Comparing horizontal white-to-white vs horizontal sulcus-to-sulcus measurements for implantable collamer lens sizing

Session Details

Session Title: Imaging II

Session Date/Time: Tuesday 13/09/2016 | 14:00-16:00

Paper Time: 14:52

Venue: Hall C1

First Author: : D.Dias PORTUGAL

Co Author(s): :    M. Lume   R. Salgado   M. Pinto              

Abstract Details

Purpose:

To assess the agreement of horizontal white-to-white (WTW) and horizontal sulcus-to-sulcus (STS) diameter measurements in preoperative implantable collamer lens (ICL) size selection, either toric or not. To compare surgical results during follow-up from the two measurement methods.

Setting:

Population of patients assessed for ICL implantation in Centro Hospitalar do Porto, Portugal.

Methods:

55 eyes from 37 patients were assessed for ICL implantation. This was a consecutive series of all patients with suitable available data. The agreement and bias between WTW (measured with Orbscan) and STS (with ultrasound biomicroscopy - UBM) were estimated. 31 eyes had ICL selection based on WTW measurement and 24 eyes had it based on STS measurement. Other measurements obtained were: endothelial cell count (ECC - with Nidek®), best visual acuity (BVA), intra-ocular pressure (measured with Goldmann aplanation tonometer), anterior chamber depth (ACD), ICL size, vault and chamber angle (CA). Complications that may have occurred have also been registered.

Results:

Mean age was 32.3 years with 13 male patients and 24 female patients. BVA improved from a mean of 0.75 to 0.87. ECC changed from a mean of 2979 cells before surgery to 2708 cells after. Mean measurement for ICL size was 11.49 mm in the STS group and 11.91 mm in the WTW group; with STS the mean CA changed from 38.6° to 24.1° and with WTW it changed from 38.8° to 26.6°; mean vault was 431 µm (min: 80 µm; max: 1210 µm; median 375 µm) in the STS group and 277 µm (min: 80 µm; max:570 µm; median 220 µm) with WTW measures. One toric ICL has rotated from its original axis in the WTW group.

Conclusions:

According to the literature UBM STS measurements are superior to WTW for the purposes of ICL selection. In our study some differences were found regarding the final vault, with more consistent values in the WTW group. These results may be due to the fact that UBM measurements are operator-dependent.

Financial Disclosure:

NONE