Analysis of the first tear film break-up point in Sjögren's syndrome and non-Sjögren's syndrome dry eye patients

Abstract

Background: Tear film instability plays an important role in the course of Sjögren's Syndrome dry eye (SSDE) even though it is generally classified as aqueous-deficient dry eye. The measurement of the first tear film break-up point (FTBUP) helps to evaluate the most unstable position of the tear film on ocular surface. We aim to investigate FTBUP in Sjögren's Syndrome dry eye (SSDE) and non-Sjögren's Syndrome dry eye (NSSDE) patients, and explore its correlation with dry eye indices.

Methods: Twenty-two SSDE patients (44 eyes) and 22 NSSDE patients (44 eyes) were enrolled in the study. Oculus Keratograph K5M was used to measure FTBUP, the first and average non-invasive keratographic breakup time (f-NIKBUT and av-NIKBUT), the tear meniscus height, and meibomian gland dropout. Other tests of tear film were also performed including Ocular Surface Dryness Index (OSDI), Schirmer I test, fluorescein break-up time and corneal fluorescein staining. Dry eye indices and the locations of the FTBUP were compared between SSDE and NSSDE patients. Generalized estimating equation (GEE) was used to ajusted the correlations between right and left eyes. The correlations between the FTBUP and ocular symptoms and signs were investigated using Pearson's correlation coefficient test.

Results: The FTBUP occurred at the supranasal quadrant in 12/88 eyes, supratemporal quadrant in 8/88 eyes, inferonasal quadrant in 34/88 eyes, and inferotemporal quadrant in 34/88 eyes. The percentage eyes with inferior FTBUP was significantly higher in the SSDE than in the NSSDE subjects (86.3% vs 68.1%, P = .049). Moreover, in SSDE subjects, temporal breakup point was seen more often in those who presented corneal fluorescein staining in any location, while nasal breakup point was more frequent in those who did not present any corneal fluorescein staining (P = .045).

Conclusion: The location of the FTBUP in SSDE patients had specific characteristics. However, the diagnostic potential of FTBUP in early recognition of SSDE needs further validation.

Keywords: Non-Sjögren’s syndrome dry eye; Sjögren’s syndrome dry eye; The first tear film break-up point.

Fig. 1

(A) Representative output images of the noninvasive tear film break-up points and tear break-up time measurement from a non-Sjögren’s Syndrome Dry Eye (a) and a Sjögren’s Syndrome Dry Eye (b). The colored tear map showed the position of tear break-up point and the break-up time. Red: 0–6 s; orange/yellow: 6–12 s; green: 12–24 s. (B) Representative output images of meibography from a non-Sjögren’s Syndrome Dry Eye (a) and a Sjögren’s Syndrome Dry Eye (b). The meibomian gland dropout was more severe in Sjögren’s Syndrome Dry Eye (b) than non-Sjögren’s Syndrome Dry Eye (a). (C) The cornea surface was divided into five areas when observing cornea fluorescein staining

Fig. 2

The correlation analysis on dry eye examinations. A Meibomian gland dropout of upper eyelid had negative correlation with fluorescein break-up time and average noninvasive keratograph tear film break-up time (R = -.227, P = .033; R = -.268, P = .012), but no correlation with first noninvasive keratograph tear film break-up time (R = -.020, P = .854). B In Sjögren’s Syndrome Dry Eye patients, OSDI had a negative correlation with fluorescein break-up time (R = -.749, P<.001) but no correlation with both first noninvasive keratograph tear film break-up time and average noninvasive keratograph tear film break-up time (R = -.029, P = .851 and R = -.060, P = .700). C In non-Sjögren’s Syndrome Dry Eye patients, OSDI had a negative correlation with fluorescein tear film break-up time and average noninvasive keratograph tear film break-up time (R = -.705, P<.001; R = -.531, P<.001), but no correlation with first noninvasive keratograph tear film break-up time (R = -.128, P = .408)