Glaucoma Lasers

Diagnostic

• Confocal scanning laser ophthalmoscopy: optic nerve head evaluation
• Laser retinal doppler flowmetry

Therapeutic

Based on anatomical site

• Iris

  • Argon/YAG peripheral iridotomy: for angle closure or occludable angles and for prophylaxis in fellow eye of patient with PACG

    • Give pre-procedure 2% pilocarpine and 1% apraclonidine

    • Position PI in upper nasal iris to avoid diplopia and macular burn

    • Aim for iris crypts if possible

    • Should see a burst of iris pigment and AC deepening. Check patency with retroillumination +/- gonioscopy to confirm open angles

    • Complications

      • Corneal or lens damage
      • Iris bleeding/hyphaema
      • Iritis
      • Raised IOP
      • Malignant glaucoma
      • Monocular diplopia
      • Glare/haloes

  • Argon iridoplasty: for unresponsive PACG. Round burns are made to compact and contract the iris stroma to stretch the angle and relieve pupil block. Contraindicated in synechial and chronic angle closure

  • Argon pupilloplasty: same use as iridoplasty

• Angles

  • Argon trabeculoplasty: temporising measure or to supplement medical therapy. Best results in PXF and POAG. Effect wears off in PDS. contraindicated in complete angle closure, corneal oedema.

    • Aim for pigmented/non-pigmented TM junction

  • Selective laser trabeculoplasty: YAG laser. Similar efficacy to ALT but easier to perform. Aim for TM

  • Trabeculocoagulation: for neovascular glaucoma

• Ciliary body

  • Transcleral cyclophotocoagulation, transpupillary cyclophotocoagulation and endoscopic cyclophotocoagulation: diode laser for refractory glaucoma. Avoid 3 and 9 o’clock to spare ciliary bundles. 20-40 burns over 270 degrees about 1mm posterior to limbus
    • Complications: pain, hypotony, phthisis, inflammation/iritis, scleral thinning, hyphaema, sympathetic ophthalmia
    • Post op steroids and analgesia and check IOP at 3 weeks

• Sclera

  • Sclerostomy: for POAG but high incidence of failure
  • Laser suture lysis: post-trabeculectomy at 2-4 weeks

• Vitreous

  • Yag hyaloidotomy: for malignant glaucoma