EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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84 EW MEETING REPORTER Reporting live from IMRSS 2013, San Antonio February 2013 Edward W. Trudo, M.D., that four years of nomogram development and data were analyzed for visual outcomes and found to exceed the FDA-approved outcomes data for LASIK. Editors��� note: Col. Torres has no financial interests related to this presentation. Improving quality Retired Navy Capt. Steve C. Schallhorn, M.D., former director, Cornea Service & Refractive Surgery, Naval Medical Center, San Diego; and professor of ophthalmology, University of California, San Francisco, talked about improving quality. ���It can be a very abstract idea,��� he said. In order to improve LASIK refractive predictability and outcomes, Capt. Schallhorn and colleagues worked on developing a nomogram for wavefront-guided procedures by assembling a large data set and using statistical modeling to create different types of nomograms. ���We had to balance the outcomes with ease of use,��� he explained, going into detail about how outcomes were improved. ���Quality improvement requires dedication, it requires time and perseverance. It needs to be a continuous process.��� Editors��� note: Dr. Schallhorn is the global medical director for Optical Express, and he has financial interests with Abbott Medical Optics (Santa Ana, Calif.). Tuesday, January 8 Surprising dry eye results Editors��� note: This Meeting Reporter contains original reporting by the EyeWorld news team from IMRSS 2013, San Antonio. Researchers analyzing the satisfaction of 32,070 laser vision correction patients discovered that gender, treatment type, and pre-op hyperopia are significant independent predictors of post-op dry eye symptoms, a highly regarded speaker reported during the second day of the International Military Refractive Surgery Symposium. Most surprising is that ���PRK results in more dry eye at three months than LASIK, and significantly so,��� said retired Navy Capt. Steve C. Schallhorn, M.D., former director, Cornea Service & Refractive Surgery, Naval Medical Center, San Diego; and professor of ophthalmology, University of California, San Francisco. Females and hyperopes tend to report more dry eye. However, ���age effect is much less than I would have expected,��� Capt. Schallhorn said. Likewise, myopia, pre-op spherical equivalent, and ablation depth didn���t seem to induce moderate to severe dry eye. ���People are saying, ���If you ablate more, you���re going to create more dry eye because you���re removing more.��� We don���t see that.��� The researchers analyzed threemonth post-op questionnaires where patients who received LASIK or PRK between January 2010 and December 2011 reported dry eye symptoms. Pre-op parameters that were looked at were age, gender, geographic location, refraction, tear break-up time, and tear film quality. Univariate, multi-regression, and generalized and ordered linear regression models were used to develop pre-op predictors of dry eye symptoms. ���We found many different variables that popped up in our univariate analysis as being contributors to dry eye ��� but it wasn���t robust enough for us to do predictive modeling. ���Dry eye is the most common side effect of laser vision correction. The symptoms are related to patient dissatisfaction. There are predictive factors, however, our most robust modeling only explains 2% of the variance.��� Still, ���we can���t explain why patients develop dry eye after surgery,��� Capt. Schallhorn concluded. ing to a paper presented at the meeting. Researchers at Fort Belvoir in Virginia looked at 26 eyes in 13 patients who underwent WFG PRK and 28 eyes in 14 patients who underwent WFO PRK. Mean pre-op manifest spherical equivalent (MSE) was ���3.31 D �� 1.41 in WFG and ���3.41 D �� 1.10 in WFO eyes (P=0.42). This is Phase II (n=52) of an ongoing prospective study in collaboration with the Army Warfighter Refractive Surgery Research Center at Fort Belvoir, Walter Reed National Military Medical Center, and the Night Vision and Electronic Sensors Directorate. Participants fired an M16-A2 rifle using only their dominant eye pre-op and at six weeks and six months post-op under low-light or nighttime conditions. Specifically, marksmanship skill was evaluated while participants used night vision goggles and aiming light, a gunmounted thermal sight and an iron sight. Pre- and post-op firing range scores were compared, and WFG and WFO PRK visual outcomes were compared at six months. ���There are pretty tight results between the [iron sight and night vision] groups. There was no significant change in the subjects over time in terms of military task performance,��� said Army Col. Mark F. Torres, M.D., U.S. Army Madigan Army Medical Center, Tacoma, Wash. ���That���s an encouraging conclusion. This plays into exactly what we want to do in our military refractive program. What the services want to make sure we���re not doing is degrading performance.��� Editors��� note: Dr. Schallhorn is the global medical director for Optical Express, and he has financial interests with Abbott Medical Optics (Santa Ana, Calif.). Editors��� note: Col. Torres has no financial interests related to this presentation. Ready, aim, research Using firing range scores, Army surgeons were able to determine that military visual and task performance outcomes are comparable between wavefront-guided (WFG) and wavefront-optimized (WFO) PRK, accord- Sizing is everything ICLs rely heavily on correct sizing calculations. Low lens vault and cataract formation is a concern in the Navy���s young active duty population, and the FDA standard of determining sulcus size through white-to-white measurements may not lead to an ideal vault height of