Defeating Astigmatism: Refractive Success With A High Power Toric Iol Implantation In A Complex Cataract Case

To describe a successful case of surgical correction of high residual astigmatism using a high power custom toric IOL (Humanoptics TORICA®) in a young patient previously submitted to penetrating keratoplasty who subsequently developed a white intumescent cataract.

Ophthalmology Department, Hospital Fernando Fonseca, Lisbon, Portugal

A 33 year old man, with a history of recurrent herpetic stromal keratitis resulting in visually significant corneal scaring in the right eye, underwent a penetrating keratoplasty with subsequent high residual astigmatism (-11D at 25º). Two years later, he developed a white intumescent cataract. Preoperative evaluation showed concordant and stable keratometry results with both TOPCON® auto kerato-refractometry, PENTACAM® corneal topography and ARGOS® SS-OCT biometry, rendering him a good candidate for toric IOL implantation. The Humanoptics TORICA-aA® IOL was selected for its wide range of available spherocylindrical powers. Using the Kane formula for a target of -1.50D, a +20,50D cil 14,50D at 115º axis was selected. The implantation of such a high toricity IOL already poses significant refractive challenges and was further made difficult in the setting of a surgically challenging white intumescent cataract and a young patient with an elastic lens capsule, being at an increased risk for intraoperative and postoperative complications. Small incision at 100º axis was made to minimize surgical astigmatism. Care was taken to ensure adequate centered capsulorexis and a capsular tension ring was placed to ensure bag stability, IOL centration and safeguard the need for later surgery. The surgery was without complications and postoperative refractive error was -2.00 -0.50 x120º with an uncorrected visual acuity of 8/10+, reaching 10/10 with -1.00D spherical correction.

This case shows high toricity IOLs can be a effective means of high astigmatism correction in selected patients with adequate preoperative evaluation. It also demonstrates the Kane formula, PENTACAM topography, ARGOS OCT biometry showed adequate predictive performance.  It further highlights the challenges faced when toric IOL implantation is combined with complex cataract cases and suggests steps than can aid surgical and refractive success.