Eyeworld

92 Reporting from the 2014 Combined Ophthalmic Symposium (COS) San Antonio, Texas September 2014 EW MEETING REPORTER T he meeting's opening session, "Cataract Surgery: Nailing the Fundamentals" gave attendees practical tips for tackling both routine and complex cataract cases. The first part of the session focused on determining optimal fluidics and pump settings to meet each sur- geon's needs. Sumit "Sam" Garg, MD, Irvine, Calif., discussed the differences between peristaltic and venturi pumps and described the benefits of using both systems in the same case. Session moderator Gary J.L. Foster, MD, Fort Collins, Colo., described phacoemulsification with an active fluidics system, which gives the surgeon control over the inflow of fluid as well as the outflow. The forced infusion system offers a larger safety net for the surgeon, Dr. Foster said, and results in a more sta- ble anterior chamber, allowing the surgeon to use less phaco energy. Jonathan B. Rubenstein, MD, Chicago, offered pearls for operating on brunescent and white cata- racts. For brunescent cataracts, the surgeon should focus on achieving adequate pupil dilation, as well as protecting the cornea with a disper- sive or high molecular weight OVD, Dr. Rubenstein said. Additionally, surgeons should use both a vertical and horizontal chopping technique. For white cataracts, it is imperative to keep the pressure outside of the capsule greater than the pressure inside the capsule. Keeping the capsulorhexis small is also import- ant for both brunescent and white cataracts, and a femtosecond-created capsulorhexis may be the ultimate solution in these cases, he said. W. Barry Lee, MD, Atlanta, shared his top 10 pearls for complex cataract cases. Preoperatively, he recommended that surgeons look for phacodonesis in patients with a history of trauma and assess the risk for intraoperative floppy iris syn- drome. Dr. Lee also recommended that surgeons learn how to make a reverse capsulorhexis, use a Malyugin ring (MicroSurgical Technology, MST, Redmond, Wash.), and remove the ring efficiently. Mitchell P. Weikert, MD, Houston, described sources of error in power calculations and the short- comings associated with existing formulas. The index of refraction, effective lens position, corneal power, axial length, and IOL design are main sources of error in power formulas, but the biggest hurdle for surgeons to overcome is determining the effective lens position, he said. A more accurate model of the human eye will yield better results, he add- ed, but the postoperative adjustment of corneal or IOL refractive power is likely the ultimate solution. Despite the limitations of existing formulas, Dr. Garg discussed the potential for intraoperative aberrometry to improve IOL power calculations. Intraoperative aberrometry helps to confirm preoperative power calculations, he said, and has the added benefit of being able to account for posterior corneal astigmatism. Editors' note: Dr. Foster has financial interests with Alcon (Fort Worth, Texas) and WaveTec Vision (Aliso Viejo, Calif.). Dr. Garg has financial interests with Abbott Medical Optics (AMO, Santa Ana, Calif.). Dr. Lee has financial interests with Allergan (Irvine, Calif.) and Bausch + Lomb (B+L, Bridgewater, N.J.). Dr. Rubenstein has financial in- terests with Alcon and B+L. Dr. Weikert has financial interests with Ziemer. Managing the complexities of corneal disease Topics including infectious keratitis, deep anterior lamellar keratoplasty (DALK), penetrating keratoplas- ty (PK), endothelial keratoplasty (EK), and moving from Descemet's stripping endothelial keratoplasty (DSEK) to Descemet's membrane en- dothelial keratoplasty (DMEK) were highlighted in a session focusing on corneal disease. Irving M. Raber, MD, Bala Cynwyd, Pa., discussed indications for PK. These indications include for a perforated cornea; if the patient has had hydrops; if there is long- standing bullous keratopathy with non-edematous stromal haze or scar- ring; if there is endothelial compro- mise and stromal scarring; if there has been a failed PK with wound ectasia, recurrent keratoconus, or high astigmatism; for aborted DALK; and for open sky cataract surgery when the cornea is too cloudy for closed phaco or an IOL. When comparing PK to DALK, Dr. Raber said PK is a tried and true procedure with favorable long- term outcomes. It is a less complex, quicker procedure than DALK but with similar concerns in astigmatism and anisometropia. PK offers better visual results than non-big bubble DALK. Dr. Rubenstein highlighted EK and the evolution of corneal transplantation, moving from thin to thinner procedures. Ultra-thin DSEK is similar to normal thickness DSEK but with a thinner graft, he said. It is thought that there is a greater chance of 20/20 vision with this technique. "The problem is that the thinner tissue is slightly harder to work with," he said. The tissue is floppier and less predictable in how it will open up in the eye. Descemet's membrane auto- mated endothelial keratoplasty (DMAEK), on the other hand, is a hybrid technique like both DMEK and DSEK. It has peripheral skirts of corneal stromal tissue with just De- scemet's membrane and endotheli- um centrally, so it handles like DSEK but gives central vision like DMEK, Dr. Rubenstein said. Finally, he discussed DMEK, where less tissue is inserted than in DSEK. There is less corneal flattening Reporting from the 2014 Combined

• Cover