The use of a pattern-scan laser system (Pascal Photocoagulator, OptiMedica Corp.) to treat diabetic retinopathy and other retinal disorders is showing substantial advantages over conventional single-burn techniques, according to a growing body of clinical experience. Early adopters say key attributes include better targeting of photocoagulation burns to fit specific retinal conditions, less patient discomfort due to lower applied laser power, and improved overall clinical efficiency because the number and duration of treatments are sharply reduced.
The original study of 10 eyes comparing panretinal photocoagulation with pattern scan with conventional panretinal photocoagulation in patients with proliferative diabetic retinopathy and diabetic macular edema was performed at the clinical practice of Hugo Quiroz-Mercado, MD, in Mexico City. Results showed increased uniformity and precision of spot placement, substantially reduced treatment time, and considerably improved patient tolerance in the treatment of proliferative diabetic retinopathy. A five-center U.S. study coordinated by OptiMedica Corp. (whose pattern-scan photocoagulator received FDA approval in 2005), now has amassed data on the treatment of more than 1,200 patients with a variety of retinal pathologies, and investigators say the results are encouraging.
More than 25 Pascal systems have been placed in mid-to high-volume practices in the United States, and international shipments are under way, an OptiMedica spokeswoman said.
"For all of the patients who would have needed multiple sessions for panretinal photocoagulation, treatments were completed in one session," Dr. Lehr said. "This has allowed more open slots in our clinic for other patients and new patients with diabetes."
Dr. Lehr said that the system's pre-programmed patterns were slashing panretinal photocoagulation treatment time.
"If a 500-single-spot session on average took 5 to 10 minutes (on a good day), with the Pascal system's 25-spot array the same 500 spots can be accomplished in about 45 seconds," Dr. Lehr added.
A complete panretinal photocoagulation delivering 1,500 spots takes 10 minutes, including lens change, he said, adding that he detected no difference in therapeutic results compared with single-shot therapy.
"What a relief for the patient," Dr. Lehr continued. "Less time and less anxiety-and with the delivery pattern and laser duration interval, less power and less discomfort. It's a true win-win for the patient and doctor."
Investigators are also testing the system for proliferative diabetic retinopathy with vitreous hemorrhage, diabetic macular edema, branch retinal vein occlusion with macular edema, sickle-cell retinopathy, Coats' disease, acute retinal tears, and postoperative tears on scleral buckles. The system can deliver a single-spot burn or a predetermined matrix array of up to 56 spots, employing a semi-automated, pattern-generation method with short 532-nm laser pulses. The pulses are delivered in a rapid, predetermined sequence.
Christine R. Gonzales, MD, of the Jules Stein Eye Institute, University of California, Los Angeles, a five-center study participant, said the pattern-scan laser has three key attributes compared with conventional panretinal photocoagulation: