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Diabetic retinopathy and age-related macular degeneration are the two leading causes of blindness in the United States. If you suffer from one of these conditions, your doctor may suggest laser photocoagulation surgery, a procedure that cauterizes blood vessels in the eye for therapeutic benefits. Photocoagulation surgery is also used to treat retinal ischemia, neovascularization of the retina, retinal detachment and choroidal neovascuar membrane (CNVM).

One of the newest methods of photocoagulation surgery is the patterned scanning laser (PASCAL) method. PASCAL is a semi-automatic pattern scan laser photocoagulation system developed at Stanford University. It was approved by the U.S. Food and Drug Administration (FDA) in 2000 and has been used by ophthalmologists since 2008. Retinal surgeons consider PASCAL photocoagulator to be the most innovative advance in retina therapy since the 1970s. PASCAL uses quick laser pulses with the purpose of improving precision, safety and comfort in a shorter treatment time compared to single-spot photocoagulation.

How it Works

PASCAL looks similar to a slit lamp mounted on a moveable slit lamp table. Your doctor may administer a drop of topical anesthetic to numb your eye. Then, a lens will be placed over your eye, and your surgeon will begin the treatment. PASCAL uses lasers in single-spot or an array pattern of up to 50 spots per second. The pulses are delivered in a quick, predetermined sequence, and the entire treatment will only last a few minutes. PASCAL uses different laser patterns according the disease or condition it is treating:

  • Square arrays for diabetic retinopathy.
  • Arc patterns for detachments and lattice degeneration.
  • Macular grid and partial modified grid for retinal vein occlusion.
  • Single-spot for choroidal neovascular membrane

Benefits of PASCAL Laser

PASCAL uses the latest technology. The slit-lamp in the PASCAL is extremely precise and provides an accurate view of the central and peripheral retina. Its semi-automatic nature, mechanical joystick and LCD screen allow your doctor ultimate control in manipulating the laser patterns to fit the treatment area of your eye. PASCAL’s efficiency keeps treatment time at a minimum, rapidly delivering up to 50 laser spots per second. Instead of the procedure taking 25 to 30 minutes, which was typical in the past, you may be finished in only 5 to 6 minutes.


Often, one PASCAL laser treatment is sufficient to treat your condition. Almost all patients who undergo PASCAL photocoagulation experience less burn discomfort than in other laser procedures because it uses reduced heat. The shorter duration of the laser pulses also creates a different effect on the eye tissues. Burns are localized, do not spread and heal quicker over time.