the prevalence of primary open angle glaucoma ( poag ) is estimated to be between 1.1% and 3% in western populations over the age of 40 years [ 1 , 2 ] .
the estimated number of poag patients in israel is 60,000 . a large survey study including 10,000 israeli participants demonstrated a similar distribution of the disease among various israeli ethnicities , including arabs . in the literature ,
compliance is reported to vary from as low as 5% to as high as 80% .
moreover , similar studies and information in the specific israeli - arab population are still lacking .
the aim of this study is to estimate the degree , components , and determinants of noncompliance among poag arab patients in israel and to verify associated factors for noncompliance .
glaucoma is insidious and disabling ; the degree of interference with vision varies from imperceptible changes to complete blindness .
several authors have indicated that noncompliance is an important factor in blindness resulting from glaucoma [ 69 ] .
poag patients attending out - patient eye clinics at the 3 cities , tira , taibi , and qalanswa in israel , were invited to join the study .
subjects were included if they were willing to participate , signed an informed consent , and fulfilled all of the following conditions : were a resident of one of the 3 cities ( tira , taibi , or qalnsawa ) and from an arab origin ethnicity;were diagnosed by an expert ophthalmologist as having poag for at least 3 months prior to the interview ; the diagnosis was based on glaucomatous cupping of the optic disc and a glaucomatous visual field loss , in one or both eyes , regardless of the intraocular pressure;were prescribed medications for glaucoma , in the past 3 months;had no mental or physical condition rendering them unable to participate in the study.exclusion criteria : evidence of angle closure glaucoma ( acg ) .
acg represents a group of ocular diseases with various causes that have a unique behavior and different treatment modalities ( such as laser iridotomy ) ; cataract surgery within 30 days prior to the study .
elevated intraocular pressure , following cataract surgery , occasionally requires a limited course of therapy to lower intraocular pressure perioperatively .   were a resident of one of the 3 cities ( tira , taibi , or qalnsawa ) and from an arab origin ethnicity ;
were diagnosed by an expert ophthalmologist as having poag for at least 3 months prior to the interview ; the diagnosis was based on glaucomatous cupping of the optic disc and a glaucomatous visual field loss , in one or both eyes , regardless of the intraocular pressure ; were prescribed medications for glaucoma , in the past 3 months ; had no mental or physical condition rendering them unable to participate in the study .
acg represents a group of ocular diseases with various causes that have a unique behavior and different treatment modalities ( such as laser iridotomy ) ;   cataract surgery within 30 days prior to the study .
elevated intraocular pressure , following cataract surgery , occasionally requires a limited course of therapy to lower intraocular pressure perioperatively .  
a closed questionnaire , filled solely by medical doctors , was used to collect data during the interview .
the first section included general data of the patient , such as age and gender .
the participants were asked three short questions : a list of prescribed glaucoma medications;the frequency of daily usage;the frequency of weekly and monthly usage .   a list of prescribed glaucoma medications ; the frequency of daily usage ; the frequency of weekly and monthly usage .    data retrieved , from both the out - patient clinic records and the questionnaires , were used to define compliance and noncompliance .
noncompliance was defined as missing at least one drop of medication per week and ( or ) the inability to accurately describe one 's own medication regimen .  
subjects whom were considered as noncompliant were asked to choose one of the eight listed reasons to explain nonadherence ( see the appendix ) .
the noncompliance - related questions covered information regarding how to use eye drops , the importance of treatment and consequences following non - adherence , intolerance , and patient - physician interaction .
responses were grouped and analyzed into 5 categories by interviewing doctors ( see the appendix ) .
multiple logistic regression analysis was performed to predict correlation between age and number of anti - iop drugs .
in addition , chi - square tests were carried out in order to examine the relationships between gender and compliance and number of anti - iop drugs .
mean age and sd among compliance patients group and noncompliance patients group were similar ( table 1 ) .  
we found a positive statistical significance in the correlation between age and number of prescribed drugs ( p < 0.05 ) .
logistic regression analysis revealed that age can not predict compliance ( p > 0.05 ) .
interestingly , the compliance was significantly higher among the two groups at either end of the curve , that is , younger than 50 years ( 77% ) and older than 81 years ( 63% ) ( p < 0.05 ) .
though patients that were prescribed 3 drugs were slightly more noncompliant , the difference is statistically not significant and compliance rates were not influenced by gender or by number of anti - iop drugs ( table 2 ) . 

lack of knowledge ( 32% ) , misunderstanding ( 25.5% ) , and denial ( 15.5% ) were the most common reasons indicated .
in addition , 14% of the participants mentioned that they could not tolerate the drops , while 13% of the patients could not point to specific reasons for their noncompliance .
the aim of this study was to find the noncompliance rates among coag israeli arab patients and to try to define the reason for their noncompliance .
the main findings of our survey are the relatively high noncompliance rates among coag israeli arab patients .
a pleasing bias may occur , in which patients may tend to orally report better compliance . furthermore , objectively measuring the effect of therapy , that is , the iop , was not performed . however , in addition to the gathered data from the questionnaires , out - patient clinic records were retrieved and used together to define noncompliant patients , thus minimizing the aforementioned bias .  
glaucoma patients who were not patients at outpatient eye clinics at tira , taibi , and qalnsawa cities in israel are not represented in this study .
these unreported patients may be receiving treatment at private clinics or may have ceased to participate in their personal treatment plans .
therefore , our study results represent only israeli - arab glaucoma patients treated in the outpatient clinics and may not represent all those suffering from glaucoma among the israeli - arab population .
furthermore , the study relies on patients ' responses and involves health - care providers .
better ways to measure disease progression compliance with medication than cross - sectional studies exist , implying that longitudinal studies are needed in the future to evaluate different levels of noncompliance .
results of this study demonstrate that over 50% of the israeli - arab glaucoma patients are not compliant to their treatment plans .
lack of knowledge and misunderstanding are the major reasons given by patients explaining their non - adherence .
the reported noncompliance rates in western populations and in the rest of israel vary from 27.4%   to 42%   according to different studies . various study designs and nonuniform compliance definitions
the relatively high levels ( 50% ) of noncompliance in the primarily israeli - arab population are consistent with many reported population - based studies in certain ethnic groups [ 12 , 13 ] .
for example , african americans are not only more likely to develop poag compared to white americans , but also less compliant in their treatment plans .
similarly , a recent study reported an even higher nonadherence rate among oman glaucoma arab patients ( up to 75.2% ) .  
purportedly , a higher rate of noncompliance among females ( 52.7% compared to males 47.2% ) was observed in our survey . yet , the differences are statistically insignificant , implying that gender per se is not associated with increased noncompliance [ 14 , 15 ] . 

figure 1 describes a positive association between age and number of anti - iop drugs .
although overall noncompliance rates increased from 28.5% with once daily drug to 38% with 3x daily , this increment was statistically insignificant ( table 2 ) .
in addition , the frequency of instillation per day did not affect compliance significantly , although studies have shown that a single daily drug dose or combination is associated with better compliance rates [ 15 , 16 ] .
granstrom and norell have clearly shown that 4x daily regimen of pilocarpine was unrelated to low compliance .
however , noncompliance , in this study , is related to the patient 's experience of side effects and/or negative attitudes to the treatment . in our study , significantly higher rates of compliance were found among the two extreme age subgroups , that is , < 50 years old and > 80 years old ( see figure 2 ) , 63% and 77% , respectively .
younger glaucoma patients are found to have a tendency to follow treatment regimens strictly probably due to proper perception of their disease and better instillation compared to older individuals . as for the elderly , gurwitz et al . found that elderly glaucoma patients started on multiple glaucoma medication were more adherent than those started on a single agent .
therefore , in our older glaucoma group , a high probability of multiple medications might explain the high compliance rates .
however , several studies clearly indicate higher prevalence rates of noncompliance among elderly , mainly due to improper installation of eye drops as well as other age - related medical illnesses , such as dementia and arthritis .
clearly , a major determinant of compliance with medical treatment in any medical illness is the patient 's awareness and understanding of his disease .
poag usually produces few external signs , making the severity of the disease more difficult to perceive and possibly causing later complications , particularly because the only symptoms may be the side effects of the medical treatment prior to later more serious complications such as visual field loss .
lack of knowledge and misunderstanding were the main factors cited for the > 57% noncompliance rates in our patients .
the association between compliance and awareness of the disease , its severity , treatment , and its late complications has been previously noted [ 9 , 14 , 20 ] .
furthermore , patients with higher levels of formal education are more accurate in describing their medication regimen .
in addition , better knowledge about glaucoma is associated positively with better compliance rates . in a recent study in oman , the knowledge about glaucoma
was reported to be good in 23.8% of patients , who demonstrated higher compliance rates .
reported that over a third of glaucoma patients failed to use their ophthalmic medications properly , mainly due to lack of knowledge .  
many patients are in denial about their health problems , especially in asymptomatic diseases such as glaucoma . not surprisingly , denial and intolerance comprised 30% of the noncompliant patients .
in addition , the patient - physician interaction remains a cornerstone in improving compliance rates due to intolerance [ 7 , 11 , 15 ] .
the physician should tailor the medication to the patient 's lifestyle after careful investigation of the patient 's routines such as sleeping , eating , and daily activity patterns [ 11 , 14 , 15 ] .
additionally , the physician must be aware of possible side effects and keenly seek them out , while always discussing various treatment options .
noncompliance was found to be relatively common among israeli - arab coag patients in both sexes .
the overall noncompliance rate was 50% and was not influenced by gender or by number of anti - iop drugs .
compliance was significantly higher among patients younger than 50 years ( 77% ) and older than 81 years ( 63% ) .
the most common reasons indicated for noncompliance were lack of knowledge , misunderstanding , and denial .
educating patients about their disease and its complications , using guiding brochures and dvds , and improving the patient - physician relation by personalizing the treatment can plausibly improve compliance rates .
furthermore , patients ' needs and knowledge should be taken into consideration in order to improve patients ' compliances .
 
 objective . to evaluate the noncompliance treatment rates among primary open angle glaucoma ( poag ) arab patients in israel and to verify the associated factors for noncompliance . 
 
 patients and methods . 
 a cross - sectional study took place using a questionnaire . 
 patients were initially interviewed and requested to answer a questionnaire . 
 the questionnaire was developed based on a pilot test . 
 items included information about age , gender , number of prescribed drugs , and multiple reasons for noncompliance with drug therapy . setting . 
 ophthalmologic hmo clinics , located in 3 arab cities in the center of israel . 
 participants . 400 arab participants ( 197 men , 203 women ) undergoing routine clinical care were recruited . 
 results . 
 general rate of noncompliance , for both genders , was found to be 50% . 
 factors associated with nonadherence included inadequate knowledge ( 32% ) , underestimation of the disease severity ( 25.5% ) , and denial 15.5% . 
 compliance rates were unaffected by gender or number of prescribed drugs . 
 compliance was significantly higher in younger patients ( age < 50 ) and in older patients ( age > 80 ) , 63% and 77% , respectively , ( p < 0.05 ) . 
 conclusion(s ) . 
 noncompliance was found to be common among an arab population in israel , particularly between the ages of 50 and 80 . 
 educational programs , improving patient - physician relationship , and personalizing treatment could provide means for improved adherence . 