Worldwide, 285 million people are estimated to be visually impaired with 39 million people estimated to be blind  . Glaucoma is the second leading cause of blindness globally after cataract. It is the leading cause of irreversible blindness, accounting for 4.5 million blindness, which is about 12% of global blindness  .
Glaucoma is a group of diseases that have optic neuropathy as a common end point. The structural and functional deficit occurs as a result of increasing intra ocular pressure leading to damage of the optic nerve at the point where it entered the eye   . The two must common types are the Primary Open Angle Glaucoma (POAG) which is characterized by progressive narrowing of the neuroretinal rim with an associated increase in the cupping of the optic disc and Angle Closure glaucoma which is less common and occurs when the drains of the eyes become blocked, the intro-occular pressure rises and the iris is pushed forward, closing off the drainage    . The incidence of POAG rises with age and is more frequent in people of African Origin  . Glaucoma affects 1 in 20 people aged fifty years and younger, and 1 in ten people over the age of eighty years  . Global prevalence of glaucoma for population 40 - 80 years from prevalence surveys as at 2013 was 3.57% with possible 64.3 million people and projections of 76 million and 111.8 million people with glaucoma by 2020 and 2040 respectively  . Glaucoma affects about 4% of African Adults aged 40 years and above and accounts for about 15% of blindness     . Nigerian blindness survey in 2009 reported blindness prevalence of 4.2%, out of which 16.7% was due to glaucoma, giving glaucoma prevalence of 5.02% and glaucoma specific blindness prevalence of 0.7%    .
The condition is reversible or if detected early and appropriated treatment instituted  . One of the methods for timely detection and treatment is by having regular eye screening during adulthood made possible with awareness of glaucoma  . Awareness about glaucoma, glaucoma risk factors and prevention has been shown to reduce the chance of functional disability and vision loss  . Studies conducted in Osun and Ebonyi States of Nigeria showed that 84.2% and 78% respectively of respondents had never heard of glaucoma   .
Several factors relating to the development of glaucoma have been identified. These include increasing age, male gender, race/ethnicity, illiteracy, level of intrao-ccular pressure, type II diabetes Mellitus, previous history of trauma to the eye, myopia, systemic hypertension, and family history of glaucoma   .
Few community studies have been conducted on glaucoma in Nigeria, particularly in Ekiti State. This study therefore, aimed to assess the prevalence, awareness and risk factors associated with glaucoma.
The Study was carried out September 2018, in Ikole Ekiti in Ikole Local Government Area of Ekiti State.
Health outreach was organized in Ikole-ekiti by the Department of Opthamology, Federal Teaching Hospital Ido-ekiti in conjunction with the department of Community Medicine of the same institution. Advocacy visit was paid to the traditional head of the community before the commencement of outreach programme. The study design was a descriptive cross sectional study. All Adults who presented for the outreach were enrolled into the study and screened for glaucoma. A total of 122 adults were screened. A semi-structured self-administered questionnaire (Appendix I) was used to elicit sociodemographic characteristics, Awareness of glaucoma, and risk factors of glaucoma. Data were analysed using SPSS version 20. Tables were generated and P value was pre-determined at < 0.05. Ethical clearance was obtained from the ethics and research unit of Federal Teaching Hospital Ido-ekiti.
Diagnostic criteria for glaucoma
Optic Disc Status―CDR (Cup-Disc Ratio). Evidence of Optic nerve damage with CDR ≥ 0.6 and/ or CDR difference of both eye ≥ 0.2.
One hundred and twenty two (122) questionnaires were properly filled, returned and analyzed. Majority, 46 (37.7%) of the respondents were 60 years and above, 44 (36.1%) of the respondents were between 51 - 60 years of age while, 32 (26.2%) were less than 50 years (Table 1). Mean age of respondents was 55.2 ± 11.7. Majority of the respondents were females, 89 (73%), most of the respondents had secondary education, 50 (41%), 25 (20.5%), had tertiary education while 20, (18.0%) had no education.
The prevalence of glaucoma in this study was 13 (10.7%) (Figure 1). Only, 44 (36.1%) of the respondents had ever heard about glaucoma while 78 (63.9%) had never heard about glaucoma (Table 2). Out of the respondents that had ever heard about glaucoma, 19 (43.2%) knew that glaucoma can cause blindness while 25 (56.8%) did not know that glaucoma can cause blindness.
Test of relationship between presence of glaucoma and sociodemographic characteristics of respondents showed significant relationship between glaucoma and increasing age (p = 0.040). There was also significant relationship between presence of glaucoma and level of education with p-value of 0.033 (Table 3).
There was statistically significant relationship between glaucoma and Sources of glasses (p = 0.014). Respondents who got their glasses from friend/relative
Table 1. Socio-demographic characteristics of respondents.
Table 2. Awareness of respondents about glaucoma.
Table 3. Relationships between socio-demographic characteristics and glaucoma prevalence.
Figure 1. Prevalence of glaucoma among respondents.
and from the roadside were about 5.76 and 7.20 times respectively more likely to have glaucoma than those who got theirs from the eye clinic. Using of eye drops not prescribed had statistical relationship with presence of glaucoma (p = 0.0310) (Table 4). Those who had ever used eye drops not prescribed had 5.81 times more likelihood of having glaucoma than respondents who had not. Also, history of previous eye injury had relationship with glaucoma (p = 0.05). Respondents who had ever had an eye injury were about 6.24 times more likely to develop glaucoma than those who had not. Finally, family history of eye problem and presence of glaucoma had statistically significant relationship (p = 0.014). Respondents who had a family history of an eye problem were 4.89 times more likely to develop glaucoma.
The prevalence of glaucoma in this study was 10.7%. This result was higher than the national prevalence of 5.02%    . This difference with the National value may be due to the fact that study was conducted only in a rural community of Southwestern Nigeria and the fact that rural dwellers have poor access to health care, including eye care. Research has also shown that ethnicity with the Igbo and Yoruba tribes of being a risk factor for glaucoma  . This may account for the high prevalence in our study. The result was however similar to a rural and urban study conducted in Ilorin, Nigeria with a rural prevalence of 12.5% and urban prevalence of 8.2%  . The high prevalence could also be as a result of more people living to old age which predisposed elderly people to degenerative changes in the body and chronic diseases like glaucoma  .
Table 4. Relationships between some risk factors glaucoma prevalence.
Few (36.1%) of the respondents in this study had never heard about glaucoma and majority (56.8%) of those that had heard about glaucoma, did not know that the condition can lead to blindness. This low level of awareness was also demonstrated with awareness of 32%  , 15.8%  , and 21.1%  obtained from studies that were conducted in southern India, Osun State and Eboyin State, Nigeria, respectively. The India study is also similar to finding in this study with 55% of respondents who had ever heard of glaucoma not knowing that it can cause blindness  . However this study differs from a community study in Canada with glaucoma awareness of 73%  . This difference could be accounted for by the high level of development, high literacy rate and good access to health care in developed countries like Canada. Also, this study result predictably differs from that of a study conducted among Primary care givers, whose training gave them the opportunity to know about glaucoma, in Shagamu, Ogun State, with awareness of 97%  . The low level of awareness could be because of the insidious and initial asymptomatic nature of the disease and poor access of the people to eye clinics with glaucoma screening facility and treatment.
This study showed a relationship between presence of glaucoma and sociodemographic characteristics of respondents. This relationship include increasing age (p = 0.040), and level of education (p = 0.033). Similar glaucoma studies by Durowade et al.  and Kyari et al.  , also showed significant relationship with increasing age and literacy (p = 0.035) and (p = 0.001). The relationship with increasing age can be explained with increasing risk degenerative diseases as one ages and the exposure to risk factors over several years. People with high level of literacy are more likely to be aware about the disease and will most likely present for screening and early treatment. This study however did not show a relationship between glaucoma and gender. This is in contrast to findings of Durowade et al. and Kyari et al. when male gender were shown to be more at risk than female gender   . This difference may be as a result of more old women living to old age as found in rural communities of Ekiti state.
Factors that were showed to have relationship with glaucoma includes procurement of glasses form friends/relatives/roadside (p = 0.014), used eye drops not prescribed by ophthalmologists (p = 10.031) previous eye injury (p = 0.05) and family history of eye problem (p = 0.014). Previous study in Ilorin  had shown Unemployment (p = 0.000004), high IOP (p = 0.029), Known hypertensive (p = 0.002) and prolonged use of analgesic (p = 0.004) as factors associated with glaucoma. A Nigerian study also showed that systemic hypertension (p = 0.002) and Underweight (p = 0.0001) are significantly related to glaucoma. Respondents who procure their glasses from eye-clinic will have the opportunity of undergoing comprehensive eye examination which will help in detecting those with raise intra ocular pressure and appropriate treatment would be instituted early to normalize the intra-occular pressure thereby preventing the occurrence/progression of glaucoma whereas those who procure their glasses from other means(road side/relative or friends etc.) will not have the opportunity of eye examination or screening by qualify health personnel thereby worsening their eye condition. This may be the possible explanation for higher prevalence of glaucoma among the respondents that obtained their glasses from road side or from relative or friends than those that obtained theirs from the eye-clinic. Higher prevalence of glaucoma among respondents with history of use of un-prescribed eye drops might be due to the fact that some eye drops contain corticosteroid. Repeated or long term use of corticosteroid containing eye-drop not prescribed by a qualify health personnel is an important risk factor for the occurrence of glaucoma Self-medication with eye drops which contains corticosteroids causes damage to the eyes and predisposes to glaucoma.
Previous injury to the eye could leave a permanent damage to structures of the eyes and the draining pathway of the lacrimal fluid. People with family history might however have a genetic predisposition to glaucoma.
A major limitation of the study is that it was carried out in only one community out of several communities in Ekiti State.
This study has shown that glaucoma is prevalent in our population, with a prevalence of 10.7%. There is, however, low level of awareness of the disease (36.1%) and low awareness of the consequence of irreversible blindness (43.2%). This study also showed increasing age and level of literacy are factors for development of glaucoma. Other factors include procurement of glasses from quacks, use of eye drops without prescription, previous history of eye injury and family history of eye problem as factors associated with glaucoma. It is therefore recommended that Community screening for glaucoma for people above 40 years should be encouraged to ensure early diagnosis and treatment. Also, health education about glaucoma risk factors and prevention should be provided to the people through the health-workers, mass media and social media. Any adult with a family history of glaucoma should be advised to go for regular screening for glaucoma. Use of eye drop without prescription should be discouraged among the populace. People with visual problem should be advised to always consult trained ophthalmologist.
Appendix I: Questionnaire
Your age in years
Sex, Male Female
Level of Education Primary secondary Graduate None
Do you wear Glasses Yes
Where did you get the glasses from Road side Friend/relative Eye Clinic
Have you ever used eye drops not prescribed by doctors? Yes No
Have you ever been treated at eye clinic Yes No
Have you ever of the word “Glaucoma” Yes No
Do you know that glaucoma can cause blindness Yes No
Have you ever measured your blood pressure (BP)? Yes No
Do you know that the eyes have its own blood pressure? Yes No
Have you ever had your eye blood pressure checked? Yes No
Have you had injuries to your eye? Yes No
Does any of your relatives have eye problem? Yes No