Eyeworld

EW NEWS & OPINION 11 O ver the past month, there has been much re- flection on the events of September 11, and many ASCRS members have been involved in activities to com- memorate the event, including rec- ognizing the first responders on whom they rely every day for the work they do with fires, car acci- dents, floods, and natural disasters. ASCRS is headquartered in Fair- fax, Va., a fast-growing and bustling suburb a stone's throw from Wash- ington, D.C. and the Pentagon, a primary target of the 9/11 attacks. The area is served by Station 21 of the Fairfax County Fire and Rescue Department. The station is a combi- nation career and volunteer organi- zation that provides fire suppression, emergency medical, technical res- cue, hazardous materials, water res- cue, life safety education, fire pre- vention, and arson investigation services. Emergency medical services include advanced life support re- sponse by ALS capable engines and transport units. As an expression of thanks, an ASCRS member organized a warmly received luncheon for the Station 21 crew, with ham, turkey, and many desserts. On any given day, there are at least 10 people at this station, 24/7/365, according to Capt. Joseph Kaleda, adding that about 20 volun- teers supplement the professional fire, rescue, and emergency medical personnel. In addition to fire response and emergency medical services, Station 21 is a Technical Rescue Station. "That means we have a heavy rescue October 2011 by John Ciccone ASCRS Director of Communications ASCRS shows its gratitude to Fire and Rescue Department Prevalence of corneal astigmatism Mohammad I. Khan, M.R.C.Ophth., Mohammed Muhtaseb, F.R.C.Ophth. Investigators in this case series took a look at the demand for toric IOLs for those slated to undergo cataract surgery, by analyzing and quantify- ing the pattern of corneal astigmatism. Included here were measure- ments from 1,230 eyes of 746 patients that attended a pre-assessment clinic over a 4-month period. When the data was analyzed investigators found that in 24.47% of eyes corneal astigmatism was 0.5 D or less and for 79.5% this was 1.5 D or less. In just 4.6% of cases was this more than 2.5 D and in 1.93% was there 3 D or more of astigmatism. When inves- tigators considered the demand for more than 1 D of astigmatism cor- rection, they found that this affects about 40.41% of patients going in for routine cataract surgery. Investigators view this data as a boon for enabling hospitals to conclude how much of a demand there is for toric IOLs to correct corneal astigmatism as well as determining how much this would cost. Infectious keratitis in 18 651 surface ablations Victoria de Rojas, M.D., Ph.D., Fernando Llovet, M.D., Ph.D., Mercedes Martínez, M.D., Rosario Cobo-Soriano, M.D., Ph.D., Julio Ortega-Usobiaga, M.D., Ph.D., Jaime Beltrán, M.D., Julio Baviera, M.D. In this case series investigators evaluated the incidence of infectious ker- atitis after surface ablation. Reviewing the records of 9,794 patients they found that after undergoing surface ablation just 39 eyes of 38 patients were affected by the condition. In 71.79% of cases the onset occurred within 7 days of undergoing the procedure. Cultures were taken in 27 cases and were positive in 13. Staphylococcus was identified in nine cases, which was the most frequent. When investigators looked at visual out- comes they found that in 58.97% of cases corrected distance visual acu- ity was 20/20 or better. In 92.30% CDVA was 20/40 or better and in 7.69% of cases was 20/40 or worse. Investigators concluded that while there is just a 0.20% chance of infectious keratitis after surface ablation, when this does occur it is a potentially vision-threatening complication. They recommend prompt and aggressive management with fortified an- tibiotic agents. Laboratory science: Residual astigmatism caused by toric IOL Adelina Felipe, Ph.D., José Ma Artigas, Ph.D., Amparo Díez-Ajenjo, O.D., M.Sc., Carmen García-Domene, O.D., MSc, Pablo Alcocer, M.D., Ph.D. The aim in this study was to analyze what happens in those cases when a toric intraocular lens rotates using two different methods to determine residual astigmatism. The first method, dubbed cylinder resultant, in- volves two cylinders C1 and C2 whose axes form angle a. To determine this, two vectors of values C1 and C2, which form angle 2a, are added together. With the second method, dubbed the power matrix, the astig- matism breaks down into three orthogonal components: the purely spherical part, the ortho-astigmatism, and oblique astigmatism. Investigators determined that when the IOL rotated plus or minus 10 degrees, in cases where the value of the cornea and the IOL were equal the residual cylinder was 1/3 of the cornea. In most cases, the value for the IOL was less than that for the cornea so small rotations of the toric IOL did not noticeably change residual astigmatism. Investiga- tors concluded that both methods gave equal results. In trying to reduce astigmatism in cases where IOL and corneal values are different, a better choice for the IOL would be one with a lower cylinder value. As a rule, there was less than a 0.50 D change in the eye's refraction when the toric IOL rotated less than 10 degrees. As a result, patients could still ob- tain reasonable astigmatism correction with toric IOLs in cases where the lens has rotated less than 10 degrees. In the journal … October 2011 continued on page 12 Part of the team at Fire Station 21 in Fairfax, Va., with members of ASCRS staff

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