New software program improves biometry measurements obtained by OLCR biometer

Lens thickness and anterior chamber duct values obtained by Lenstar can be improved by SpikeFinder to reduce errors in measurements.

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