Ophthalmology

//Ophthalmology
Ophthalmology 2017-09-25T15:36:05+00:00

Veterinary Ophthalmology

Veterinary Ophthalmology services treat complicated or difficult problems such as cataracts, corneal ulcers, Entropion, Glaucoma, prolapsed gland of the nictitans (cherry eye) and Uveitis.

While your general practitioner veterinarian can diagnose and treat many routine eye conditions, certain diseases and injuries require the care of a doctor who has had specialized, intensive training in veterinary ophthalmology in order to provide the very best outcome for your pet.

A veterinary ophthalmologist is a doctor who specializes in diseases that can affect your pet’s eye and vision. A veterinary ophthalmologist is also equipped to diagnose and treat diseases that affect the structures surrounding the eye, such as the eyelids, conjunctiva, and some of the bones of the skull that comprise the eye socket. A veterinary ophthalmologist will combine medical and surgical treatments in order to most effectively treat your pet’s eye problem. While your general practitioner veterinarian can diagnose and treat many routine eye conditions, certain diseases and injuries require the care of a doctor who has had specialized, intensive training in veterinary ophthalmology in order to provide the very best outcome for your pet. Pet eye diseases that you may be familiar with as a result of your own visits to a human ophthalmologist include cataracts, glaucoma, retinal detachments, and corneal ulcers.

Why Does My Pet Need A Veterinary Ophthalmologist? 

While your general practitioner veterinarian can handle many aspects of your pet’s care, just as in human medicine, sometimes there is a need for the attention of a specialist. If your pet has a complicated or difficult problem, your pet may need the care of a veterinary ophthalmologist. You can be assured that a veterinarian who knows when to refer you and your pet for more specialized diagnostic work or treatment is one that is caring and committed to ensuring your pet receives the highest standard of medical care for his or her problem. While in some cases, your veterinarian may be able to simply consult with a specialist about your pet’s care, in other cases it is necessary to actually refer you and your pet to the specialist for more advanced diagnostics and treatment, including surgery.

Your veterinary ophthalmologist will work together with your veterinarian as part of your pet’s total veterinary health care team. Your general practitioner veterinarian will still oversee all aspects of your pet’s care, but with the added, specialized input of a veterinary ophthalmologist. For example, if a veterinary ophthalmologist ultimately diagnoses diabetes in your pet as a result of an eye examination for cataracts, that information will be relayed back to your general practitioner veterinarian, who will treat your pet’s diabetes. The additional input of the veterinary ophthalmologist will be called upon as needed as your veterinarian manages your pet’s illness.

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The Orthopedic Foundation for Animals (OFA) and the Canine Eye Registration Foundation (CERF) are two organizations that breeders can register their dogs’ annual ophthalmic breeding exams. Owners and breeders can have a breeding eye exam perform by a boarded veterinary ophthalmologist (DACVO). These examination findings can then be presented to the one of these organizations and in turn a registration number will be issue for that dog. This number can then be used to show potential buyers, breeders and researchers that this dog was free of heritable ocular disease. This certification is good for one year and the information from these exams is compiled to give ophthalmologists, researchers and breed clubs statistical data on the prevalence of specific ocular disease in a breed. The purpose of the the breeding eye exam is to help breeders limit the number of dogs bred with heritable ocular conditions. The American College of Veterinary Ophthalmologists currently supports the OFA for breeding eye exams. For more information or to make an appointment for a breeding eye exam please contact Dr. Nunnery at Veterinary Referral Associates. For additional information about OFA see www.offa.org and about CERF www.vmdb.org.

An electroretinogram (ERG) is an electrical test of the retina. Similar to the recording of the electrical wave and rhythm of the heart or electrocardiogram (ECG), the response of the retinal photoreceptors to light also has an electrical wave that can be recorded. The ERG is a test of the ability of the retinal photoreceptors, the rods and cones, to respond to light. ERG’s are performed when an ophthalmologist cannot visualize the retina on examination due obstruction, like cataracts, or when the retina can be visualized but looks normal or abnormal. Patients that are having cataract surgery will have an ERG to test the function of the retina so that after surgery we a confident that the patient will be visual. Patients that have sudden blindness and no retinal examination abnormalities may have a condition call Sudden Acquired Retinal Degeneration Syndrome (SARDs) or may have central blindness from a dysfunction of the brain or optic nerve. The diagnosis of SARDs is based no response of the photoreceptors on ERG or a flat ERG. If a patient is blind and the ERG and ophthalmic exam are normal then central blindness is the likely diagnosis. These are the most common ways that ophthalmologists used ERG in practice. Conditions like early progressive retinal atrophy (PRA) and specialized ERG’s can also be performed. Patients having an ERG at Veterinary Referral Associates are awake for the procedure. For more information about the ERG testing and to make an appointment please contact Dr. Nunnery at Veterinary Referral Associates.

Eyelid surgery is used to correct abnormalities of the eyelid in dogs and cats. Eyelid abnormalities can occur for many reasons. The most common causes of eyelid abnormalities that need surgery include; entropion, ectropion, distichaisis, ectopic cilia, eyelid tumors, cherry eye, eyelid laceration, proptosis and eyelid agenesis. Many of these conditions if left untreated will cause discomfort due to corneal ulcerations. Eyelid surgery is best done by a veterinary ophthalmologist as this type of surgery is plastic surgery and takes years of training to master.

Corneal surgery is used to repair abnormalities of the surface of the eye. The cornea is the wind shield of the eye and is vital for vision to keep clear. The most common causes of the corneal abnormalities that require surgery include; corneal ulcerations, corneal perforation, corneal edema, corneal lacerations, corneal squestrum, corneal/limbal tumor and corneal dermoids. Surgeries to repair or correct these conditions are performed under an operating microscope and often require a covering or graft to help the wound heal. The most common graft is to use the patient’s own conjunctiva, the lining of the eyelids.

The fluid inside the eye is called the aqueous humor. The aqueous humor is produced and drains from the eye at approximately the same rate, resulting in a stable pressure inside the eye of 15 to 20 mmHg (millimeters of mercury). Glaucoma occurs as a consequence of a defect in the drainage angle resulting in inadequate outflow of aqueous humor and a subsequent buildup of pressure inside the eye. The resulting high pressure damages the optic nerve and results in blindness.

Gonioscopy is a technique used to evaluate the drainage angle. A goniolens (also known as a gonioscope) in conjunction with a slit lamp or operating microscope to gain a view of the drainage angle. The technique is essential to evaluate the non-glaucomatous eye for risk of a future attack of glaucoma.

Cataracts are a leading cause of visual impairment in dogs and frequently progress to cause total blindness. Vision of affected dogs can often be restored to a normal state by surgically removing the abnormal lens and substituting an artificial lens in its place.

A cataract is opacity or clouding of the lens within the eye. The lens’ function is to focus light rays on the retina, and cataracts decrease vision by interfering with light reaching the retina. Advanced cataracts are a leading cause of blindness in dogs and are generally recognizable by pet owners as a decrease in the dog’s vision or by a cloudy, whitish-blue appearance to the eye. Cataracts must be distinguished from a normal aging change in the lens termed “lenticular sclerosis,” which causes a bluish appearance to the eye but generally does not interfere with vision.

Currently, the only effective treatment for cataracts is through surgical removal of the defective lens. Lens removal is done under general anesthesia by making an incision in the eye and using special equipment to ultrasonically fragment and remove the diseased lens material. In most cases, an artificial intraocular lens is implanted to replace the diseased lens.

The fluid inside the eye is called the aqueous humor. The aqueous humor is produced and drains from the eye at approximately the same rate, resulting in a stable pressure inside the eye of 15 to 20 mmHg (millimeters of mercury). Glaucoma occurs as a consequence of a defect in the drainage angle resulting in inadequate outflow of aqueous humor and a subsequent buildup of pressure inside the eye. The resulting high pressure damages the optic nerve and results in blindness.

The Tono-Pen is a hand held instrument used to measure fluid pressure in the eye. By gently tapping on the cornea three measurements are taken. The unit then displays an average of the readings. The Tono-pen allows us to monitor the progression of glaucoma.