[PPT] - Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty SLT PowerPoint Presentation

SLIDE 1

Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty “ “SLT SLT” ”

Jorge L. Fernandez Jorge L. Fernandez-

Bahamonde, M.D.

Bahamonde, M.D.

SLIDE 2

Background and Rationale for laser therapy Background and Rationale for laser therapy in Glaucoma. in Glaucoma.

Compliance with therapy is poor for chronic

diseases.

– 20% or less follow adequate dosage regime.

Pressure spikes may be partially responsible for

further optic nerve deterioration.

In severe disease goals are hard to achieve with

medical therapy only.

– IOP never above 18 mm Hg. – Average below 14 mm Hg.

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Background and Rationale for laser Background and Rationale for laser therapy in Glaucoma. therapy in Glaucoma.

Lasers have a long history of use in the

management of glaucoma

ALT was initially utilized in patients who failed

medical therapy

The Glaucoma Laser Trial (GLT) established

efficacy of ALT in lowering IOP in previously untreated primary open-angle glaucoma patients

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Background and Rationale for laser Background and Rationale for laser therapy in Glaucoma. therapy in Glaucoma.

Glaucoma Laser Trial

271 patients with previously untreated primary open angle

glaucoma randomized to ALT or medication

Through 2-year follow-up, ALT eyes had lower intraocular

pressure (IOP) than medication-treated eyes.

– 25% did not require Rx

At 7 years, ALT-treated eyes:

– lower IOP – better visual field and optic disc appearance.

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Why SLT? Why SLT?

Limitations of argon laser trabeculoplasty (ALT)

♦ Post-treatment increase in IOP; PAS ♦ Limited efficacy of ALT re-treatment ♦ Coagulative damage to the trabecular meshwork

(TM)

Selective laser trabeculoplasty (SLT) is developed as

an alternative to ALT

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Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty “ “SLT SLT” ”

Q-Switched frequency doubled

(532 nm) Nd:YAG Laser

– Selecta 7000 Glaucoma Laser System*.

Permits selective targeting of

pigmented trabecular meshwork (TM) cells without causing structural or coagulative damage to the TM

*Lumenis, formerly Coherent

SLIDE 7

Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty Latina et al. Latina et al.

Selective Photothermolysis

– Requirements

Intracellular target chromophore (melanin) and no

competing chromophores

Targets must absorb laser energy better than surrounding

tissues

Short Laser Pulse to generate and confine heat

– Only pigmented cells within the irradiation zone will be targeted

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Selectivity Selectivity

Confine heat diffusion

spatially by limiting the applied light pulse duration below the thermal relaxation time of the target.

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Laser and the TM. Laser and the TM.

TM cells are phagocytic

and contain variable amounts of melanin

ALT induces focal scarring

and coagulative damage with reduced flow through the laser-treated site.

– Non-repeatable.

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TM Cell Culture Fluorescence TM Cell Culture Fluorescence Live/ Live/Cytotoxicity Cytotoxicity Microscopy Microscopy -

SLT

SLT

SLIDE 11

Structural changes ALT vs. SLT. Structural changes ALT vs. SLT.

Human TM. Human TM.

ALT 50 um spot SLT 400 um spot.

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Selective Targeting of TM Cells Selective Targeting of TM Cells In Vitro Studies. In Vitro Studies.

Pigmented TM cells can be selectively targeted

without damage to adjacent non-pigmented cells

Optimal laser is a Q-switched Frequency Doubled

532 nm Nd:YAG laser (3 nsec pulse)

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1064 nm

532 nm 810 nm

Pulse Duration

3 nsec CW (0.1 sec)

Q-switched Nd:YAG (7970) Diode -LTP or

cyclophoto

SLT

514 nm

532-green LTP Argon LTP

Comparison of Lasers

M. Latina, M.D

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Comparison of SLT Comparison of SLT vs vs ALT ALT

SLT ALT Ratio

No. of spots

50 50 Energy 0.8-1.4 mj 400-600mw 1:100 Fluence (mj/mm

2)

6 40,000 1:6000 Exposure Time 3 nsec 0.1 sec

SLIDE 15

ALT spot vs. SLT spot size

Courtesy M. Berlin, M.D.

SLIDE 16

SLT vs. ALT Treatment

Courtesy M. Berlin, M.D.

SLIDE 17

Spot Size Comparison Spot Size Comparison

1064 nm q-sw Nd:YAG (dia. =10 um) (dia. = 400 um) SLT spot size

SLIDE 18

Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty

FDA Clinical Results Summary. FDA Clinical Results Summary.

Both U.S. and Canadian data sets show comparable SLT-

related IOP lowering effects, response rates and safety profiles.

– Canadian data now to 2 years with comparable results.

10
8
6
4
2

b a s e l i n e 1 d a y 1 w k 2 w k s 4 w k s 8 w k s 1 4 w k s 2 w k s 2 6 w k s Weeks IOP (mmHg) Max Rx Group PFLT Group Combined

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Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty

FDA Clinical Results Summary. FDA Clinical Results Summary.

70% of patients [uncontrolled OAG on Max. Rx and

prior failed laser trabeculoplasty (PFLT)] respond with > 3mmHg drop in IOP

Average, sustained IOP drop 6.0 + mmHg or 25%.
Over 2000 patients have been treated and followed

for as long as two years in numerous international studies with similar results.

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SLT Study Designs for FDA SLT Study Designs for FDA

U.S. - Historical Control MaxRx PFLT SLT SLT Canada - Prospective Randomized MaxRx PFLT SLT SLT ALT ALT

SLIDE 21

Objectives. Objectives.

US Study. Safety and effectiveness of SLT to reduce IOP in patients with open-angle glaucoma. Canadian Study. Compare SLT with ALT in treatment of patients with

pen angle glaucoma.

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SLT – Treatment Parameters SLT SLT – – Treatment Parameters Treatment Parameters

Wavelength - 532 nm Pulse duration

3 ns

Spot size

400 µm

Energy / pulse

0.6-1.2 mJ

Fluence

600 mJ / cm

2

Spots

45-55 confluent

inferior or nasal 180 Lens - Goldmann 3 mirror

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Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty Patient Demographics Patient Demographics (US) (US)

120 patients treated

– 65 females (54.2%) – 55 males (45.8%) – Mean Age 67.7 yrs (ages 29-90 yrs)

77 (64.2%) Caucasians
34 (28.3 %) African-Americans
9

(7.5%) Hispanics

Asians

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Selective Laser Trabeculoplasty

Diagnosis - 120 patients enrolled

POAG

99 (82.5%) PXF 7 (5.8%) Pigmentary 7 (5.8%) Mixed Mec. 5 (4.2%) Pseudophakia 3 (2.5%) Juvenile 1 (0.8%)

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Trabecular Pigmentation Trabecular Pigmentation

Graded on Scale of 1- 4+

– 1+ pigmentation - 35.6% – 2+ pigmentation - 37.3% – No difference between eyes or treatment groups

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Selective Laser Trabeculoplasty

Treated vs. Untreated Eyes All eyes (120) at 26 wks f/u

Pre-op IOP

(mm Hg)

Post-op IOP

(mm Hg)

Δ IOP % drop p value SLT Treated Eye 25.3 20.9

4.4

17.1%

<.001

Untreated Eye

21.4

19.5

1.9 8.3% <.001

P-value Difference (treated vs. untreated) <.003

SLIDE 27

SLT-Treated Eyes

Mean IOP Reductions at 26 weeks Intent-to-Treat Analysis (120 patients)

No. of

Eyes Pre-op IOP

(mm Hg)

Mean Δ IOP

(mm Hg)

% IOP Drop P Value

Max Rx 53 (44%)

25.3

5.1

20.0 <0.001

PLTP 67 (56%)

25.3

3.8

14.7 <0.001

Combined 120(100%)

25.3

4.4

17.1 <0.001

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SLT SLT-

Treated Eyes

Treated Eyes

Mean IOP Reductions at 26 weeks Mean IOP Reductions at 26 weeks Responders ( Responders (> > 3 mm Hg IOP reduction) 3 mm Hg IOP reduction) -

71/101 eyes

71/101 eyes

No. of

Eyes Pre-op IOP

(mm Hg)

Mean Δ IOP

(mm Hg)

% IOP Drop P Value All Responders

71 (70%)

25.5

6.0

23.6 <0.001 MaxRx

34 (76%)

25.3

6.5

25.3 <0.001 PLTP

37 (66%)

25.6

5.7

22.1 <0.001

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Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty

Adverse Events Adverse Events -

120 eyes

120 eyes

MaxRx group PLTP group Combined

No. of Subjects

Event

53 67 120 A/C Inflammation 47 (89%) 60 (90%) 107 (89%) Pain/Discomfort 1 (2%) 5 (8%) 6 (5%) Redness 2 (4%) 4 (6%) 6 (5%)

IOP Elevation

(within 2 hrs post-op)

> 10 mm Hg

3 (2.5%) 4 (3%) 7 (6%)

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Post Post-

op Ocular Characteristics
p Ocular Characteristics
Peripheral Anterior Synechiae

– None considered to be related to the study device or treatment

treated eye -

8 patients (6.7%)

1 MaxRx
7 PLTP
non-treated eye - 7 patients (5.8%)
No relation between TM pigmentation and

IOP reduction

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Selective Laser Trabeculoplasty Conclusions (US).

A safe and effective treatment to lower IOP

in patients with open angle glaucoma.

IOP reduction has been maintained for up to 26 weeks

in this clinical trial

International studies show IOP reductions of 22%-28%

with 36-49 weeks follow-up

Effective in patients with prior ALT with

uncontrolled IOP.

Response similar to MaxRx Group.

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Baseline Characteristics Baseline Characteristics Total Study Population (n=77) Total Study Population (n=77) Canadian Study. Canadian Study.

ALT Group (n=42) SLT Group (n=35) P-value Age (mean, in years) 70.1 (SD 10.2) 66.2 (SD 10.4) 0.10 Diagnosis 0.50 POAG 25 (59.5%) 20 (57.1%) Pseudoexfoliative 12 (28.6%) 7 (20.0%) Pigmentary 1 (2.4%) 3 (8.6%) Other 4 (9.5%) 5 (14.3%) IOP (mean,SD - mmHg) 23.6 (3.5) 23.6 (4.1) 0.99

K. Damjii, et al

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Total Study Population IOP Total Study Population IOP (mean, SD (mean, SD -

mmHg) Canadian.

mmHg) Canadian.

ALT SLT P-value N Mean (SD) N Mean (SD) Baseline 42 23.6 (3.5) 35 23.6 (4.1) 0.99 Day 7 39 20.1 (5.1) 32 21.3 (5.0) 0.35 Month 1 38 19.7 (4.3) 33 20.6 (4.7) 0.38 Month 3 35 20.2 (5.4) 32 20.1 (5.2) 0.90 Month 6 34 18.3 (4.8) 30 18.0 (4.6) 0.79

K. Damjii, et al

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PFLT Population PFLT Population IOP IOP (mean, SD

(mean, SD -

mmHg)

mmHg)

ALT SLT P-value N Mean (SD) N Mean (SD) Baseline 17 22.2 (3.9) 10 24.3 (3.8) 0.18 Month 1 16 19.4 (4.7) 10 18.8 (6.2) 0.79 Month 3 13 22.5 (7.2) 9 16.3 (4.3) 0.03 Month 6 16 19.6 (5.3) 10 15.9 (4.2) 0.07

K. Damjii, et al

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Mean Reduction in IOP for All Patients, Mean Reduction in IOP for All Patients, by Time and Treatment. by Time and Treatment.

Canadian Study. Canadian Study.

1 2 3 4 5 6 Day 7 Month 1 Month 3 Month 6 ALT SLT

K. Damjii, et al

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Percentage of Patients Showing Substantial Percentage of Patients Showing Substantial (3 mmHg or greater) IOP Reduction at 6 Months (3 mmHg or greater) IOP Reduction at 6 Months

10 20 30 40 50 60 70 80 90 All Patients (n=77) MMT Subset (n=48) PFLT Subset (N=29) ALT SLT

K. Damjii, et al

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Percent Reduction in IOP in PFLT Patients, Percent Reduction in IOP in PFLT Patients, by Time and Treatment. by Time and Treatment.

5

5 10 15 20 25 30 35 Day 7 Month 1 Month 3 Month 6 ALT SLT

K. Damjii, et al

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Distribution of MMT and PFLT Patients in the Study Group. Distribution of MMT and PFLT Patients Distribution of MMT and PFLT Patients in the Study Group. in the Study Group.

65% 35% MMT Pts PFLT Pts 65% 35% MMT Pts PFLT Pts

K. Damjii, et al

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Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty Summary of Clinical Results. Summary of Clinical Results.

ALT Group Canada (mean, SD) SLT Group Canada (mean, SD) SLT Group US (mean, SD) Baseline IOP (mmHg) 23.6 (3.5) 23.6 (4.1) 25.3 (2.9) Month 6 IOP (mmHg) 18.3 (4.8) 18.0 (4.6) 20.9 (3.6) Decrease in IOP (mmHg) 5.0 (5.2) 5.2 (3.9) 4.4 (3.4) Percentage Reduction IOP 20.4 (20.5) 22.0 (16.0) 17.1 (12.9) AC Cells Cellular reaction greater in SLT group at 1 hour (1.5 ± 0.0 vs 0.8 ± 0.7 for ALT) but resolved completely at 1 week Cellular reaction was 1.0 ± 0.6 at 1 hour and resolved by 1 week

SLIDE 40

Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty Summary Summary

SLT selectively targets pigmented trabecular meshwork

cells without coagulative damage to adjacent tissues

Selective targeting demonstrated in in vitro, ex vivo, and

primate models

In a prospective, randomized clinical trial, SLT and ALT

were shown to have a similar effect on IOP reduction

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Selective Laser Trabeculoplasty Selective Laser Trabeculoplasty Summary Summary

SLT is a safe alternative to ALT, with little or no

coagulative damage to the trabecular meshwork

Effectiveness of SLT in PFLT patients represents an

important therapeutic advance for this population of patients refractory to further medical treatment

SLT preserves the trabecular meshwork tissue for the