Abstract
Purpose :
Filamentary keratitis (FK) is reportedly associated with increased friction during blinking, and is often, yet not always, observed in cases of severe aqueous tear-deficient dry eye (sATDDE). The purpose of this present study was to investigate the mechanism of the association between FK and sATDDE by comparing the differences of clinical manifestations between sATDDE with and without FK.
Methods :
This study involved 28 eyes of 28 female dry-eye patients with severe aqueous tear deficiency (sATD). sATD was diagnosed based on tear-film (TF) lipid layer spread grades assessed by video-interferometer (DR-1TM; Kowa) (grades 1-5, 1 being the best grade; Yokoi N, et al., AJO 180, 2017) in which all enrolled subjects showed either grade 4 (TF on 25% of the corneal surface) or grade 5 (TF on 0% of the corneal surface). The enrolled subjects were categorized into 2 groups: 1) those with FK [FK(+); 12 eyes of 12 cases, mean age: 66.9 years] and 2) those without FK [FK(-); 16 eyes of 16 cases, mean age: 66.6 years]. In all 28 eyes, tear meniscus radius (mm), fluorescein breakup time (seconds), corneal epithelial damage score (15-points maximum), conjunctival epithelial damage score (6-points maximum), lid-wiper epitheliopathy grade (3-points maximum), and the Schirmer 1 test (mm) were examined. Blink rate (per minute), palpebral aperture height (mm), upper-eyelid closing/opening-phase amplitude (mm), upper-eyelid closing/opening-phase duration (msec), and upper-eyelid closing/opening-phase maximum velocity (mm/sec) were also measured by use of a custom-made high-speed blink analyzer.
Results :
In the comparison of the results for each examination [FK(+); FK(-)] between the FK(+) eyes and the FK(-) eyes, a statistically significant difference (p<0.05) was found in lid-wiper epitheliopathy grade (2.6±0.8; 1.9±1.0), upper-eyelid closing-phase maximum velocity (117.6±34.0; 150.5±48.1), and upper-eyelid opening-phase maximum velocity (38.7±10.8; 52.0±17.6).
Conclusions :
The findings of this study suggest that FK with sATDDE might occur by the mechanism of increased friction during blinking due to eyelid-related factors such as greater eyelid pressure in addition to, or not, tear abnormalities.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.