Abstract
Purpose :
Tear film (TF) is established on the cornea through the process of aqueous tear deposition when the eye is opened, followed by the redistribution of aqueous tears dragged by the upward spread of the TF lipid layer (TFLL) after the eye is opened (Yokoi N, et al. Am J Ophthalmol. 2017). In cases of severe aqueous tear deficiency cases, the layer of deposited aqueous tears is so thin that the upward spread of the TFLL is greatly attenuated, as aqueous tears work as a scaffold for the TFLL to spread. In this study, we investigated whether TFLL spread can be an indicator for determining the severest form of aqueous tear deficient dry eye (ATDDE).
Methods :
This study involved 61 eyes of 61 cases [mean age: 65.3±13.6 (mean±standard deviation) years] with no meibomian gland dysfunction that presented with incomplete upward TFLL spread after the eye is opened as evaluated by video-interferometer (DR-1®; Kowa). The eyes were sub-classified into the following two groups based on the amount of observable TFLL within a 6.8 x 8.8mm area of the cornea: 1) Group A, incomplete, yet observable, upward TFLL spread (n=23 eyes) and 2) Group B, no observable incomplete upward TFLL spread (n=39 eyes). In the 2 groups, we assessed dry eye-related symptoms using the visual analog scale (VAS, 100mm max.) and the Dry Eye Related Quality of Life Score, tear meniscus radius (TMR, mm) evaluated by meniscometry, non-invasive breakup time (BUT) (NIBUT, seconds) evaluated by video-interferometry, fluorescein BUT (FBUT, seconds), corneal-epithelial damage (CED) scores (15 points max.), ocular surface epithelial damage (OSED) scores (9 points max.), and the Schirmer 1 test (ST1, mm).
Results :
Compared to Group B, Group A showed significantly greater symptoms [i.e., dryness (p<0.05) and difficulty in opening the eye (p<0.05)], lower NIBUT and FBUT values, and higher CED and OSDE values. However, there were no significant differences between Group A and Group B in tear volume parameters including TMR and ST1 (p=0.20 and p=0.57, respectively). In addition, 29.0% of the Group B eyes were treated with eye drops alone [no punctal plugs (PPs) needed], yet 95.7% of the Group A eyes required PPs for proper treatment.
Conclusions :
Non-invasive assessment of the upward TFLL spread can be a possible indicator for evaluating the severest form of ATDDE.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.