Feasibility and Acceptability of a new Clinical Pathway for the Identification of Non-Responders to Glaucoma Eye Drops (the TRIAGE study)

Ocular hypotensive eye drops can reduce the risk of disease progression in patients with glaucoma by lowering intraocular pressure (IOP) in the eye. However, not all patients respond to eye drops or instil them as prescribed.

Typically after the first prescription of eye drops, the patient's response to treatment is assessed at return clinic visits that are six-12 weeks apart. However, when patients present, it is difficult to discern whether any higher than expected IOP reflects a true non-response to the eye drops (pharmacogenetics) or limited adherence to using them as prescribed (behaviour).

NHS clinics are not set up to differentiate between these two factors. Patients may be switched unnecessarily to different medications because of a perceived lack of response which may have, in fact arisen as a result of poor adherence. Considerable clinic time is wasted in sorting these reasons. No research to date has evaluated how clinic workflows can be designed to separate the effects of poor adherence from a poor response to medication.

This project forms the first stage in a programme of research. In this study, we aim to develop and test the feasibility of a new approach to identifying non-responders to glaucoma eye drops; the Cardiff Model of Glaucoma Care (CMGC). We have drafted an outline of the CMGC based on the findings of previous research and wish to develop and implement this through qualitative and quantitative work.

If CMGC proves to be feasible and acceptable in this study, we would then test the model in future research to determine the effectiveness of the approach to improve the prompt recognition of non-responders.

In this study, we will answer the following key research questions:

1- What is usual care for patients with glaucoma who are about to commence eye drop treatment in Wales, in terms of identifying patients? responses to treatment?
2- Is it possible to develop and implement the CMGC in routine clinical practice?
3- What is the feasibility and cost of implementing the CGMC?
4- Is the CMGC acceptable to patients and healthcare professionals?
5- How could the CMGC become embedded in practice?

Using an integrated knowledge to action framework, we will first undertake an observational study to understand how patients are identified currently as non-responders to eye drops and how clinics are organised to support this. Then in partnership with key stakeholders including patients, we will develop, implement and evaluate the feasibility and cost of the CMGC at two health boards.

The proposed CMGC comprises two extra clinic visits four weeks apart immediately after the patient is viewed as needing glaucoma eye drops. It will be embedded in current clinics.

During these visits, the adherence to treatment is ensured by nurse instillation of eye drops and eye pressure is measured to assess the effect of the eye drops. Benefits to patients and NHS The CMGC will reduce the likely time taken to identify the most efficacious eye drops for the patient within four weeks of the initial prescription or to identify that they are a non-responder to eye drops and need alternative treatment.

The CMGC will enable non-adherent patients to be identified who could then be targeted for supportive care. Implementation of the CMGC will likely translate into cost savings for the NHS in terms of reducing the use of ineffective medications and improving clinical outcomes for the patient.