Novel Ocular Surface Metrics Detect Tear Film Changes Following Disturbances

Placido disk patterns and post blink tear film particle speed demonstrate efficacy as tools for detecting tear film disruptions, according to research published in Contact Lens and Anterior Eye. Dry eye signs and symptoms, which worsened during computer activities and contact lens insertion during the investigation, were resolved with artificial tears. 

Researchers included 84 healthy participants (61.9% women; mean age, 22.4 years, 100% White) in a study to assess ocular surface changes following 20 minutes of computer use, contact lens insertion, and artificial tear instillation.

Participants underwent ocular surface evaluation with established assessments, which included the Ocular Surface Disease Index (OSDI), 5-item Dry Eye Questionnaire (DEQ-5), bulbar redness, tear meniscus height (TMH), and noninvasive keratograph break-up time (NIKBUT). The cohort also underwent testing with novel metrics that involved lipid layer thickness measurement from the intensity of the reflected Placido disk and speed of the tear film particles after blinking.

Overall, dry eye symptoms, TMH, and bulbar redness were higher among participants following the computer task. Lower values in metrics related to the intensity of the Placido disk pattern and particle speed indicated a thinning lipid layer following the task, according to the report. When fitted with a contact lens, participants demonstrated lower TMH, NIKBUT and particle speed metrics (P <.044). 

The report shows artificial tears significantly improved the worsening of dry eye symptoms resulting from computer use and contact lens insertion.

“Newly developed methods can serve as a tool to detect changes in the tear film triggered by different ocular surface-disturbing conditions,” according to the researchers. “In this way, the present work further helps to validate these novel methods as a reliable tool to quickly, non-invasively and objectively assess the changes in the tear film induced by different conditions. Therefore, they could be included in a battery of tests to improve the detection and monitoring of dry eye disease and meibomian gland dysfunction in clinical practice.”

Study limitations include a 1-day washout period, the use of a headrest to ensure downward gaze, an overrepresentation of individuals who were White in the study sample, and failure to directly measure the lipid layer.