Efficacy of selective laser trabeculoplasty for normal tension glaucoma: 1 year results.

Jacky Wy Lee,Jimmy Sm Lai,Wing Lau Ho,Jonathan Ch Chan

doi:10.1186/1471-2415-15-1

Jacky Wy Lee, Jimmy Sm Lai + Show 2 more

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https://doi.org/10.1186/1471-2415-15-1

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Abstract

BackgroundNormal tension glaucoma (NTG) is commonly treated with anti-glaucoma medications. Recently, selective laser trabeculoplasty (SLT) has been demonstrated to lower the intraocular pressure (IOP) and medication use in NTG. The purpose of this study was to investigate the efficacy of a single session of SLT for NTG at 1 year.MethodsThis prospective cohort study recruited NTG patients taking anti-glaucoma medication. Potential subjects were excluded if they had had previous glaucoma surgery or laser and also if intraocular surgery or additional SLT procedures were performed after the first treatment. All subjects underwent a 1-month washout. A 30% IOP reduction was set as the target IOP. A single session of SLT was performed to 360 degrees of the trabecular meshwork. At 1-month after SLT, medication was resumed to achieve the target IOP. The IOP was measured every 3 months, and the number of medications was recorded at 3, 6, and 12 months. Only the right eye was used for statistical analysis.ResultsIn 41 right eyes, the mean pre-study IOP was 14.3 ± 3.4 mmHg while on 1.5 ± 0.8 eye drops. The post-washout IOP was 16.2 ± 2.2 mmHg. A mean of 191.1 ± 26.3 SLT shots at 1.0 ± 0.07 mJ were applied. There was significant IOP reduction at all time intervals following SLT when compared to the post-washout IOP (P < 0.0001). The number of medications was significantly reduced at all time intervals following SLT when compared to the pre-study level (P < 0.0001). At 12 months, the mean IOP was 12.2 ± 2.2 mmHg while on 1.1 ± 0.9 eye drops.ConclusionsA single session of SLT for NTG achieved an additional 15% IOP reduction while using 27% less medication at 1 year compared to pre-study levels.Trial registrationThe Clinical Trials Register of the University of Hong Kong HKCTR1847The European Clinical Trials Database 2014-003305-15 (August 11, 2014) (https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-003305-15)

Highlights

Normal tension glaucoma (NTG) is commonly treated with anti-glaucoma medications
The intraocular pressure (IOP) was reduced from 12.4 ± 2.0 mmHg at 1month to 11.2 ± 1.9 mmHg at 3 months after the resumption of anti-glaucoma medication in subjects who fell short of reaching their target IOP
We did notice a gradual decline in the absolute success of 61% at 6 months [10] to an absolute success of 22% at 12months. This entailed that a proportion of subjects did required the resumption of anti-glaucoma medications, as the effect of selective laser trabeculoplasty (SLT) is well known to decrease with time

Summary

Introduction

Normal tension glaucoma (NTG) is commonly treated with anti-glaucoma medications. Selective laser trabeculoplasty (SLT) has been demonstrated to lower the intraocular pressure (IOP) and medication use in NTG. Normal tension glaucoma (NTG) accounts for the majority of primary open angle glaucoma (POAG) in Asian countries like Japan and Korea [1,2]. Selective laser trabeculoplasty (SLT) is a well-established treatment for POAG with a comparable efficacy to medications and its high safety profile and repeatability being its greatest strengths [3,4,5,6,7,8,9]. Evidence on the use of SLT for NTG is scanty in the literature, with reported IOP reductions ranging from 12 to 15% in only a few small

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