Intraocular Pressure-Lowering Potential of Subthreshold Selective Laser Trabeculoplasty in Patients with Primary Open-Angle Glaucoma.

Hong Yang Zhang,Min Bin Yu,Jian Gang Xu,Yang Fan Yang,Yong Jie Qin

doi:10.1155/2016/2153723

Abstract

Purpose. To compare the efficacy of subthreshold and conventional selective laser trabeculoplasty (SLT) in lowering intraocular pressure (IOP) in the patients with primary open-angle glaucoma (POAG). Methods. Fifty-two eyes from fifty-two POAG patients were randomized into two groups, one group treated with subthreshold SLT using two-thirds of the conventional energy and the other one treated with the conventional energy. IOP was measured with the Goldmann tonometer and the anterior chamber inflammation was determined using laser flare meter. Results. The initial energy dosage used in subthreshold SLT group was significantly lower than the amount of the energy used in conventional SLT group (0.4 ± 0.1 mJ versus 0.6 ± 0.1 mJ, P = 0.030). The total energy dosage was also significantly lower in subthreshold SLT group compared to the other group (37.6 ± 3.3 mJ versus 51.8 ± 5.7 mJ, P = 0.036). However, the level of inflammation in aqueous humor, amount of reduction in IOP, and the success rate in controlling IOP was the same in both groups. Conclusion. The efficacy of subthreshold SLT group in reducing IOP in POAG patients is comparable to the efficacy of conventional SLT group.

Highlights

Selective laser trabeculoplasty (SLT) was considered as an effective and safe surgery for lowering intraocular pressure (IOP) [1,2,3] since it has initially been described in 1995 [4]
In vitro histological observations of the human trabecular meshwork demonstrated that cracking of the intracytoplasmic pigment granules and disruption of the trabecular endothelial cells were the only findings after SLT
The initial energy dosages used in subthreshold SLT group and the conventional one were 0.4 ± 0.1 mJ and 0.6 ± 0.1 mJ, respectively

Summary

Introduction

Selective laser trabeculoplasty (SLT) was considered as an effective and safe surgery for lowering intraocular pressure (IOP) [1,2,3] since it has initially been described in 1995 [4]. SLT, a 532 nm frequency-doubled and Q-switched neodymium (Nd): yttrium-aluminum-garnet (YAG) laser, is capable of targeting pigmented trabecular cells without producing thermal damage to the adjacent nonpigmented cells or structures of trabecular meshwork [1, 4]. In vitro histological observations of the human trabecular meshwork demonstrated that cracking of the intracytoplasmic pigment granules and disruption of the trabecular endothelial cells were the only findings after SLT. These studies showed that coagulative damage or disruption of the corneoscleral or uveal trabecular beam structure never happens after SLT [5]. SLT has been recommended as the first-line treatment for the patients with open-angle glaucoma, including primary open-angle glaucoma (POAG), pigmentary glaucoma, and exfoliative glaucoma [9,10,11]

Methods

Results

Conclusion