The Toric MicroSil 6116TU (HumanOptics AG, Erlangen, Germany) is a three-piece silicone IOL with an optic diameter of 6 mm and overall length of 11.6 mm. The lens has a spherical anterior and toric posterior surface and undulating Z-loop haptics.
Compared with standard spherical or aspheric lenses, there are a few extra steps for toric IOL implantation. The references axes on the cornea are marked preoperatively at the slit lamp. The implantation axis is marked when the patient is on the table. After the lens is implanted, it is dialed into the proper alignment (Figure 1). Careful attention to the Z-haptics is essential to achieve correct placement of the IOL, including centration, axis of orientation, and stability.
In a study that will be presented at this year's European Society of Cataract and Refractive Surgeons (ESCRS) meeting in Barcelona, Spain, we analyzed results of Toric MicroSil 6116TU implantation in 27 eyes of 21 patients with cataract and corneal astigmatism. Phacoemulsification was performed through a 3.2-mm incision. The mean astigmatism to be corrected was 3.40 D (range, 2.00–5.75 D). The mean implanted IOL power was 19.10 D (range, 9.00–29.00 D) sphere and 4.20 D (range, 2.00–8.00 D) cylinder. Postoperatively, Snellen UCVA was 0.82 and BCVA was 0.92; mean spherical equivalent refraction was -0.23 D. Mean IOL axis rotation at 6 months was 1.3° (range, -3.5° to 9.7°). In one eye, IOL rotation was caused by capsular fibrosis; in another eye IOL reposition was required at day 1 postop because of more than 10° of rotation. Correction of preexisting astigmatism at cataract surgery with the HumanOptics Toric MicroSil 6116TU is safe and effective in our experience.
Marek Rekas, MD, PhD, practices in the Ophthalmology Department of the Military Health Service Institute, Warsaw, Poland. Dr. Rekas states that he has no proprietary interest in the materials, products, or methods mentioned. He may be reached at e-mail: firstname.lastname@example.org.