New software program improves biometry measurements obtained by OLCR biometer

Presented by Raj P. Patel, BSc, “New Software Program to Improve Biometry Measurements Obtained by an Optical Low-Coherence Reflectometry (OLCR) Biometer,” hypothesized that:

• While AL and K measurements obtained with OLCR are similar to SS-OCT, the device may be inaccurately reading the spikes for ACD and LT calculations
• We sought to implement and evaluate a new program, SpikeFinder, which attempts to more accurately capture internal optical path measurements, specifically for LT and ACD measurements

Results:

• We chose to study the eyes with the largest differences
  • 3,197 eyes had LoTs differing by at least 0.6mm, 2,471 of these could be analyzed using SpikeFinder
    • A subgroup of 350 eyes was chosen at random from this group from which 5 were excluded due to LS and IOLM exams having been done on different days
• Difference between values (IOLM — LS), mean (SD) before SpikeFinder:
  • AL: 0.00 mm (0.06)
  • LT: 1.15 mm (0.38)
  • ACD: -0.66 mm (0.31)

Summary of results:

• SpikeFinder improves agreement between IOLM 700 and LS
• However, inner segments from 49 (14%) eyes still differed by more than 0.10mm

Conclusions:

• LT and ACD values obtained by Lenstar can be improved by SpikeFinder to reduce errors I measurements
• Recalibrated measurements after SpikeFinder are equivalent to lengths obtained by the IOL Master 700
• Performance of modern multivariable IOL formulas which use LT and ACD may be improved to be more accurate through the use of SpikeFinder
• We are currently evaluating SpikeFinder in additional larger datasets, concluding international datasets, before offering this for public use