Journal List > J Korean Ophthalmol Soc > v.54(12) > 1009560

Min and Yim: Pattern Laser Trabeculoplasty Intraocular Pressure Reduction Efficacy in Open-Angle Glaucoma Patients on Medical Therapy

Abstract

Purpose

To assess the effectiveness and safety of Pattern Laser Trabeculoplasty (PLT) in patients with primary open-an-gle glaucoma (POAG) and normal tension glaucoma (NTG).

Methods

Twenty-six eyes in patients with POAG and 14 eyes in patients with NTG were targeted in this study. The intraocular pressure (IOP) for each patient needed to be reduced within proper ranges. The clinical outcome was assessed by IOP at 1 week, 1 month, 3 months, 6 months and 9 months after PLT.

Results

The mean (± standard deviation) IOP in the POAG group was 20.7 ± 4.1 mm Hg before treatment. After PLT, the IOPs in POAG group were 16.4 ± 3.1 mm Hg, 16.9 ± 3.8 mm Hg, and 16.5 ± 5.2 mm Hg at 1, 6 and 9 months, respectively, and the pressure remained stabled over 9 months of post-procedural follow-up. However, no statistical difference in IOP reduction was observed in the NTG group before and after treatment.

Conclusions

PLT provides a possibility to decrease additional medical therapy in patients with POAG. In addition, PLT can be considered as an auxiliary therapy for POAG patients who tolerate maximal medical therapy prior to undergoing surgical treatment.

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Figure 1.
The mean post-procedural intraocular pressure (IOP). Follow-up visits were scheduled at 1 week, 1, 3, 6, and 9 months after treatment. Each point and bar represents the mean ± standard error.
jkos-54-1862f1.tif
Figure 2.
The mean intraocular pressure reduction percentage along the course of the follow-up period.
jkos-54-1862f2.tif
Figure 3.
In the Kaplan-Meier chart for both groups (POAG versus NTG) using the definition of success, the course of the curves was dispersed. There were statistically significant differences between the survival curves in the follow-up period (log-rank test, p = 0.006).
jkos-54-1862f3.tif
Table 1.
Baseline characteristics of patients
Characteristics POAG NTG p-value
No. of eyes (patients) 26 (23) 14 (12)  
Age (years) 58.2 ± 11.8 54.9 ± 11.0 0.383*
Sex (M/F) 17 / 6 7 / 5 0.346
Laterality (right/left) 15 / 11 6 / 8 0.370
No. of glaucoma medications 2.1 ± 1.0 1.5 ± 1.2 0.108
Best-corrected visual acuity (log MAR) 0.15 ± 0.1 0.19 ± 0.2 0.565*

Values are presented as mean ± SD.

POAG = primary open-angle glaucoma; NTG = normal tension glaucoma.

* Independent t-test

Chi-square test

Mann-Whitney test.

Table 2.
The mean post-procedural IOP change and mean percentage of IOP reduction from baseline IOP along the course of the follow-up period
F/U periods IOP (mm Hg, mean ± SD)
IOP reduction (%)
POAG p value* NTG p value p value POAG NTG
Pretreat 20.7 ± 4.1   13.1 ± 3.0   0.000    
1 week 17.3 ± 4.4 0.000 12.2 ± 1.6 0.253 0.000 16.2 3.6
1 month 16.4 ± 3.1 0.000 11.5 ± 2.4 0.168 0.000 20.0 6.8
3 months 16.9 ± 4.1 0.001 11.7 ± 2.8 0.001 0.000 15.8 12.0
6 months 16.9 ± 3.8 0.001 12.2 ± 3.6 0.291 0.001 17.0 5.0
9 months 16.5 ± 5.2 0.003 12.9 ± 3.5 0.438 0.033 18.1 3.3

Values are presented as mean ± SD.

IOP = intraocular pressure; POAG = primary open-angle glaucoma; NTG = normal tension glaucoma.

* Comparison of IOP between baseline and each follow up in the POAG group (Paired t-test)

Comparison of IOP between baseline and each follow up in the NTG group (Paired t-test)

Comparison of IOP between both groups at each follow up (Independent t-test).

Table 3.
Multiple comparisons of characteristics between successful and fail groups in PLT
Characteristics Success Fail p-value*
No. of eyes 10 27  
Age (years) 55.6 ± 10.7 56.2 ± 11.6 0.912
No. of eyes (M/F) 6 / 4 18 / 9 0.793
Anterior chamber angle 38.9 ± 5.2 35.3 ± 5.3 0.235
MD -11.4 ± 10.5 -16.9 ± 9.1 0.310
PSD 6.37 ± 4.4 8.68 ± 3.3 0.233
Pre. IOP 22.8 ± 4.9 16.5 ± 4.3 0.017
Lens state (phakic/pseudophakic) 8 / 2 21 / 6 0.071
DM 2 3 0.380
HTN 4 11 0.185
No. of glaucoma medications 1.80 ± 1.3 2.23 ± 0.8 0.577
PG analogue 7 25 0.368

Values are presented as mean ± SD or number.

DM = diabetes mellitus; HTN = hypertension; IOP = intraocular pressure; MD = mean deviation; PG = prostaglandin; PSD = pattern standard deviation.

* Logistic regression analysis.

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