I had a good experience with SLT, however, my father's first attempt with a local eye doctor produced no drop in eye pressure with SLT, but he had pain from the procedure. He then went to a glaucoma specialist who repeated the procedure because he was not contraindicated to have it. I was wondering, why the better result on second attempt? So, I started digging and found this article that is geared to doctors who treat glaucoma patients and perform SLT and it mentions that doctors sometimes target Schwalbe’s line or the ciliary body band while performing SLT instead of trabecular meshwork. I just thought I would share. Wondering how many people this error affects.
Source where I saw mention of this potential issue: https://www.reviewofophthalmology.com/article/treating-with-slt-first-the-pros-and-cons
Specific section from source:
**• Be certain you’re lasering the correct target. Dr. Asrani notes that this is a common surgical error. “Intra-operatively, it’s crucial to make sure you’re lasering the trabecular meshwork, not Schwalbe’s line, which sometimes is pigmented,” he says. “You also must avoid lasering the ciliary body band, which sometimes can be mistaken for the trabecular meshwork.
If the ciliary body band is lasered, the patient will get iritis and experience ciliary body spasm, with changes in refraction. The patient won’t get any treatment benefit and will have quite a few side effects. “This kind of surgeon error may be more common than we realize,” he continues. “This happens mainly to patients who have a very lightly pigmented trabecular meshwork. So, when doing this laser procedure you want to have good gonioscopy skills and be very conversant with the landmarks. Always be sure you’ve identified the correct target before you start the laser.
“Thankfully,” he adds, “if you laser Schwalbe’s line, which is pigmented, you won’t cause any side effects. But again, the treatment will be completely ineffective.”
• Change the angle of the mirror when lasering the nasal and temporal quadrants. “When you’re lasering the superior and inferior quadrants, the laser hits the trabecular meshwork end-on,” Dr. Asrani points out. “However, when lasering the nasal and temporal quadrants, you have to angle the mirror so the beam of the laser hits the trabecular meshwork perpendicularly, not at an angle. If it hits at an angle, you’re effectively only doing 180 degrees of SLT, not 360 degrees, because the lateral sides are barely skimmed with the laser. Moving the mirror and angling it is vitally important.” Dr. Asrani adds that this is why surgeons should take a course or work with an experienced surgeon before attempting SLT.**