Retinal Detachment and Retinal Reattachment Surgery
The retina is a thin piece of nervous tissue lining the back of the eye. When comparing the eye to a camera, the retina is the film in the camera. Light enters the eye and is focused onto the retina, where specialized light gathering cells transform light energy into electrical energy. That electrical energy is then sent to the brain to be interpreted as vision. Retinal detachment is a condition where the retina separates from its normal position inside the back of the eye, causing damage and dysfunction of the light gathering cells with resulting vision loss. If the retina is left detached, permanent blindness results.
There are many potential causes for a retinal detachment in dogs including infection, inflammation, high blood pressure, congenital abnormalities, trauma, and cancer to name a few. If treated promptly, patients with a retinal detachment can regain vision when the retina reattaches. Depending on the cause of detachment, treatment can be primarily medical or surgical. Many times if the retina is detached but not torn, medical therapy can lead to reattachment of the retina without the need for surgery. When retinal tissue is torn (a rhegmatogenous retinal detachment) or is being “pulled on” by inflammatory membranes, (tractional retinal detachment) surgery is required to reattach the retina. The goal of surgery is to remove any source of traction, reattach the retina back to its normal anatomic position, and seal any holes or tears in the retinal tissue. In some cases, a laser can be used to create
what is called a barrier retinopexy, to prevent further retinal detachment in a visual eye with a partial retinal detachment. However, the ideal treatment is to address the underlying cause of the detachment and reattach any retinal tissue that is detached.
Retinal reattachment surgery is a complex, multistage procedure that in dogs almost always involves complete removal of the vitreous gel in the back of the eye (vitrectomy), using heavy fluids such as perfluorocarbon to “push” the retina back to its normal anatomic position, precise laser burns to “spot weld” the retina onto the back of the eye, and injection of silicone oil into the back of the eye to replace the vitreous and help hold the retina in place while it heals from surgery. Similar to cataract surgery, the procedure is performed under general anesthesia with the aid of a surgical microscope.
Successful surgery is measured in two ways. Anatomic success, or being able to successfully reattach the retina, is the primary goal of surgery. Factors that can influence anatomic success include retinal membrane formation, the degree of torn retinal tissue or size of retinal holes, decreased visibility from bleeding and scar tissue formation, concurrent inflammation, and congenital or acquired anatomic abnormalities. Anatomic success is achieved in 95-98% of dogs undergoing retinal reattachment surgery. The second type of success, and the type that is most important, is functional success. Namely, if the retina is reattached successfully, will it regain function and return vision to the patient. The most important factor that helps determine functional success is the duration the retina has been detached prior to surgery. Studies suggest that reattachment of the retina within 1 month of detachment give the best chance of functional success. Functional success ranges from 60-90%. The variability in success rates is based on several factors that vary from patient to patient. A thorough patient history and ophthalmic examination will help the surgeon determine the likelihood of functional success for a given patient.
What to expect during your visit to The Animal Eye Institute
The morning of surgery you will arrive with your pet at The Animal Eye Institute. A technician will perform several diagnostic tests to evaluate your pet’s tear production, intraocular pressure, and presence or absence of a corneal ulcer. Following these tests, your pet’s eyes will be dilated in prepartion for a complete ophthalmic examination. Dr. Spatola will perform a complete ophthalmic examination, including a detailed exam of the posterior segment and retina. An ocular ultrasound may also be performed to help better assess your pet’s candidacy for retinal reattachment surgery. Upon completion of the ophthalmic examination and any additional testing, Dr. Spatola will thoroughly discuss his findings with you, and determine your pet’s candidacy for retinal reattachment surgery. If your pet is a candidate for retinal reattachment surgery and you elect to pursue surgery, the procedure will be performed that morning.
Once your pet’s procedure is finished, they will recover in our hospital for the remainder of the day. It is important that we make sure your pet recovers safely from general anesthesia, and that their intraocular pressure is stable in the immediate hours after the procedure. Provided your pet recovers as expected, they will be discharged that evening. Your pet will be sent home with several drops to help decrease inflammation, prevent infection, and keep intraocular pressure from becoming high. Additionally, oral medications will be sent home to decrease inflammation, prevent infection, and reduce discomfort associated with the procedure. A recheck examination will be performed the following morning to assure your pet is healing as expected 24 hours after surgery, and that their intraocular pessure is within normal limits. The next recheck exam will be recommended for one week following the procedure. The one week recheck exam can be performed with your primary veterinary ophthalmologist, or with Dr. Spatola. If you elect to have the one week recheck exam with your primary veterinary ophthalmologist, Dr. Spatola will communicate with her/him as needed.
Recheck examinations are generally recommended at 1 week, 1 month, 2 months, and then every 4 months following surgery. However, recommendations for the frequency and timing of recheck examinations is dependent on how each patient is healing and whether or not complications are developing. Dr. Spatola will work closely with your primary veterinary ophthalmologist to assure the best postoperative care for your pet.
When will my pet see again?
This is a very common question following retinal reattachment surgery. The answer is variable and depends on multiple factors. In general, the time it takes for vision to return following surgery correlates with the duration that the retina has been detached prior to surgery. The longer the retina has been detached, the longer it can take for vision to return. It can take up to two months for vision to return in some patiens, however in those that regain vision (approximately 75% of patients) most have regained vision within one month following surgery. Vision will be assessed at each recheck examination.