Posters

Measuring effective lens position with intraoperative ocular coherence tomography

Poster Details

First Author: M.Kummelil INDIA

Co Author(s):    S. Das   K. Barman   A. Mallipatna   A. Roy   R. Shetty   B. Shetty     

Abstract Details

Purpose:

30% to 40% of an IOL power calculation formula’s accuracy depends on the preoperative estimation of the effective lens position (ELP). Theoretical methods that we have used including the most modern formulae like the Holladay 2, Olsen or the Barrett universal formula may have reached the limit of their ability to improve the refractive outcomes due to the inability to more accurately estimate the ELP. Intraoperative Ocular Coherence Tomography (OCT) based ELP measurement seems to be the next logical step to improve the percentage of refractive outcomes within ±0.50 D spherical equivalent accuracy of the intended target.

Setting:

Tertiary Teaching Eye Care Institute, India

Methods:

Intraocular lenses (IOLs) are placed in the capsular bag and the plane of the IOL is the equatorial plane of the capsular bag. A novel method of actually measuring the distance of the equatorial plane of the capsular bag from the endothelium is used after validation in the wet lab on animal eyes. A capsular tension ring (CTR) is inserted into the capsular bag with sterile 8-0 monofilament nylon tied to the center of the CTR and threaded through the eyelets so as to create a crisscross pattern in the visual axis that could be imaged by the intraoperative OCT.

Results:

The equatorial plane measured by the CTR technique showed good agreement with the actual anterior IOL plane as more than 95% of the values fell between the limits of agreement on the Bland Altman plots. Serial follow up of the IOL plane did not show any significant change over time.

Conclusions:

The Intraoperative OCT with CTR technique to measure the actual distance of the plane of IOL from the endothelium may permit A constants customized to the patient also rather than just empirical surgeon specific personalization.

Financial Disclosure:

NONE