Acute transient corneal endothelial changes following selective laser trabeculoplasty

Abstract

Selective laser trabeculoplasty appears to cause transient corneal endothelial changes in most patients that have no impact on cell count or visual acuity. Further work is required to elucidate the mechanism of this phenomenon and any long-term impact.

Corneal changes after a single session of selective laser trabeculoplasty for open-angle glaucoma

“…The endothelial cell count measured at 1 h after SLT (2237 ± 211 cells/mm 2 ) and 6 weeks after SLT (2278 ± 242 cells/mm 2 ) were comparable and normal. 12 In our larger study, we used objective assessments, using specular microscopy, videokeratography, and kerato-refractometer to document corneal changes in the initial month following SLT. In the 111 eyes with OAG treated with a single session of SLT, we noted a transient but significant 5% apparent reduction in endothelial cell count from 2465.0 ± 334.0 cells/mm 2 at baseline to 2355 ± 387 cells/mm 2 at 1 week and increasing back to 2424.0 ± 379.4 cells/mm 2 at 1 month.…”

Polymegathism, Pleomorphism, and Endothelial Cell Count after Selective Laser Trabeculoplasty

“…In case of low-quality image series, automatic cell counting was considered unreliable, and counting was performed manually. The pleomorphism and polymegathism values were defined against normal values of 59.0 for pleomorphism and 30.0% for polymegathism, which means that a normal healthy cornea should have at least 60% endothelial cells with regular shape or hexagonality and should not have abnormal endothelial cell sizes or areas (normal 312-320 micron square) in more than 30% of cells [10].…”

“…It is important to note that patients with PXF were also enrolled in the present study. Wali U. and coauthors have revealed that corneal decompensation in PXF eyes can occur in presence of abnormalities in polymegathism and pleomorphism, even when the endothelial cell counts may be normal [10].…”

“…In our previous study we reported about early changes of the corneal endothelium cells in some patients aft er SLT [9]. At that time there were only few studies concerning endothelial cell count before and aft er SLT [10][11][12][13]. Th e results of these studies are controversial.…”

Mechanisms of selective laser trabeculoplasty: a review

“…19 Notably, subtle corneal endothelial changes have been observed following SLT as well. 59,60 Heat damage in particular has been implicated in endothelial membrane formation. In their study comparing ALT treatment to that with a Nd:YAG laser (1.1-4.8-mJ/pulse at 1064 nm with a 10-mm spot size), while noting severe focal destructions of the meshwork with shrinkage and scarring at laser spot sites in both treatments, Hollo et al observed scarring to be less extensive with neither endothelial membrane development nor any juxtacanalicular tissue damage in the latter.…”