Glaucoma awareness and knowledge among adults in woliso town, South West Ethiopia

Glaucoma is the leading cause of irreversible blindness worldwide and it is next to cataract as common cause of blindness [1-4]. The global prevalence of glaucoma for population aged 40–80 years is 3.5%. The magnitude of glaucoma is expected to keep increasing with the world population growth and increasing number of ageing people [5]. Ninety percent of affected people in the developing countries and 50% in developed world do not know that they have the disease [6]. In Sub-Saharan Africa glaucoma is more prevalent and has been considered as a major public health issue for the region [7,8]. Up to 50% of glaucoma patients are already blind at least in one eye at presentation in Africa including Ethiopia [7,9].


Introduction
Glaucoma is the leading cause of irreversible blindness worldwide and it is next to cataract as common cause of blindness [1][2][3][4]. The global prevalence of glaucoma for population aged 40-80 years is 3.5%. The magnitude of glaucoma is expected to keep increasing with the world population growth and increasing number of ageing people [5]. Ninety percent of affected people in the developing countries and 50% in developed world do not know that they have the disease [6]. In Sub-Saharan Africa glaucoma is more prevalent and has been considered as a major public health issue for the region [7,8]. Up to 50% of glaucoma patients are already blind at least in one eye at presentation in Africa including Ethiopia [7,9].
Individual awareness and knowledge of glaucoma has important role in screening, diagnosis, treatment compliance, and prevention. Eye health education that infl uences people to participate in regular ophthalmologic care is an important step to detect glaucoma early, thereby preventing blindness. Studies have indicated that patients, knowledge (or lack of knowledge) concerning eye care may play signifi cant role in seeking timely care and treatment [10][11][12].
In Ethiopia, public glaucoma awareness activities have been done over years. The level of glaucoma awareness could vary as to the type of studied community and possibly period of study time. For instance, the awareness level was 2.4% among rural community coming for cataract screening service in 2009 and 28.4 % among ophthalmic patients at tertiary ophthalmic center in 2010 [13,14]. The objective of this study was to determine level of glaucoma awareness and knowledge among adults residing in Woliso, a rural town.

Methods and subjects
A community based cross sectional study among adults aged 18 years and above in Woliso town was conducted from March 10 th to April 10 th , 2017. Based on the 2007 fi gures from the national census of Ethiopia, Woliso town had an estimated total population of 37,878 among which 18,880 are men and 18,998 women [12]. The source populations were adults living in Woliso town and the study populations were adults residing in households at the time of the survey.
The sample size was calculated using a 95% confi dence interval and allowing tolerable margin of error to be 1.4% and an expected prevalence rate of 2.4% awareness taken from a previous study in southwest Ethiopia [12]. Adding 10% nonresponse rate and design effect (multiplied by 1.5), the fi nal sample size became 757. To get the calculated participants sample size, three Kebeles, sub-district administrations of the town, were randomly selected as clusters, and for each Kebele 252 participants were allocated. Using area map of the town and a lottery method , the fi rst house was identifi ed for survey for each Kebele, and then, subsequent household dwellers were interviewed until the allocated sample size was mate House to status, awareness and knowledge on glaucoma. One individual from each household who was available and willing to be interviewed during the survey time was involved.
Data was entered into Statistical Package for Social Science (SPSS) version 20 soft-ware for data analysis. Descriptive statistics with mean, frequency and percentage was used to describe and summarized the data. P value less than 0.05 was considered statistically signifi cant.
The study was ethically approved by the research and publication ethics committee of the Department of Ophthalmology, Collage of Health Science, Addis Ababa University.
To conduct the study, permission was requested and obtained from the Woliso town Municipality offi ce and Health Bureau. Informed verbal consent was gained from every participant before proceeding with the interview.

Operational defi nitions
Awareness was defi ned if the participant has heard about glaucoma and said it is different from trachoma. Participant was leveled as having Knowledge if he/she mentioned factual information about glaucoma. Knowledge was further classifi ed as good, fair and poor based on the answer given to questions of what is glaucoma?, risk factors: increased Intraocular Pressure (IOP), age above 40, family history of glaucoma and others, and the treatment options. Good knowledge was defi ned when participant mentioned glaucoma as a blinding eye disease and mention at least one risk factor and one treatment option. Fair knowledge was stated when participant mentioned either of glaucoma as a blinding eye disease, risk factors or treatment options and Poor knowledge was defi ned if the participant mentioned glaucoma as an eye disease only. Experience of previous studies was used to empirical classify the level of glaucoma knowledge.

Results
A total of 757 adults residing in three Kebeles of Woliso town were interviewed from March 10 th -April 10 th 2017. The mean age of the participant was 35.3 (SD 14.15), ranging from 18-75 years. Table 1. shows the sociodemographic characteristic of participants in the study. Females were larger in ratio than males, 1.6:1. Majorty, 84.8%, were Christian in religion. The proportion of people who can not read and write was low (14.3%, 108/757), while educational level high school and above accounted for 66.9% (506/757). Afan-Oromo and Amharic were the two commonly spoken languages by 92.6 % (701/757) of the participants.
Among the interviewed individuals, 33.6% (254/757) were found to be aware about glaucoma, while the remaining 66.4% (503/757) participants were not aware about the eye disease. The mean age of those participants who were aware and unaware was comparable, 35.47 (SD 13.43) and 35.26 (SD 14.52), respectively.     [18,19]. All these differences can possibly explained by variation in glaucoma services and awareness activities in the different communities, places and countries.
In this study, media accounted the largest proportion as a source of information for the aware participants, 81.1% (206/254). Television was the commonest source of information for 60% (152/254) of the people, and it was also the commonest source, accounting for 29.2% (35/120), in tertiary hospital study in 2010 in the country [14]. This is related to the awareness activities that have been performed over the previous 9 years using mainly the mass media by the Glaucoma group of the Ophthalmologiacal Society of Ethiopia (OSE).
The studies from Nigeria and India have also reported mass media to be the main source of information, 53.3% and 29%, respectively [16,19]. The contribution of health professionals as source of information was 5.5% in this study and 6.6% in the previous hospital based study [14], which are low as compared to 22.3% and 20.0% from that of Nigeria and Central India [16,19]. Health professionals are the ones delivering the information using the mass media, other means and providing health education at eye clinics, but the low level in the country requires attention.
In this study females were largely (71.7%) unaware (Table   4) and the reasons could be limited access to media and time limitation due to social and domestic burden, but it requires further study to get evidence and come up with solutions.
Educational status had association with the level of awareness in this study (P = 0.00) and the ones done in 2010 and 2018 (P< 0.05) in the country and with that of studies from Nepal (P < 0.001) and India (P < 0.001) (14.15,17,18).
The level of knowledge was good in only 7.9% (20/254) and fair in 48.2% (120/254). The low level of good knowledge is comparable with that of reports from Chennai (8.7%) and Nigerian (5.5%) [16,18] In conclusion, the study determined the level of glaucoma awareness and knowledge, mass media to be the major source of information, males to be more aware than females and the higher the educational level, the greater the awareness level in the community during the study time. As glaucoma awareness and knowledge about the disease have major role for early
Comparing with studies done in other countries, there are higher level of awareness reports of 47 % (94/200) and Citation: Giorgis