EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/111385
February 2013 250-750 ��m for the lens, reported Lt. Cmdr. Corby D. Ropp, M.D., Naval Hospital, Camp Lejeune, N.C., who spoke on ���The Navy Phakic Intraocular Lens Study: Factors Affecting the Vault Height.��� ���The problem is that we���re still using white-to-white to size these lenses rather than sulcus diameter, but even sulcus diameter nomograms aren���t perfect,��� Dr. Ropp said. ���Rather than targeting greater than 90 ��m as our lowest acceptable vault height, we should be looking at a minimum acceptable of 140 ��m based on Dr. Howard Gimbel���s work utilizing a much larger sample size.��� In the study, researchers reviewed the records of 163 eyes of 85 consecutive patients who received the Visian Implantable Collamer Lens V4 (ICL, STAAR Surgical, Monrovia, Calif.). They used Multivariate Analysis of Variance (MANOVA) and Visante OCT (Carl Zeiss Meditec, Jena, Germany) measurements to determine the factors affecting the lens vault height. They also evaluated the effect of pupil constriction on vault measurements. They concluded that estimating the anterior chamber volume (ACV) was the best determinate of the lens vault height and anterior chamber depth (ACD) seems to have the most influence on ACV. ���If we exclude implantation of the lens with low estimated ACV, then we lose 30% of low vaults,��� Dr. Ropp said. ���If we additionally exclude implantation for ACD less than or equal to 3.0, which is consistent with a large European study by Alfonso, then we lose another 35%. If we place the FDA-recommended lens instead of the optimized one (i.e., 12.6 instead of 12.1, and 13.2 instead of 12.6, but exclusive of the 13.7 FDA recommendation), we eliminate another 25% of low vaults. If we stick to the FDA age limits and avoid placing lenses in patients over age 45, we have another 5% reduction in low vaults.��� Even using ultrasound biomicroscopy (UBM), which directly measures internal structures, isn���t perfected, although it���s a step in the right direction, Dr. Ropp said. ���UBM nomograms don���t always factor ACD and can have high interexaminer variance that can affect sizing,��� he said. Editors��� note: Dr. Ropp has no financial interests related to this presentation. ���Enhancement Survival Kit��� During a talk on enhancements, Col. Torres offered his set of ���Enhancement Survival Skills��� and cautioned surgeons against aiming for perfection just for the sake of getting optimized results. ���Are you enhancing your patient or your results?��� he asked. ���Perfection is one of our attributes, but it also can be an enemy.��� Col. Torres said surgeons should be ruled by subjective factors when deciding whether to enhance a patient. ���Ninety-nine percent of the time, if they���re not complaining, leave it alone,��� he advised. ���Just be- EW MEETING REPORTER 85 cause we can measure it, doesn���t mean we should treat it.��� He added that enhancements should be individualized for a patient and that surgeons should know about their patient���s refraction and occupation and activities. ���Don���t batch your treatments,��� he said. Editors��� note: Col. Torres has no financial interests related to this presentation. EW