The goal of this clinical trial is to evaluate whether a structured blinking exercise can improve symptoms and signs of dry eye disease (DED) in adults with glaucoma who are using topical intraocular pressure-lowering medications. The study will also assess the effects of the intervention on tear film stability, blink function, and participant adherence to the exercise.

The main questions this study aims to answer are:

Does a two-week structured blinking exercise reduce dry eye symptoms, as measured by the Ocular Surface Disease Index (OSDI) and Symptom Assessment in Dry Eye (SANDE) questionnaires? Does the blinking exercise improve objective measures of ocular surface health, including non-invasive tear break-up time (NITBUT) and blink dynamics?

Researchers will compare glaucoma patients receiving topical medications (intervention group) with glaucoma suspects not using topical therapy (control group) to evaluate the effectiveness of the blinking exercise on dry eye outcomes.

Participants in both groups will receive instruction on a standardized blinking exercise protocol consisting of repeated close-squeeze-open blinking cycles performed three times daily for two weeks. Participants will attend study visits at baseline, 2 weeks (post-intervention), and 4 weeks (follow-up). At each visit, participants will complete validated dry eye questionnaires and undergo non-invasive assessments of tear film stability, blink characteristics, and meibomian gland function. Adherence to the blinking exercise will be monitored using self-reported logs or reminders.

Dry eye disease (DED) is a chronic, multifactorial disorder of the ocular surface characterized by tear film instability, inflammation, and ocular discomfort. The prevalence of DED is significantly higher in patients with glaucoma, largely due to long-term use of topical intraocular pressure-lowering medications. Many of these medications contain preservatives, such as benzalkonium chloride, which are associated with ocular surface toxicity, tear film disruption, and inflammation. As a result, glaucoma patients frequently experience worsening dry eye symptoms, reduced quality of life, and decreased adherence to prescribed therapy, potentially compromising disease control and increasing the risk of vision loss.

In addition to pharmacologic factors, behavioral contributors such as reduced or incomplete blinking play an important role in the development and progression of DED. Inadequate blinking impairs tear film distribution, reduces lipid layer replenishment, and increases tear evaporation. These effects are particularly pronounced during prolonged visual tasks such as screen use. Despite the known importance of blink dynamics in ocular surface health, current management strategies for DED in glaucoma patients primarily focus on pharmacological or surgical approaches, with limited attention to modifiable behavioral interventions.

Blinking exercises have emerged as a promising non-pharmacological strategy to improve tear film stability and ocular surface function. Prior studies in non-glaucoma populations have demonstrated that structured blinking exercises can improve tear film parameters, meibomian gland function, and subjective comfort. However, there is limited evidence evaluating the effectiveness of such interventions in glaucoma patients, who represent a high-risk population due to chronic medication exposure.

This study is a prospective, controlled interventional trial designed to evaluate the effect of a structured blinking exercise on both subjective symptoms and objective signs of DED in adults with glaucoma. The intervention group will include patients with a confirmed diagnosis of glaucoma who are currently using at least one topical intraocular pressure-lowering medication. The control group will consist of glaucoma suspects who are not receiving topical therapy. Allocation to groups is based on clinical status and is not randomized.

Participants in both groups will be instructed in a standardized blinking exercise protocol consisting of 15 cycles of close-squeeze-open blinking, performed three times daily for a period of two weeks. Instruction will be provided through in-person demonstration and written materials, and participants will be encouraged to use reminders or tracking tools to support adherence.

Participants will attend three study visits: baseline, 2 weeks (post-intervention), and 4 weeks (follow-up). At each visit, validated subjective and objective assessments of dry eye will be performed. Primary outcome measures include the Ocular Surface Disease Index (OSDI), the Symptom Assessment in Dry Eye (SANDE), a blink-related comfort test, and non-invasive tear break-up time (NITBUT). Secondary outcomes include blink rate and completeness assessed through video analysis, meibomian gland function, adherence to the blinking exercise, and participant-reported acceptability.

The study aims to determine whether a brief, low-cost behavioral intervention can improve ocular surface health and reduce symptoms of DED in glaucoma patients. By targeting a modifiable behavioral factor, this intervention has the potential to complement existing glaucoma management strategies, improve patient comfort, and support adherence to long-term therapy. Findings from this pilot study will provide preliminary evidence to inform the design of larger randomized controlled trials and may contribute to the integration of behavioral interventions into comprehensive glaucoma care.

Inclusion Criteria:

• 18 years of age or older.
• Those in the intervention group must have a confirmed diagnosis of glaucoma and be using at least one topical antiglaucoma medication.
• Control participants must be glaucoma suspects who have not yet commenced topical therapy.

Exclusion Criteria:

• Glaucoma patients who have had ocular surgery within the previous six months, contact lens wear, systemic inflammatory or autoimmune diseases affecting the ocular surface, or other ocular surface disorders such as severe blepharitis or keratoconjunctivitis sicca.

IPD from this study will not be made publicly available due to the small sample size and single-center design, which may increase the risk of participant re-identification despite de-identification procedures. Additionally, data are collected under institutional ethics approval with restrictions on data sharing beyond the study team. However, aggregated results and summary findings will be disseminated through peer-reviewed publications and presentations to support transparency and scientific contribution