Abstract
Purpose: :
To use Fourier-Domain Optical Coherence Tomography to study the longitudinal effect of instillation of artificial tears on tear meniscus volume in patients with dry eyes.
Methods: :
Four patients with significant dry eyes were recruited in a consecutive manner from a tertiary cornea practice. The lower tear meniscus of the right eye in each subject was imaged by vertical scans centered on the inferior cornea and the lower eyelid using a Fourier-domain optical coherence tomography system (RTVue; Optovue, Inc., Fremont, CA) with a corneal adaptor. Two baseline measurements were taken for each subject prior to administration of a drop of artificial tears (Optive). Five serial pairs of measurements were then taken after the instillation of artificial tears at 1 minute, 2 minutes, 5 minutes, 10 minutes, and 15 minutes. Each measurement was taken two seconds after a blink. The lower meniscus height, depth, and angle were measured with a computer caliper. The cross-sectional area was calculated using a two-triangle approximation.
Results: :
The baseline tear measurements were 317 µm, 512.5 µm, 0.0695 mm2 for meniscus height, depth, and area respectively. At 1 minute after instillation of artificial tears the measurements increased by 212%, 488%, 2212%. The time to depletion of half of the gains in tear meniscus were 2.75 minutes, 4.75 minutes, and 2 minutes for height, depth, area respectively. The time to depletion of 75% of the tear meniscus gains was 3.5 minutes, 5.5 minutes, and 5.5 minutes.
Conclusions: :
Optical coherence tomography is able to quantify the increase in lower tear meniscus after installation of artificial tears in patients with dry eyes. This increase is transient, with a 50% reduction of both height and area within 3 minutes of drop instillation and a 75% reduction in all parameters by 6 minutes. Optical coherence tomography may serve as an invaluable tool in objectively quantifying the efficacy of dry eye treatments.
Keywords: cornea: tears/tear film/dry eye • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical