Surgery, imaging year's hot topics

New surgical procedures and advances in structural imaging were once again the focus of interest in glaucoma during 2011. Despite the absence of any major news events emerging from either area during the past year, both continue to be hot topics based on anticipation that forthcoming developments will significantly affect glaucoma management in the future, agree specialists in the field.

Robert D. Fechtner, MD, professor, Institute of Ophthalmology and Visual Science, and director, glaucoma division UMDNJ-New Jersey Medical School, Newark; Joel S. Schuman, MD, Eye and Ear Foundation Professor and Chairman of Ophthalmology, University of Pittsburgh School of Medicine, and director, UPMC Eye Center, Pittsburgh; and Kuldev Singh, MD, MPH, professor of ophthalmology, and director, glaucoma service, Stanford University, Stanford, CA, spoke to Ophthalmology Times about glaucoma care in 2011 and the year ahead.

Structural imaging

Dr. Schuman noted there is intensive research under way to elucidate the role of structural testing in assessing glaucoma progression, including increasing attention on measurement of retinal nerve fiber layer thickness changes using SD-OCT.

"Using this technology we are seeing that structural changes can occur independently of visual field changes and vice versa," he said. "These findings suggest the structural measurements provide information that is supplemental to or different from that obtained through functional measurement of glaucoma progression. While it is still illuminating when structural and functional progression agree, disagreement may also have value. This is an area of high interest in imaging research."

He mentioned there are other potential advances in structural imaging that are still relatively early in the developmental stage and will require much more research before they become clinically applicable.

Posterior segment SD-OCT is also being combined with Doppler imaging to characterize retinal blood flow, and this technology is being formally investigated in the context of the Advanced Imaging in Glaucoma Study, a multicenter NIH-funded trial being headed by David Huang, MD, PhD.

Canaloplasty using a microcatheter (iTrack, iScience Interventional) with placement of a trabecular tensioning suture is continuing to gain popularity, and recently published results from 3 years of prospective follow-up [J Cataract Refract Surg. 2011;37:682-690] are encouraging in showing maintenance of the IOP-lowering effect with a low rate of late complications, Dr. Schuman said.

The trabecular meshwork bypass device ( iStent, Glaukos) is still awaiting FDA approval, and research is continuing with other stent and drainage devices (Hydrus, Ivantis; CyPass, Transcend Medical). While the clinical development program for all of these procedures has focused on their use in combination with cataract surgery, Dr. Schuman noted it will be interesting to see if they might be used off-label for primary surgical intervention once they become commercially available.