Abstract
Purpose :
Dry eye (DE) is an ocular surface disease characterized by unstable tear film due to the quantitative and/or qualitative abnormalities of tears. Among those abnormalities, aqueous tear volume is one of the main factors for determining the stability of tear film, and therefore, the assessment of tear volume is important for the diagnosis of DE. Most tears are distributed in the tear meniscus, and there have been advancements in several methods for the assessment of tear volume at the meniscus. Meniscometry was developed to measure the radius of the tear meniscus, and interferometry and optical coherence tomography (OCT) can both non-invasively provide meniscus height-related parameters. Slit-lamp biomicroscopy (SL) also measures meniscus height, although fluorescein is sometimes necessary to visualize the meniscus. The purpose of this study was to clarify the possible relationship between the meniscus parameters evaluated by different methods.
Methods :
This study involved 42 eyes of 42 subjects comprising DE patients and normal subjects (35 females and 7 males; mean age: 60.5 years). We investigated the correlation between two parameters including the tear meniscus radius (R, mm) evaluated by use of a video-meniscometer and tear meniscus height evaluated by use of a video-interferometer (DR-1®; Kowa) (VI-H, mm), anterior OCT (OCT-H, mm), and SL (SL-H, mm). SL-H was assessed before and after fluorescein instillation.
Results :
There were significant correlations between R and VI-H, OCT-H, and SL-H (all p<0.01). Spearman’s rank correlation coefficients were 0.93, 0.83, and 0.89 (R and VI-H, OCT-H, and SL-H, respectively). For the assessment of OCT-H, there were limitations in smaller OCT-H cases, in which OCT was unable to visualize the meniscus clearly. In addition, in SL-H, no significant difference was noted between before (0.26±0.21) and after (0.26±0.21) fluorescein instillation.
Conclusions :
The findings in this study suggest that aqueous tear volume can be assessed via the meniscus parameters, such as meniscus radius or height, through several available methods, despite some possible limitations of the OCT used in this study. The standard fluorescein staining method was found not to yield any difference in the measurements of meniscus height.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.