Eyeworld

EW NEWS & OPINION 11 At the ASCRS•ASOA Symposium & Congress, the best paper of session is selected by the moderator and panel for each free paper symposium. In the next several issues of EyeWorld, the medical editors will be highlighting some of these best papers by inviting the authors to submit a brief summary or abstract David F. Chang, M.D., chief medical editor Long-term results of cataract surgery in patients with traumatic zonular dialysis and mydriasis Boris Malyugin, M.D. The Malyugin CTR (Morcher GmbH, Stuttgart, Germany) is the modified version of the Cionni ring designed to center the subluxated lens capsule by securing it to the scleral wall. The basic design idea consisted of mov- ing the fixation element to the very tip of the ring, making it completely retractable into the injector tube, subsequently allowing the device to be used through a micro-incision (2.2 mm). The main idea of the current study was to investigate safety, visual functions, pupil appearance, and final IOL position after Malyugin CTR-assisted phacoemulsi- fication in six patients with trau- matic cataracts, extensive zonular dialysis, and fixed dilated pupil. Final steps of the surgery included iridoplasty with three to four inter- rupted Siepser sliding knot 10/0 polypropylene sutures. No major complications were observed during and after the sur- gery; follow-up was 7.8±2.2 months. Pre-op BCVA varied from counting fingers to 20/70 and improved to the mean 20/30 after the surgery. IOP was normal, pupils usually hav- ing a polygonal shape varying from 3.5 mm to 4.0 mm in diameter. Cor- rect capsular bag and IOL position was achieved, the latter verified with ultrasonic biomicroscopy. Based on the results of this study we came to the conclusion that the Malyugin CTR is a useful new tool providing a safe and effec- tive solution for patients suffering from cataract and zonular compro- mise. Comparison of capsulotomy strength with and without trypan blue dye using a mechanized model for capsulorhexis resistance to tearing Nick Mamalis, M.D., Liliana Werner, M.D., Don K. Davis Jr., M.D., Surekha Maddula, M.D., Michael K. Burrow Continuous curvilinear capsu- lorhexis (CCC) is a critical procedure in cataract surgery. CCC is difficult in eyes with white cataracts or a poor red reflux. Trypan blue dye has been used to stain the capsule in these cases and there is some evi- dence that this may weaken the cap- sule. Fresh human cadaver eyes were used to study the CCC strength comparing trypan blue and control eyes using a mechanized separation of the CCC, stretching it to its rup- ture point. The rupture load [new- tons (N)] was measured as well as the extension in millimeters (mm). Ten study eyes were compared to 23 control eyes. The mean rupture load was 0.40 N (SD=0.13) in the trypan blue group and 0.39 N (SD=1.16) in the control CCC group. The mean ex- tension at CCC tearing was 5.7 mm (SD=0.99) in the trypan blue group and 5.85 mm (SD=1.17) in the con- trol CCC group. Trypan blue dye was not found to significantly weaken the CCC strength in this mechanical model evaluating the strength and extensi- bility of the capsular bag in fresh human cadaver eyes. Personalized pseudophakic model for refractive assessment Filomena Ribeiro, M.D., Antonio Castanheira-Dinis, M.D., Ph.D., Joao M. Dias, Ph.D. We have developed a pseudophakic eye model (PM) that allows a per- sonalized assessment of intraocular lens (IOL) power. The Liou-Brennan eye model was used as a starting point. Individual biometric values Best papers of session July 2011 and detailed elevation corneal sur- face data were imported to optical ray-tracing software (Zemax, Belle- vue, Wash.). Optimization criteria based on values of the modulation transfer function weighted accord- ing to contrast sensitivity function were applied. The model was tested in 104 eyes scheduled for LASIK. Results obtained with our PM were compared to SRK/T before LASIK and after with the average IOL power available on the ASCRS web- site. Results showed that our PM is applicable to IOL power calculation in a personalized way, with the added advantage of being independ- ent of population data and correc- tion factors in post-LASIK cases, being able to meet future demands for correcting higher-order aberra- tions with IOLs, which is not possi- ble with the currently available formulas. Comparison of femtosecond laser and manual capsulotomy on post- operative quality of vision Zoltan Z. Nagy, M.D. I have been working with the fem- tolaser in lens refractive surgery for 3 years. The first lens operation was performed in a human eye in the Department of Ophthalmology, Semmelweis University, Budapest, Hungary, in August 2008. The femtolaser is able to substantially increase the safety of cataract operations. I have per- formed more than 400 femtolaser lens procedures. Based on my experi- ences, I found: The femtolaser can create a laser precise, centered capsulorhexis in the desired diameter, able to liquefy the lens nucleus up to grade 2.0 cataract and able to fragment the lens up to grade 3.5 cataract into four or more pieces. It can create any type of corneal wound in the desired location, structure, and size. This is a 60-second procedure. It needs precise and thorough prepara- tion before surgery. The advantage of the femtolaser is very important in premium lens surgery because surgeons can achieve all the benefits of premium lenses (multifocal, toric, and accom- modative) with a precise surgery (central capsulotomy, 0.5 mm over- lapping of the optics of the PCL by the anterior capsule and a self-seal- ing corneal wound). The results with femtolaser tech- nology are statistically significantly better compared to manual cataract techniques in predictability and ef- fective lens position. Less force is produced from capsular fibrosis due to central IOL position, less lower- and higher-order aberration are cre- ated, and less phacoemulsification time is needed. From a safety point of view, I found that there is no change in endothelial density and no danger of post-operative macular edema (CME) after femtolaser cataract surgery. EW

• Cover