ESCRS - PO0989 - To Compare White To White Measurements Obtained From Pentacam, I Trace Aberrometer, Lenstar And Digital Caliper In Myopic Eyes And Its Effect In Determining The Correct Size Of Implantable Collamer Lens By Measuring Post Operative Vault.

To Compare White To White Measurements Obtained From Pentacam, I Trace Aberrometer, Lenstar And Digital Caliper In Myopic Eyes And Its Effect In Determining The Correct Size Of Implantable Collamer Lens By Measuring Post Operative Vault.

Published 2023 - 41st Congress of the ESCRS

Reference: PO0989 | DOI: 10.82333/7zw5-6s21

Authors: Shritu Shail* 1 , Gaurav Luthra 1 , Ruchika Pattnaik 1

1Ophthalmology,Drishti Eye Centre,Dehradun,India

To compare White to White ( 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 Implantable Collamer Lens ( ICL ) by measuring post operative vault size by Optical Coherence Tomography at two different visits. 

82 eyes of myopic patients aged 21 – 40 years who underwent ICL surgery were included in the study . WTW measurements were obtained using different devices and compared with the measurements obtained by the caliper, which served as the basis for our final selection of ICL sizing.                                           ICL sizing was determined using the STAAR Surgical Online Calculation and Ordering System (OCOS). 

Post operative vault was measured using Optical Coherence Tomography.

A retrospective cross- sectional study was done for patients who underwent ICL implantation (Visian ICL by STAAR Surgical) from January 1, 2021 to March 18, 2023. Thorough Pre operative assessments for all patients were done including Refraction, Anterior chamber depths measurements, Gonioscopy and Specular Biomicroscopy. 
White to white measurements using different devices were taken and compared to calculate the recommended ICL size to be implanted. ICL size and its relationship to post operative vault measurements were taken and measured on two different occasions i.e., first post operative day and then on second postoperative visit usually between  2-4 weeks to see any significant change in vault size . 

Mean white to white measurements varied significantly between the devices.  The range of caliper WTW varied from 10.8 to 12.4 mm.  Pentacam WTW with mean (11.81 ± 0.41mm) was most comparable to Caliper mean WTW (11.59 ± 0.36mm). The highest value was with Lenstar with mean (12.01 ± 0.44mm) followed by Pentacam and I Trace with smallest mean WTW (11.35 ± 0.25mm).

The Pentacam WTW yielded an ICL size similar to Caliper in 86.66% eyes while the Lenstar and I trace yielded an ICL similar in 71 % and 66.6% eyes respectively. Post operatively Caliper and Pentacam WTW yielded higher percentage of eyes with desired vault.

Although several parameters have been used to calculate ICL size to get desired post operative vault, WTW still remains the most preferred and objective values obtained from these machines were compared to see which one of these yielded a consistent and interchangeable result. Digital calipers and Pentacam had the highest percentage of eyes achieving the desired vault.

In Patients with post operative vault less or more than the desired vault of 0.25 to 0.75 mm, we tried to determine the device which can achieve the desired vault size.