Reproducibility of Tear Meniscus Measurement by Fourier Domain Optical Coherence Tomography

Abstract

 

Purpose:

 

To study the reproducibility of tear meniscus measurement withhigh-speed high-resolution Fourier-domain optical coherencetomography (FD-OCT).

 

Methods:

 

The lower tear meniscus (TM) was imaged by vertical scans centeredon the inferior cornea and the lower eye lid using an FD-OCTsystem (RTVue, Optovue Inc., Fremont, CA) with a corneal adaptormodule (CAM) in the right eyes of 20 normal subjects. The systemperforms 26,000 axial scans per second and has a 5-micron axialresolution.Each subject was examined at 2 visits at least onemonth apart. Each eye was scanned twice on each visit. The scanswere taken 2 seconds after a blink.The TM angle (α), height (TMH)and depth (TMD) were measured (Figure) with a computer caliper.The TM area was calculated by the formula 0.5 × height × depth,based on a triangular approximation.

 

Results:

 

Fair to good intervisit reproducibility was demonstrated bythe intraclass correlation (ICC), pooled standard deviation(SD) and coefficient of correlation (CV) (Table).

 

Conclusions:

 

Lower tear meniscus dimensions and angle can be measured byFD-OCT with fair to good intervisit reproducibility. The heightwas the most repeatable meniscus dimension. FD-OCT may be auseful way to measure dry eye severity and treatment effectiveness.  

 

 

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • cornea: tears/tear film/dry eye