Table 1.
Summary of studies that investigated retinopathy knowledge among patients with diabetes and health care providers
| Study | Country | Study Type & Population | Measure | Main Findings |
|---|---|---|---|---|
| Patients with Diabetes | ||||
| Addoor 2011 [84] | Malaysia | Cross-sectional 351 from 1 ophthalmology clinic | Study-created KAP survey | 87% aware diabetes affects eye. Predictors of knowledge: duration of diabetes (p<0.01), eye exam in last 6 months (p<0.04) |
| Adriono 2011 [85] | Indonesia | Cross-sectional 196 from 3 primary care clinics | Study-created KAP survey | 38% aware diabetes causes blindness. Prior exam linked to better knowledge (p=0.002). |
| Ahmed 2017 [52] | Bangladesh | Cross-sectional 122 from 1 diabetes clinic | Study-created KAP survey | 24% with poor knowledge about the effect of diabetes on the eye. |
| Al-Asbali 2020 [80] | Saudi Arabia | Cross-sectional 200 from 1 endocrine and 1 ophthalmology clinic | Study-created KAP survey | 45% excellent knowledge. Predictors of knowledge: duration diabetes (p=0.03). |
| AlHargan 2019 [83] | Saudi Arabia | Cross-sectional 280 from 2 primary care clinics | Adapted KAP survey [152, 154] | 88% knew diabetes affects the retina. Predictors of knowledge: formal education (p<0.01), higher income (p<0.05). |
| Almalki 2018 [57] | Saudi Arabia | Cross-sectional 253 T2D from 1 endocrinology clinic | KAP survey adapted from prior study [84] | 64% knew diabetes affects the eye. |
| Alsaidan 2019 [71] | Saudi Arabia | Cross-sectional 174 T2D from 1 primary care clinic | Details not provided | 82% aware diabetes affects eye. Predictors of knowledge: male gender (p=0.045), well controlled T2D (p=0.021). |
| Alwazae 2019 [58] | Saudi Arabia | Cross-sectional 404 from 4 clinics | Study-created KAP survey | 73.5% with adequate knowledge. |
| Al-Yahya 2020 [155] | Saudi Arabia | Cross-sectional 313 from 52 primary care clinics | Validated KAP survey [54] | 53% knew diabetes affects the eye. Predictors of knowledge: higher income (p<0.02). |
| Alzahrani 2018 [62] | Saudi Arabia | Cross-sectional 377 from 38 primary care clinics | Study-created KAP survey | 82% knew diabetes affects the eye. |
| Al Zarea 2016 [154] | Saudi Arabia | Cross-sectional 439 from 5 clinics | Study-created KAP survey | 75% aware diabetes can cause eye disease. |
| Assem 2020 [59] | Ethiopia | Cross-sectional 230 from 1 diabetes clinic | Study-created KAP survey | 52% with poor knowledge. Predictors of knowledge: urban residence (p<0.05), income, diabetes (p<0.05), duration (p<0.01), |
| Bakkar 2017 [152] | Jordan | Cross-sectional 237 T2D randomly selected from 3 cities | Study-created KAP survey | 88% aware diabetes can affect the eyes. Predictors of eye knowledge: more than high school education (p<0.01). |
| Balasubramanian 2016 [61] | India | Cross-sectional 105 from 1 clinic | Details not provided | 76% aware diabetes affects the eye. Predictors of knowledge: education (p<0.05) |
| Çetin 2013 [49] | Turkey | Cross-sectional 437 seen at 1 ophthalmology and 1 endocrinology clinic | Study-created questionnaire | 88% knew diabetes affects eyes. 25% thought eye exams only necessary if having troubled vision or poorly controlled diabetes. |
| Das 2016 [50] | India | Cross-sectional 240 from 1 ophthalmology clinic | Study-created KAP survey | 65% knew diabetic retinopathy affects the eyes. 42% disagreed that eyes could be affected, even if blood sugar was controlled. Predictors of eye knowledge: none significant |
| Duan 2020 [69] | China | Cross-sectional 1972 in 1 community health system | Study-created KAP survey | 62% knew diabetes affects eyes. Predictors of knowledge: younger age, male sex, higher education, longer diabetes duration (all p<0.01). |
| Fallatah 2918 [55] | Saudi Arabia | Cross-sectional 380 from 1 ophthalmology clinic | Study-created KAP survey | 92% aware diabetes affects eyes. Predictors of knowledge: formal education (p<0.05), urban residence (p>0.05). |
| Gillibrand 2000 [68] | UK | Cross-sectional 2,815 community patients not engaged in eye care | One knowledge question | 18.3% did not know diabetes affects eyes. |
| Khandekar 2010 [48] | Oman | Cross-sectional 750 in 1 region | Study-created KAP survey | 61% aware diabetes affects eyes. |
| Konstantinidis 2017 [53] | Switzerland | Cross-sectional 323 recruited from community pharmacies | Study-created questionnaire | 96% aware diabetes can cause eye disease. 98% knew good glycemic control could prevent occurrence or deterioration of eyes. |
| Lian 2018 [75] | Hong Kong | Cross-sectional 2,593 at 2 clinics | Study-created questionnaire | 11.5% knew retinopathy could be asymptomatic. |
| Livingston 1998 [79] | Australia | Cross-sectional 205 urban, 240 rural | Study-created knowledge score | 37% aware eye problems can occur. Predictors of increased awareness: younger age: rural OR 2.89 [95% CI 1.36–6.06] urban OR 2.32 [95% CI 1.24–4.22]; eye exam in last 2 years: rural OR 1.89 [95% CI 1.04–3.42] urban OR 2.43 [95% CI 1.29–4.57]. |
| Manu 2018 [76] | India | Cross-sectional 150 T2D from 1 hospital | Details not provided | 58% aware diabetes affects the eye. No significant predictors of knowledge. |
| Mueke 2008 [90] | Myanmar | Cross-sectional 480 cared for by surveyed GPs | Study-created questionnaire | 80.6% knew diabetes affects eyes. 90.4% agreed patients with diabetes should see an eye specialist. |
| Mumba 2007 [70] | Tanzania | Cross-sectional 316 at 1 diabetes clinic | One knowledge question | 34% knew diabetes can damage eye. |
| Nathaniel 2015 [82] | Nigeria | Cross-sectional 225 at 1 endocrinology clinic | Study-created questionnaire | 57% knew diabetes can affect eye. |
| Ovenseri-Ogbomo 2013 [156] | Ghana | Cross-sectional 360 at 1 diabetes clinic | Study-created questionnaire | 49% knew diabetes can affect eye. No significant predictors of knowledge. |
| Pasagian-Macaulay 1997 [77] | US | Cross-sectional 150 women from 1 medical center | Study-created knowledge and belief score | 17% did not know required frequency of eye exams. 40% knew controlling glucose was important. Formal education linked to greater knowledge. |
| Rizwan 2004 [56] | Pakistan | Cross-sectional 132 from 1 ophthalmology clinic | Details not provided | 57% knew diabetes affects the eye. 22% reported eye exams should occur once vision was affected. |
| Saikumar 2007 [157] | India | Cross-sectional 1,000 at 1 clinic | Study-created awareness score | 84% aware diabetes can affect the eye. 46.9% knew related to glucose control. 50% thought routine eye exams not necessary. |
| Schmid 2003 [153] | Australia | Cross-sectional 68 T1D, 187 T2D in Diabetes Australia | Study-created questionnaire | 96.2% knew diabetes causes eye problems. |
| Schoenfeld 2001 [87] | US | Cross-sectional 2,308 in 1 county | Study-created questionnaire | 47% knew eye examinations were needed for people with diabetes. |
| Srinivasan 2017 [54] | India | Cross-sectional 288 from 1 ophthalmology clinic | Study created questionnaire | 58% had poor knowledge. |
| Tajunisah 2011 [63] | Malaysia | Cross-sectional 137 from 1 ophthalmology clinic | Details not provided | 86% aware diabetes can affect the eye. Predictors of knowledge: formal education (p>0.05). |
| Vanugopal 2020 [60] | India | Cross-sectional 350 from 1 hospital | Study-created questionnaire | 34% had adequate knowledge of diabetic retinopathy. Predictors of knowledge: formal education (p<0.001). |
| Walker 1997 [6] | US | Cross-sectional 67 Black Americans with diabetes in New York | Study-created questionnaire | 87% believed diabetic eye problems were symptomatic. 21% thought there were effective treatments. |
| Wang 2010 [86] | China | Cross-sectional 53 T1D 836 T2D from 1 endocrine and 1 general clinic | Study-created KAP survey | 77% aware diabetes affects eyes. Prior exam linked to better knowledge (p<0.001). |
| Whiting 1998 [78] | Australia | Cross-sectional 121 patients with retinopathy from 1 ophthalmology clinic | Study-created questionnaire | 95% knew diabetes affects the eyes |
| Zou 2017 [74] | China | Cross-sectional 519 with diabetes in 1 community | Study-created questionnaire | 95% aware diabetes affects the eye, 12% aware it can be asymptomatic. |
| Health Care Providers | ||||
| Abdulsalam 2018[65] | Nigeria | Cross-sectional 105 physicians from 4 hospitals | Study-created KAP survey | 36% perform eye exams, 90% do not use dilating eye drops |
| Abu-Amara 2019 [40] | Saudi Arabia | Cross-sectional 182 GPs, 115 internists | Study-created KAP survey | 45% with poor knowledge. |
| Al Rasheed 2017 [64] | Saudi Arabia | Cross-sectional 142 family, 10 pediatric, 8 internists, 56 GPs | Study-created questionnaire | Knowledge linked to: family medicine subspeciality training (p<0.01), years of practice (p<0.01). |
| Al-Rashidi 2020 [72] | Saudi Arabia | Cross-sectional 76 GPs in 1 province | Previously used KAP survey [64] | 37% performed dilated fundus exams. |
| Alhejji 2020 [100] | Saudi Arabia | Cross-sectional 141 GPs from 63 centers | Study-created questionnaire | 56% with good knowledge. |
| Al-Wadaani 2012 [101] | Saudi Arabia | Cross-sectional 73 medical students | Study-created KAP survey | Moderate overall KAP score, linked to male sex (p=0.02). 66% knew correct timing for eye exams. |
| Daly 2014 [93] | New Zealand | Cross sectional 287 nurses | Study-created survey | 89% identified retinopathy as a diabetes complication. Predictors of knowledge: level of training (p=0.006). |
| Delorme 1998 [66] | Canada | Cross-sectional 648 GPs, 96 trainees | Study-created questionnaire | Correct timing for screening in T1D: 74% vs T2D: 82%. 33% knew macular edema could be asymptomatic. |
| Foster 1996 [96] | US | Cross-sectional 23 optometrists | Study-created survey | Low level of knowledge regarding need for dilated fundus exams. |
| Ghosh 2007 [158] | India | Cross-sectional 36 optometrists, 241 GPs | Study-created questionnaire | <23% optometrists and <33% GPs had acceptable knowledge regarding risk factors and management of diabetic retinopathy. |
| Goodman 1997 [39] | South Africa | Cross-sectional 12 doctors, 23 nurses | Study-created survey | 100% knew diabetes affected the eye. |
| Khandekar 2008 [95] | Oman | Cross-sectional 42 ophthalmologists, 33 mid-levels, 12 GPs | Study-created questionnaire | Acceptable knowledge: 71% ophthalmologists, 54% mid-levels, 33% GPs. |
| Mueke 2008 [90] | Myanmar | Cross-sectional 100 GPs | Study-created questionnaire | Correct timing for screening in T1D: 2% vs T2D: 93%. |
| Namperumalsamy 2004 [159] | India | Cross-sectional 199 paramedical personnel | Study-created questionnaire | 88.5% knew diabetes could affect eyes. 20% knew uncontrolled diabetes is a risk factor. 75.9% unaware of treatments for retinopathy. |
| Raman 2006 [160] | India | Cross-sectional 159 GPs | Study-created questionnaire | 54% aware patients with diabetes should have annual dilated eye exams. |
| Wright 2001 [161] | Australia | Cohort 310 optometrists | Study-created questionnaire | 74.5% perform dilated exams on new patients with known diabetes. |
| Yan 2012 [97] | China | Focus groups 22 physicians, 25 village health workers | Study-created interview guide | Good overall knowledge, physicians did not dilate pupils to detect asymptomatic disease. |
Studies arranged alphabetically. Abbreviations: CI, confidence interval; GP general practitioner; KAP knowledge attitudes and practices; OR, odds ratio; T1D, type 1 diabetes; T2D, type 2 diabetes.