Predictability of refractive outcome of a small-aperture intraocular lens (IC-8, Acufocus) in lens exchange surgery with advanced irregular corneal astigmatism

Session Details

Session Title: Presented Poster Session: Cataract Surgery Special Cases

Venue: Poster Village: Pod 1

First Author: : J.Langer GERMANY

Co Author(s): :    M. Mackert   M. Shajari   S. Priglinger   W. Mayer              

Abstract Details

Purpose:

Comparing different new generation biometric formulas for small aperture IOL implantation in patients undergoing lens exchange surgery with highly irregular corneas

Setting:

Interventional prospective case series; University Eye Hospital, Munich , Germany

Methods:

This monocenter study included 17 eyes of 17 patients with high irregular astigmatism, 8 eyes with keratoconus, 4 with previous keratoplasty, 3 after previous radial keratotomy and 2 with corneal scar formation. Biometric and topographic data was assessed using IOL-Master 700 (Zeiss) and Pentacam (Oculus). Prediction and absolute error were compared after 3 months based on manifest refraction.Furthermore, change of total corneal refractive power in different corneal pathologies was also evaluated. For IOL power calculation three standard IOL 4th generation formulas were compared (Haigis, SRK-T, Barrett)and then compared with Raytracing analyzes to improve prediction error in this highly irregular corneas.

Results:

All patients show an increase in visual acuity postoperatively with a postoperative spherical equivalent range of -2.1D to -0.3D ( Mean -0.96D).  Overall comparison of three 4th generation formulas showed the Haigis formula to be superior in the total as well as in the subgroup collective in terms of smallest deviation of predictive error compared to absolute error. The complete results of Raytracing analyses will be presented at the congress.

Conclusions:

The IC-8 IOL is well suited for patients with cataract and high irregular astigmatism. For a precise prediction of refractive outcome, the Haigis formula is the most accurate in our patient group, although there are high deviations regarding to astigmatism but not to axial length measurements. Raytracing should be compared with standard biometric formulas to address corneal irregularities and to minimize refractive surprises after surgery.

Financial Disclosure:

... research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented