Patients with Sjögren syndrome dry eye (SSDE) and non Sjögren syndrome dry eye (NSSDE) more frequently have a first tear film break-up point (FTBUP) at the inferior quadrants rather than the superior quadrants of the cornea, researchers report. Investigators also say the presence of corneal fluorescein staining affects the location of FTBUP in patients with SSDE. The findings, which were published in BMC Ophthalmology, suggest FTBUP could aid in the recognition of SSDE.
“The measurement of the FTBUP helps to evaluate the most unstable position of the tear film on ocular surface,” according to the study.
To investigate the FTBUP in patients with SSDE and NSSDE, and explore its correlation with dry eye indices, the researchers recruited consecutive patients from the dry eye clinic at the hospital from between March and October 2019. Patients were eligible for inclusion if they experienced at least 1 dry eye symptom (dryness, burning sensation, grittiness, photophobia, pain, tickle) and showed 1 of the following signs: Schirmer I test of 5 mm/5 minutes of less; tear film breakup time (TBUT) less than 5 seconds; the presence of fluorescein staining with either 5 mm/5 minutes <Schirmer I test ≤10 mm/5 minutes, or 5 seconds≤TBUT<10 seconds.
A total of 44 patients (88 eyes), 22 patients with SSDE (20 women/2 men; mean age, 58.32±12.11 years) and 22 patients with NSSDE (19 women/3 men; mean age, 53.41±11.78 years), were enrolled in the study.
Using Keratograph® K5M (Oculus) measurements, the researchers demonstrated that the FTBUP occurred more frequently at the inferior cornea than at the superior cornea in patients with SSDE (86.3% vs 13.6%; P <.001) and with NSSDE (68.2% vs 31.8%; P =.014). The percentage of eyes with inferior FTBUP was significantly higher in the SSDE groups than in the NSSDE group (86.3% vs 68.2%; P =.049).
In patients with SSDE, the temporal breakup point was observed more often in those who presented corneal fluorescein staining in any location (P <.001); the nasal breakup point was observed more often in those who did not present any corneal fluorescein staining (P =.045). In patients with NSSDE, neither presence or absence of corneal fluorescein staining impacted the location of FTBUP.
Limitations of the study included the short timeframe covered by the questionnaire evaluating ocular surface disease (within the most recent week), potential incongruency between symptoms evaluated by the questionnaire and ocular surface signs, different treatment regimens among previously diagnosed patients, and a limited sample size.
“FTBUP was more likely to occur in the inferior quadrant in both SSDE and NSSDE. The location of FTBUP in SSDE had a close relationship with the presence of corneal fluorescein staining. Hence, the maintenance of an intact and healthy corneal epithelium is crucial to a stable tear film and good visual quality,” according to the report. “Nevertheless, the application of FTBUP to help the diagnosis of SSDE still needs confirmation by large-scale studies.”
Zhao S, Le Q. Analysis of the first tear film break-up point in Sjögren’s syndrome and non-Sjögren’s syndrome dry eye patients. BMC Ophthalmol. Published online January 3, 2022. doi:10.1186/s12886-021-02233-6