1. Winthrop University Hospital
Effect of Selective Laser Trabeculoplasty on Diurnal Fluctuations of Intraocular Pressure
ASCRS 2009
Richard A. Luck, DO
Winthrop University Hospital
Elaine M. Miglino
Floral Park Ophthalmology
Lawrence F. Jindra, MD
Columbia University
Winthrop University Hospital
Joseph A. Donnelly
Hofstra University
1st, 2nd and 3rd authors have no financial disclosure
4th author has independently conducted and financed clinical research study presented and has provided technical advice and consultant services to Lumenis Corporation in the past year

2. Introduction
Selective Laser Trabeculoplasty (SLT) uses a Q-Switched frequency-doubled (532 nm) Nd:YAG laser, which targets melanocytes in the trabecular meshwork1,2
SLT treatment induces a biologic response in the trabecular meshwork, which involves the release of cytokines that trigger macrophage recruitment and other changes, leading to IOP reduction2
SLT treats the meshwork without causing any thermal or coagulative damage to surrounding structures1,2
1. Latina MA, et al. Selective targeting of trabecular meshwork cells: in vitro studies of pulsed and CW laser interactions. Exp Eye Res. 1995;60: Latina MA, et al. Q-switched 532-nm Nd:YAG laser trabeculoplasty (selective laser trabeculoplasty): a multicenter, pilot, clinical study. Ophthalmology. 1998;105:

3. Purpose and Methods Purpose
To examine the effect of Selective Laser Trabeculoplasty (SLT) on diurnal fluctuations of intraocular pressure (IOP) in patients receiving primary or secondary therapy.
Methods
Retrospective chart review was performed on 48 eyes out of a consecutive case series of 2056 eyes treated with SLT. Eyes were selected for analysis which had follow-up IOP values over four years after primary or secondary treatment with SLT.

4. Results (Primary)
For eyes with SLT as primary treatment, morning and afternoon IOP values were not significantly different (p > 0.05)

5. Results (Secondary)
For eyes with SLT as secondary treatment, morning and afternoon values were significantly different (p < 0.01)

6. Results
Total follow up time after SLT was 1600 days
Mean fluctuation in IOP for primary / secondary groups:
days ± 2.0 / 2.1 ± 2.2 mmHg
days ± 0.9 / 0.2 ± 1.9 mmHg
days ± 1.0 / 1.8 ± 3.2 mmHg
days 0.9 ± 1.7 / 4.3 ± 4.2 mmHg
Results were significant with p < 0.01; 95% confidence intervals (p < 0.05)

7. Discussion The Glaucoma Laser Trial
Established the efficacy of laser trabeculoplasty to lower IOP in previously untreated glaucoma patients1
The Ocular Hypertensive Treatment Study &
The Early Manifest Glaucoma Trial
Established the efficacy of early and effective treatment to preserve long-term visual function in glaucoma patients2,3
Our findings build on these studies and suggest treatment with SLT controlled IOP better in eyes with primary therapy than in eyes with secondary therapy (p < 0.01). 7
1. The GLT Research Group. GLT. Ophthalmology. 1990;97: Kass MA, et al. OHTS. Arch Ophthalmol. 2002;120:
3. Heijl A, et al. EMGT. Arch Ophthalmol. 2002;120:

8. Conclusion In this series over the long-term:
Eyes in which SLT was used as primary therapy, the diurnal fluctuation of IOP appeared to be eliminated.
Eyes in which SLT was used as secondary therapy, the diurnal fluctuation of IOP appeared to remain.
Further study with controlled clinical trials is indicated.