Transcript LASER THERAPY IN GLAUCOMA

LASER THERAPY IN
GLAUCOMA
Sun Xiao Dong
Laser Procedures
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Laser trabeculoplasty(LTP)
Laser peripheral iridotomy(LPI)
Cyclophotocoagulation(CPC)
Other uses
Laser Trabeculoplasty(LTP)
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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
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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
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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
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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