Goldenfeld and colleagues have reported the first-in-humans use of an automated laser system to perform direct selective laser trabeculoplasty (DSLT). DSLR is a novel approach to SLT in which laser energy is applied directly to the perilimbal sclera externally, without a contact lens, to target the trabecular meshwork. Studies of manual DSLT have demonstrated comparable outcomes to conventional SLT. The proprietary system (BELKIN Laser Ltd) evaluated in the current study incorporates image processing software to identify and align the laser along the perilimbal sclera, as well as gaze tracking to maintain alignment and focus throughout the procedure. The device delivers 100-120 7-ns 400-micron pulses from a q-switched, 532-nm, frequency-doubled YAG laser with energy of 0.8-1.4 mJ estimated to equate to 0.3-0.5 mJ at the TM level. In the study, 15 eyes with ocular hypertension or open-angle glaucoma underwent the procedure and demonstrated mean IOP reductions at six months of ~19% at the lower energy level and 27% at the higher energy level, with a 75% reduction in the need for IOP-lowering medications. A prospective randomized trial comparing DSLT performed with this device to conventional SLT is underway (and by way of disclosure, I serve as that study's medical monitor).
By eliminating the need for gonioscopy skills and fully automating the procedure, DSLT could realistically be performed by non-physician providers
The obvious advantage of DSLT over conventional SLT is speed--obviating the need to position the patient, apply coupling agent, position a goniolens, align, focus, and rotate the lens throughout the procedure. In practice, however, conventional SLT is a quick and easy procedure and the economics of healthcare make it unclear if there will be perceived value in DSLT in the developed world, particularly if reimbursement for the procedure diminishes over time. In the developing world, however, DSLT has the potential to make a significant impact. By eliminating the need for gonioscopy skills and fully automating the procedure, DSLT could realistically be performed by non-physician providers - a critical attribute for any viable glaucoma procedure intended to address the burden of glaucoma in sub-Saharan Africa (SSA). Clearly, logistical and ethical considerations would have to be addressed in contemplating the performance of ocular laser procedures by non-physicians, but bending the glaucoma-related blindness curve in SSA will require outsidethe- box solutions. Validating this new technology is an important first step, after which the work of optimizing its utilization in developed and developing settings can begin.