Abstract
Purpose :
To measure the upper and lower tear menisci in dry eye (DE) patients by 2 Spectral Domain Optical Coherence Tomography (SD-OCT) systems and to compare measurements’ values, repeatability, and diagnostic accuracy of the 2 instruments.
Methods :
We consecutively recruited a convenience sample of 100 DE patients and 100 age- and gender-matched control subjects (C). Inclusion criterion for DE was the presence of 3 of the following criteria: Ocular Surface Disease Index > 12, tear film Break-Up Time < 10 seconds, corneal staining > 1, and Schirmer test without anesthesia < 10 mm/5 minutes (procedures performed in this order). One hour before the clinical exam, SD-OCT (Cirrus OCT 5000, Carl Zeiss Meditec, Jena, Germany and RTVue-100, Optovue, Fremont, CA) was used to measure upper and lower tear meniscus height, depth, and cross-sectional area (UTMH, LTMH, UTMD, LTMD, UTMA, LTMA, respectively). One eye of each subject underwent 4 consecutive scans of the menisci (2 exams with each instrument, in random order).
Results :
Values obtained by Cirrus were generally higher than those by RTVue. The difference was statistically significant for UTMH and UTMD in both DE and C subjects (254±39 vs 227±44 and 168±33 vs 148±36 in DE, 296±68 vs 261±40 and 207±43 vs 172±38 in C; P<0.05, Wilcoxon signed-rank test). All the parameters showed a significant correlation between Cirrus and RTVue (P<0.001, Spearman). Both instruments showed no significant differences (Wilcoxon) and significant correlations (Spearman) between the repeated measurements for all the parameters. Comparing DE patients and C subjects, both instruments showed significantly reduced values in DE for the UTM measurements and no differences for the LTM measurements (Mann-Whitney U test, Table 1). ROC Curves showed poor diagnostic accuracy for all the parameters (Figure 1), with Areas Under the Curve ranging from 0.484 (LTMA) to 0.772 (UTMD) for Cirrus and from 0.511 (LTMH) to 0.712 (UTMH) for RTVue. A sub-analysis performed on Aqueous Deficient DE eyes (ADDE: Schirmer < 10mm) showed higher diagnostic accuracies.
Conclusions :
Both Cirrus and RTVue provided repeatable measurements of upper and lower tear menisci. The 2 instruments showed good correlations and a systematic difference (to be studied more in depth). SD-OCT systems can give useful information on tear menisci in DE patients but their diagnostic application seems to be limited to ADDE.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.