Laser Induced Damage to Disposable Gonioscopy Lenses During Selective Laser Trabeculoplasty

The substitution of reusable gonioscopy lenses for disposable gonioscopy lenses during selective laser trabeculoplasty (SLT) has occurred over the last few years to mitigate infection risk. However, concerns have been raised regarding the potential of laser damage to the lens itself during SLT, which can lead to laser scattering, increasing the possibility of unintended adverse effects. We have noticed that over 90% of the disposable lenses used for SLT sustained some sort of laser-induced damage with routine laser energies (0.4-1.0 mJ). Comparisons of clinical efficacy of SLT, measured by reductions in intraocular pressure (IOP), between the use of reusable and disposable lenses has shown no difference in IOP reduction, with both groups achieving a 20% reduction in IOP over the course of 12 months. While no clinical difference in outcomes was observed, further investigation into this issue, most notably the possibility of adverse effects due to laser scattering, is warranted.