EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/115557
March 2013 EW CATARACT 69 Determining visual outcomes by Michelle Dalton EyeWorld Contributing Writer With all the improvements in technology, is measuring vision by Snellen alone enough these days? you want to capture that complex phenomenon in a single measurement of visual acuity, Snellen remains the best." Improving visual outcome measurements Dr. Waring said contrast sensitivity is "the most important thing we measure. In our clinic, we measure it U sing a letter chart to measure vision is cheap, easy, and quick. If a patient reads the letters on the chart correctly and at a reasonable visual acuity, then it's likely the rest of the visual system is functioning correctly as well. But if a patient cannot read those letters well, what then? "Being able to see the letters on a chart in a really high contrast situation is relatively easy to do even if the visual quality is poor," said Uday Devgan, M.D., in private practice, Los Angeles, and chief of ophthalmology, Olive View–UCLA Medical Center. "Snellen is, and will remain, the standard. But it's not the be-all and end-all. It's just a small portion of what makes up a person's vision." Character recognition on a letter chart (as proposed by Snellen in 1862) should still be the standard for "visual acuity" measurement, said August Colenbrander, M.D., the Smith-Kettlewell Eye Research Institute and California Pacific Medical Center, San Francisco. "Visual acuity alone is not enough to define vision, but neither is visual field, or contrast sensitivity, or color vision, or dark adaptation, or any other parameter," he said. "Is Snellen acuity assessment going anywhere? No. But is it adequate? No," said George O. Waring IV, M.D., assistant professor of ophthalmology, and director of refractive surgery, Medical University of South Carolina. "They're important, but they're not enough. We need better objective analyses that describe quality of vision and functionality." Snellen may be a "very strong indicator of vision," but "real world vision is very different and impacts directly on quality of life," said Eric D. Donnenfeld, M.D., partner, Ophthalmic Consultants of Long Island, Rockville Centre, N.Y., and clinical professor of ophthalmology, NYU School of Medicine, New York. "Vision is a complex phenomenon," Dr. Colenbrander said. "But if under varying conditions to determine what a person's functional vision is." One of the most common complaints he addresses is from pacontinued on page 70 The The power of one THE ONE FEMTO PLATF OR M FE MTO PLATF PLATFORM for cornea, presbyopia and cataract. cataract. for cornea, presbyopia Presenting the unparalleled Ziemer FEMTO LDV Z Models – a technical revolution in ocular surgery. No laser is more precise, more powerful or more progressive when it comes to meeting all your procedural needs in a single platform. With Ziemer's FEMTO LDV Z Models, now you can operate Ziemer's with a modular femtosecond system that is easy to configure, designed to grow with your practice – cornea tomorrow. and presbyopia today, cataract tomorrow. www.ziemergroup.com www.ziemergroup.com The Ziemer FEMTO LDV Z Models are FDA cleared and CE marked and available for immediate delivery. For some countries, availability may be restricted due to local regulatory requirements; please contact Ziemer for details. The creation of a corneal pocket is availability part of a presbyopia intervention. Availability of related corneal inlays and implants according to policy of the individual manufacturers and regulatory status in the individual countries. Cataract procedures with the FEMTO LDV Z2, Z4 and Z6 models are not cleared manufacturers in the United States and in all other countries. An upgrade possibility for these devices is planned once cataract options are available and cleared by the responsible regulatory bodies.