Ultrastructural Changes in Human Trabecular Meshwork Tissue after Laser Trabeculoplasty.

Area of Science:

• Ophthalmology
• Cell Biology
• Biomaterials Science

Background:

• Trabecular meshwork (TM) is crucial for aqueous humor outflow and intraocular pressure (IOP) regulation.
• Laser trabeculoplasty, including selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT), are common glaucoma treatments.
• Understanding the morphologic effects of different laser treatments on the TM is essential for optimizing IOP-lowering strategies.

Purpose of the Study:

• To compare the morphologic changes in human trabecular meshwork (TM) following selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT).
• To evaluate the impact of varying laser powers on TM tissue structure after SLT and ALT.

Main Methods:

• Ex vivo human corneoscleral rims were treated with SLT or ALT at varying powers.
• Specimens were analyzed using light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Main Results:

• SLT induced TM cell disruption with cracked pigment granules at all powers.
• High-power SLT revealed tissue destruction and scrolling of trabecular beams.
• ALT demonstrated increasing TM tissue damage with higher energy levels, affecting superficial and deeper tissues.

Conclusions:

• SLT causes TM cell disruption and pigment alteration, with more pronounced effects at higher powers.
• ALT induces significant, dose-dependent damage to TM tissues.
• Further research is needed to optimize laser treatment parameters for maximal IOP reduction and minimal tissue damage.