Eyeworld

77 EW GLAUCOMA February 2016 A longer period of study follow-up would help show if IOP decrease was sustained 1 or 2 years postoperatively, he said. Dr. Lee noted that the study included 31 eyes of patients with open angles who underwent laser peripheral iridotomy prior to cata- ract surgery. "It could potentially be useful for clinicians to predict the IOP change after cataract surgery in such patients and if the predicted IOP af- ter cataract surgery falls within their target IOP," he said. "Clinicians who do not have anterior segment OCT can use the values from biometry to calculate the lens position (ACD + half lens thickness) and predict the percent of IOP change." Beyond cataractous lens po- sition, Robert J. Weinstock, MD, director, cataract and refractive services, Eye Institute of West Flor- ida, Tampa, Fla., raised compelling points about IOL position after surgery. If there is a narrow posterior chamber and the IOL is placed in the sulcus or anteriorly, then there could be aqueous blockage if the iris is touching the IOL. Sometimes this can lead to iris chafing by the lens in a small eye. Pigment dispersion can worsen the glaucoma and raise the pressure even further. That said, routine cataract sur- gery performed on patients with pri- mary open-angle glaucoma (POAG) is almost equivalent to standard cataract surgery; complications are exceedingly rare. Even if the pressure is a little high postoperatively, it's unusual for eyes to run into pressure-related trouble, he said. EW Reference 1. Hsu CH, et al. Lens position parameters as predictors of intraocular pressure reduction after cataract surgery in nonglaucomatous patients with open angles. Invest Ophthalmol Vis Sci. 2015;56(13):7807–7813. Editors' note: Dr. Lin has no financial interests related to his research. Drs. Lee and Weinstock have no financial interests related to this article. Contact information Lee: kelvinlee@eagleeyecentre.com.sg Lin: shan.lin@ucsf.edu Weinstock: rjweinstock@yahoo.com Most importantly, according to Hsu and colleagues, the well-de- scribed diurnal fluctuation in IOP is a variation that makes other predic- tive parameters (i.e., preoperative IOP and PD ratio) less reliable. On the other hand, because LP is com- puted by ACD and LT (more stable parameters), that makes it more accurate, they noted. Based on the findings, Hsu and colleagues concluded that in non-glaucomatous patients with open angles, LP is strongly associat- ed with IOP reduction after cataract surgery. "One possible explanation for this phenomenon is that the more anteriorly positioned the lens is, the more likely it is to result in 'partial pupillary block,'" they explained. "Lens position, which is simple to calculate by basic optical biomet- ric data, is a widely available param- eter with relatively better predictive value for postoperative IOP change; the result could explain a poten- tial mechanism for IOP reduction after cataract surgery for eyes with open-angle configuration," they concluded. Small, but interesting Kelvin Lee, MD, senior consultant ophthalmologist, and director of glaucoma services, Eagle Eye Centre, Singapore, noted that although this was a small study, it effectively showed "that the percentage de- crease in IOP 4 months after cataract surgery in non-glaucomatous eyes was greater in more anteriorly posi- tioned lenses [with cataract]." "In other words, if you have patients with shallower anterior chambers and anteriorly positioned lenses (potentially narrow/occlud- able angles), you would expect a greater percentage decrease in IOP compared to patients with a deeper chamber (open angles) and poste- riorly positioned lenses," he told EyeWorld. "As this study was in non-glaucomatous eyes, the findings may not be comparable to exist- ing glaucoma patients, specifically chronic angle-closure patients, who may already have pre-existing tra- becular damage, such that the IOP change after cataract surgery may be minimal and unpredictable with a compromised trabecular function even with open angles postop." A F R E S H P E R S P E C T I V E ™ © 2015 Lacrivera, a division of Stephens Instruments. All rights reserved. 2500 Sandersville Rd ■ Lexington KY 40511 USA lacrivera.com ( 855 ) 857-0518 William J. Faulkner, M.D. Cincinnati Eye Institute The VeraPlug ™ challenge results are in. Try the VeraPlug. ™ What will you say? "The VeraPlug ™ has become my punctal plug of choice. Design features allow easy sizing, quick insertion and longer stability. Both patient and doctor are pleased."

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