Laser treatment for glaucoma is used in a variety of ways. Laser can be used for angle closure, when it is applied to form a tiny opening in the iris (known as an iridotomy), or laser is used to treat the ciliary body (either externally or internally), or laser can be applied to the drainage angle (selective laser trabeculoplasty) to lower eye pressure.

YAG laser iridotomy

Laser iridotomy is performed as a preventative measure against, or as treatment for, narrow angle glaucoma. It is a relatively simple treatment nowadays, with more modern lasers delivering very little energy (eg 20-30mJ) to make a tiny opening in the iris, tucked away under the upper lid. The iridotomy is usually positioned just to one side of the "12 o'clock" position, and in size it is less than 1mm in diameter. The laser treatment typically takes less than 5 minutes, although drops are given beforehand (pilocarpine drops) in most cases so that the laser opening is positioned as peripheral as possible, minimising glare symptoms. Recovery after YAG PI is quick, typically 2-3 days. A short course of topical steroid drops after treatment helps to keep the eye comfortable as there can be some sensitivity to light for a few days after treatment.

Selective laser trabeculoplasty

SLT treatment lowers eye pressure by treating the drainage angle - the trabecular meshwork. It typically lowers IOP (eye pressure) by several points, and lasts for years in most cases. Like all treatments for glaucoma, the effect can wear off in time. This is important to understand, as in many chronic conditions (for example like arthritis) the treatments are aimed to prevent the situation from getting worse (in the case of glaucoma by lowering IOP to a safe level), rather than from curing the condition. Unfortunately, any field lost from glaucoma is invariably permanent, however the good news is that every point of IOP lowering makes the risk of progression of glaucoma lower. SLT also helps to reduce the fluctuations in eye pressure noted moreso in glaucoma patients.

SLT laser machine