Costing the cataract learning curve

Teaching residents cataract surgery is an expensive undertaking in terms of both time and money. US researchers sought to quantify theses costs in a comparative case series. They evaluated the differences in the time of completion of cataract surgery for nine residents and six attending surgeons. The mean attending surgeon case time was 25.75 minutes Â} 12.32 and the mean resident case time, 46.35 Â} 16.75 minutes. Using a dollar cost of approximately $11.24 per minute at the institution, the cost difference was calculated to be $138,926.40 had both groups performed the same number (600) of procedures. They note that if the completion of a case for residents could be lowered on average by five minutes for 600 cases, the cost savings to our hospital would approach $33,720. The researchers posit that investments in time and money for classroom, wet lab and simulation instruction before allowing residents to perform surgery might reduce costs and prove to be cost effective.

MJ Taravella et al., JCRS, “Time and cost of teaching cataract surgery”, Volume 40, Issue 2, 212-216.

Refractive surprises with toric IOLs

Refractive cylinder surprises can occur after toric intraocular lens (IOL) implantation, even when state-of-theart measurement devices and planning software are used. The orientation of the IOL must be considered in addition to the cylinder power and the spherical power of the IOL. Other factors include surgically induced astigmatism and ocular residual astigmatism. In an experimental study, Alpins and colleagues employed vergence formulas using a standard eye model to bring all lens powers to the corneal plane. Double-angle vector diagrams were then used to determine the refractive cylinder effect of rotating a toric IOL and show how the prevailing astigmatism and the various planning and surgical steps involved in implanting a toric IOL contribute to the postoperative manifest refractive cylinder. They demonstrate how to calculate the angle of rotation, which is the toric IOL rotation, to minimise the amount of manifest refractive cylinder in any eye using optimised lens constants to account for eye-specific and surgeon-specific factors that affect the equivalent power of the toric IOL at the corneal plane. They conclude that understanding the causes of refractive surprise enables surgeons to address contributory factors and choose an appropriate surgical method for managing individual cases of refractive cylinder surprise.

N Alpins et al., JCRS, “Refractive surprise after toric intraocular lens implantation: Graph analysis”, Volume 40, Issue 2, 283-294.

Multifocal IOL indications

Which cataract patients are most suitable for multifocal IOL implantation? Braga- Mele and colleagues reviewed preoperative diagnostic evaluations, patient selection criteria and counselling practices. The comprehensive US study concludes that appropriately selected patients can achieve spectacle independence and good visual outcomes at both near and distance with current multifocal IOLs. The selection process begins with proper patient education and individualised weighing of benefits and side-effects of multifocal IOLs. Given the high sensitivity of multifocal IOL function to minor ocular aberrations, preoperative clinical evaluation is crucial to postoperative success. While some patients will experience unsatisfactory outcomes due to issues that are unique to this class of IOLs, suitable postoperative management of both satisfied and dissatisfied patients will ultimately improve the visual benefits of these IOLs, they note.

R Braga-Mele, et al., JCRS, “Multifocal intraocular lenses: Relative indications and contraindications for implantation”, Volume 40, Issue 2, 313-322.