Panretinal photocoagulation (PRP) is a laser treatment for specific eye conditions. This procedure uses a laser to target the retina, aiming to prevent severe vision loss and preserve existing eyesight.
Understanding Panretinal Photocoagulation
Panretinal photocoagulation is a laser treatment that creates tiny burns on the peripheral areas of the retina. The retina is the light-sensitive tissue at the back of the eye that converts light into signals sent to the brain, enabling sight. These laser burns reduce the oxygen demand in the diseased portions of the retina.
PRP addresses retinal ischemia, a condition where parts of the retina do not receive enough oxygen. This lack of oxygen can trigger the growth of abnormal, fragile blood vessels, known as neovascularization. By treating the oxygen-starved peripheral retina, PRP reduces the production of growth factors that stimulate these abnormal vessels, causing existing ones to shrink and discouraging new ones from forming. This treatment aims to preserve central vision, which is responsible for sharp, detailed sight.
When Panretinal Photocoagulation Is Needed
PRP is recommended for conditions with abnormal blood vessel growth inside the eye that can lead to severe vision impairment. The most common indication for PRP is proliferative diabetic retinopathy (PDR), an advanced stage of diabetic eye disease. In PDR, damaged blood vessels in the retina close off, prompting the retina to grow new, abnormal vessels.
These new, fragile vessels are prone to leaking blood into the vitreous gel, called vitreous hemorrhage, which causes blurry vision or floaters. They can also pull on the retina, potentially leading to tractional retinal detachment, where the retina separates from its underlying support. PRP helps prevent these complications by causing the abnormal vessels to shrink and scar, reducing the risk of bleeding and detachment. Other conditions that may necessitate PRP include severe ischemic retinal vein occlusion or ocular ischemic syndrome, where reduced blood flow to the retina also leads to abnormal vessel growth and potential vision loss.
The Panretinal Photocoagulation Process
Before the PRP procedure, patients receive eye drops to dilate their pupils, allowing the ophthalmologist a better view of the retina. Anesthetic eye drops are also applied to numb the eye, minimizing discomfort. In some instances, an anesthetic injection behind the eye may be given for greater comfort.
During the procedure, the patient sits with their chin placed on a rest, similar to a standard eye exam. A special contact lens is placed on the eye to help focus the laser and keep the eye still. The laser delivers brief flashes of light to the peripheral retina, creating tiny burns. Patients may experience a mild to moderate aching or pinching sensation with each laser application, but the procedure is well-tolerated. The treatment is performed in an outpatient setting and may require multiple sessions, with each session lasting between 15 to 30 minutes, to apply 1,200 to 2,000 laser spots.
Immediately after the PRP procedure, patients can expect their vision to be temporarily blurred, and their eyes may be sensitive to light. It is advisable to arrange for someone to drive them home due to these temporary visual disturbances. Patients are encouraged to relax for the remainder of the day. Mild headaches are common and can be managed with over-the-counter pain relievers.
What to Expect After Panretinal Photocoagulation
Following panretinal photocoagulation, vision may remain blurry for several days, clearing within 24 to 48 hours. Some patients might experience a dull ache in the treated eye, light sensitivity, or notice new floaters. While these effects are common during the initial recovery, they subside. The primary aim of PRP is to prevent further severe vision loss, rather than to improve existing vision.
Patients should be aware that some long-term visual changes can occur. Peripheral (side) vision may be reduced, and there might be some impact on night vision or color perception. These changes are a consequence of the laser treatment to the peripheral retina, but they are considered an acceptable trade-off for preserving central vision and preventing serious complications like blindness. Ongoing monitoring by an ophthalmologist is necessary after PRP, as the underlying eye condition is not cured by the laser treatment. Some individuals may require additional laser applications or other interventions over time to maintain the stability of their eye health.