|Year : 2021 | Volume
| Issue : 2 | Page : 71-80
Prevalence of diabetic retinopathy and risk factors among diabetic patients at university of gondar tertiary eye care and training center, North-West Ethiopia
Tesfahun Ejigu, Asamere Tsegaw
Department of Ophthalmology, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
|Date of Submission||22-Jan-2021|
|Date of Acceptance||11-Aug-2021|
|Date of Web Publication||25-Sep-2021|
Dr. Asamere Tsegaw
Department of Ophthalmology, College of Medicine and Health Sciences, University of Gondar, Gondar
Source of Support: None, Conflict of Interest: None
| Abstract|| |
PURPOSE: Diabetic retinopathy (DR) is one of the most serious complications of diabetes mellitus (DM). It is the most common cause of blindness among the working age group in the developed world and the fifth leading cause of global blindness. In Sub-Saharan Africa, 2.8% of all blindness is caused by DR. Studies addressing the prevalence of DR and associated factors are scarce in Ethiopia. The objective of this study was to determine the Prevalence and associated factors of DR development among DM patients attending University of Gondar, Tertiary Eye Care and Training center.
METHODS: A cross-sectional study was carried out from March 2019 to February 2020 involving all consecutive diabetes patients who visited the center during the study period. Data were collected using a semi-structured questionnaire and data extraction check list and entered into SPSS version 20 and analyzed. Univariate and multivariable logistic regression analysis were done to identify predictors of DR. Statistical significance was determined with 95% confidence interval (CI) using odds ratio and P < 0.05.
RESULTS: A total of 225 DM patients with a mean age of 55.4 ± 13.5 years were studied, of whom 95 (42.2%) had DR. Duration of diabetes ≥6 years (AOR = 2.91: 95% CI; 1.01–8.35) and baseline age < 60 years (AOR = 3.2: 95% CI; 1.19–8.63) were significantly associated with DR. DR was significantly associated with the form of therapy. Those on insulin (P = 0.025) and oral hypoglycemic agents (OHA) with insulin combination (P = 0.014) had statistically significantly associated with the development of DR. Patients with systolic blood pressure of <140 mmHg were 3.6 times (AOR = 0.28: 95% CI: 0.09–0.82) less likely to have DR. A majority of patients had nonproliferative DR without diabetic macular edema (DME) (34.2%). DME and proliferative DR were seen in 5.7% and 3.6% of the patients, respectively. Vision threatening DR (VTDR) was seen in 10.7% of patients. There was a significant association between age <60 years and VTDR (AOR = 4.19: 95% CI; 1.23–14.35).
CONCLUSION: The prevalence of DR among our study patients was very high. Longer duration of diabetes, higher systolic blood pressure, baseline age <60 years, use of insulin alone, and use of combination of insulin with OHA were independently associated with DR. Health education, early screening, and treatment are recommended.
Keywords: Diabetic retinopathy, Ethiopia, Gondar, prevalence
|How to cite this article:|
Ejigu T, Tsegaw A. Prevalence of diabetic retinopathy and risk factors among diabetic patients at university of gondar tertiary eye care and training center, North-West Ethiopia. Middle East Afr J Ophthalmol 2021;28:71-80
|How to cite this URL:|
Ejigu T, Tsegaw A. Prevalence of diabetic retinopathy and risk factors among diabetic patients at university of gondar tertiary eye care and training center, North-West Ethiopia. Middle East Afr J Ophthalmol [serial online] 2021 [cited 2021 Oct 26];28:71-80. Available from: http://www.meajo.org/text.asp?2021/28/2/71/326665
| Introduction|| |
Diabetic retinopathy (DR) is one of the most serious complications of diabetes that imposes a great burden on the patient, the health-care system, and the global economy. It involves damage to the microvasculature of the retina from prolonged exposure to the metabolic changes associated with diabetes.
Visual impairment as a result of DR has a significant impact on patients' quality of life, and can compromise their ability to manage their diabetes mellitus (DM) successfully, which can in turn have a positive impact on the incidence of other diabetic complications and negative impact on overall life expectancy and productivity.
According to estimates from a meta-analysis of published population studies from 1990 to 2012, DR accounted for 2.6% of all blindness and 1.9% of all moderate-to-severe visual impairment worldwide in 2010. This indicated an increase from 2.1% and 1.3%, respectively, in 1990. It was shown that 2.8% of the blindness in sub-Saharan Africa was caused by DR.
Globally, the prevalence of DR among diabetic adults was estimated to be 34.6%. The epidemiology of DR in Africa has also been systematically reviewed. In population-based studies, the reported prevalence range in patients with diabetes for DR was 30.2%–31.6%, proliferative DR (PDR) 0.9%–1.3%, and any maculopathy 1.2%–4.5%. In diabetes clinic-based surveys, the reported prevalence range for DR was 7.0%–62.4%, PDR 0%–6.9%, and any maculopathy 1.2%–31.1%.
Few available diabetes clinic-based studies in Ethiopia reported the prevalence of DR ranging from 34% to 51%.,,,
DR is an emerging cause of blindness in the developing world. Identification of the prevalence and associated risk factors of DR in our particular community could indicate areas to focus on in the follow-up and care of diabetic patients.
Preservation of sight in DR can be achieved through effective screening, timely laser treatment, intraocular injection of antivascular endothelial growth-factor drugs, and intraocular surgery.,
Despite the rising prevalence of diabetes and DR, studies addressing the prevalence of DR and associated factors in Ethiopia are scarce. This study was aimed at determining the prevalence and associated determinants of DR among diabetes patients who visited the University of Gondar (UOG) Tertiary Eye care and Training center Ethiopia.
| Methods|| |
Study design and period
A hospital-based prospective cross-sectional study was carried out from March 2019 to February 2020 at UOG Tertiary Eye Care and Training Center, Ethiopia.
The study was conducted at UOG Tertiary Eye Care and Training Center, a major eye care and training center in Ethiopia. It is an ophthalmic referral center for an estimated 14 million people living in North-West Ethiopia. The center provides eye care services both at the base hospital and rural outreach sites and annually, over 80,000 patients are seen at both sites. The base hospital has 8 outpatient clinics, facilities for inpatient care with 30 beds, and five operation theaters. Currently, the center has ten ophthalmologists, five of them with subspecialty training in glaucoma, vitreoretina, cornea and external eye diseases, and ophthalmic plastic and reconstructive surgery. There are also 26 ophthalmology residents, 21 optometrists, 5 ophthalmic officers, and 29 general clinical nurses actively working in the outpatient clinics and operation theatres of the tertiary eye care and training center.
All consecutive diabetic patients who attended UOG Tertiary Eye care and Training Center retina subspecialty clinic in the study period, who fulfilled the inclusion criteria were studied.
All medically diagnosed diabetic patients of any age who visited the UOG Tertiary eye care center and gave consent to be included in the study.
Diabetic patients with opaque ocular media due to corneal abnormalities or cataract obscuring adequate visualization of the posterior segment of the eye were excluded.
Sample size and sampling procedure
All consecutive diabetic patients who visited UOG comprehensive specialized referral hospital tertiary eye care and training center in the specified study period and who fulfilled the inclusion criteria were enrolled into the study.
Type 1 DM: Diabetes diagnosed before 30 years of age and whose initial treatment is Insulin.
Type 2 DM: Diabetes diagnosed after 30 years of age and whose initial treatment does not include Insulin.
WHO definitions of hypertension
Pre Hypertension: Systolic BP = 120 mmHg–139 mmHg and/or diastolic BP = 80 mmHg–89 mmHg
Stage 1 hypertension systolic BP = 140 mmHg–159 mmHg and/or diastolic BP = 90–99 mmHg
Stage 2 hypertension systolic BP ≥ 160 mmHg and/or diastolic BP ≥ 100 mmHg
Vision threatening diabetic retinopathy (VTDR): Severe non-PDR (NPDR), PDR, or diabetic macular edema (DME)
Body mass index (BMI), WHO classification (kg/m2)
<18.5 = Underweight
18.5–24.9 = Normal
25–29.9 = Overweight
≥30 = Obese.
Data collection procedure and quality control
Semi-structured interviewer-administered questionnaire, document review, and ocular examination were used to collect data. The questionnaire consisted of three sections: sociodemographic variables (nine items), medical history (nine items), and checklist for clinical and laboratory data extraction (five items). Data quality was ensured through pretesting the questionnaire before the actual data collection period.
Sociodemographic data and relevant medical history were filled into the pretested semi-structured questionnaire. Laboratory test results of fasting blood glucose (FBG) and lipid profile were obtained, in which a single record of recent FBG level was taken. Blood pressure was measured in sitting position after 5–10 min of rest. Hypertension is defined as systolic BP of ≥140 mmHg and/or diastolic BP of ≥90 mmHg. BMI was calculated from weight in kilograms and height in meters squared and categorized according to WHO classification. Best-corrected visual acuity was taken using Tumbling E Snellen visual acuity chart and patient sitting at 6 m position, and classified according to WHO grading of visual acuity as follows: visual acuity better or equal to 6/18 – normal; visual acuity ≤6/24 and better than or equal to 6/60 – moderate visual impairment; visual acuity <6/60 and better than or equal to counting fingers at 3 m – severe visual impairment; visual acuity less than counting fingers at 3 m – blindness; the results for the eye with better visual acuity was recorded.
Anterior and posterior segment examinations were done using slit-lamp biomicroscope and 90D condensing lens was used for detailed evaluation of the retina after dilating the pupil with 1% tropicamide. Grading of the retinal changes was made using the Diabetic Retinopathy Study guidelines and recorded in six categories: mild, moderate, and severe nonproliferative retinopathy and early, high risk, and advanced proliferative retinopathy. DME was diagnosed when there were hard exudates on the macula and/or macular thickening obvious on slit-lamp examination and clinically significant macular edema (CSME) was diagnosed based on ETDRS study criteria. In cases of asymmetric involvement of eyes, the eye with the most severe DR grade was taken. In patients with concomitant central or branch retinal vein occlusion, the DR grade in the eye not involved in the vein occlusion was used. All data were collected and recorded by an ophthalmologist, and all diagnoses were confirmed by a retina specialist at the retina clinic of the study center.
Data processing and analysis
The collected data were checked for accuracy and consistency, and manual data clean up and correction of any errors were done. Data were coded and entered into Epi Info version 7 (CDC, USA) and exported to Statistical analyses were performed using SPSS version 20 (IBM Corp, Armonk, New York). for analysis. The dependent variables were diabetic retinopathy and vision threatening diabetic retinopathy and the independent variables were age, sex, residency, type of DM (type 1 or type 2), duration of DM, blood pressure, BMI, fasting blood sugar level, lipid profile, form of DM therapy.
Descriptive statistics were performed to describe the study population in relation to relevant variables. A univariate logistic regression analysis was done to select the variables to be entered into the final multivariable logistic regression analysis. Explanatory variables (with P < 0.2) were entered into the final multivariate logistic regression model based on the likelihood ratio. Then, association between the independent variables and the outcome variable was assessed using AOR and 95% confidence interval (CI) for the AOR and P < 0.05 as cutoff point for statistical significance. Results were described in terms of numbers, percentages, means, and medians and displayed on tables and bar graphs.
Ethical clearance was obtained from UOG ethical review board. Witten informed consent was obtained from the study participants after clear explanation concerning the purpose and importance of the study. The identity of the patient was not exposed in any way and confidentiality of patient record was respected.
| Results|| |
A total of 225 diabetic patients were enrolled into the study. There were 135 (60%) males and 90 (40%) females. The mean age was 55.4 ± 13.5 years (range: 16–85 years). A majority of patients 160 (71.1%) were 50 years old and above and most of the participants 191 (84.9%) came from urban areas [Table 1]. Type 2 DM was the diagnosis in 199 (88.4%) patients and the remaining 26 (11.6%) had type 1 DM. The mean and median duration of diabetes were 8.18 years and 7 years, respectively (ranges from <1 year to 31 years). One hundred and fifty six (69.3%) had diabetes for 10 years or less and only 5 (2.2%) had diabetes for more than 20 years [Figure 1].
|Table 1: Sociodemographic characteristics of diabetic patients presented to University of Gondar, tertiary eye care and Training Center North West Ethiopia, (n=225)|
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|Figure 1: Duration of diabetes of diabetes mellitus patients who presented to the University of Gondar, Tertiary Eye Care and Training Center North West Ethiopia, 2020 (n = 225)|
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Regarding treatment modality for diabetes, 135 (60%) were on oral hypoglycemic agents (OHA) alone, 60 (26.7%) were using insulin alone, 25 (11.1%) were taking OHA in combination with insulin injection, and 5 (2.2%) patients were on dietary management alone.
Patients were inquired for the presence of any associated systemic condition, and hypertension was the most frequent concomitant illness present in 100 (44.4%) of them followed by dyslipidemia in 42 (18.7%), kidney disease 7 (3.1%), heart disease 3 (1.3%), and others in 8 (3.6%).
The number of patients with prior eye examination for DM-related eye disease were 144 (64%) and 39 (17.3%) patients had previous cataract surgery done on one or both eyes. A majority of the patients (57.3%) reported visual reduction as their main ocular complaint. Moderate and severe visual impairment was seen in 34 (15.1%) patients and 8 (3.6%) patients were blind [Table 2].
|Table 2: Best corrected visual acuity in the better eye of diabetic patients who presented to University of Gondar, Tertiary Eye care and Training Center North West Ethiopia, 2020 (n=225)|
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DR was diagnosed in 95 (42.2%) DM patients, of which 62 (65.2%) were male patients and 32 (36.8%) female patients [Table 3]. A greater percentage of patients in the age categories below 60 years had DR. The mean age in patients with DR was 53.23 ± 13 which is lower than those without DR (57.11 ± 13.67) [Figure 2].
|Table 3: Types of diabetic retinopathy diagnosed in diabetes mellitus patients presented to University of Gondar, tertiary eye care and training center, North West Ethiopia, 2020 (n=225)|
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|Figure 2: Age distribution of diabetic patients and diabetic retinopathy status at University of Gondar, tertiary eye care and training center, North West Ethiopia, 2020 (n = 225)|
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There was no statistically significant difference in the prevalence of DR between patients from urban and rural settings (P = 0.61). More percentage of patients with Type 1 DM had DR (46.2%) as compared to Type 2 DM patients (41.7%), but there was no statistically significant relationship between the type of diabetes and development of DR (P = 0.67).
Patients with disease duration of 6 years and more were more likely to develop DR than those with disease duration of <6 years with the difference being was statistically significant (P = 0.047) [Table 4].
|Table 4: Multivariate logistic regression analysis of factors associated with diabetic retinopathy in patients presented to University of Gondar tertiary eye care and training center, North West Ethiopia, 2020|
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When the study subjects were categorized based on the form of therapy for diabetes and the status of their eyes, 47 (34.8%) of the OHA group, 33 (55%) of insulin group, and 15 (60%) of the OHA insulin combination group were diagnosed to have DR [Figure 3].
|Figure 3: Treatment modalities for diabetes mellitus and prevalence of diabetic retinopathy at University of Gondar, Tertiary Eye care and Training Center, North West Ethiopia, 2020 (n = 225)|
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DR was significantly associated with the form of therapy. Those on insulin (P = 0.025) and OHA with insulin combination (P = 0.014) groups had statistically significantly associated with the development of DR [Table 4].
The mean systolic and diastolic blood pressures of the study population were 128.9 ± 14.5 mmHg and 79.17 ± 8.2 mmHg, respectively. There was a significant association between systolic hypertension and development of DR (P = 0.02) [Table 4] and [Table 5].
|Table 5: Blood pressure and body mass index of diabetic patients presented to University of Gondar, tertiary eye care and training center, North West ethiopia, 2020 (n=225)|
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More than one-third of the patients (39.5%) were overweight or obese and 56.9% had normal BMI. Thirty-eight (40%) patients with DR and 51 (39.3%) patients without DR were found to be overweight or obese. There was no statistically significant association between BMI and DR (P = 0.9) [Table 5].
The mean FBG level of the respondents was 157.68 ± 64.5 and only 79 (35.1%) had their FBG below 126 mg/dl. The mean total cholesterol and triglycerides determined for about half of the respondents were 178.1 ± 59.2 and 173.83 ± 82, respectively [Table 6].
|Table 6: Mean values of selected parameters and diabetic retinopathy at University of Gondar, tertiary eye care and training center, North West Ethiopia, 2020|
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Cataract was the most common concomitant ocular condition present in 112 (49.8%) patients. There were two patients with monocular vision loss from central retinal vein occlusion and nine patients with glaucoma [Table 7].
|Table 7: Ocular co-morbidities in patients with diabetes presented to University of Gondar, tertiary eye care and training center North West Ethiopia, 2020 (n=225)|
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The majority of patients with DR had NPDR without DME (34.2%) and NPDR with macular edema was seen in 4.4%. DME was identified in 13 patients (5.7%) of whom 6 (2.7%) had CSME. The number of patients with PDR was 8 (3.5%), of whom 6 (2.7) had high-risk PDR [Table 3].
VTDR was seen in 24 (10.7%) of the studied patients. There was a significant association between age of patients <60 years and VTDR (P = 0.022). More percentage of patients with Type 1 DM (41.7%) developed VTDR compared to patients with Type 2 DM (22.9%), but there was no significant association between the type of DM and development of VTDR (P = 0.251) [Table 8].
|Table 8: Multivariate logistic regression analysis of factors associated with vision threatening diabetic retinopathy in patients presented to University of Gondar, tertiary eye care and training center North West Ethiopia, 2020 (n=225)|
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A univariate logistic regression was done for every explanatory variable to include into the final multivariable logistic regression model. Then, variables with P < 0.2 in the univariate logistic regression were included into the final model, and association of the explanatory variables with DR and VTDR was assessed.
Marital status, educational status, occupation, residence, monthly income, type of DM, BMI, and FBG level showed no association with DR (P ≥ 0.2) on univariate logistic regression analysis and were not included into the final multivariable logistic regression analysis.
Multivariable logistic regression analysis was done for factors with preset P value cut point of <0.2 on univariate logistic regression; it showed that baseline age, duration of diabetes, modality of treatment with insulin or combination of OHA with insulin, and systolic blood pressure were significantly associated with DR [Table 4].
Patients with baseline age of <60 years were three times (AOR = 3.2:95% CI: 1.19–8.63) more likely to develop DR. The odds of DR is about 3 times (AOR = 2.91:95% CI: 1.01–8.35) higher for patients with disease duration of ≥6 years as compared to disease duration of <6 years. Systolic blood pressure also had statistically significant association with patients having blood pressure of <140 mmHg being about 3.6 times (AOR = 0.28:95% CI: 0.09–0.82) less likely to have DR as compared to hypertensive patients with systolic blood pressure of ≥140 mmHg. The other cofactors, history of hypertension, and total cholesterol level were not independent significant factors for the development of DR in our study [Table 4].
| Discussion|| |
The prevalence of DR in this study was 42.2% which is higher than most of the results of previous studies done in Ethiopia and other African countries.,,,,,, The high prevalence seen in our study could be due to the fact that the sample population was taken from a retina subspecialty clinic where most of the patients were referred from the medical diabetic clinic for visual complaints unlike the studies mentioned above which were done at medical diabetic clinics. Different sampling techniques, sample size, and diagnostic method may have also contributed to this difference. The very low prevalence (13%) seen in the Arbaminch General Hospital study in Ethiopia by Chisha et al. may be due to the fact that a majority of patients had a diabetes duration below 6 years and age <60 years as well as the retrospective record review design of the study.
The prevalence in the current study was also higher than the findings from New Zealand, Spain, and USA where rates of 22.5%, 14.9%, and 14.7% were reported, respectively.,, This difference could be due to the very large sample size in those studies, the difference in economic status between Ethiopia and the countries, in which those studies were conducted affecting patient care.
However, the finding in our study is lower than the prevalence reported by Shibiru et al. (51.3%) from Tikur Anbessa Hospital in Ethiopia. The variations in sample size and diagnostic method may have caused this discrepancy. Some studies from other parts of the world also reported figures higher than the prevalence seen in the current study.,,, Many factors may have contributed to this difference including variations in sampling techniques, sample size, study setting, methods of screening, level of awareness among study participants, level of glycemic control, and diabetic patient care.
A majority of the study population was constituted by Type 2 DM patients (88.4%) in this study, a trend similar to studies done at Tikur Anbessa hospital Ethiopia, Jimma University hospital Ethiopia, and Arbaminch General hospital Ethiopia where type 2 DM constituted 53.6%, 72.8%, and 74.1% of the study subjects, respectively.
The prevalence of DR in Type 1 DM patients (46.2%) was slightly higher than the prevalence among Type 2 DM patients (41.7%), but the difference was not statistically significant. This is in line with the findings reported from Cameroon, Zimbabwe, and Kenya where no significant difference was noted in the prevalence of DR between the two groups.,
Although there was no statistically significant difference between males and females in the prevalence of DR, the prevalence was higher in males (46.7%) compared to females (35.6%). Similar finding was seen in the study done in Cameroon by Njikam et al. in 2011 where the prevalence of DR in males and females were found to be 54.2% and 46.3%, respectively, with no statistically significant association between DR and gender. This was in contrast to the report from Kenya by Mariangela in 2011 where the prevalence of 19.7% and 37.4% were reported in males and females, respectively, and showed significant association of DR with female gender. This difference might be partly due to the large number of female patients in the later study.
Longer duration of diabetes was significantly associated with the occurrence of DR in this study and patients with disease duration of 6 years or more were more likely to develop DR (AOR = 2.91: 95% CI; 1.01–8.35) as compared to those with disease duration of <6 years. This finding was consistent with major global meta-analyses and most of the studies done in other African countries.,,,,
The mean age of diabetes patients in this study was 55.4 (±13.5) years which was higher than studies done in Ethiopia, and similar to studies done in other parts of the world.,,, However, the mean age of patients with DR (53.23 ± 13 years) was lower than those without DR (57.11 ± 13.67 years) in our study. Patients who were <60 years of age constitute 56% of the participants and they were more affected by DR than those ≥60 years of age with statistically significant difference (AOR = 3.2: 95% CI; 1.19–8.63) contrary to many of the other studies that showed advanced age was associated with DR.,,,,,
There was correlation of DR with the form of therapy in this study, and diabetic patients who were on insulin alone or combined insulin and OHA therapy had higher prevalence of DR. This was in contrast to the report in Cameroon (2011) which showed a higher prevalence in those on OHA therapy. With increasing duration of diabetes and advancing age, patients with type 2 DM may be unable to control their blood sugar level with OHA only and these patients often start insulin alone or combination of insulin and OHA therapy to improve glycemic control. Poor glycemic control may have contributed for the high prevalence of DR in the group of patients who were on insulin alone or combination of insulin and OHA therapy in our study.
Poor glycemic control is a risk factor for the development and progression of DR and is associated with higher prevalence of DR as shown by reports from different studies. Due to unavailability of HbA1c test, which is the best indicator of the level of glycemic control in the few months preceding the test, FBG level at the time of data collection was used to assess the level of glycemic control in our study.
Only 35.1% of study patients had their FBG level below 126 mg/dl, and the overall mean FBG level was 157.68 ± 64.5 mg/dl. Diabetic patients with DR had slightly higher mean FBG level (160.86 ± 70.6 mg/dl) than those who had no DR (155.35 ± 59.9 mg/dl), but there was no significant association between FBG level and DR. This was contrary to the finding reported by Sharew et al. in Jimma University Hospital Ethiopia (2009) which showed that FBG level was significantly associated with DR. This may be due to the fact that patients with DR in the Jimma University Hospital study had poor glycemic control with relatively much higher FBG level than those without DR at presentation compared to the findings in our study. Association of poor glycemic control with DR was also shown by studies done in other parts of the world.,,,, This difference in the findings between our study and other studies may have resulted from the use of HbA1c to assess the level of glycemic control in the studies mentioned.
The mean systolic blood pressure of patients with DR in this study was 130.56 ± 15.7 mmHg which is slightly higher than that of patients without DR (127.73 ± 13.4 mmHg). It is well established that systemic hypertension affects development and progression of DR in patients with diabetes. Our study showed a significant relationship between systolic blood pressure ≥140 mmHg and the occurrence of DR. This correlates well with research findings from other settings in Ethiopia,,, as well as elsewhere.,,
A majority of patients with retinopathy had NPDR (38.6%) which was similar to figures reported from Tikur Anbessa Hospital, Ethiopia (36.1%) and Jimma University Hospital, Ethiopia (38.9%) but higher than those reported from Kenya (25.7%) by Dr. Mariangela and Nigeria (24%) by Lawan et al. DME was seen in 13 (5.7%) patients of whom 6 (2.7%) had CSME which is lower than Jimma University Hospital study in Ethiopia, (5.5%), the 2011 Kenyatta National Hospital study (4.2%), and 2011 Yaoundé Central Hospital study (8.1%). The prevalence of PDR in this study was 3.6% which is higher than those reported from studies done in Ethiopia, but lower than those reported from other African countries, 5.9% in Kenya (2011), 3.7% in Nigeria (2009), and 14.3% in Cameroon (2011).
VTDR was seen in 24 (10.7%) patients which is comparable with results from Zimbabwe (11.4%), Kenya (11.9%), and Uganda (14.6%) among studies done in Africa., Slightly higher findings were reported by Sultan et al. and Stram DA et al. which showed VTDR in 17.6% and 16.3%, respectively. The prevalence of VTDR in our study was also lower than that was seen in Cameroon (27.3%), which may be due to the high prevalence of DR and associated poor glycemic control in the Cameroon study. Some studies reported the lower prevalence of VTDR than ours.,,,,, This discrepancy could be a result of variations in sample size, sampling techniques, and studies setting as most of these studies were population based.
One of the limitations of our study is the relatively modest sample size but similar studies done in African health-care settings rarely have larger sample size. Another limitation is our inability to determine HbA1C level due to unavailability of the test at the study center. As a result, we took only a single measurement of FBG level to assess the level of glycemic control in our patients and that is not the ideal way of measuring the glycemic status of patients. Another limitation of this study is the fact our study patients were taken from retina clinic and this might have increased the prevalence of DR.
| Conclusion|| |
The prevalence of DR and VTDR at UOG referral hospital, tertiary eye care and training center was high. Longer duration of diabetes, being on insulin alone or combination of insulin and OHA, and systolic hypertension were independently associated with the presence of DR. Only about two-third of diabetic patients had prior eye examination in relation to their illness. There was poor glycemic control with only one-third of diabetic patients having their FBG level below the recommended level. Patients with DR had higher mean FBG level compared to those without retinopathy.
The high prevalence of DR and VTDR in our study implies the need to improve routine patient care including treatment facility. Continuous effort is required from health-care professionals in counseling diabetic patients about the role of blood sugar level and hypertension control in reducing the risk of onset and progression of DR. Health education for diabetic patients about the need to have regular eye evaluation for early detection and management of diabetes-related eye complications is recommended.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]