Corneal endothelial abnormalities after selective laser trabeculoplasty (SLT).

PURPOSE: Whitish spots are sometimes observed in the corneal endothelium after selective laser trabeculoplasty (SLT). To evaluate the corneal endothelium after SLT, corneal specular microscopy was performed.

METHODS

A total of 142 eyes with open angle glaucoma that underwent SLT during the period of 9 months from February 10 to November 10, 2012, had their corneal endothelium examined with specular microscopy before and after SLT.

RESULTS

Dark spots were observed in the corneal endothelium on corneal specular microscopy immediately after SLT. Seventy-one of the 142 eyes had no significant dark spots or increase in dark spots after SLT. Thirty-seven of the 142 eyes showed few dark spots after SLT. Thirty-four of the 142 eyes showed numerous dark spots after SLT on specular microscopy imaging, which resolved by 1 month. The last group had the greatest decrease in the corneal endothelial cell count at 1 month after SLT, but this was not statistically significant in this study (P=0.1).

CONCLUSIONS

The corneal endothelial abnormalities after SLT shown in this study may be transient, and long-term effects are probably negligible in normal corneas or single treatments. However, in corneas with reduced transparency of the endothelium, such as compromised corneas and corneas with pigment deposits on the endothelium, there may be a risk of further corneal endothelial compromise, especially after repeated SLT. Larger and longer term studies with histopathologic evaluation would be useful to evaluate the effect of SLT on normal and subnormal corneal endothelium. Until further studies are done, it would be wise to minimize the number and energy of SLT laser shots.