Pattern Scan Laser System
The PASCAL Delivers Laser Treatments with Less Pain in Less Time.
LESLIE GOLDBERG, ASSISTANT EDITOR
OptiMedica Corporation (Santa Clara, Calif) has developed the pattern scan laser (PASCAL) for use in standard photocoagulation procedures. The laser's primary applications are panretinal photocoagulation for treatment of proliferative diabetic retinopathy (PRP) and macular grid treatment for diabetic macular edema.
The PASCAL photocoagulator is based on the use of a proprietary, semi-automated pattern generation method using short 532-nm laser pulses. These laser pulses are delivered in a rapid predetermined sequence resulting in improved precision, safety, patient comfort, and significant reduction in treatment time compared with conventional photocoagulation, according to David Mordaunt, CEO at OptiMedica.
"This laser allows you to preselect a pattern of grid laser for varying degrees of macular edema. It also allows application of a very uniform pattern of PRP treatment, says Harry W. Flynn, Jr., MD, professor of ophthalmology at the Bascom Palmer Eye Institute in Miami. Dr. Flynn also listed other potential advantages to the PASCAL laser for PRP:
► Multiple spot placement
► Short duration burns
► Improved efficiency
► Less pain
► Less patient fatigue
► Potential for one session to complete PRP
PATTERN SCANNING TECHNOLOGY
"The idea behind pattern scanning is that it allows the surgeon to deliver a more precise photocoagulation with more standardized energy in a quicker manner," says George Williams, MD, chairman, Department of Ophthalmology and director of the Beaumont Eye Institute at Beaumont Hospital in Royal Oak, Mich. "The net effect is that when performing a panretinal photocoagulation, each time the surgeon steps on the foot pedal, instead of delivering 1 spot he can deliver up to 25 spots. And each of those spots is going to be the same, so it allows for more precision in the actual distribution of the spots, the actual pattern."
The pattern array options include single spot, square arrays, octants, quadrants, macular grid, and arcs (Figure 1). As many as 25 spots may be delivered in 0.5 seconds. The PASCAL software allows surgeons to adjust the pattern as they see fit.
"For different sections of the eye, you may want a tighter or more dispersed pattern," explains Dr. Williams. "For example, one pattern presents a 5x5 array. Each of those spot distributions can be controlled by adjusting how close one spot is to another. They can be within a 1�4 spot of each other and up to 3 spot sizes apart. We can manually space our burns a certain distance apart."
|Figure 1. The PASCAL's touchscreen user interface.|
Dr. Williams explains that for a standard panretinal photocoagulation,
most surgeons deliver somewhere around 1000 spots per treatment. "With a conventional
laser, a surgeon would have to hit the foot pedal 1000 times. With this type of
technology, if you are using the 5x5 square array, you can get there with 40 hits,"
LESS PAIN EXPERIENCED BY PATIENTS
Dr. Williams says that because the burns are delivered in a shorter time duration, his practice's clinical experience to date is that patients find that this type of treatment is much more comfortable. "In addition to the time savings, each depression of the pedal is less uncomfortable," says Dr. Williams. "My personal experience is that patients are more likely to come back for additional treatments when they haven't had a painful experience with the first treatment."
PASCAL USE FOR MACULAR DISEASE
The PASCAL has features that allow placement of a very precise grid pattern for macular disease. Again, it is possible to adjust spacing as well as number of spots for macular treatment. "One of the nice features of PASCAL," says Dr. Williams, "is that the energy delivery is so quick that patients do not have the time to change their fixation. We are always worried that when we are photocoagulating the macula, the patient will change their fixation and get a foveal burn. With this type of technology, this becomes less likely."
Figure 2. The PASCAL delivers a pattern-generated laser burn [at top left], while the conventional laser burn [at bottom left] delivers a more random result.
CONVENTIONAL VS. PASCAL PHOTOCOAGULATION
Retinal disease is expected to grow by more than 70% by 2020 based on increasing life expectancies and the prevalence of diabetes, according to the Archives of Ophthalmology. There has been little change in photocoagulation delivery throughout the past 3 decades. While laser treatment is the standard of care, it is time consuming, reimbursement occurs only once per course of treatment (regardless of the number of sessions needed), and treatment is painful. "With the PASCAL method of photocoagulation," says Dr. Mordaunt, "less heat is transferred to the choroid, there is improved patient tolerance, and there may be potential clinical benefits due to less collateral damage, less inflammatory response, and preservation of retinal nerve fiber." (Figure 2)
FEATURES OF THE PASCAL
The PASCAL has an intuitive touchscreen interface, pattern scanner technology, an advanced-optics slit lamp, micromanipulator, and it is LIO compatible. It also has ergonomic features that benefit both the patient and the physician.
"The design of the laser table allows wheelchair access so that they can put their feet directly under the slit lamp," says Dr. Flynn.
For more information visit OptiMedica's Web site at www.optimedica.com. Dr. Flynn and Dr. Williams serve on OptiMedica's medical advisory board.