Evaluating the refractive outcomes of older generation formulas in predicting the intraocular lens power required for insertion during cataract surgery by comparing it with new generation formulas

Session Details

Session Title: Presented Poster Session: Training & Quality of Vision

Venue: Poster Village: Pod 3

First Author: : G.Vakros UK

Co Author(s): :    M. Dehabadi   R. Jones   H. Abdalla                 

Abstract Details

Purpose:

To assess the accuracy of current formulas used in lens estimation in UK centers by using refractive outcomes in patients undergoing phacoemulsification cataract sur-gery. To assess the possibility that newer generation formulas can predict more accu-rate intraocular lens (IOL) power.

Setting:

Data collected from electronic patient record from three ophthalmic departments in London, UK (Hillingdon Hospital, North Middlesex Hospital, Moorfields Eye Hospital).

Methods:

A retrospective audit comparing post-operative refractive outcome with predicted refractive outcome (PRO) from optical biometry (Zeiss IOLMaster® 500; calculated using the SRK-T formula for axial length (AL) 22.00mm or more and Hoffer Q for AL less than 22.00mm) was conducted. A new generation universal formula (Barrett universal II;BUII and Hill-Radia Basis Function; HRBF) was used, with the same measurements from the IOLMaster® 500, to calculate the predicted spherical equivalent. Data was collected from 01/08/2017 to 27/2/2018 and 159 cases were identified (89 females versus 70 males) operated by three surgeons.

Results:

The mean operated age of 74±9.0. The mean IOL implanted was 20.5D±3.4D. For AL≥22mm measured eyes the mean PRO was -0.31±0.13, the BUII for-mula was -0.25±0.23 and HRBF -0.23±0.25. For AL<22mm measured eyes the mean PRO was -0.33±0.25 while with the BUII formula was -0.41±0.31 and HRBF was -0.33±0.36. The mean prediction error for AL≥22mm was -0.03±0.57,with BUII was -0.09±0.54 and with HRBF was -0.10±0.54.The mean prediction error for AL<22mm was 0.80±230, with BUII formula was 0.88±230 and with HRBF was 0.94±230.

Conclusions:

Our results suggest that SRK/T used in AL≥22mm, the IOL resulted in a more myopic shift versus BUII and HRBF. In AL<22mm, both Hoffer Q and HRBF calculated IOL re-sults in more hypermetropic shift than BUII formula.

Financial Disclosure:

None