SLT Effective for Narrow Angle Glaucoma?

Female (around 60y) recently diagnosed with Narrow Angle Glaucoma. Over the past two months, Timolol 2x/day and iridotomies in both eyes have lowered right eye IOP from mid-30s to 11-14 range, and left eye IOP from high 30s to 14-18 range. My ophthalmologist is now strongly suggesting that I have Selective Laser Trabeculoplasty (SLT) in my left eye only, and wants to do it soon, in about 3 weeks. I have found articles about SLT that indicate it is helpful for Open Angle Glaucoma. Does anyone with Narrow Angle Glaucoma have experience or information about the appropriateness / effectiveness of SLT that they can share? Thanks in advance.