Autologous serum eye drops reduce ocular surface disease symptoms
Downsides include risk of bacterial infection and the need to refrigerate drops.
PHILADELPHIA — Eye drops made from blood serum improved symptoms of ocular surface disease and improved patients’ quality of life, according to a study presented here.
“Autologous serum eye drops are a good option for ocular surface disease,” Katie E. Schrack, MD, said at the Wills Eye Institute Alumni Conference.
“It is felt that autologous serum eye drops are beneficial because they contain diluted concentrations of vitamins and growth factors that are important for corneal epithelial health,” she said.
The first study on autologous serum eye drops for ocular surface burns was published in the 1970s. The drops were first used for ocular surface disease such as dry eye syndrome in the 1980s and gained somewhat wider acceptance in the 1990s, Schrack said.
“But [autologous serum eye drops] are still not widely used. Part of that could be because there is some international debate about standards regarding drop preparation and usage,” Schrack said.
The downsides of using the drops include not all patients being eligible for blood donation, the need to refrigerate drops and a risk of microbial contamination, she said.
Current indications for autologous serum eye drops include Sjögren’s syndrome, dry eye, some types of keratitis and other disorders, Schrack said.
Preparation and handling
Preparing autologous serum eye drops involves handling blood and blood products, which poses a risk of viral infection, Schrack said.
The patient’s blood is drawn and placed into a centrifuge for about 10 minutes to separate blood components. Blood serum is diluted into a bottle of preserved artificial tears. The patient receives a 3-month supply of drops and is instructed to store all of the bottles in the freezer except for the current bottle they are using, which should be stored in the refrigerator.
Many clinicians believe that autologous serum eye drops are inherently bacteriostatic, while others opt to include an antibiotic or some type of preservative to ensure safety, Schrack said.
Preferred serum concentrations range widely, from 20% to 100%, she said.
“Some studies have found that a 20% dilution of autologous serum is more similar to what you would find in the normal tear film surface,” she said. “It’s important because some of the growth factors such as TGF beta can have an impact on other growth factors if they are in high concentrations.”
Methods and findings
The study included 53 patients who received autologous serum eye drops and other treatments for ocular surface disease. A questionnaire was used to gauge patients’ satisfaction and functional status. The survey was loosely based on the Ocular Surface Disease Index. Scores were ranked on a scale of 1 (least satisfied) to 10 (most satisfied).
Investigators used Pearson Correlation Coefficients to compare rates of satisfaction and functional improvement for various treatments, which included autologous serum eye drops, topical cyclosporine, artificial tears, punctal cautery, lubricating ointments and flaxseed oil.
Results showed that of 39 patients with a mean follow-up of 3 months, 26 patients (67%) reported improvement in symptoms.
Autologous serum eye drops, topical cyclosporine and artificial tears yielded the greatest satisfaction scores. Ointments and flaxseed oil garnered the lowest scores, Schrack said.
Topical antibiotics and steroids were more effective than autologous serum for patients with significant lid margin disease.
Additionally, patients who ranked artificial tears highly were also more likely to rate topical cyclosporine highly, Schrack said.
Patients reported the greatest improvement in function from autologous serum eye drops compared with other treatments, Schrack said.
Christopher J. Rapuano, MD, chief of the cornea service at Wills Eye Institute, commented that the high rate of symptomatic improvement reported by the study authors is commendable.
“I believe there are several reasons this treatment is not used more frequently,” Rapuano said. “The most important is that the drops are difficult to obtain. The patient’s blood needs to be tested for infectious diseases such as hepatitis B and C and HIV for the safety of the technicians preparing the serum tears.
“Then several vials of the patient’s blood need to be drawn, the blood centrifuged, the serum selected and then placed into sterile containers (usually with artificial tears) at the appropriate concentration and shipped to the patient,” he continued. “The safest way to do all this is using a laminar hood.”
Rapuano said most compounding pharmacies are not willing to prepare autologous serum eye drops due to liability issues.
“Additionally, insurance coverage for the drops is poor,” he said.
Rapuano concluded that while autologous serum drops help many patients, they are not readily available. – by Matt Hasson