Comparing the effects of two types of eye drops on eye health

Department of Ophthalmology, Rigshospitalet-Glostrup Valdemar Hansens Vej 13, 2600 Glostrup, Denmark

PHASE4 · Rigshospitalet, Denmark · NCT04957329

This study tests whether eye drops with preservatives or preservative-free eye drops are better for eye health in people with glaucoma or high eye pressure.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment28 (estimated)
Ages18 Years and up
SexAll
SponsorRigshospitalet, Denmark (other)
Locations2 sites (Glostrup Municipality, Danmark and 1 other locations)
Trial IDNCT04957329 on ClinicalTrials.gov

What this trial studies

This study investigates the impact of benzalkonium-chloride preserved eye drops versus preservative-free eye drops on conjunctival goblet cells in patients with open-angle glaucoma or ocular hypertension. A total of 28 subjects will participate, applying one type of eye drop in each eye for three months. The study is randomized and investigator-blind, ensuring unbiased results. Before and after the treatment period, conjunctival prints will be taken to evaluate changes in goblet cell density and intraocular pressure.

Who should consider this trial

Good fit: Ideal candidates are Danish-speaking adults over 18 years old with open-angle glaucoma or ocular hypertension and an average intraocular pressure of 22 mmHg or higher.

Not a fit: Patients with significant eye diseases other than glaucoma, those on steroid treatment, or individuals with untreated systemic diseases may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved eye drop formulations that minimize damage to ocular surface cells, enhancing patient comfort and treatment outcomes.

How similar studies have performed: Previous studies have shown varying results regarding the effects of preservatives in eye drops, making this approach both relevant and necessary for further exploration.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age \>18years
2. Danish speaking
3. Open angle glaucoma or ocular hypertension
4. Average intraocular pressure equal to or above 22 mmHg

Exclusion Criteria:

a. history of significant eye diseae (including okular trauma) other than open angle glaucoma and ocular hypertension d. treatment with steroids within the last 3 months from inclusion e. Significant untreated systemic disease such as hypertension, heart failure, diabetes mellitus, stroke, lung disease and autoimmune diseases. Diseases are not reason for exclusion if they are well treated or does not need treatment g. pregnant or breast feeding h. women using unsafe anticonception i. allergy towards trial medication j. patients who cannot cooperate in eye examination k. ocular surface defects l. need for polytherapy in glaucoma treatment

Where this trial is running

Glostrup Municipality, Danmark and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Glaucoma, Ocular Hypertension

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.