Assessing the implantable collamer lens (ICL) simulator software to predict the postoperative vault height with traditional white-to-white (WTW) vs sulcus-to-sulcus (STS) based ICL sizing methods

Session Details

Session Title: Phakic IOLs II

Session Date/Time: Tuesday 08/09/2015 | 14:00-16:00

Paper Time: 15:03

Venue: Room 17

First Author: : T.Haldipurkar INDIA

Co Author(s): :    S. Ganesh   S. Brar                 

Abstract Details

Purpose:

ICLs are used routinely for the correction of myopic refractive errors. Postoperatively, complications are seen due to a high or a low vault causing much distress. Most of these are due to incorrect ICL sizing techniques. The traditional ICL sizing techniques are inadequate. A simulator that can predict a postoperative vault for a particular ICL size was the need of the hour. We studied the predictability of ICL simulator software for postoperative vault height and compared STS based ICL sizing techniques from conventional WTW methods. This will help titrate the size according to the postoperative vault predicted.

Setting:

Nethradhama Super Speciality Hospitals, Bangalore, Karnataka, India

Methods:

Myopic patients with –0.5 D to –18 DS error, ACD >2.80mm, ages 21-40 yrs.were enrolled. Institutional Ethics committee approval was taken. Every patient underwent anterior segment examination, WTW, ACD measurement with orbscan and digital caliper, specular microscopy. Postoperatively, AS OCT was done for vault height. Sulcus measurement was done with STS UBM compact touch (VHF ultrasound 50MHz). The ICL simulator software (Quantel medical) predicted the central and mid-peripheral postoperative vault height. A normal range of 250μ- 800μ central and 150μ-500μ mid-peripheral vaults was aimed. The appropriate ICL size that provided this vault was chosen based on the sulcus diameter.

Results:

Our study enrolled 45 eyes of 23 patients (11 females, 12 males) with mean age of 25 yrs. Mean SEQ treated -11.6 D. Mean ACD 3.2mm, WTW 11.9mm, STS: 11.6mm. Mean central vault predicted was 690μ±58μ and mean vault achieved 542μ±48μ. Mean vault error was 154μ±24μ. In 35% of eyes, ICL size that was used differed from the STAAR calculator size. Among these eyes, ICL with 2 sizes lesser than STAAR calculator was implanted in 14%. Of the eyes where a different sized ICL was used, smaller size ICL was implanted in 71.5% and 28.5% eyes, a larger size was implanted. 60% of the eyes had STS measurement smaller than WTW, with mean difference of 0.41mm.

Conclusions:

The ICL simulator is a handy tool in predicting the postoperative central and mid-peripheral vault heights for a particular ICL size. The mean vault error was 154μ±24μ, which is an acceptable range. Studies have elucidated the sulcus anatomy and its relation to WTW. 60% of our patients had sulcus diameter smaller than WTW, which would have resulted in a wrong sized ICL placement according to the conventional methods. 60% of the eyes were within 200μ of the predicted vault-height by the simulator. The software definitely helps in the titration of the ICL size and is sulcus based.

Financial Interest:

NONE