The primary objective of this study is to evaluate the ocular surface safety of an ophthalmic solution indicated for the management of glaucoma, containing the active ingredients dorzolamide, timolol, and brimonidine, in patients diagnosed with primary open-angle glaucoma. The most relevant questions to be answered by this study are:

In patients with ocular hypertension or open-angle glaucoma, does treatment with the preservative-free dorzolamide-timolol-brimonidine combination improve ocular surface health?

Will there be differences in treatment adherence between patients with ocular hypertension or open-angle glaucoma using a preservative-free dorzolamide-timolol-brimonidine combination versus a combination with preservatives?

Will there be differences in therapeutic efficacy between patients with ocular hypertension or open-angle glaucoma when using a preservative-free dorzolamide-timolol-brimonidine combination versus a preservative-containing dorzolamide-timolol-brimonidine combination?

Will there be differences in changes in biomolecular markers on the ocular surface between patients with ocular hypertension or open-angle glaucoma when using a preservative-free dorzolamide-timolol-brimonidine combination versus a preservative-containing dorzolamide-timolol-brimonidine combination?

Researchers will study these differences by comparing a formulation with the dorzolamide, timolol, and brimonidine combination that uses a preservative versus another with the same combination that does not use preservatives. Preservatives are used in ophthalmic solutions to prevent bacterial contamination. New technological developments in bottles allow for solutions without the need for preservatives. Participants must:

• Take their medication according to the investigator's instructions for at least 4 months
• Attend follow-up appointments at the beginning, and every 2 months until 4 months have passed
• Answer phone calls every 15 days
• Complete the quality of life questionnaires within the timeframes defined by the investigator

A prospective, randomized, comparative, single-blind (masked evaluator) clinical trial will evaluate the preservative-free fixed-dose combination of dorzolamide, timolol, and brimonidine versus the same combination with preservatives in patients diagnosed with primary open-angle glaucoma or ocular hypertension treated in Cali, Colombia.

Adult patients with a clinical indication for topical triple hypotensive therapy, currently receiving treatment with the preservative formulation or in the process of initiating or changing treatment, will be included. Participants will be assigned to one of the two treatment groups and will be followed longitudinally under real-world clinical practice conditions, with standardized measurements.

The primary objective of the study is to compare the impact of both formulations on ocular surface health, integrating objective and subjective measures of dry eye. Secondary objectives include evaluating intraocular pressure control, ocular and systemic safety and tolerability, treatment adherence, vision-related quality of life, and signs of structural and functional glaucomatous progression. In addition, the study incorporates two substudies. The technology substudy will evaluate the effect of an educational chatbot and reminders on patient adherence, disease knowledge, and self-efficacy. The molecular substudy will explore the proteomic profile of the tear film and its variation in response to treatment, in order to identify molecular markers associated with tolerability, ocular surface inflammation, and clinical response.

Inclusion Criteria: Age 18 years or older.

• Diagnosis of primary open-angle glaucoma or ocular hypertension, confirmed by the treating ophthalmologist.
• Continuous and stable treatment with a topical fixed-dose combination of dorzolamide, timolol, and brimonidine in a preservative formulation, for a minimum of 3 months and a maximum of 12 months prior to study enrollment.
• No prior use of preservative-free formulations of dorzolamide, timolol, and brimonidine.
• Exclusive use of the fixed-dose combination of dorzolamide, timolol, and brimonidine, without other concomitant ocular hypotensive agents.
• Ability to attend all study visits and procedures.
• Signed written informed consent.

Exclusion Criteria: Patients with any of the following conditions will be excluded:

• History of glaucoma, retinal, or cataract surgery.
• History of corneal refractive surgery (LASIK, PRK, SMILE).
• Diagnosis of secondary glaucoma (neovascular, inflammatory, traumatic, or other secondary causes).
• History of previous iridotomy, iridoplasty, or trabeculoplasty procedures.
• Presence of concomitant ocular diseases that may interfere with the evaluation of the ocular surface (e.g., Sjögren's syndrome, active infectious keratitis, or severe ocular allergy).
• Decompensated systemic conditions that contraindicate the use of topical beta-blockers (uncontrolled asthma, bradycardia, second- or third-degree AV block).
• Pregnancy or breastfeeding.
• Any medical or ophthalmological condition that, in the investigator's judgment, compromises the participant's safety or the validity of the data.

The information obtained in the study will be at the research center and the analysis will be carried out exclusively by the principal investigator and staff in charge at the Sigma Clinic.

The evaluator will be blind