or reverse vision loss. 

Corneal sequestrum typically appears as a tan to dark brown-black area of corneal discoloration due to corneal necrosis, and is frequently surrounded by inflammation and vascularization.  The sequestrum is frequently observed with refractory (chronic or slow-healing) corneal ulcers.  Contributing factors include breed predisposition (seen in Persian and Himalayan breeds more frequently), entropion (rolling in of the eyelid), and Feline Herpes Virus.  Cats with corneal sequestrum should be evaluated for management by a board certified veterinary ophthalmologist. Several factors, including your pet’s general health, determine the treatment options for this condition. Some sequestrums are managed with medical therapies, but if significant discomfort to the pet is noted, surgical options are usually indicated.

 A corneal ulcer is a wound on the surface of the eye. The damage would be similar to a scrape or cut on your skin resulting in an unprotected wound.  Squinting, winking, redness, watering, discharge, cloudiness or a change in appearance can indicate that an ulcer is present.  There are many causes of corneal ulcers. Damage to the cornea can occur due to external trauma, irritation from eyelashes or eyelid tumors, environmental irritants, abnormal eyelid anatomy or poor eyelid nerve function. Systemic disease and tear film abnormalities also can result in deterioration of the corneal health and integrity.  Treatment depends on the cause and severity of the ulcer and may include medical therapy alone or medication combined with surgery.

Distichiasis is a condition in which abnormal hairs emerge from the openings (ducts) of glands (Meibomian glands) along the eyelid margin. These glands do not normally produce hairs. The abnormal hairs can rub on the surface of the eye and may cause irritation or corneal ulceration. The severity of the problem and the need for treatment vary from patient to patient.  Although some patients live their entire lives without being bothered by their distichia, others require medical or surgical treatment to alleviate irritation caused by the hairs rubbing on the cornea.

Entropion is a condition that arises where the eyelid margins invert and hair or fur around the eyes contacts the corneal surface.  Entropion causes discomfort due to the hair and/or lashes rubbing on the cornea. Pain, corneal ulcerations, perforations, and scarring can occur. It can be caused by genetic predisposition (especially in certain breeds), ocular discomfort, intraocular inflammation, systemic dermatologic conditions, infectious eyelid and conjunctival diseases, and scarring of the eyelids due to trauma or injury.  Treatment often requires surgery to correct the eyelid position.  Evaluation with a board certified veterinary ophthalmologist can assure that correct surgical timing and technique are utilized to provide your pet with optimum comfort and corneal health.

Equine recurrent uveitis (ERU), also known as “moon blindness” is the leading cause of blindness in horses.  Equine Recurrent Uveitis is characterized by recurrent episodes of inflammation inside the eye, with periods of quiescence in between “flare- ups.” The frequency and severity of inflammatory episodes is variable between individual horses, but can become progressively worse and more frequent over time. Every episode of inflammation contributes to cumulative damage to the structures inside the eye responsible for vision, as well as cause discomfort for the horse. The cause of the inflammation is not always determined but should always be investigated.  Signs can be subtle and include tearing, squinting, ocular discharge, rubbing, redness of the whites of the eye, or cloudiness. Treatment depends on the cause, duration and severity of disease.  Medical therapy is aimed at quieting the immune response in the eye and addressing the underlying cause whenever possible. 

Feline herpesvirus (FHV-1) is a highly contagious virus and one of the major causes of upper respiratory infections in cats. One of the many potential long-term sequela of exposure to this virus is damage to the ocular tissues.  The feline herpesvirus can replicate within the conjunctival epithelia, upper respiratory tract epithelia, and neurosensory ganglia.  Neuronal infection with FHV-1 establishes lifelong latency with intermittent re-activation and viral shedding.  The primary source of kitten infection is from their mothers at birth or during the first few weeks of life, but it can also be easily spread between adult cats through sneezing, grooming or fighting. Active infection can cause sneezing, coughing, runny nose, squinting, eye swelling, tearing, discharge, or corneal ulceration.  Treatment is generally supportive since the viral infection is self-limiting, unless secondary complications have developed, such as secondary bacterial infection, sequestrum, keratoconjunctivitis sicca, or eosinophilic keratitis.

Geriatric patients can require special care, but some “normal” aging changes occur in older animals.  These changes may need to be differentiated from possible pathologic problems which may present in a similar manner.  The most common change noted in older animals is lenticular sclerosis, or hardening of the lens.  Often a hazy blue appearance to both eyes is noted and can appear similar to cataract, but lenticular sclerosis does not obstruct vision or cause any pain.  Another frequent aging change is thinning and atrophy of the muscle responsible for iris constriction (iris atrophy). These animals may be sensitive to bright light but can otherwise see normally.  Corneal degenerations can cause cloudiness and can sometimes be painful if associated corneal ulcerations or infections develop.  A veterinary ophthalmologist can differentiate between benign age-related conditions and those that require treatment.

Pigmentary Uveitis (PU), also known as Golden Retriever Pigmentary Uveitis (GRPU) or Pigmentary and Cystic Glaucoma (PCG) is a relatively common inherited disease of Golden Retrievers with severe, blinding and painful complications that may require surgery.  Subtle signs of early disease, including mild redness, make it difficult to detect a problem at home until the disease is more advanced.  There may be pigment dispersion inside the eye, uveal cysts, adhesions between the iris and lens, cloudiness, cataract, and eventually glaucoma.  The disease usually presents when the pet is between 5-10 years of age.  Treatment is challenging because the underlying cause is not well described, but topical anti-inflammatory therapy is the standard of care.  If glaucoma has developed, additional anti-glaucoma medications are indicated.  Unfortunately, about half of Golden Retrievers with GRPU develop blindness and glaucoma within about six to nine months following diagnosis.

Glaucoma is a painful disease in which the pressure inside the eye increases and causes damage to the structures responsible for vision.  Elevated intraocular pressure results in clinical signs such as a cloudy eye, redness, squinting, poor appetite, decreased energy, or sleeping more than usual.  The longer the pressure in the eye is elevated, the more damage occurs to the structures in the eye responsible for vision (especially the retina and optic nerve), eventually resulting in permanent blindness.  Glaucoma can be either primary (genetic) or secondary caused by chronic inflammation, lens luxation, trauma, and intraocular tumors, all of which obstruct normal drainage of fluid from the eye through the iridocorneal angle.  Treatment is aimed at maintaining the pressure in a comfortable range and limiting damage to the retina and optic nerve through medications, surgery, or both.  Prognosis of an eye with glaucoma depends on early detection and the patient’s response to therapy. 

Keratoconjunctivitis sicca (KCS) is a disease characterized by inflammation of the cornea and conjunctiva (pink tissue covering the whites of the eyes and the inside of the eyelids) secondary to inadequate tear production by the tear glands.  This leads to a build up of debris and bacteria that are normally washed away by the tears and a thick mucous discharge forms.  The disease is usually caused by inflammation of the lacrimal glands, but can also be caused by the toxic effect of certain drugs on the lacrimal glands or by lack of nerve innervation to the lacrimal glands.  Redness, squinting or blinking, and discharge are early signs of disease and indicate irritation and discomfort due to inadequate tears.  Treatment is aimed at promoting your pet’s tear production, reducing inflammation, and supplementing the inadequate tears through the use of topical eye drops and ointments.  

The crystalline lens is normally a clear rounded structure suspended in the middle of the eye with the purpose of focusing an image onto the retina in the back of the eye.  A luxation occurs when the fibers that hold the lens in place (called zonules) are weakened and break, and the lens subsequently shifts out of its normal position.  Causes can include severe trauma, weakness of  the zonules that is either inherited or secondary to chronic inflammation, or breakage due to stretching (usually because of glaucoma).  When the lens falls forward, it will cause significant discomfort and is an emergency.  When the lens falls backward, it is more benign and not uncomfortable for the animal.  Common sequelae of lens luxation are glaucoma and retinal detachment.  Treatment for lens luxation includes both medical and surgical options and depends upon chronicity, degree of pain, visual prognosis, and development of secondary complications. 

Pigmentary keratitis in the dog is due to pigment migration onto the cornea and is a frequent cause of blindness in the Pug, Shih Tzu and Pekingese breeds. The pigment is darkly colored, and as it progresses across the clear cornea it interferes with light entering the eye. Many owners are not aware of the problem until their pet becomes visually impaired.  The cause is multifactorial and can include corneal irritation from abnormally placed lashes, medial entropion (eyelids rolling inward), shallow orbits, incomplete blinking, excessive eyelid length, nasal fold trichiasis, and “dry eye” (KCS).  Treatment is directed at halting the progression of pigmentation through a combination of medical and surgical therapy, especially in advanced cases or younger dogs who are likely to become blinded by the disease in their lifetime.

Pannus is the common term for Chronic Superficial Keratitis (CSK) and/or plasma cell infiltrate of the third eyelids. Pannus is an immune-mediated, inherited problem most frequently identified in Shepherd breeds and Greyhounds.  However, other breeds and mixed breed dogs can also be affected. Pannus occurs when there is an immune response of the eye toward the clear cornea. It frequently starts as cloudiness, redness, and/or pigmentation at the ventrolateral (outer and lower) aspect of the eye and progresses across the cornea.  Treatment is aimed at reducing the inappropriate inflammatory response in the eyes using anti-inflammatory and immune-modulating medications.  There is no cure; treatment to control active disease must be continued for the life of the patient to minimize the blinding effects of corneal scarring.

Progressive Retinal Atrophy (PRA) is a degenerative disease of the retina that ultimately leads to loss of vision. The retina is the neurosensory structure in the back of the eye that transmits images to the brain. In one of the most common forms of PRA called prcd-PRA (progressive rod-cone degeneration), the rods degenerate first leading to a loss in night vision followed by the cones with a loss of day vision. PRA is an inherited disease observed in purebred dogs but may be seen in mixed breeds.  Generally, there is no treatment for PRA. However, veterinary ophthalmologists are conducting research to find treatments for this disease. Fortunately, the condition is not painful. Animals adapt well to vision loss especially with help from their owners. Training techniques have been described. A veterinary ophthalmologist can discuss how you can help your animal adjust and even thrive with blindness.

In animals, a gland located at the base of the third eyelid (nictitans) is responsible for making 33-66% of normal tears to keep the eye lubricated.  When the attachments holding the gland in place are loose or weak, it can prolapse from behind the third eyelid and appear as a red or pink mass. This prolapsed tear gland is commonly referred to as “cherry eye”.  The cause is most often genetic.  Removal of the gland is never recommended since dogs these individuals are predisposed to developing Keratoconjunctivitis Sicca (dry eye) later in life. To correct prolapse, surgical replacement of the gland is necessary.  Early replacement of the gland provides the best chance of normal tear gland function and anatomic appearance.

The retina is a very complex neurologic structure that normally lies flat against the back of the eye, collecting light impulses which are then transferred to the brain and interpreted as vision.  If the retinal cells detach from their normal position, they cease to function appropriately and the patient becomes blind.  Retinal detachment can be caused by severe trauma, tumors, fungal infections, inflammation, genetic predisposition, high blood pressure, complications from ocular surgery, or immune system dysfunction.  Early detection, diagnosis, and treatment of retinal detachment is extremely important for your pet’s general health and prognosis for retention or return of vision. Depending on what caused the detachment and how long the retina has been detached, in some cases the retinas can be reattached (medically or surgically) and vision restored.

Sudden Acquired Retinal Degeneration Syndrome (SARDS) is a poorly understood condition that affects the function of the retinal tissues of the eye. Clinical symptoms of this condition are characterized by acute (sudden) onset of blindness and dilation of the pupils. Many dogs concurrently show systemic and behavioral changes such as panting, increased appetite, increased thirst and urination, and sudden gain in weight.  The cause of SARDS is being investigated and is still unknown. Much clinical interest and research funding has been dedicated to finding answers about this condition.  Therapies that target these disease pathways have been proposed to reverse or prevent further vision loss in SARDS-affected dogs, but many of these treatments are controversial and no specific therapy has been documented as reliably successful.  Your veterinary ophthalmologist can discuss your pet’s specific situation with you and provide advice and tips on how to help adjust to the change in their lifestyle.

Uveitis is the term used for inflammation of the uveal tract of the eye (the iris, ciliary body, and choroid).  The uveal tract is the middle layer of the eye and is rich in blood vessels, which makes it very susceptible to diseases present in other parts of the body.  Animals with uveitis can show a number of different signs including squinting, watery discharge, light sensitivity, cloudiness or redness, or visual deficits.  Many different conditions can cause uveitis in animals.  In general, they can be categorized into four large groups: infection, neoplasia (cancer), trauma, and immune-mediated.  In all cases of uveitis, it is important to try to determine the underlying cause so that it may be appropriately treated.  Therapy is aimed at reducing the inflammation and targeting the underlying cause of illness.  Without treatment, uveitis can cause devastating complications, permanent damage inside the eye, persistent discomfort and irreversible blindness.