GLAUCOMA MANAGEMENTThe Role for

S.L.T.

Points to consider

• SLT works in 80% of eyes treated• Average IOP reduction is 25% (around

5mmHg)• Average duration of efficacy prior to

statistically-significant “drift” is 18 months

More Points to consider

• Average IOP reduction in eyes previously treated with ALT is approximately 23%

• SLT re-treatment provides an average IOP reduction of 25%

• SLT enhancement (treating previously untreated 90-degree quadrant) lowers IOP by approximately 22%

Still More Points to consider• The majority of US ophthalmologists are NOT

using laser as 1st line therapy.• Most are (Now! Finally!) initiating therapy with a

“once per day, hypotensive lipid”• 2nd line therapy has now become “alpha agonists or

topical carbonic anhydrase inhibitors”• Topical beta-blockers are notably less popular

today than 5 years ago

• The majority of ophthalmologists are now turning to laser in those cases where two concurrent topicals are failing to achieve desired results

• There are increasingly more “exceptions to that rule!

Studies suggest:• SLT is as effective as conventional drug

therapy as a primary therapy option• SLT is effective when repeated• SLT is effective when performed on eyes

with successful or failed ALT’s• SLT enhancements are effective

• SLT appears equally effective in pseudophakes (?)

• SLT reduces diurnal IOP fluctuations

SLT/MED Study Group

• 17 sites• Evaluating SLT as the primary therapy for

open angle glaucoma• “SLT = Medication”• “Less concern with side effects with the

laser treated patients”• “Less concern with compliance with the

laser treated patients”

Glaucoma Laser Trial

• Looked at A.L.T. vs topical medicationas first-line

• At 7-year marker:• Many laser patients now on Mx• Had required 40% less Mx during the interval• Had retained (slightly) better IOP control• Had retained (slightly) better visual fields• Had lost (slightly) less optic disk tissue

DRAWBACKS to DRUGS

DRAWBACKS to Single Mx Therapy

• Ocular Side Effects• Systemic Side Effects• Compliance/Noncompliance• Cost

DRAWBACKS to MULTIPLE Mx Therapies

• Increased Risk:• Ocular side effects• Systemic side effects

• Compliance/Noncompliance• Cost

Some recommendations from the literature “SLT’s Role in the Armamentarium” Smith MF, Doyle JW

• “We routinely offer SLT rather than a second medicine as a second-line treatment option for most of our glaucoma patients with open angles”

• “We offer the procedure [SLT] as first-line treatment in patients who have budgetary concerns, or who are not good candidates for medicine”*

Authors’ “Not good candidates” for Mx• Severe arthritis• Early dementia• History of significant forgetfulness with

other prescribed medications

Others (?)

• Patients on multiple medications for multiple problems

• Patients with very busy, erratic schedules• Patients who travel a lot

• Time zone changes• Luggage limitations

• Contact Lens wearers• “Sensitive Ocular Surface”

• Dry Eye• Allergies• Ocular Rosacea

Major indicator for 1st Line SLT

• Erratic Compliance

“Compliance barriers in glaucoma: a systematic classification”

• Tsai JC, McClure CA, Ramos SE, et al.• J Glaucoma. 2003; 12:393-398

0

10

20

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Day 1 Day 2 Day 3 Day 4

Compliance

50% subjects blamed “social and environmental” factors• Travel• Change in Daily Routine

30% of noncompliants blamed:

• COST• SIDE EFFECTS• COMPLEXITY OF DOSING REGIMEN

19% blamed

• THEMSELVES• THEIR DOCTOR

• Inadequate patient education• General dissatisfaction

Oklahoma College of Optometry

• Residents are more likely than faculty to recommend SLT over medication

• Specialty Care Clinic faculty are more likely than other faculty to recommend SLT

• Dean George Foster is the most aggressive at recommending SLT

No Two Faculty Manage Glaucoma the Same Way• Individual clinicians often do not manage

each of their patients in the same manner• My general approach: If SLT Day is near,

recommend SLT as first-line therapy to new patients

• If SLT Day is a ways off,Rx a prostamide

My personal experience:SLT as first-line therapy• Most new (previously untreated) patients

will prefer to try medication first

My personal experience:SLT as second-line therapy• I almost always discuss SLT with a patient

who is not achieving target IOP using a prostamide drug

• 50% will prefer to have another drop added50% will decide to try the laser

“SLT Day”

• Referrals pick up as “SLT Day” draws closer

• We lease the SLT laser system that we use at the Oklahoma College of Optometry

• Most of our SLT’s are performed on patients who have already been started on medications

• Failed to achieve Target IOP• Usually due to non-compliance

• Complaining about drug-related issues• Access• Burning/Stinging• Red eye• Blur• other

S.L.T.Selective (wavelength) Laser Trabculoplasty

For Open Angle Forms of Glaucoma

S.L.T. Basics

• Q-switched, Frequency-doubled Nd:YAG Laser System

• Outputs 532 nm emission• Brief 3 nsec pulse• “Low Power” (Energy) burns

• Targets Pigmented Trabecular Meshwork Cells• Minimal “peripheral damage” to non-

pigmented cells and/or collagen

Laser Trabeculoplasties;SPOT SIZES• ARGON procedures: 50 microns• DIODE procedures: 60 microns• S.L.T. procedures : 400 microns

How is it working?

• “Gentle mechanical effect” (min)• Reshaping meshwork anatomy and

mechanics• Less dramatic than the A.L.T. effect

• “Biostimulatory effect” (major)• Increased cellular metabolism• Increased cellular mitosis

“Enhanced Housekeeping”

Stimulate macrophages

Release cytokines

Remove metalloproteases

S.L.T.

Performing Selective Wavelength Laser Trabeculoplasy

Discontinue all glaucoma medications 1-2 weeks prior to S.L.T. (?????)• Ellex SLT website • Mrs. Madhu Nagar• “I prefer to discontinue all glaucoma

medications prior to SLT, rather than post SLT. The higher the baseline IOP, the greater the IOP reduction.”

Perform Gonioscopy

• Obtain Informed Consent• Instill 1 gt. Iopidine or 1 gt. Alphagan-P• (rarely) Instill 1 gt. 1-2% Pilocarpine

S.L.T. Treatment Parameters

• Wavelength: 532 nm• Pulse: 3 nsec• Spot: 400 microns• Energy per pulse: .6 to 1.2 mJoules• Shots: 45-55 “adjacent”• Location: inferior or nasal

180-degrees

Laser Lens

• Goldmann 3-Mirror• A.L.T. Trabeculoplasty Lens• Better to NOT use a Diode

Trabeculoplasty Lens

Titrate the Energy Setting

• Start with around .6 mJoules• Gradually increase setting to produce a

visible “steam” of micro-bubbles upon firing the laser (viewed through the slit-lamp and laser lens)

Or……Just make it easy!

• Set energy at 1.0mJ

Best to Avoid the11:00 – 1:00 Zone?• Better to leave the meshwork “virgin” in the

area where a filtering procedure might need to enter the angle?

• Also Consider: The Advanced Glaucoma Intervention Study indicated that African-American patients have better surgical outcomes when A.L.T. is done prior to a filtering procedure

Treat 180 or Treat 360 Degrees• 180 advocates

• Less risk of a laser-induced IOP spike• (Perhaps) advisable for Pigmentary and

Pseudoexfoliative Glaucoma patients

• 360 advocates• (Perhaps) greater IOP reduction• (Perhaps) longer duration of efficacy

Post-Procedure

• Don’t use steroids unless an intense iritis occurs• Expect to see pigment immediately post-op

• Use Topical and System Non-Steroidals• Acular, Nevanac, Voltaren (1 drop 4-5 times

daily)• Ibuprofen (two 200mg tables 4 x daily)• Treat for 3-4 days

Don’t try to judge the efficacy for at least a month, and 6-8 weeks is really a better time for assessment of treatment success

When to retreat/repeat SLT?

• As soon as pressure starts rising again.• No harm done by waiting until IOP

surpasses target IOP…..but why wait?