Initial impressions with pattern laser indirect ophthalmoscope in first 10 patients

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Nassim Abreu, MD, reported the initial experience while applying panretinal photocoagulation (PRP) using the new LYNX pattern laser indirect ophthalmoscope (LIO) (Norlase). Abreu, who is an associate professor in the Retina Department of Elias Santana Hospital, Santo Domingo, Dominican Republic, described the technology and its performance at the Retina World Congress in Fort Lauderdale, FL.

The LYNX LIO is the latest generation of pattern scanning lasers that were first introduced in 2006. This LIO differs from conventional pattern lasers in that nothing is fixed, ie, the lens, eye, and laser beam have unrestricted movement, while the eyelids have slightly restricted movement. In conventional pattern lasers, the movements of the lids and laser beam are fixed, and the eyes and lens have minimal movement, according to Abreu, who is a speaker and consultant for Norlase.

Case study

The laser was put through its paces during a single-center, case series study that enrolled 10 patients, all of whom were to undergo PRP. All procedures were performed at the Elias Santana Hospital. The primary points of interest were the duration of the procedure, the spots delivered, and the laser parameters that were used, Abreu recounted.

Of the 10 patients, eight had proliferative diabetic retinopathy (PDR) and two had central retinal vein occlusion. The patients with diabetes underwent bilateral laser treatments during one session.

Results

Time: Abreu reported that the mean treatment time was 16 minutes, 43 seconds, with the mean time for each eye being 8 minutes, 6 seconds. Notably, one eye of a patient with PDR was treated in less than 7 minutes.

Spots: A mean of 3,489 spots was delivered per patients; the mean spots per eye were 1,710.

Laser parameters: The laser powers ranged from 200 to 400 mW; duration from 20 to 50 ms; intervals between patterns from 500 to 750 ms; grid sizes used 2 x 2, 3 x 3, and 4 x 4; and spot spacings from 1 to 2 disc diameters (DD).

Abreu related that in the patient undergoing treatment, a 2 x 2 grid was used and the spots were placed 1 DD apart. Because the surgeons were not satisfied with the PRP delivered during the first case, the parameters of the second case were modified to use of a 3 x 3 grid with spots placed at 2 DD apart. This resulted in “more organized PRP” with fewer overlapping spots.

Assessment of the first 10 cases showed that all patients were treated successfully with the LYNX LIO. The surgeons found that complete PRP was tolerated in all eyes, with only two patients describing uncomfortable pain. The mean time of treatment and the spots delivered to each eye agreed with previously reported data for pattern laser PRP. Finally, symmetrical patterns were observed more in association with the use of the 3x 3 grid with 2 DD spacing and shorter spot duration times, Abreu concluded.