EyeWorld Asia-Pacific March 2015 Issue

March 2015 46 EWAP GLAUCOMA by Ellen Stodola EyeWorld Staff Writer The value of gonioscopy Gonioscopy is just as valuable as anterior segment imaging for glaucoma, a physician says A t the 2014 Combined Ophthalmic Symposium (COS) meeting in San Antonio, Douglas J. Rhee, MD , Cleveland, gave a presentation focusing on anterior chamber visualization, mentioning ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT) as two main anterior segment imaging tests. An advantage of OCT is that the resolution is higher, but it cannot visualize behind the iris. Anterior segment imaging can be helpful for confirming several diagnoses such as plateau iris, iris bombe, and angle recession, Dr. Rhee said. Importance of gonioscopy Although anterior segment imaging is important, gonioscopy remains an essential tool. Sometimes surgeons may feel that they are being “left behind” without having an anterior segment imager. “There is nothing that you can diagnose with an anterior segment imager that you cannot diagnose with gonioscopy,” Dr. Rhee said. “Gonioscopy is still the gold standard.” One of the things that anterior segment imaging has shown as compared to gonioscopy, he said, is that the angle is much narrower under low light situations than it is when checking with gonioscopy, which is a high light situation. But Dr. Rhee stressed that it is unlikely this will play a large factor in treating patients because most cases of acute angle closure glaucoma result from patients who do not seek care and not from those who are already being monitored by a physician. Although Dr. Rhee stressed the necessity for gonioscopy, he said that anterior segment imaging can be additive to gonioscopy. UBM can be helpful for diagnosing posterior chamber abnormalities (e.g., UGH syndrome and plateau iris). Both OCT and UBM can be helpful in finding small or occult cyclodialysis clefts and to map larger cyclodialysis clefts for surgical planning, Dr. Rhee said. Anterior segment imaging playing a supplemental role Following up after his presentation, Dr. Rhee again stressed that “there are no diseases that can only be diagnosed with an anterior segment imaging device and not gonioscopy.” However, he said that anterior segment imaging devices can be useful. Ultrasound technologies are excellent at helping to look at the ciliary sulcus, he said. This can be particularly valuable for plateau iris, ciliary body cysts, tumors, masses, and uveitis glaucoma hyphema (UGH), which is caused by an improper placement of the haptic of an IOL. Dr. Rhee said that OCT offers the advantage that it is easier to operate, unlike an ultrasound, which generally requires more training. OCT is good in that you can more easily quantify various aspects of the angle than you can with gonioscopy, he said. Dr. Rhee sees the importance of anterior segment imaging playing a supplemental role to gonioscopy. One of the best resources is www.gonioscopy.org , he said. This website provides videos and tips for surgeons performing gonioscopy. If you do not use gonioscopy, he said, you could miss narrow angles, plateau iris, and a whole host of other conditions. “Gonioscopy skills are more important than ever, not just diagnostically, but therapeutically,” he said in his presentation. Many of the newest surgical procedures have an ab interno approach, e.g., the new microinvasive glaucoma surgery (MIGS) devices that are approved and those in development. Currently, the only approved devices are the Trabectome (NeoMedix, Tustin, Calif.) and iStent (Glaukos, Laguna A normal gonioscopy Source: Ricardo Amin, MD continue on page 49