EyeWorld Asia-Pacific September 2020 Issue

GLAUCOMA 44 EWAP SEPTEMBER 2020 lying in a supine position,” he said. “In the office setting, gonioscopic assessment of both eyes utilizes both hands to hold the goniolens, whereas during surgery, the non-dominant hand plays a critical role in holding the lens in place to visualize the angle structures enabling the dominant hand to perform the MIGS procedure.” Dr. Shareef recommends all cataract surgeons use a fixation ring during surgery to get used to holding the handle with the non-dominant hand before transitioning to a goniolens for MIGS. Dr. Lehrer stressed the importance of a mentor when learning how to use gonioscopy in the office and the OR. When learning in-office gonioscopy, he said to know the angle grading systems, as well as different techniques. Dr. Lehrer offered several tips for in- office gonioscopy: 1) Both the surgeon and patient should get comfortable. 2) Rest your elbow on the table or on an elbow rest or lens box. 3) Rest your fingers holding the lens against the patient’s cheek to steady the lens. When using a direct gonio- prism to view the nasal angle in the OR, it is important to tilt the patient’s head away from the surgeon and the microscope toward the surgeon to achieve ideal visualization. Other newer lenses, including disposable lenses, may not require positioning or tilting and may T here are a number of commercially available direct surgical goniolenses that vary by handle length and field of view, 2 Dr. Shareef said. They are all a modification of the Swan- Jacob goniolens, and some come with adjustments to counter involuntary ocular movements, such as a flange or a fixation ring. Disposable goniolenses are also available. Much of the choice among goniolenses is surgeon preference, Dr. Noecker said. There are a variety of options to address different issues. Dr. Lehrer’s preferred lens for office diagnostics is the Posner lens with octagonal handle (Ocular Instruments). He described it as easy to use, clean, and manipulate for compression and tilting. Reay Brown, MD, is working on a SecureFlex (Ocular Instruments) goniolens with a wider view. He described this as a goniolens connected to a contact lens and said it works well be useful in operating on other angles than the nasal quadrant. Use in the clinic and the OR There are key differences between using gonioscopy intraoperatively and in the office, said Robert Noecker, MD. The first is the position of the patient (upright or laying down), presenting different views. Lighting can differ between the two as well. In the office, the physician can push on the eye a bit more and change the shape, he said. If the angle is narrow, the physician can sometimes push it open wider. The slit lamp typically provides more of a 3D view, and it’s harder to achieve that in the OR with the microscope, he explained. In the OR, there are some tricks to manipulate the position of the patient, Dr. Noecker said. One is you can change the patient’s head position to get a better look. Another key in the OR is keeping the eye well inflated. EWAP References 1. Alward WL. A history of gonioscopy. Optom Vis Sci. 2011;88:29–35. Editors’ note: Dr. Brown practices at Atlanta Ophthalmology Associates, Atlanta, Georgia. Dr. Lehrer is director of Glaucoma Services, Ohio Eye Alliance, Alliance, Ohio, and has relevant interests with Glaukos and Ivantis. Dr. Noecker practices at Ophthalmic Consultants of Connecticut, Fairfield, Connecticut. Dr. Shareef is director of Glaucoma Service, University Hospitals Eye Institute, Case Western Reserve School of Medicine, Cleveland, Ohio. Drs. Brown, Noecker, and Shareef declared no conflicts of interest. for MIGS procedures, especially when a wider view is critical. He wanted a wider view because he performs many OMNI Surgical System (Sight Sciences) procedures and likes to see the catheter advance in the canal to confirm that it is properly placed. “Visibility is one of the keys to all MIGS,” Dr. Brown said. “I was using the original SecureFlex and liked it; I approached the company and asked if we could work together on a design to give surgeons a wider view.” Most goniolenses give about a 90-degree view, but even that is degraded at the edges, he said. “This is fine for a single ‘classic’ iStent [Glaukos], but a wider view is helpful if you are placing two iStent injects [Glaukos] or performing an OMNI or Hydrus [Ivantis] or any of the angle procedures.” The new design gives a clear view for 120 degrees. Reference Shareef S, et al. Intra-operative gonioscopy: a key to successful angle surgery. Expert Rev Ophthalmol. 2014;9:515–527. Types of goniolens