The retina is the delicate light-sensitive membrane that lines the inside of the eye. The vitreous is the clear gel that fills the inside of the eye. When we are young, the vitreous gel is attached to the retina throughout the back of the eye. As we age, the vitreous slowly liquefies and its attachment to the retina weakens. Eventually, the vitreous gel may collapse in on itself peeling away from the retina. This event is called a posterior vitreous detachment (PVD), and is often accompanied by flashes and floaters.
When a PVD occurs, the vitreous usually peels cleanly away from the retina without causing any harm. In a small percentage of patients, however, the vitreous gel may be unusually adherent to the retina or the retina may be unusually weak. In these patients, the vitreous may tug hard enough on the retina to cause a retinal tear. If untreated, a retinal tear may allow fluid to pass from the vitreous cavity into the space beneath the retina causing a retinal detachment. A retinal detachment can cause severe vision loss if not treated.
When a patient presenting with flashes or floaters is found to have a retinal tear on examination, treatment for the tear is almost always recommended. The most common treatment today is laser retinopexy. In this procedure, laser spots are applied in a confluent ring to surround the retinal tear. The laser acts like a spot-weld to “glue” the retina down to the back of the eye and reduce the chance of a retinal detachment occurring. Cryotherapy (freezing the tear) can also be used to spot-weld the retina around a tear but is usually reserved for cases where laser is difficult (i.e. vitreous hemorrhage or dense cataract). Both laser and cryotherapy can be performed in the office and are successful at preventing a retinal detachment in more than 97% of patients when applied early. Retinal tears that are found on routine examination and are not accompanied by flashes and floaters have a fairly low risk of causing a retinal detachment and may be observed in many cases.
Patients who go on to develop a retinal detachment will usually notice a shadow or curtain covering a portion of their vision. For these patients, several treatment options are available depending on the location and severity of the retinal detachment. In rare cases, a small peripheral retinal detachment may be observed or treated only with laser demarcation (placing a barricade of laser around the detachment) if the patient has no symptoms. In most cases, however, a surgical procedure is required to reattach the detached retina. Three such procedures are in common use: pneumatic retinopexy, scleral buckling and vitrectomy. Pneumatic retinopexy is an in-office procedure during which the eye is numbed and then a gas bubble in injected into the vitreous cavity. The patient is asked to position such that the bubble will float up against the retinal tear and hold it closed. If the bubble successfully closes the tear, the fluid under the retina will absorb allowing the retina to reattach. Cryotherapy or laser is also applied to create an adhesion that will keep the retina flat after the bubble disappears.
Scleral buckling is a procedure performed in the operating room during which a belt of silicone plastic is placed around the outside of the eye. The scleral buckle indents the eye underneath the retinal tear relieving traction and allowing the retina to reattach. Cryotherapy is also applied to create a permanent adhesion to keep the retina in place. Vitrectomy surgery is fast becoming the most popular treatment for many patients with retinal detachments. This operating room procedure involves making small incisions in the sclera (the white of the eye) to allow instruments access to the vitreous cavity. A vitrector is used to remove the vitreous gel and relieve any traction pulling on the retinal tear. The vitreous is replaced with a gas bubble, and laser or cryotherapy is applied to spot-weld the retina in place.
The Retina Care Center doctors have extensive experience treating patients with retinal tears and detachments. If you are noticing new flashes, floaters or any loss of your peripheral vision, please call us today to schedule an urgent evaluation.