Knowledge of diabetic retinopathy among fifth- and sixth-year medical students at the Faculty of Medicine, University of Khartoum, Sudan: a cross-sectional study 2022

Abstract

Background

Diabetic retinopathy (DR) is a leading cause of preventable blindness worldwide. As future frontline healthcare providers, medical students must be equipped with the knowledge necessary for early detection and timely referral. This study aimed to assess the level of knowledge regarding the symptoms, risk factors, and management of DR among final- and semifinal-year medical students at the University of Khartoum, Sudan.

Methods

A descriptive cross-sectional study was conducted between February and March 2022 among 166 fifth- and sixth-year medical students. Participants were recruited via systematic random sampling. Data were collected via an adapted questionnaire, which was reviewed for face and content validity and subsequently pilot-tested. Total knowledge scores were categorized as poor (1–9), moderate (10–19), or good (20–27). The data were analyzed using SPSS version 23. Independent-samples t-tests and multivariable linear regression were performed to identify predictors of knowledge levels.

Results

The mean knowledge score was 18.11 ± 3.65, indicating a moderate level of overall knowledge. While the majority (79.5%) identified the duration of diabetes as a primary risk factor and emphasized glycemic control (94.6%), significant gaps remained. Only 63.3% recognized DR as a vascular disease, and only 37.3% correctly identified the recommended timing for initial comprehensive ophthalmic examinations. Furthermore, 56% were aware of laser photocoagulation as a treatment modality. Multivariable analysis revealed that reliance on medical college education (p = 0.015) and having a first-degree relative with diabetes (p = 0.031) were significant independent predictors of higher knowledge scores.

Conclusion

Medical students demonstrated moderate knowledge of diabetic retinopathy with notable gaps in screening and treatment. Medical college education was associated with higher knowledge scores; however, causal relationships cannot be inferred. Strengthening undergraduate medical curricula may enhance their readiness to manage diabetic eye complications. Further multicenter studies are recommended to explore these knowledge gaps across Sudan.

Introduction

Diabetes mellitus (DM) is a long-term, progressive condition characterized by high blood sugar levels due to problems with insulin production, insulin action, or both. It is a growing global health issue, with its prevalence expected to double by 2025. This rise is mainly due to aging populations, reduced physical activity, and dietary changes, especially in low- and middle-income countries [1, 2]. In Sudan, increasing urbanization and lifestyle changes have contributed to the increasing burden of diabetes and its related complications [3].In a study conducted in 1996 in North Sudan, the prevalence of diabetes was 8.3%, and prediabetes was 7.9% [4]. By 2017, these rates had increased significantly to 18.7% for diabetes and 12.9% for prediabetes [5]. Providing sufficient infrastructure and staffing capacity is important for addressing the increasing prevalence of DM and DR [6].

One of the most common and serious complications of diabetes is DR, a condition that affects the small blood vessels in the retina. It is a major cause of preventable blindness among working-age adults around the world [7, 8]. DR is caused by long-term high blood sugar, which damages tiny blood vessels in the retina, leading to fluid leakage, poor blood flow (ischemia), and abnormal new blood vessel growth (neovascularization) [9]. Common clinical signs include microaneurysms, retinal bleeding, cotton wool spots, and, in severe cases, abnormal vessel growth and swelling in the retina (macular edema) [10]. The risk of DR increases with increasing duration of diabetes and poor glycemic control. The prevalence of DR may reach 97.5% among individuals with diabetes duration of 15 years or more [11].

Although effective treatments such as laser therapy and eye injections are available, many patients lose vision because DR is not diagnosed or treated early enough. This highlights the necessity of effective diabetes mellitus management, comprehensive DR service coverage to facilitate early DR screening among diabetic patients [12], and the implementation of routine eye examinations and appropriate counselling for these individuals [13, 14].

Healthcare workers, especially those in primary care, are crucial in detecting and managing diabetic complications, including DR [15]. Therefore, medical students, who are future doctors, must have solid knowledge and practical skills in this area to provide better care and education for diabetic patients.

Studies in other countries have shown that medical students have varying levels of awareness of DR. Many students are not fully informed about DR risk factors, when to screen patients, or available treatment options [16, 17]. In Sudan and other countries, most studies involving the general population and individuals with diabetes have primarily focused primarily on diabetes mellitus and diabetic retinopathy, as demonstrated by recent studies conducted in Dongola, Sudan, and other settings [18–21].

However, research on the level of preparation of medical students to manage diabetes-related ocular complications remains limited.

This study aims to assess the knowledge of final- and semifinal-year medical students at the University of Khartoum about diabetic retinopathy. It examines their knowledge of the condition’s risk factors, clinical manifestations, and management approaches, as well as the sources from which they obtain the information.

Methods

Study design

This was an observational, descriptive, institution-based cross-sectional study conducted from February-March 2022 to assess the knowledge of diabetic retinopathy among final and semifinal medical students at the University of Khartoum.

Study setting

The study took place at the Faculty of Medicine, University of Khartoum, located in Khartoum city, Sudan. This institution is the oldest and most highly ranked medical school in the country, admitting more than 300 students annually. The Bachelor of Medicine and Bachelor of Surgery (MBBS) program spans six years and 12 semesters and is organized into three phases. Phase I (Semesters I–IV) focuses on the basic medical sciences and community health. Phase II (Semesters V–VIII) integrates paraclinical and clinical disciplines and includes the mandatory undergraduate ophthalmology course, which is delivered during the fourth year of the program (Semester VIII). Phase III (Semesters IX–XII) consists primarily of clinical clerkships and specialty-based clinical training. Overall, the curriculum comprises approximately two years of preclinical education followed by four years of predominantly paraclinical and clinical training.

Study population

The study population consisted of fifth- and sixth-year (semifinal and final-year) MBBS students enrolled in Phase III of the program at the Faculty of Medicine, University of Khartoum. All had completed the mandatory fourth-year core ophthalmology course prior to the study. Students who were not attending classes during the study period or who declined participation were excluded.

Sampling method and sample size

A systematic random sampling technique was used to recruit fifth- and sixth-year medical students (Batches 92 and 93) at the Faculty of Medicine, University of Khartoum. The minimum required sample size was calculated via Open Epi version 3 based on a total population of 657 eligible students, with expected frequency of 82.6%, a 95% confidence level, confidence limits of ± 5%, and a design effect of 1, yielding a target of 166 students. A complete sampling frame (n = 657) was obtained from the academic secretary. Using a randomly selected starting point, every fourth student was systematically invited to participate until 166 students were recruited. Invitations were distributed electronically via institutional communication channels, and data were collected via a Google Forms questionnaire. The response rate was 100%, following repeated reminders to invited participants. No incomplete questionnaires were returned.

Data collection

Data were collected via a modified, self-administered, closed-ended questionnaire distributed electronically via Google Forms. The questionnaire was largely adapted from an instrument previously used in a study at King Faisal University Medical College, Al-Hasa, Saudi Arabia [16]. To ensure its relevance and clarity for the Sudanese educational context, the adapted questionnaire underwent face and content validation by a panel of three research experts from the Faculty of Medicine, University of Khartoum. Based on their feedback, minor modifications were made.

Subsequently, the revised questionnaire was piloted on a small group of 15 medical students (not included in the final sample) to assess comprehensibility, average completion time, and technical functionality. No substantive issues were identified, and the final version was used for data collection.

The instrument consists of 24 items grouped into three domains: (1) demographic characteristics, (2) basic knowledge of DR covering symptoms, signs, pathophysiology, and risk factors, and (3) attitude and practice-related knowledge covering screening, referral, counselling, and treatment options.

For single-response questions, one point was awarded for each correct answer, whereas incorrect answers received zero points. The options “uncertain” and “I don’t know” were scored as zero. For three multiple-response items in the questionnaire (counselling, treatment, and symptoms), one point was given for each correctly selected option. Incorrect selections were not penalised and received zero points. The total score for each multiple-response item depended on the number of correct responses selected, allowing for partial credit. No weighting was applied to individual questionnaire items; all correct responses contributed equally to the total score regardless of domain or perceived importance.

The internal consistency reliability was assessed after data collection via Cronbach’s alpha coefficient. The basic knowledge domain demonstrated an alpha of 0.454, which is consistent with multi-domain knowledge assessments where items are designed to assess distinct content areas rather than a single unidimensional construct. The practice-related knowledge domain yielded an alpha of 0.664, indicating that moderate internal consistency was appropriate for an exploratory survey instrument.

The maximum possible score for basic knowledge was 10. Scores of 1–3 were categorized as poor knowledge, 4 − 7 as moderate knowledge, and 8–10 as good knowledge. The maximum possible score for attitude and practice-related knowledge was 17, with scores of 1–6 classified as poor, 7–11 as moderate, and 12–17 as good. Hence, the total knowledge scores (maximum 27) were categorized as poor (1–9), moderate (10–19), or good (20–27).

Data analysis

The data were coded, entered, and cleaned into Excel sheets, and then analyzed using the Statistical Package for Social Sciences (SPSS version 23; IBM Corp., Armonk, NY). Descriptive statistics were used to summarize the data. The knowledge scores were analyzed as continuous variables. Associations between knowledge categories and sociodemographic variables or sources of information were assessed using independent sample t-tests. Multivariable linear regression was subsequently performed to identify independent predictors of knowledge scores, with the total knowledge score as the dependent variable. A p-value < 0.05 was considered statistically significant.

Ethical considerations

Ethical approval was obtained from the Department of Community Medicine, University of Khartoum; approval ID [COMMED 2021-93-40]; Date of issuing: 1st March 2021. Written informed consent was obtained from each participant before participation. All the data were anonymized, and no personally identifiable information was collected. The collected data were used solely for research purposes.

Results

Sociodemographic characteristics

A total of 166 students participated in the study, yielding a 100% response rate, as no incomplete questionnaires were received, and all participants were reached through repeated follow-up. Of the respondents, 82 (49.4%) were sixth-year students and 84 (50.6%) were fifth-year students. The mean age was 23.96 ± 1.15 years (range 21–28), and the majority were female (n = 114; 68.7%).

Regarding sources of information on diabetes and diabetic retinopathy, most students (95.2%) cited medical college education as their primary source. Additional sources included the internet (25.3%), journals or CME sessions (12%), and books or other materials (22.3%). Only 10.8% reported taking a dedicated course on public education related to diabetes and diabetic retinopathy.

Personal exposure to diabetes was frequently reported: 44.6% had a first-degree relative with diabetes, 52.4% had a second-degree relative with diabetes, and 22.3% were closely related to diabetic retinopathy. These findings are summarized in Table 1.

Table 1.

Sociodemographic characteristics and sources of information on diabetic retinopathy among fifth- and sixth-year medical students at the Faculty of medicine, University of Khartoum, Sudan, (n = 166)

Variable	Category	N	%
Sex	Male	52	31.3
	Female	114	68.7
Academic year	Sixth year (Batch 92)	82	49.4
	Fifth year (Batch 93)	84	50.6
Age (years)	Mean ± SD	23.96 ± 1.15	—
Source of information about DR*	Medical college education	158	95.2
	Journals / CME	20	12.0
	Internet	42	25.3
	Books / other sources	37	22.3
Course on public education about DM/DR	Yes	18	10.8
	No	148	89.2
Someone close with diabetes*	First degree relative	74	44.6
	Second degree relative	87	52.4
	Friend	18	10.8
	Neighbor	29	17.5
	Someone else	15	9.0
	No one close with diabetes	16	9.6
Close contact has DR	Yes	37	22.3
	No	114	68.7
	No one close with diabetes	15	9.0

DR diabetic retinopathy, DM diabetes mellitus

*Multiple responses allowed; percentages do not total 100%

Total knowledge scores

The maximum possible total knowledge score was 27. Based on predefined categories, scores of 1–9 were considered poor, scores of 10–19 were considered moderate, and scores of 20–27 were considered good. The mean of the total knowledge score was 18.11 ± 3.658. The distribution of overall knowledge scores among participants is shown in (Fig. 1).

Fig. 1.

Distribution of overall knowledge scores on diabetic retinopathy among fifth- and sixth-year medical students at the Faculty of Medicine, University of Khartoum, Sudan, (n = 166)

Basic knowledge

The maximum basic knowledge score was 10, with students classified as having poor (1–3), moderate (4–7), or good (8–10) knowledge. The mean basic knowledge score was 5.82 ± 1.95, indicating a generally moderate level of understanding among the participants. As shown in Table 2, the students demonstrated variable recognition of key DR concepts. For example, just over half (50.6%) correctly identified the normal HbA1c range, and only 63.3% recognized DR as a vascular disease. Symptom awareness also varied markedly: while floaters (66.9%) and blurred vision (64.5%) were commonly recognized, fluctuating vision had the lowest recognition rate at 31.9%. The strongest area of knowledge was identifying the duration of diabetes as the most critical risk factor for DR (79.5%).

Table 2.

Basic knowledge of diabetic retinopathy among fifth- and sixth-year medical students at th e Faculty of Medicine, University of Khartoum, Sudan, 2022 (n = 166)

Question	Response	Frequency n/N (%)
Normal HbA1c level	Between 4% and 5.6%	84/166 (50.6)
	Between 5.7% and 6.4%	78/166 (47.0)
	6.5% or higher	4/166 (2.4)
DR is a disease of	Blood vessels	105/166 (63.3)
	Optic nerve	51/166 (30.7)
	Increased intraocular pressure	10/166 (6.0)
Symptoms of DR*	Seeing spots or dark strings (floaters)	111/166 (66.9)
	Blurred vision	107/166 (64.5)
	Could be asymptomatic	72/166 (43.4)
	Dark or empty areas	70/166 (42.2)
	Fluctuating vision	53/166 (31.9)
	I don’t know	27/166 (16.3)
Most critical risk factor	Duration of diabetes	132/166 (79.5)
	Hypertension	27/166 (16.3)
	Nephropathy	6/166 (3.6)
	Pregnancy	1/166 (0.6)
Risk reduction through	Both glycemic and BP control	115/166 (69.3)
	Optimizing glycemic control only	46/166 (27.7)
	Optimizing BP control only	5/166 (3.0)
Most common cause of gradual chronic visual impairment in DM	Diabetes related macular edema	117/166 (70.5)
	Vitreous hemorrhage	38/166 (22.9)
	Cataract surgery	11/166 (6.6)

DR diabetic retinopathy, DM diabetes mellitus

*Note: Multiple responses allowed for symptoms; percentages do not total 100%

Attitude and Practice-Related Knowledge

The maximum attitude and practice-related knowledge score was 17, with categories of poor (1–6), moderate (7–11), and good (12–17). The mean score was 12.29 ± 2.58, indicating generally strong attitudes and practice-related knowledge. Nearly all the participants acknowledged the importance of regular ophthalmic examinations (99.4%), and 86.7% recognized the need for timely treatment. Most students demonstrated sound attitude and practice-related understanding, with 81.3% correctly disagreeing with the notion that patients with well-controlled diabetes can forgo ophthalmology referral. Similarly, 78.9% appropriately rejected the misconception that routine eye examinations are unnecessary. Despite this generally strong performance, only 38.0% accurately identified the recommended interval for the initial detailed ophthalmic examination, indicating a notable gap in practical guideline awareness. Detailed item-level responses for attitude and practice-related knowledge are presented in Table 3.

Table 3.

Attitudes and practice-related knowledge regarding diabetic retinopathy among fifth- and sixth-year medical students at the Faculty of Medicine, University of Khartoum, Sudan, 2022 (n = 166)

Question/Statement	Response	Frequency n/N (%)
DM patient should have regular ophthalmic examination	Agree	165/166 (99.4)
	Disagree	1/166 (0.6)
No need to visit an ophthalmologist if DM is well-controlled	Agree	22 (13.3)
	Disagree	135/166 (81.3)
	uncertain	9 (5.4)
Timely treatment of DM slows or prevents DR	Agree	144/166 (86.7)
	Disagree	22/166 (13.3)
Patients waste time and money on eye check-ups	Agree	10/166 (6)
	Uncertain	25/166 ( 15.1)
	disagree	131/166 (78.9)
Timing of initial comprehensive ophthalmic examination	Type I DM 5 years post-diagnosis and Type II DM at diagnosis	62/166 (37.3)
	Either Type I or Type II DM at diagnosis	53/166 (31.9)
	Either Type I or Type II DM 5 years post-diagnosis	25/166 (15.1)
	Type I DM at diagnosis and Type II DM 5 years post-diagnosis	24/166 (14.5)
	Other responses	2/166 (1.2)
Patients require ophthalmic referral	All patients with DM	124/166 (74.7)
	Patients with visual symptoms only	24/166 (14.5)
	Patients with retinal changes on ophthalmoscopy only	18/166 (10.8)
Which type of DM patient at high risk of DR	Patients with either Type I or Type II DM	74/166 (44.6)
	Type II DM patients	51/166 (30.7)
	Type I DM patients	38/166 (22.9)
	Other responses	3/166 (1.8)
DR patient should be examined by	Ophthalmologist at local hospital	120/166 (72.3)
	PHC general practitioner	26/166 (15.7)
	Optometrist	20/166 (12.0)
Treatment options for DR*	Eye injections (eye shots )	53/166 (31.9%)
	Laser photocoagulation	93/166 (56%)
	Eye surgery	58/166 (34.9%)
	I don’t know	61/166 (36.7%)
Counseling topics for diabetic patients*	Glycemic control/taking medications properly	157/166 (94.6)
	Healthy lifestyle and eating habits	150/166 (90.4)
	Regular ophthalmic visits	146/166 (88.0)
	Blood pressure control	129/166 (77.7)
	Exercise	128/166 (77.1)
	Coping with the emotional side of diabetes	107/166 (64.5)

DR diabetic retinopathy, DM diabetes mellitus

*Note: Multiple responses allowed for counselling options and treatment options; percentages do not total 100%

Associations between sociodemographic characteristics, information sources, and knowledge scores

Associations between sociodemographic characteristics, information sources, and total knowledge scores are presented in Table 4. Bivariate analyses were first conducted using independent-sample t-tests to examine associations between participants’ sociodemographic characteristics, primary sources of information, and DR knowledge scores. Significant relationships were observed for academic year (p = 0.017) and engagement with journals or CME activities (p = 0.023). Sixth-year students demonstrated higher total knowledge scores compared to fifth-year students in the bivariate analysis.

Table 4.

Associations of sociodemographic characteristics and information sources with total knowledge score: bivariate and multivariable linear regression analyses (n = 166)

Category	Mean ± SD	Bivariate P-value	β	95% CI	Multivariate p-value
Gender
Male	17.92 ± 4.072	0.661	0.004	-1.219–1.283	0.960
Female	18.19 ± 3.469
Academic Year
5th year	17.44 ± 3.655	0.017*	-0.144	-2.181–0.081	0.069
6th year	18.79 ± 3.555
Someone close with diabetes
Haven’t	17.44 ± 4.732	0.442	0.032	-2.436–3.233	0.781
First-degree relative	18.55 ± 3.520	0.160	0 0.234	0.157–3.280	0.031*
Second-degree relative	18.51 ± 3.323	0.142	0.233	0.104–3.302	0.037*
Friend	18.61 ± 3.744	0.539	-0.002	-1.893–1.855	0.984
Neighbour	18.97 ± 3.179	0.166	-0.045	-1.181–2.052	0.595
Someone else	18.33 ± 3.395	0.804	-0.022	-2.329–1.781	0.781
Close contact has DR
Yes	19.76 ± 2.813	0.001*	0.004	-0.969–1.012	0.966
No	17.81 ± 3.662
Primary Source of Information
Medical college education	18.22 ± 3.616	0.077	0.202	0.677–6.197	0.015*
Journals/CME	19.89 ± 3.143	0.023*	0.122	-0.647–3.446	0.179
Internet	17.89 ± 3.636	0.181	0.019	-1.340–1.651	0.837
Books with other sources	19.00 ± 3.456	0.099	0.139	-0.339–2.797	0.124
Course about community education about DR
Yes	17.11 ± 3.479	0.222	-0.114	-3.159–0.485	0.149
No	18.23 ± 3.672

Variables representing exposure to diabetes and sources of information were analyzed as separate dichotomous (yes/no) variables. Bivariate analysis was performed via an independent t-test. Variables were entered into multivariate linear regression via the Enter method

β regression coefficient, CI confidence interval

p-values are two-tailed; significance was set at p ≤ 0.05

*Data presented as mean ± SD; p < 0.05

Multivariable linear regression was then performed to identify independent predictors of total knowledge scores. The overall model was statistically significant (F = 2.080, p = 0.016), accounting for 16.2% of the variance in total knowledge scores (R² = 0.162; adjusted R² = 0.084). Regression assumptions, including linearity, normality of residuals, homoscedasticity, and absence of multi-collinearity (all VIF < 2.5) were satisfied. In the adjusted model, several variables emerged as significant independent predictors. Reliance on medical college education as the primary information source was associated with higher total knowledge scores (B = 3.437, 95% CI 0.677–6.197, β = 0.202, p = 0.015). Additionally, having a first-degree relative with diabetes (B = 1.719, 95% CI 0.157–3.280, β = 0.234, p = 0.031) or a second-degree relative (B = 1.703, 95% CI 0.104–3.302, β = 0.233, p = 0.037) were both independently associated with higher knowledge scores.

In contrast, the multivariable model for basic knowledge scores was not statistically significant (p = 0.356), indicating that no independent predictors were identified for this domain.

For attitude and practice-related knowledge, bivariate analysis revealed significant associations with academic year (p = 0.006) and the use of books combined with other information sources (p = 0.044), with sixth-year students achieving higher scores than fifth-year students (mean ± SD: 12.84 ± 2.23 vs. 11.75 ± 2.79; p = 0.006). The multivariable regression model for practice-related knowledge was also significant (F = 1.927, p = 0.028). Although many associations from the bivariate analysis did not persist, reliance on medical college education remained a significant predictor (B = 2.194, β = 0.183, p = 0.028).

Discussion

This study assessed the level of knowledge regarding diabetic retinopathy among final- and semifinal-year medical students at the University of Khartoum. As future physicians on the front lines of managing diabetes and its complications, these students are expected to identify early manifestations of diabetic retinopathy and contribute to timely referral and patient counselling. Evaluating their level of knowledge is therefore essential to identify potential gaps that may impact early detection and prevention of vision-threatening complications.

In the present study, 46.99% of participants demonstrated good knowledge of diabetic retinopathy, which is comparable to findings from a study done in Saudi Arabia [22], where more than half of the students had good knowledge. Despite methodological differences, this finding suggests a consistent pattern of moderate-to-good knowledge among medical students.

Only 50.6% of the students correctly identified the “normal” HbA1c level. This finding should be interpreted with caution, as the questionnaire item did not clearly distinguish between normal physiological values, prediabetes thresholds, and therapeutic targets for patients with diabetes (< 7%). The variability in responses may therefore reflect item ambiguity rather than a true knowledge deficit, indicating a limitation of the assessment tool.

According to a KAP study that was carried out in Pakistan to evaluate medical students’ knowledge, attitudes, and practices regarding diabetic retinopathy, more than half of the students (63.3%) were aware of the pathophysiology of DR, while 39.1% of the students did not know what the HbA1c value was, and 36.8% gave incorrect responses [17]. Another study conducted on students at Qassim University where 51.6% answered correctly to the question, “What is the acceptable target range for HbA1c for most of the diabetic patients?” [23].

While a majority (79.5%) of the students identified DM duration as the primary risk factor, this proportion was lower than that reported among medical students in Pakistan (97%) [17] and Saudi Arabia (80.9%) [24]. This difference may reflect variability in the depth of knowledge, potentially attributable to differences in curriculum structure, clinical exposure, or emphasis on ophthalmology training.

Regarding prevention, 94.6% of the participants recognized that glycemic control is essential for DR risk reduction. This aligns with findings from Pakistan (98.5%) [17], indicating that the core concept of metabolic control is well-established across these medical curricula.

DR was identified by two-thirds of the participants as a blood vessel disease. This percentage is greater than what is reported at King Khalid University in Saudi Arabia, where more than half of the study participants did not know the cause of DR. 44.3% of the participants were aware that DR is caused by damage to retinal blood vessels. While 24.9% did not know the cause [25].Despite this relatively better performance, nearly one-third of the participants in the current study still failed to recognize the vascular basis of diabetic retinopathy, indicating a persisting gap in fundamental pathophysiological understanding.

Clinically, DR often progresses without symptoms until significant damage occurs. Despite this, fewer than half of the participants identified its silent nature, whereas more commonly recognized symptoms such as floaters (66.9%) and blurred vision (64.5%) were better identified. This finding implies that future graduates may erroneously rely on patient-reported symptoms as a trigger for referral, rather than adhering to a systematic screening schedule.

More than two-thirds of the students identified diabetes-related macular oedema as the most common cause of visual impairment. Patients with diabetes mellitus should undergo a thorough ocular examination. Both at the time of diagnosis for people with type II diabetes and 5 years after diagnosis for those with type I DM, our research revealed that just one-third of the students responded correctly. This result is lower than what was reported in a 2019 KAP study on DR at Qassim Medical University in Saudi Arabia, where more than 50% of participants responded accurately [23]. This discrepancy may indicate that, although general awareness of diabetic retinopathy is relatively adequate, detailed knowledge of screening protocols remains limited among the study participants. This may have important implications for timely referral and early detection in clinical practice.

With respect to knowledge of available treatments, approximately half of the students correctly identified laser photocoagulation, whereas only about one-third were aware of other modalities such as intravitreal injections and surgical interventions. This indicates limited awareness of the full range of therapeutic options. In contrast, attitudes toward patient management were more favorable, with the majority recognizing the importance of routine ophthalmic follow-up for all patients with diabetes regardless of glycemic control, as well as the role of timely treatment and appropriate counselling. These findings are consistent with studies conducted at King Faisal and Qassim Universities in Saudi Arabia [16, 23], where positive attitudes toward referral and follow-up were also observed despite gaps in specific clinical knowledge.

The importance of strengthening knowledge at early stages of medical training is further highlighted by findings from a study among physicians in Northwestern Nigeria [26], where only 37.1% correctly identified that all patients with diabetes should be referred for ophthalmic evaluation. Taken together, these results suggest that while general awareness and attitudes toward diabetic retinopathy management may be adequate, detailed knowledge of treatment modalities and referral indications remains suboptimal.

While the bivariate analysis initially demonstrated a significant association between academic year and total knowledge, consistent with findings from Qassim University [23], this association was not retained in the multivariable model. This finding indicates that the observed difference is likely influenced by confounding factors rather than academic progression itself, suggesting that progression through medical school alone may not be sufficient to ensure improved knowledge of diabetic retinopathy.

Interestingly, while academic year was not an independent predictor of total knowledge in the multivariable model, it remained significantly associated with attitude and practice-related knowledge (p = 0.028). Sixth-year students achieved higher mean scores in clinical application domains compared to their fifth-year counterparts. Notably, this finding differs from a study reported in Saudi Arabia [22], where no significant association was observed between academic year and either overall knowledge or practice-related knowledge. This discrepancy may be explained by differences in curriculum structure, clinical training opportunities, or methods of knowledge assessment between institutions.

A high proportion of participants (94.6%) reported having someone close to diabetes, which is consistent with the known high burden of diabetes mellitus in Sudan [5]. Notably, 22.3% also reported close contact with individuals affected by diabetic retinopathy, representing a substantial level of exposure to this complication. Students who had a first- or second-degree relative with diabetic retinopathy were found to have higher knowledge scores. This may reflect the influence of personal exposure on awareness.

Regarding sources of information, students who identified medical college education as their primary source (95.2%) achieved significantly higher knowledge scores in the multivariable analysis. Consistent with findings from Saudi Arabia [23], this supports the role of the formal university curriculum as the most influential and reliable driver of clinical knowledge acquisition. In contrast, although higher knowledge scores were observed in the bivariate analysis among students who reported using journals or CME, this association was not retained in the multivariable model, indicating that it was likely confounded by other factors.

Most diabetic retinopathy cases are first encountered at the primary care level, yet regional data indicate that fewer than one-third of practicing primary care physicians possess a high level of knowledge [15]. This established deficit among graduates highlights a critical need to reinforce undergraduate curricula, ensuring medical students are equipped with the foundational screening and referral competencies required before entering the workforce. By addressing these gaps early, Sudan can better prepare its future frontline to serve as effective gatekeepers in the prevention of diabetes-related blindness.

Future studies should consider formal validation of the questionnaire by a qualified ophthalmologist to further strengthen its content validity and enhance its clinical relevance and accuracy in assessing ophthalmology-related knowledge.

Conclusion

Medical students demonstrated a moderate level of knowledge regarding diabetic retinopathy, with notable gaps in some concepts, such as appropriate screening timing and awareness of available treatment modalities, including laser therapy and intravitreal injections. These findings highlight the need for strengthened curricular emphasis on diabetic eye disease and greater integration of evidence-based learning resources. Medical college education was associated with higher knowledge scores; however, causality cannot be inferred. Further multicenter studies are recommended to better characterize knowledge gaps among medical students across Sudan.

Limitations

This study has several limitations. First, as a single-center study conducted at one medical school, the findings may not be generalizable to all medical students in Sudan. Second, the cross-sectional design provides a snapshot of knowledge at a single point in time and does not permit assessment of changes over time or causal relationships. Despite these limitations, this study offers valuable insights into medical students’ knowledge of diabetic retinopathy and identifies important areas for educational improvement.

Author's contributions

Conceptualization and design: SI; Data collection: SI; Statistical analysis LS; Drafting and writing: TI, AB, SI, SM, LS, HO, NS; Supervision and revision: EMA, LS. All the authors have read and agreed to the published version of the manuscript.

Funding

The authors received no specific funding for this study.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethical approval and consent

Ethical approval for this study was obtained from the Department of Community Medicine at the University of Khartoum. The research was conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participants before data collection.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.