Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
LASER THERAPY IN GLAUCOMA Sun Xiao Dong Laser Procedures Laser trabeculoplasty(LTP) Laser peripheral iridotomy(LPI) Cyclophotocoagulation(CPC) Other uses Laser Trabeculoplasty(LTP) Apply multiple laser burns to the trabecular meshwork to improve aqueous outflow Lasers Argon(ALT) Nd:YAG(SLT) Indications for LTP Supplement to maximum tolerated medical therapy Poor compliance Initial therapy(GLT) Laser Trabeculoplasty(LTP) Contraindications: 1.Corneal edema 2.Complete angle closure glaucoma 3.Age﹤35 years 4.Some secondary open angle glaucomas(eg uveitic glaucoma,angle recession glaucoma) Relative contraindication ALT Preoperative treatment: 1 drop of lopidine 1hour before treatment Postoperative treatment: 1.1 drop of lopidine immediately after treatment 2.Iop check 1-3 hours after treatment and first postlaser day 3. Pres Forte 1% qid for 4 days 4.Evaluate effect in 4-6 weeks ALT Laser technique: 1.Goldmann 3-mirror or 1-mirror lens 2.Argon laser settings: 300-1200mW(average 800mW) 50 μm 0.1sec 3.50 burns over 180°or100 burns over 360°applied to junction of pigmented and nonpigmented TM ALT Complications: 1. Elevation of IOP 2. Progression of visual field 3. Iritis 4. Peripheral anterior synechiae 5. Corneal epithelial and endothelial damage ALT 1.Short-term results initial success: Reduction in IOP: 2.Long-term results Attrition rate: 5 year succes rate: 65-95% 20-30% 5-10% per year 50% ALT Factors influencing response: 1.Pre-treatment IOP 2.Aphakia/pseudophakia 3.Age 4.Race 5.Type of glaucoma Laser Trabeculoplasty Pathophysiology: 1. Shrinkage of collagen in TM which pulls open the intertrabecular spaces between treatment sites(Wise &Witter) 2. Stimulates trabecular endothelial cells to divide and migrate(Acott) 3. Stimulates trabecular endothelial cells to produce an altered extracellular matrix that is less outflow-obstructing(VanBuskirk) SLT Author/Year Eyes Response Rate IOP Decrease Latina,1998 53 70% 23.5% Lanzetta, 1999 8 Gracner, 2001 Melamed, 2003 Cvenkel,2004 50 88% 21.6% 45 96% 30% 44 62% 17.1% 39.5% ALT vs SLT Author/Year Damji,1999 Eyes 18 ALT 18 SLT Popiela,2000 27 ALT 27 SLT Martinez-de-la- 20 ALT casa,2004 20 SLT IOP Decrease 22% 21% 13.0% 13.4% 19.5% 22.2% Laser Peripheral Iridotomy(LPI) Create a hole in the iris to relieve pupillary block Lasers Argon Nd:YAG Pupillary Block LPI Indications: 1. Acute ACG 2. Chronic ACG 3. Aphakic/pseudophakic pupillary block 4. Partial thickness surgical iridectomy 5. Before laser trabeculoplasty in eyes with narrow angles 6. Pigment dispersion syndrome/pigmentary glaucoma LPI Indications: Prophylactic laser iridotomy 1.Acute ACG in other eye 2.Symptoms of subacute ACG 3.Appositional closure 4.PAS 5.↑IOP and closure of angle with dilation 6.Inability to be evaluated promptly 7.Patient anxiety regarding risk of ACG LPI Contraindications: 1.Significant corneal edema 2.Flat AC 3.Completely closed angle 4.Angle closure glaucoma not caused by pupillary block LPI Preoperative treatment: 1 drop of lopidine and pilocarpine 1 hour before treatment Postoperative treatment: 1. 1 drop of lopidine immediately after treatment 2. IOP check 1-2 hours after treatment 3. Pred Forte 1% qid for 1 week LPI Laser technique: 1.Abraham or Wise lens 2.Laser settings: Argon: 700-1500mW 50μm 0.02-0.1 sec Nd:YAG: 3-7mJ 1-3shots/pulse LPI Laser technique: 1.Select site at 12:00 in base of a peripheral iris crypt 2.Endpoint: Pigment epithelium storm Lens capsule visualized Clear iris transillumination LPI Complications: Hyphema Iritis Increased IOP Corneal epithelial and endothelial burns Lens opacities Pupillary distortion Monocular diplopia and glare Closure of iridotomy Cyclophotocoagulation(CPC) Destroy cilary body to reduce the rate of aqueous production Lasers Diode Nd:YAG CPC Indications: 1.Pain caused by high IOP in eye with little or no visual potential 2.Unable to undergo filtering surgery for medical reasons 3.Failed piror filtering surgery and/or at high risk of failure for repeat filtering surgery CPC Preoperative treatment: Retrobulbar anesthesia Postoperative treatment: 1. Patch for 24 hrs 2.Atropine 1% bid and Pred Forte 1% q 2 hrs WA gradually tapered over several weeks 3. Resume glaucoma medications except miotics CPC Postoperative treatment: Narcotic analgesic prn pain Retreatment if needed about 1 month after initial procedure CPC Laser technique: Noncontact,slit lamp system or contact probe,fiberoptic system Nd:YAG laser settings: 4-8J 30-40 burns over 360°about 1 mm posterior to limbus CPC Laser technique: Diode laser settings: 1-2W 2.0 sec 18 burns over 270°about 1 mm posterior to limbus CPC Complication: Iritis Pain Conjunctival burns Visual loss Phthisis bulbi Hypotony Cystoid macular edema CPC Complications: Corneal graft rejection Hyphema Vitreous hemorrhage Cataract Suprachoroidal hemorrhage Serous choroidal effusion Sympathetic ophthalmia Other uses of Laser Therapy Laser suture lysis 1.Use laser to cut sutures in the trabeculectomy flap to improve filtration in the early postoperative period 2.Laser technique Hoskins or Ritch lens Argon laser settings: 300-800 mW 50 μm 0.02-0.1sec Other uses of Laser Therapy Laser peripheral iridoplasty 1.Use laser to create contradiction burns in the peripheral iris to open an appositionally closed angle (eg plateau iris syndrome,nanophthalmos) 2.Laser technique: Abraham or Goldmann lens Argon laser settings: 150-300mW 500μm 0.2-0.5sec