Optometric Management

FEB 2017

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36 F E B R U A R Y 2 0 1 7 • O P T O M E T R I C M A N A G E M E N T . C O M CLINICAL GLAUCOMA A N 88-YEAR-OLD Caucasian female presented for a glaucoma evalu- ation. Due to her physical limita- tions, obtaining an accurate VF and OCT was not possible. How can one ensure an accurate diag- nosis when the go-to tools can't be used or are unobtainable? Here, I discuss how to accom- plish this. 1 PERFORM GONIOSCOPY Gonioscopy can aid in the di- agnosis of glaucoma on patients unable to position themselves for advanced technologies. When performing a gonioscopy, note the presence of pigment in the trabecular meshwork and extra lines of pigment, indicating pig- ment dispersion and pseudoexfo- liative syndromes or glaucoma. e presence of blood or membranes is typical of pathologies, such as neo- vascular glaucoma or iridocorneal endothelial syndrome. In addition to aiding in diag- nosis, gonioscopy allows you to determine the best treatment. For example, a patient with an open angle is a candidate for selective laser trabeculoplasty. With the movement toward minimally in- vasive glaucoma surgery (MIGS), accurate gonioscopy is critical. Aer all, the angle is where the majority of MIGS procedures are performed, and an open angle with no pathologies is needed for success. (See gonioscopy.org.) 2 USE THE MARCUS GUNN TEST Although not specific for glau- coma, the Marcus Gunn test does indicate a compromise to the op- tic nerve head. 3 DO A STEREOSCOPIC EVAL. Evaluate the optic disc and nerve fiber layer (NFL) for defects. A nor- mal NFL has a striate appearance with underlying vessels obscured, as if a transparent tape is placed over the vessels. NFL defects ex- tend to the disc and can be in a slit, wedge or diffuse pattern. Also, be aware of optic nerve head notch- ing, which appears as focal loss of tissue and vertical elongation and narrowing of the neuroretinal rim, commonly superiorly and inferi- orly. In addition, disc hemorrhages should be a red flag for glaucoma. Major studies, including the Early Manifest Glaucoma Trial, indicate that disc hemorrhages are strongly associated with glaucoma progres- sion. Finally, keep an eye out for vascular changes, such as a bayonet sign and vessel baring. e former shows retinal vessels deviating from their normal course. A "z" appear- ance is common, as vessels emerge at a sharp angle over the edge of the cup. e latter shows that vessels are no longer supported by rim tis- sue and have an appearance of be- ing suspended over free space. RETURNING TO OUR ROOTS Let's not forget about the classic tools available to aid in diagnosis. e 88-year-old patient men- tioned above was ultimately diag- nosed with primary open-angle glaucoma based on a stereoscopic evaluation of the optic nerve heads and gonioscopy, showing open normal angles. OM DON'T FORGET THE CLASSICS KEEP THESE CLASSIC TECHNIQUES IN MIND FOR DIAGNOSIS Stereoscopic view of a glaucoma- tous optic nerve head. JUSTIN SCHWEITZER, O.D., F.A.A.O. DR. SCHWEITZER specializes in advanced glaucoma, refractive sur- gical clinical care and an- terior segment pathology at Vance Thompson Vision. He has had mul- tiple articles published and has de- livered lectures on glaucoma, ante- rior segment pathology, refractive surgical clinical care and surgical management. Email him at justin.sch weitzer@vancethompsonvision.com, or send comments to tinyurl.com/ OMcomment.

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