A 65-year-old man with primary open-angle glaucoma (POAG) undergoes selective laser trabeculoplasty (SLT). Which cellular mechanism underpins SLT's IOP-lowering effect?
- A Thermal coagulation of trabecular endothelial cells increasing outflow facility
- B Selective photothermolysis of pigmented trabecular cells with macrophage recruitment and cytokine-mediated remodelling ✓
- C Creation of a bleb between sclera and conjunctiva to bypass trabecular resistance
- D Photocoagulation of ciliary processes reducing aqueous production
Correct answer: B. Selective photothermolysis of pigmented trabecular cells with macrophage recruitment and cytokine-mediated remodelling
Explanation
SLT uses a 532-nm Q-switched Nd:YAG laser that selectively targets pigmented trabecular meshwork cells (melanin-containing cells) through selective photothermolysis, sparing surrounding non-pigmented cells and the trabecular architecture. This leads to recruitment of macrophages and cytokine release that remodel the extracellular matrix of the TM, restoring outflow. Unlike ALT (argon laser trabeculoplasty), SLT causes no coagulative tissue damage and can be repeated.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.