Ahmed hails rise of microinvasive glaucoma surgery

Trabeculectomy, once the gold standard for glaucoma surgery, likely will be replaced by emerging microinvasive procedures in the near future, said Ike K Ahmed MD of the University of Toronto in his Binkhorst Medal Lecture at the 2014 Congress of the American Society of Cataract and Refractive Surgery in Boston.

“Certainly in my career and my lifetime I hope this will happen sooner rather than later. There is no reason why an ab-interno bleb cannot do just as well as an external bleb,” said Dr Ahmed, a pioneer in developing ab-interno pressure control devices who coined the term microinvasive glaucoma surgery, or MIGS.

Historically, glaucoma surgery was reserved for advanced cases largely because trabeculectomy and even tube shunts involve significant surgical and long-term risk. That left only medications for earlier stage disease, even though they are much less effective in controlling IOP, Dr Ahmed noted.

Ab-interno devices including the iStent and CyPass, as well as devices such as the trabectome, SLT and ECP, reduce surgical risk while improving IOP control. Clinical trials of devices in development such as the CyPass shunt and AqueSys Xen bypass suggest they may increase efficacy to trabeculectomy levels, Dr Ahmed said.

“The promise of MIGS is that you can intervene early in the disease reducing the morbidity of progression – glaucoma being a leading cause of blindness. This hopefully will reduce the need to expose ourselves and our patients to more aggressive surgical options when we are already too late in the disease process,” Dr Ahmed said.

Cataract surgeons will play a significant role. “Any patient with glaucoma going to cataract surgery I think needs a really hard look for possibly combining [MIGS] with phaco. … We have very little to lose by trying an implant that does not preclude future surgery, particularly in mild to moderate [glaucoma] patients, with some of the ab-interno devices,” Dr Ahmed said.

Dr Ahmed also sees MIGS as an option for solo procedures in both phakic and pseudophakic eyes, with earlier surgical intervention possible due to reduced risk with the microinvasive devices. “We will be looking at MIGS after MIGS as well.”