Platelet-Rich Plasma (PRP) is a regenerative therapy that uses a patient’s own blood components to promote healing and tissue repair. This technique, which harnesses natural biological growth factors, is used across various medical disciplines, including orthopedics, dermatology, and dentistry. In ophthalmology, PRP is a specialized approach focused primarily on treating challenging conditions affecting the delicate surface of the eye, often when conventional therapies fail.
Defining Platelet-Rich Plasma
Platelet-Rich Plasma is an autologous blood product, meaning it is derived directly from the patient’s own blood and then concentrated. To create PRP, a small volume of blood (typically 20 to 60 milliliters) is drawn from the patient, similar to a standard blood test. This sample is then spun in a specialized machine called a centrifuge, which separates the blood into its distinct layers: red blood cells, plasma, and a layer rich in platelets.
The centrifugation process concentrates the platelets into a small volume of plasma, achieving a concentration 2.5 to 8 times higher than in whole blood. Platelets are essential for tissue repair because they store and release numerous growth factors upon activation. These factors include Platelet-Derived Growth Factor (PDGF), Transforming Growth Factor-beta (TGF-\(\beta\)), Epidermal Growth Factor (EGF), and Vascular Endothelial Growth Factor (VEGF). These proteins stimulate cell growth, encourage the migration of healing cells, and reduce inflammation at the application site.
Conditions Treated with PRP
PRP is used in ophthalmology primarily to treat chronic or severe disorders of the ocular surface that have not responded adequately to standard treatments. A common application is for severe dry eye disease, including cases resulting from post-LASIK complications or Ocular Graft-Versus-Host Disease (GVHD). The growth factors in the plasma improve the health of the tear film and the cells on the eye’s surface, reducing inflammation and discomfort.
PRP is also used to manage persistent epithelial defects and corneal ulcers, especially those that are slow to heal or refractory. The concentrated factors accelerate the proliferation and migration of corneal cells, which is necessary for repairing the clear front layer of the eye. PRP provides essential biological components, such as fibronectin, that are structurally similar to those naturally found in tears and tissue, promoting a robust healing environment. Its anti-inflammatory and analgesic properties offer relief while supporting the restoration of the corneal structure.
The Patient Treatment Experience
The most common method of delivering PRP in ophthalmology is through topical application, formulated as preservative-free eye drops. After the blood draw and preparation, the resulting PRP is divided into small, single-use dropper bottles or vials for the patient. This process ensures a sterile application and helps maintain the biological integrity of the product.
Patients typically use the eye drops four to six times daily over a treatment course lasting several weeks to a few months. Strict storage guidelines are necessary because the product lacks preservatives and is biological in nature, preventing degradation and bacterial growth. Unused portions of the PRP eye drops must be kept frozen, where they typically maintain a shelf life of up to three months.
A small supply of the drops is moved to the refrigerator for immediate use, where it can be stored for five to seven days before disposal. Patients must take precautions when transporting the drops, using a cooler or frozen gel packs to keep them cold, especially if away from home for more than an hour. While less common, PRP can also be prepared as a gel or clot for surgical application in complex corneal reconstruction cases.
Efficacy and Adverse Effects
The effectiveness of PRP eye drops stems from the high concentration of growth factors that directly support the regeneration of the ocular surface epithelium. Clinical studies show that treatment with PRP drops leads to significant improvements in symptoms for patients with severe ocular surface disease. For conditions like refractory corneal ulcers, patients often show clinical improvements in wound healing within a few weeks of starting therapy.
PRP has an excellent safety profile because it is an autologous product derived from the patient’s own body. This eliminates the risk of disease transmission or allergic reaction, which are concerns with non-autologous treatments. The most common adverse effects are minor and temporary, such as mild, transient irritation or redness immediately following application. A protein deposit may occasionally form on the eye surface, which is easily resolved by temporarily stopping the treatment.