ESCRS - PO1229 - Comparison Of White To White (Wtw) Measurements Using Four Devices And Their Determination Of Implantable Collamer Lens (Icl) Sizing By Measuring Post Operative Vault

Comparison Of White To White (Wtw) Measurements Using Four Devices And Their Determination Of Implantable Collamer Lens (Icl) Sizing By Measuring Post Operative Vault

Published 2024 - 42nd Congress of the ESCRS

Reference: PO1229 | Type: Free paper | DOI: 10.82333/63w3-tk08

Authors: Shritu Shail* 1 , Gaurav Luthra 1 , Ruchika Pattanaik 1 , Kumar Anshuman 2

1Ophthalmology,Drishti Eye Institute,Dehradun,India, 2Ophthalmology,James Cook University Hospital,Middlesbrough,United Kingdom

Purpose

To compare WTW measurements obtained from the Pentacam, I Trace Aberrometer, Lenstar and Digital Caliper in Myopic eyes and its effect in determining the correct size of ICL by measuring post operative vault size by Optical Coherence Tomography.

Setting

Drishti Eye Institute, Dehradun, India 

Methods

Retrospective Cross Sectional Study

98 eyes of myopic patient of age 21-40 years

Underwent ICL implantation (Visian ICL by STAAR Surgical AG, Nidau, Switzerland) from January 1, 2021 to February 10, 2024

Thorough Pre operative assessment for all patients was done

WTW was measured on different devices and compared with caliper WTW which served as the baseline

Measurements obtained by the caliper, served as the basis for our final selection of ICL sizing

ICL size was determined using the STAAR Surgical Online Calculation and Ordering System (OCOS)

Post operative vault was measured using Optical Coherence Tomography  after one month.

Results

Mean WTW measurements varied significantly between the devices.
The range of Digital caliper WTW varied from 10.8 to 12.6 mm with mean (11.66 ± 0.38mm) & was most comparable with Pentacam mean WTW                   (11.84 ± 0.45 mm)
Lenstar had the largest mean WTW (12.05± 0.37mm) while,I Trace had the smallest mean WTW  (11.29± 0.43mm)
65 % of eyes achieved vault within 0.25 to 0.75 mm in 1 month, while Appx 10% eyes achieved vault < 0.25 mm                                                                                                                               & 25% eyes achieved vault >0.75mm in a month
The shallowest vaults were 0.14 mm and 0.24 mm, while the deepest vault was 1.31 mm

Conclusions

In conclusion, WTW measured by the 4 devices varied significantly which led us to conclude that WTW measured from these devices were not interchangeable
We tried to determine which of these devices had the highest likelihood of measuring WTW that can calculate ICL size which would result in desired vault range
If we consider manual measurement by Digital Caliper as baseline then WTW measured by Pentacam comes closest to it as compared to the other newer devices to calculate ICL size which can achieve desired post operative vault