A large number of people do not use eye drops as prescribed. Glaucoma is a slowly progressive eye disease, which can result in severe vision loss. Drops prescribed for raised eye pressure or glaucoma are aimed at lowering the pressure to assist in reducing the rate of progression, or preventing the conversion of raised eye pressure to glaucoma. It is important that these eye drops are used continually, usually for life. Approximately one-third of people who are prescribed eye drops for the first time fail to continue collecting prescriptions within the first year and even when patients collect prescriptions they do not always use the drops as frequently as they should. A number of reasons are thought to be the cause, for example, forgetfulness, being prescribed a large number of medications, difficulties instilling drops, lack of knowledge about glaucoma, a busy lifestyle and seeing no benefit.
This review is based on 16 studies (1565 participants) that tried out different methods to help people to use drops as prescribed. All the studies took place in industrialised countries (Belgium, Denmark, France, Greece, Iceland, Japan, Sweden, Switzerland, UK and USA) and recruited participants in outpatient clinics. The following interventions were included: simplifying drop routines, reminder devices, automated telephone service, providing information about glaucoma and offering advice regarding day to day issues with eye care. Those studies which combined the provision of information about glaucoma and eye drops with other interventions, such as helping people to fit instillation of eye drops into their daily routine, appear to be more successful. Unfortunately, not all of these studies were of high quality and, therefore, until more evidence is available we cannot recommend any particular method. Good quality research is needed in this area in order to develop a better understanding of patients' individual needs and to help us provide more effective eye care services.
Although complex interventions consisting of patient education combined with personalised behavioural change interventions, including tailoring daily routines to promote adherence to eye drops, may improve adherence to glaucoma medication, overall there is insufficient evidence to recommend a particular intervention. The interventions varied between studies and none of the included studies reported on the cost of the intervention. Simplified drug regimens also could be of benefit but again the current published studies do not provide conclusive evidence. Future studies should follow up for at least one year, and could benefit from standardised outcomes.
Poor adherence to therapy is a significant healthcare issue, particularly in patients with chronic disease such as open-angle glaucoma. Treatment failure may necessitate unwarranted changes of medications, increased healthcare expenditure and risk to the patient if surgical intervention is required. Simplifying eye drop regimes, providing adequate information, teaching drop instillation technique and ongoing support according to the patient need may have a positive effect on improving adherence.
To summarise the effects of interventions for improving adherence to ocular hypotensive therapy in people with ocular hypertension (OHT) or glaucoma.
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 6), MEDLINE (June 1946 to June 2012), EMBASE (June 1980 to June 2012), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (June 1937 to June 2012), PsycINFO (1806 to June 2012), PsycEXTRA (1908 to June 2012), Web of Science (1970 to June 2012), ZETOC (1993 to June 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 26 June 2012. We did not search the National Research Register (NNR) as this resource has now been now archived. We contacted pharmaceutical manufacturers to request unpublished data and searched conference proceedings for the Association for Research in Vision and Ophthalmology (ARVO), and the Annual Congress for the Royal College of Ophthalmologists (RCO).
We included randomised controlled trials (RCTs) and quasi-RCTs that compared interventions to improve adherence to ocular hypotensive therapy for patients with OHT or glaucoma.
At least two authors independently assessed the search results for eligibility and extracted data for included trials onto specifically designed forms. We did not pool data due to clinical and methodological heterogeneity.
Sixteen trials (1565 participants) met the inclusion criteria. Seven studies investigated some form of patient education. In six of these studies this education was combined with other behavioural change interventions including tailoring daily routines to promote adherence to eye drops. Eight studies compared different drug regimens (one of these trials also compared open and masked monitoring) and one study investigated a reminder device. The studies were of variable quality and some were at considerable risk of bias; in general, the length of follow-up was short at less than six months with only two studies following up to 12 months. Different interventions and outcomes were reported and so it was not possible to produce an overall estimate of effect. There was some evidence from three studies that education combined with personalised interventions, that is, more complex interventions, improved adherence to ocular hypotensive therapy. There was less information on other outcomes such as persistence and intraocular pressure, and no information on visual field defects, quality of life and cost. There was weak evidence as to whether people on simpler drug regimens were more likely to adhere and persist with their ocular hypotensive therapy. A particular problem was the interpretation of cross-over studies, which in general were not reported correctly. One study investigated a reminder device and monitoring but the study was small and inconclusive.