Intraocular Pressure (IOP) Lowering Effect of Selective Laser Trabeculoplasty Versus Prostaglandin Analogues in Angle Closure Glaucoma

Summary

Glaucoma affects 66 million people worldwide and is the leading cause of irreversible blindness, and Primary angle-closure glaucoma (PACG) is a major form of glaucoma in Asia. Laser peripheral iridotomy (LPI) has been advocated as the first line treatment in all cases of PACG. In addition to relieving the relative pupil block element of the condition, it can open up the drainage angle, alleviating appositional and synechial angle-closure and in the long-term this may control intraocular pressure (IOP) and prevent progression of glaucomatous optic neuropathy. However recent data indicate that iridotomy is not successful in controlling IOP in the long term, and the majority of cases develop a clinically significant rise in IOP requiring medical therapy or surgery. Laser trabeculoplasty has been a recognized treatment option for Primary open angle glaucoma (POAG) since the 1980s. Recently a more selective and less destructive method of performing laser trabeculoplasty has evolved. Selective Laser Trabeculoplasty (SLT) specifically targets the pigmented trabecular meshwork cells without producing collateral damage and destruction to adjacent structures. Morphologic study performed on human autopsy eyes treated with SLT noted no structural or collateral thermal damage to the trabecular beams in the uveal and corneoscleral meshwork. As SLT specifically has its effect on the targeted pigmented trabecular meshwork it is unlikely to generate PAS. It may be a useful treatment option for PACG patients in whom the angle has widened following laser peripheral iridotomy. The proposed study is a randomized controlled trial to assess the effectiveness of SLT in reducing IOP in cases of PACG in which the angle has opened up following LPI, but IOP remains high(\>21 mmHg). 100 subjects will be randomized to receive either SLT or medical treatment to achieve IOP control. They will be followed up for 6 months.

Timeline

Start

2009-06

Primary completion

2011-03

Completion

2011-03

Publications

• Narayanaswamy A, Leung CK, Istiantoro DV, Perera SA, Ho CL, Nongpiur ME, Baskaran M, Htoon HM, Wong TT, Goh D, Su DH, Belkin M, Aung T. Efficacy of selective laser trabeculoplasty in primary angle-closure glaucoma: a randomized clinical trial. JAMA Ophthalmol. 2015 Feb;133(2):206-12. doi: 10.1001/jamaophthalmol.2014.4893.

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