Surgical Advances Provide Options In Treating Common Eye Conditions
Small animal ophthalmology has seen both incremental and significant advances in awareness and treatment in recent years. But multiple areas remain in which enhanced treatment options would be welcomed by specialists, general practitioners and pet owners alike.
“If you look at diseases that affect the eye, I don’t think they’ve changed much over the years,” says David Wilkie, DVM, Dipl. ACVO, head of the comparative ophthalmology department at Ohio State University.
“Many of the conditions are seen in purebred dogs because they are inherited or breed-associated. So what drives trends in ophthalmology are the breeds that are popular at the time.”
One such breed-related condition is eyelid imperfections.
“As the trend in breeding brachycephalic pets becomes more popular, we see a huge trend in poor eyelid conformation,” says Teresa Tucci, DVM, Dipl. ACVO, of Veterinary Specialists Inc. in Homestead, Fla.
“Corneal neovascularization, pigmentation, ulceration and perforation can be incited by eyelid imperfections.”
Dr. Tucci notes that many conditions related to poor eyelid conformation can be corrected or prevented, particularly if detected and treated early.
Although occurrence of eye-related conditions in small animals remains fairly constant, the rate at which veterinarians see certain cases present in their clinics may be related to multiple factors.
“Over the years, I’ve noticed that we see more elective cataract surgeries when the economy is doing well and more eye perforations and infections when the economy is poor,” says Audrey Yu-Speight, DVM, Dipl. ACVO, of Veterinary Eye Centers in Round Rock, Texas.
Jeff Bowersox, DVM, Dipl. ACVO, of the Veterinary Specialty and Emergency Referral Center of Delaware in Wilmington, says that the most common problems he sees at his practice are cataracts, glaucoma and uveitis. His success in treating these conditions, he notes, depends largely on the general practitioners who refer patients to him.
“The frequency and timeliness of referral have improved over the years due to the advancements in technology for treatment of these conditions at the specialty level and the improved education at the level of the general practitioner to recognize ocular problems earlier in the course of disease,” he says.
“Many times these problems are related to systemic disease, so the ophthalmologist’s job is to help the general practitioner identify and treat not only the condition as it affects the eyes, but also the condition as it relates to the patient’s complete systemic health.”
Tucci agrees that timely referrals are key.
“Glaucoma in dogs, if caught early, can be treated with medical and surgical management,” she says. “Premature vision loss can be prevented by referring a patient with glaucoma early.
“In many cases, the owner may not even realize the pet has glaucoma,” she adds. “A history of the eye appearing red intermittently is a good indication the pet is having intraocular pressure elevations and should be referred immediately.”
Advancing Surgical Options
Multiple treatment advances are aiding veterinarians in managing common eye-related conditions.
“Over the last 10 years, the thrust of advances in small animal ophthalmology has been largely on the surgical side,” Dr. Wilkie says.
Dr. Bowersox says that recent advancements in the area of vitreoretinal surgery and retina reattachment surgery have increased the treatment options for patients that previously would be permanently blind.
“As the equipment and experience with these procedures improves, more pets will benefit from return of vision,” he says. “Also, newer generation foldable intraocular lens implants and intraocular viscoelastic materials have improved cataract surgery success.”
Because veterinary ophthalmologists use the same technology as human ophthalmologists for cataract removal, the field continues to benefits from improvements made in human ophthalmology, says Dr. Yu-Speight.
“The cataract technology is becoming more advanced to remove cataracts with less energy in the eye, using phacoemulsification tip motion and changes in how ultrasound energy is delivered,” she says.
Similar advances are being seen in the surgical treatment of glaucoma. One of the latest approaches to controlling intraocular pressure is a surgical procedure that employs an endolaser.
Dineli Bras, DVM, Dipl. ACVO, of MedVet Associates in Worthington, Ohio, says the technique provides direct visualization of the ciliary body, thereby reducing the potential for collateral tissue damage.
Use of an endolaser not only provides a better means for controlling intraocular pressure and preserving vision than traditional techniques, but it also seems to minimize post-operative inflammation and common complications, Dr. Bras says.
She adds that the procedure has also allowed her to reduce the use of topical and systemic medications in her patients following surgery.
“Another great advance that we have been able to offer to patients in the past year is removal of intraocular tumors arising from the ciliary body,” Bras says.
“With the endolaser, we have been able to laser the base of the tumor. If small, we have been able to remove it and obtain histopathology. If large, we have had a great success rate interrupting the vascular supply to the mass. A blanching effect is observed, and we have been able to halt the progression of the mass, preserving sight, preventing secondary glaucoma and obtaining histopathology.”
In addition to these advances in surgical techniques, Bowersox points out that veterinary ophthalmologists also have improved pharmaceutical and imaging options at their disposal.
“Newer generation pharmacologic medications, particularly anti-glaucoma and anti-inflammatory medications, have increased the treatment options for medical management of glaucoma and for chronic inflammatory or auto-immune conditions,” he says.
“Newer imaging techniques such as high frequency ultrasonography and increased availability of MRI facilities have provided increased understanding of certain ocular disease processes and allowed earlier intervention in orbital or anterior chamber disease conditions,” he adds.
Despite advances, many veterinary ophthalmologists say there are areas where they still lack sufficient treatments.
And in some cases, commercially available treatments are not as effective as customers might hope, says Amy Hunkeler, DVM, Dipl. ACVO, of the Hunkeler Animal Eye Clinic in Lee’s Summit, Mo.
“I have not been overwhelmed by the topical drops to dissolve cataracts,” she says. “Pet owners need to understand that cataract surgery is still going to be the best way to restore their pets’ vision.”
Yu-Speight says she feels that veterinarians’ skills at surgically treating certain types of retinal detachments are still lacking.
“In human ophthalmology, subspecialists in vitreoretinal surgery exist, but veterinary ophthalmologists still have only a small number of people with a lot of experience with this area,” she says. “I hope that we will continue to increase training, experience and knowledge of vitreoretinal surgery in veterinary ophthalmology.”
Bowersox notes multiple other areas in which he would like to see advances.
“Current treatment options and understanding of several conditions frustrate the veterinary ophthalmologist,” he says.
“Glaucoma continues to be a blinding, painful condition with very limited long-term management answers. Sudden acquired retinal degeneration is also a devastating condition that is poorly understood.”
Bowersox adds that idiopathic feline uveitis and chronic herpesvirus infections in cats also continue to be difficult to manage, and he says he would also like to see more advancement in the area of corneal transplant therapy.
Wilkie agrees that corneal transplants in veterinary medicine are challenging.
“I would like to see expansion in corneal transplants,” he says. “In human medicine, there is an endless supply of transplant corneas available. This is not the case in the veterinary world.
“Most shelters and pounds don’t want to be seen as organ procurement facilities, so without a national registry of available donors, it’s difficult to find a reliable supply.”