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 Table of Contents  
Year : 2017  |  Volume : 16  |  Issue : 1  |  Page : 12-18

Glaucoma medication adherence in an adult population in Nigeria

Department of Optometry, Faculty of Life Sciences, University of Benin, Benin, Nigeria

Date of Web Publication5-Jul-2017

Correspondence Address:
Jennifer A Ebeigbe
Department of Optometry, Faculty of Life Sciences, University of Benin, Benin
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ajmhs.ajmhs_80_16

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Introduction: Glaucoma is a common and potentially blinding condition, which can be managed with the use of appropriate medication therapy. For the medication to be effective, there has to be strict adherence to drug regimen. However, this is not usually the case for many glaucoma patients. The aim of this study was to identify the barriers and facilitators related to glaucoma medication adherence among an adult population. Materials and Methods: Forty-nine participants who had been diagnosed with glaucoma and had been on glaucoma medications for at least a year were recruited and interviewed. They were aged between 18 and 70 years with a mean age of 54 years. The one-on-one in-depth interviews were recorded using an audio recorder. Data obtained were transcribed and analysed using rank ordering to determine the degree of importance. Results: Results identified eight barriers to drug adherence among which were finance/cost of medication (195), forgetfulness (160) and side effects of drops (155). Other barriers were difficulty with drop administration (143), busy schedule (130) and non-availability of eye drops (122) among others. Facilitators identified included fear of blindness (185), desire for improved vision (152) and knowledge about the disease (112). Other facilitators were convenience of eye drop schedule (99), availability of drops (91) and use of alarms (89) among others. Conclusion: Understanding these factors would help eye care practitioners to advice their patients better and greatly slow down the progression of the disease.

Keywords: Drug adherence, medication, patients, vision, glaucoma

How to cite this article:
Ebeigbe JA. Glaucoma medication adherence in an adult population in Nigeria. Afr J Med Health Sci 2017;16:12-8

How to cite this URL:
Ebeigbe JA. Glaucoma medication adherence in an adult population in Nigeria. Afr J Med Health Sci [serial online] 2017 [cited 2018 Oct 19];16:12-8. Available from: http://www.ajmhs.org/text.asp?2017/16/1/12/209490

  Introduction Top

Worldwide, glaucoma is becoming an increasingly important cause of blindness as the world’s population ages. After cataract, glaucoma is the second cause of blindness worldwide. Glaucoma is a group of diseases that results in damage to the optic nerve and subsequently in vision loss.[1] It is a common and potentially blinding condition.

Glaucoma, as estimated by the World Health Organization in 2010, accounts for 8% of severe sight loss globally and is the leading cause of irreversible blindness.[2] In Africa, glaucoma accounts for 15% of blindness, and it is the region with the highest prevalence of blindness relative to other regions worldwide. In 2006, the number of people who were estimated to be blind in both eyes was projected to increase from 8.4 million in 2010 to 11.1 million by 2020. Approximately 2% of the population with the age 40 years and above have glaucoma, rising to almost 10% in people older than 75 years.[3] Globally, about 314 million people are visually impaired, whereas 45 million of them are blind with 87% of the visually impaired living in the developing countries.[4]

Certain ethnic populations are especially at risk; this includes blacks, individuals of African ancestry, Hispanic individuals and certain Asian populations.[5] The elderly who are at the greatest risk for developing glaucoma often attribute their loss of vision to just growing old.[6] Vision loss from glaucoma is silent, slow, progressive and irreversible; hence the saying, ‘glaucoma is the silent thief of sight’. It cannot be cured, but it is treatable.

Friedman[7] described adherence as the degree to which a patient follows the instructions to take a prescribed treatment during a defined period of time and that the outlooks, behaviours and circumstances that lead a patient to take prescribed medications should not just be referred to as compliance but as adherence. He further stressed that such a behaviour was a result of complex interplay of many factors that were not easily generalised.

Patients with poor health literacy and blacks have been reported to have poor adherence with glaucoma medication and greater disease progression.[8],[9] To preserve vision and minimise deterioration, a successful long-term pharmacological therapy is of paramount importance in the lowering of intra-ocular pressure, and this required the strict adherence of the patient to prescribed ophthalmic eye drops as the treatment of choice.[10]

Dunker et al.[11] reported that due to the fact that patients with glaucoma are not reminded by the disease process itself of the importance of taking medications as prescribed, poor adherence to medication is high. Hahn[12] reported that ophthalmologists have been shown to do a poor job of detecting non-adherence by their patients, and glaucoma patients have been known to overestimate their adherence to medical therapy. Patients are often resistant to reveal non-adherence for the fear of not being seen as good patients by their physicians. As such, in glaucoma therapy, as in other chronic disease states, the ‘dental floss phenomenon’ may occur, in which patients are extremely adherent to the regimen in the time leading up to the appointment with their doctor, and a falsely good impression can be made with the care provider. However, the patients may be less adherent to the regimen in the months away from the office appointment, and this lack of adherence may lead to irreversible damage.[12]

There are no available data on glaucoma medication adherence among patients in Nigeria. The purpose of this study, therefore, was to determine the factors that facilitate or prevent glaucoma patients from adhering to their medication.

  Materials and Methods Top

This was a qualitative study using one-on-one in-depth interviews (IDIs). The study was conducted between August 2015 and April 2016. Participants were recruited by convenient sampling from the patient pool of the optometry eye clinic in the University of Benin, Benin City, Nigeria. Forty-nine (49) participants who had been diagnosed with glaucoma and had been on glaucoma medication for at least a year, were interviewed on different days during their various visits to the clinic. The participants were within the ages of 18 and 70 years, with a mean age (SD) of 54 ± (2.1) years.

The patients who were recently diagnosed with glaucoma were excluded from the study as well as patients who were less than 18 years of age. Ethical clearance was obtained from the University of Benin Research and Ethics Committee. Written informed consent was obtained from the participants, after an explanation of the aims of the study was given. Optimum care was taken to ensure that the participants were not hurried, as they were interviewed so as to get adequate responses from them.

The participants were interviewed by the author with the aid of a voice recorder just after seeing their doctor. The socio-demographic information of each patient was taken; this included age, sex, educational level, employment status and marital status.


Step one

The participants were each asked the question, ‘what things make it difficult or harder for you to take your eye drop medications as the doctor had prescribed’. They were encouraged to exhaustively list the factors that hindered them from taking their eye drop medications in the way the doctor had prescribed for the drugs to be taken. Time was given to elicit as much responses as possible.

Step two

The participants were then asked to identify the five most important factors hindering proper adherence from among all the previously listed factors and then rank them in their order of importance. These five most important factors were quickly jotted down by the researcher on a writing sheet as and when they were listed, and ranked using 5 for the most important and 1 for the least important factors. Those who listed less than five were also asked to rank their answers in their order of importance.

Step three

The participants were each asked the question, ‘what things make it easier for you to take your eye drop medications as the doctor had prescribed’. They were encouraged to exhaustively list the factors that encouraged them to take their eye drop medications in the way the doctor had prescribed for the drugs to be taken. Time was given to elicit as much responses as possible.

Step four

The participants were then asked to identify the five most important factors that helped them to properly adhere to the doctor’s instructions among all the previously listed factors and then rank them in their order of importance. The five most important factors were quickly jotted down, as they were listed and ranked using 5 for the most important and 1 for the least important factor. Those who listed less than five were also asked to rank their answers in their order of importance.

Data analysis

Verbatim transcription of all interviews was executed by a transcriber, ensuring the entirety of meaning in the context of the words. The analysis of textual data was performed by rank ordering the results in their order of importance to the patients.

Most important factor to least important factor was ranked 5, 4, 3, 2 and 1 respectively. A few number of participants listed four or three factors as being the top most on their minds, and these were ranked from 5 downwards to the least. The rationale behind this was that since these were the major factors that the participants could come up with, they deserved to be given as much weight as for those who listed five. In addition, if these participants had been able to come up with any other factors, these would have been less important to them and would have been ranked lower.

  Results Top

Forty-nine IDIs were conducted for 49 adults within the ages of 18–70 years. The mean age of the participants was 54 years. Of the 49 participants, 28 were men (57.14%), whereas 21 were women (42.86%). [Table 1] shows the socio-demographic characteristics of the participants.
Table 1: Demographic characteristics of the participants

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Eight themes were raised for barriers to topical glaucoma medication adherence [Table 2], whereas nine themes were raised for facilitators of topical glaucoma medication adherence [Table 3]. These themes are presented in tables according to their order of rank of importance. Examples of certain key statements have been included for substantiation.
Table 2: Glaucoma medication barrier themes, examples and rank-ordering votes from interviews

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Table 3: Glaucoma medication facilitator themes, examples and rank-ordering votes from interviews

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Method of summation of rank-ordering votes

Rank-ordering votes from the interviews were summed up for each theme using the following method. For the barriers, finance/cost of medication was number 1 on [Table 2], because it had the highest sum of votes. This was arrived at thus:

This showed that all the participants interviewed listed finance/cost of medication as a barrier to them in different order of importance. This summed up to 195, which was the highest rank; hence it was listed as the number 1 barrier in [Table 2]. Other themes were summed up in like manner, and these have been presented in [Table 2] and [Table 3].

  Discussion Top

The major facilitator of adherence to glaucoma medications from this study was the fear of going blind or losing vision. This was stated by almost all patients interviewed. Some participants reported that they understood the gravity of the disease from the materials read online and from the doctor’s explanation. This finding is similar to that of Lacey et al.,[13] wherein the major motivation was fear of blindness, which induced self-motivated perseverance in the participants of that study. Therefore, there is a need for eye doctors to properly educate any patient recently diagnosed with glaucoma on the chronic, progressive and insidious nature of the disease and the effects of non-adherence to medications given. This education can be provided with pictorial representations of what the damage caused by neuronal death found in glaucoma can be like. Pictures can be related to more easily than just words.[14]

For those, who have been diagnosed with glaucoma for quite a while, reiteration of the effects of non-adherence should be performed on each visit to help improve adherence. Patients should be introduced to educational resources, which are available online. Clinicians should be pragmatic when explaining the risks and consequences of the disease process.[15]

Another major facilitator of adherence was the desire of the patient for vision to get better. Many of the participants believed that their continued adherence to the medication would improve their eyesight. When advising patients with glaucoma, especially those with significant loss of vision due to the disease, care should be taken to ensure that the hopes of the patient are not raised unnecessarily. The patient should be educated on the fact that the medication is to reduce the IOP and subsequently, prevent further damage rather than restore lost vision.

Other facilitators revealed from this study included knowledge of the disease from either the doctor or materials read, convenience of the drugs schedule for some, availability of the drugs and the use of alarms and cues such as placing the eye drops by their bedside or next to the toothbrush. The patients reported that setting alarms, which rang at the pre-scheduled time, went a long way in helping them to adhere to the drug regimen.

Clinicians should suggest setting a daily routine for when drops are to be taken. Patients should also be encouraged to incorporate the time for taking drops with other daily activities such as brushing the teeth, watching the news at night, eating breakfast and dinner or while taking other systemic drugs.

Other patients reported that having a member of their family or friends remind them about their medications helps them to maintain their regimen. Having a good support system from family members who are knowledgeable about the disease goes a long way in helping patients adhere to their medication. Patients who report difficulty in remembering to take their drugs, should be encouraged to elicit the help of family members.

The study by Dreer et al.[16] also reported major facilitators to include fear of the consequences, use of memory aids, cues and strategies, recognising the importance of eye drops on eye health/knowledge, keeping the same schedule or routine, affordability of eye drops and keeping medications in the same area, where they can be seen.

To aid medication adherence, patients should be taught the dos and don’ts of eye drop application. This involves telling them the number of drops to be used and showing them the right instillation techniques. They should be educated on the side effects that could result from taking these medications so as to prevent them from stopping, when they do occur. The patients should also be encouraged to report any adverse effects of the drugs as soon as they are experienced.

A major barrier identified in this study was finance or cost of medication. This was the case especially in patients who were retired, students and young persons. In cases where multiple drug regimens are needed, combination drugs containing the necessary classes of drugs should be prescribed.

Clinicians should also endeavour to prescribe drugs that are readily available and that are equally as effective in managing glaucoma. This finding differs from the results reported by Lacey et al.[13] who reported a lack of proper education on the disease as the major barrier to adherence to medication. It also differs from the reports by Dreer et al.[16] and Taylor et al.,[17] wherein the major barrier to adherence was forgetfulness. This may be due to the presence of a good insurance system and a higher income level as exists in the United States of America[18] unlike Nigeria, which is a third-world country. A lot of patients in Nigeria do not have health insurance coverage; hence, cost of medication continues to be a major issue in healthcare.[19]

Another barrier identified from this study was forgetfulness. This barrier can be eradicated or greatly minimised with the use of alarms and cues or with the help of a family member. Eye clinics can aid adherence by sending emails, text messages or making telephone calls to patients on a regular basis reminding them of appointment dates, prescription refill and an occasional reminder to take medications.[20]

The side effect of some of the eye drops was another barrier raised during the course of this study with complaints of stinging sensation in the eye or bitterness in the mouth after drop instillation. Some patients reported changing their drug regimen as a result of these side effects and not alerting their doctor to these changes. At first time prescription, the patients should be advised on the possible side effects that could occur and then instructed to return if they experience these side effects.[21]

Doctor–patient communication is of the essence here, as many patients are hesitant to report any side effects or deviations from drug regimen to their doctor.

Other barriers to medication adherence identified in this study included difficulty with drop instillation. This was common among the elderly patients. Busy schedule throughout the day with patients reporting not having time from their day’s work to put the eye drops in, lack of drugs due to it getting exhausted or scarce, discouragement from multiple drug usage and a tiring eye drop schedule were other barriers listed. All these are consistent with the findings from Lacey et al.[13] and Dreer et al.[16]

Glaucoma is a progressively debilitating disease if not properly managed with the appropriate medication therapy.[22] The effect of these topical glaucoma drugs would not manifest if there is poor adherence to the drug regimen. Poor adherence to drug regimen especially in patients with glaucoma who are asymptomatic, is a major reason behind the disease’s progression.[23] A good patient–doctor relationship is therefore of the essence, as this would make the patient trust the doctor with any reports of non-adherence.

Studies[24],[25] from the systemic hypertension literature suggest that simplifying medication regimen, lowering costs and patient education about the disease and the importance of taking medications are successful strategies for improving adherence. In addition, good family or social support, frequent doctor’s visits and pairing medication administration with specific daily activities can help improve adherence. Optometrists and ophthalmologists involved in eye care should therefore, educate patients and emphasise on the importance of taking medications as prescribed.


The author thanks Dr. Fredrick-Igbedion E. for her assistance in data collection.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

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  [Table 1], [Table 2], [Table 3]


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