Minimally Invasive Glaucoma Surgery

Approximately 1.4 % of the German population aged 35 to 74 suffers from glaucoma, which is one of the more common causes of blindness. The only evidence-based treatment option at present is lowering the intraocular pressure. Modern minimally invasive surgical procedures hold out the prospect of lowering the intraocular pressure without the risk of serious complications.

This is a selective review of pertinent publications retrieved by a search in PubMed, including randomized, controlled trials and meta-analyses.

The intraocular pressure can be lowered with eyedrops, laser procedures, and surgery. Trabeculectomy is the reference standard in glaucoma surgery but leads to complications in 3-15% of cases. In minimally invasive glaucoma surgery, very small stents can be implanted to lower the intraocular pressure. These proce - dures have a better safety profile but are only indicated for mild or moderate glaucoma. The Kahook Dual Blade, iStent inject, and Hydrus Microshunt procedures have been studied in randomized, controlled trials. An additional pressure-lowering effect beyond that of cataract surgery was demonstrated only for the latter two procedures (1.9 mmHg and 1.8 mmHg, respectively). Other procedures have only been investigated in cohort studies to date; a pressure-lowering effect was found for some of them. Moreover, iStent and Hydrus Microshunt have been found to slow the progression of visual field defects.

There are robust data documenting the effect of iStent and Hydrus Microshunt in lowering the intraocular pressure and lessening the need for eyedrops. High-quality controlled trials are still needed to test the efficacy of other procedures.