Reduced tear break-up time in the fellow eye of patients with unilateral primary acquired nasolacrimal duct obstruction

Abstract

Purpose: To measure tear osmolarity, Schirmer I test and tear break-up time (TBUT) values in the obstructed and non-obstructed fellow eye of unilateral primary acquired nasolacrimal duct obstruction (PANDO) patients and compare them with healthy controls.

Methods: In this prospective noninterventional study, the tear osmolarity, Schirmer I test, and TBUT values from unilateral PANDO eyes, fellow eyes, and control eyes of all subjects were measured.

Results: The study included 114 eyes of 30 PANDO patients as well as 27 healthy controls. There was a significant difference between TBUT and Schirmer values of fellow eyes and PANDO eyes (p = 0,035; p = 0,001). There was no significant difference in any of the ocular surface parameters between PANDO eyes and control eyes (p > 0.05). When fellow eyes were compared to control eyes, there was a significant difference in TBUT (p = 0.046).

Conclusions: Decreased TBUT was exhibited by the fellow eye of unilateral PANDO patients, compared to the PANDO side and controls. Compensatory changes in PANDO eyes due to a decrease in the tear secretion reflex may lead to tear dysfunction of the fellow eye. Clinicians should assess tear stability in the fellow eye of PANDO patients as this could be leading to added symptomatic complaints.

Keywords: Lacrimal functional unit; Primary acquired nasolacrimal duct obstruction; Schirmer; Tear break-up time; Tear film instability; Tear osmolarity.