Introduction: Hypertension is a major etiological factor in hypertensive retinopathy, a microangiopathy resulting from structural and functional retinal vascular alterations induced by chronic blood pressure elevation. In sub-Saharan Africa, this complication remains frequent, yet data from Niger, particularly from Zinder, are still limited. This study aimed to describe the epidemiological and clinical characteristics of hypertensive retinopathy at the National Hospital of Zinder and to identify the factors associated with its occurrence.

Methodology: A descriptive cross-sectional study with prospective data collection was conducted over a 10-month period in the Ophthalmology Department of the National Hospital of Zinder. Hypertensive patients aged 18 years or older were consecutively included after confirmation of hypertension based on a documented history of hypertension, ongoing antihypertensive treatment, or elevated blood pressure measured during clinical evaluation according to standard diagnostic thresholds. All included patients underwent a complete ophthalmologic examination with funduscopy after pupillary dilation. Hypertensive retinopathy was graded using the Kirkendall classification, based on the severity of retinal arteriolar narrowing, arteriovenous crossing changes, hemorrhages, exudates, and optic disc edema.

Results: A total of 152 hypertensive patients were initially enrolled, among whom 146 completed fundus examination; six patients were not analyzed because the examination could not be performed or interpreted adequately. Fundus abnormalities were found in 79 patients (54.11%), including 63 cases of hypertensive retinopathy (43.15%). The mean age was 51.82 ± 13.05 years, and females predominated (58.22%). Most patients lived in urban areas (78.77%) and had no formal education (36.99%). Among the 120 patients receiving antihypertensive treatment, 71 had poor adherence, corresponding to 59.17%. According to the Kirkendall classification, stage 1 accounted for 60.32% of cases, followed by stage 2 (30.16%) and stage 3 (9.52%). Older age, male sex, diabetes, and poor treatment adherence were significantly associated with hypertensive retinopathy.

Conclusion: Hypertensive retinopathy is common at the National Hospital of Zinder and mainly occurs in patients with poor treatment adherence and cardiometabolic comorbidities. Early screening, improved blood pressure follow-up, and better therapeutic adherence may help reduce retinal and systemic complications.

• Hypertension

• Hypertensive Retinopathy

• Risk Factors

• Zinder National Hospital

Laouali L, Idrissa H, Diori A, Garba AA, M’Baye S, et al. (2026) Epidemiological Characteristics of Hypertensive Retinopathy at Zinder Na tional Hospital. Ann Cardiovasc Dis 10(1): 1048.

Hypertension is defined by the World Health Organization (WHO) as a systolic blood pressure of 140 mmHg or higher and/or a diastolic blood pressure of 90 mmHg or higher [1]. A major global public health issue, it is the most common chronic disease, affecting more than 1.5 billion people and causing more than 10 million deaths annually [2].

The complexity of hypertension stems from the interaction of genetic, environmental, and physiological factors [3]. It is a major risk factor for target-organ damage,particularly affecting the brain, heart, kidneys, and eyes [4]. The eye is of particular interest because it allows direct in vivo visualization of the microvascular consequences of elevated blood pressure through fundus examination [5,6].

Hypertensive retinopathy encompasses the retinal vascular and parenchymal changes associated with elevated blood pressure and vascular aging [7]. Since the first clinical classifications, its evaluation has expanded with newer imaging techniques, although fundus examination remains the cornerstone of diagnosis in low resource settings [8,9].

The prevalence of hypertensive retinopathy varies widely depending on the population studied and the diagnostic approach, ranging from 2% to 15% in the United States and reaching much higher levels in African hospital-based studies [10-12]. In Niger, hypertension affects approximately 27.7% of the general population, and local hospital data suggest a substantial burden of both hypertension and ocular target-organ damage [13-16].

Despite these data, recent evidence specifically describing the epidemiological and clinical profile of hypertensive retinopathy in Zinder remains limited. Establishing these characteristics is important because it may improve local screening strategies, facilitate earlier multidisciplinary management, and provide region specific evidence for clinicians working in resource constrained settings. The present study was therefore undertaken to describe the epidemiological and clinical characteristics of hypertensive retinopathy at the National Hospital of Zinder and to identify the factors associated with its occurrence.

This was a descriptive cross-sectional study with prospective data collection, conducted over a 10-month period from January to November 2025 in the Ophthalmology Department of the National Hospital of Zinder, Niger. Sampling was exhaustive and included all hypertensive patients aged 18 years or older who were referred for ophthalmologic assessment during the study period.

Hypertension was confirmed on the basis of a prior medical diagnosis of hypertension, ongoing antihypertensive treatment, or blood pressure values meeting standard diagnostic thresholds during clinical assessment. Patients were included after ophthalmologic evaluation when fundus examination confirmed hypertensive retinopathy.

The ophthalmologic assessment was bilateral and included visual acuity measurement, slit-lamp examination, and fundus examination using a 90 D lens after pharmacologic pupillary dilation with 0.5% tropicamide. Retinal lesions were graded according to the Kirkendall classification: stage 1 corresponded to generalized arteriolar narrowing; stage 2 to more marked narrowing with arteriovenous crossing abnormalities; stage 3 to the presence of hemorrhages and/or exudates in addition to vascular changes; and stage 4 to stage 3 lesions associated with optic disc edema.

A total of 152 hypertensive patients were initially enrolled. Among them, 146 underwent an interpretable fundus examination and were retained for analysis. Six patients were excluded from the final analysis because fundus examination could not be completed or the findings were not interpretable.

Data were entered, processed, and analyzed using Excel and Epi Info software. Quantitative variables were expressed as mean ± standard deviation or median according to distribution, while qualitative variables were presented as frequencies and percentages. Bivariate analysis explored associations between hypertensive retinopathy and selected independent variables by calculating odds ratios with 95% confidence intervals. The chi-square test and Fisher’s exact test were used where appropriate. Statistical significance was set at p < 0.05.

Over the 10-month study period, 152 hypertensive patients were enrolled. Of these, 146 underwent an interpretable fundus examination and were included in the final analysis, while 6 patients were excluded because the examination could not be completed or interpreted. The prevalence of hypertensive retinopathy was 43.15% (n = 63).

The mean age of the patients was 51.82 ± 13.05 years, with extremes of 25 and 85 years. Women accounted for 58.22% of the sample, yielding a male-to-female ratio of 0.71. Most participants lived in urban areas (78.77%), had an socioeconomic level (57.53%), and had no formal education (36.99%). Housewives were the most represented occupational category (36.30%).

Clinically, hypertension was incidentally discovered in 13.70% of patients. The disease duration was less than 5 years in 54.11% of cases. At inclusion, hypertension was uncontrolled in 71.23% of subjects and classified as grade 1 in 34.25% of cases. Overweight was observed in 40.41% of patients. The main comorbidities were diabetes (26.03%) and kidney disease (17.81%).

Regarding ophthalmologic findings, visual acuity was preserved (>3/10) in 67.12% of right eyes and 66.44% of left eyes. Examination of the anterior segment revealed progressive cataract in 31.51% of cases. Fundus abnormalities were observed in 79 patients (54.11%). According to the Kirkendall classification, stage 1 hypertensive retinopathy was predominant (60.32%), followed by stage 2 (30.16%) and stage 3 (9.52%).

Concerning treatment, 120 patients (82.19%) were receiving antihypertensive therapy, mainly as monotherapy (52.74%). Regular blood pressure monitoring was observed in only 28.77% of patients. Among treated patients, 71 had poor therapeutic adherence, corresponding to 59.17%. After the diagnosis of hypertensive retinopathy, antihypertensive treatment was modified in 12 patients (19.05%), most often by switching to dual therapy.

In bivariate analysis, age > 60 years, male sex, diabetes, and poor treatment adherence were significantly associated with hypertensive retinopathy (p < 0.05). In contrast, no statistically significant association was found with recently diagnosed hypertension, duration of known hypertension, or isolated systolic or diastolic blood pressure elevation measured on the day of examination (p > 0.05).

The prevalence of hypertensive retinopathy in this study was 43.15%, a level comparable to findings reported in Nepal, Burkina Faso, and Chad, but lower than some series from the Democratic Republic of the Congo and Nigeria and higher than reports from India and Madagascar [17-37]. These variations probably reflect differences in study settings, patient selection, disease severity, and diagnostic approaches.

Women predominated in the sample, although male sex was significantly associated with hypertensive retinopathy in bivariate analysis. The mean age above 50 years and the excess risk observed after age 60 are consistent with the cumulative vascular effects of long-standing hypertension and aging.

The predominance of Kirkendall stage 1 suggests that most retinal lesions were identified at an early vascular stage. This pattern is clinically relevant because it indicates that fundus examination may detect microvascular damage before the onset of advanced ophthalmic complications.

Poor treatment adherence was frequent among treated patients and was significantly associated with hypertensive retinopathy. This finding supports the central role of sustained blood pressure control in preventing retinal target-organ damage.

Diabetes also emerged as a major associated factor, consistent with the additive microvascular burden imposed by combined metabolic and vascular disease. By contrast, variables such as lifestyle, diet, sedentary behavior, or other unmeasured contextual factors were not directly assessed in this study and therefore should not be interpreted as demonstrated explanatory factors.

The absence of association between retinopathy and blood pressure values measured on the day of examination may be related to the limitations of a single office measurement, which does not necessarily reflect long term exposure to elevated blood pressure. Likewise, the lack of association with duration of known hypertension may be influenced by delayed diagnosis or imprecision in patient-reported disease history.

Because this was a cross-sectional study, the identified associations should not be interpreted as causal relationships. The results nevertheless emphasize the value of routine fundus examination in hypertensive patients, particularly in older individuals, men, and patients with diabetes or poor treatment adherence.

Hypertensive retinopathy is a frequent complication among hypertensive patients seen at the National Hospital of Zinder, with a predominance of early-stage lesions. Older age, male sex, diabetes, and poor treatment adherence were the principal factors associated with its occurrence in this study.

These findings support the strengthening of systematic ophthalmologic screening, better long-term blood pressure follow-up, and interventions aimed at improving adherence to antihypertensive therapy. Larger prospective studies would be useful to clarify the prognostic implications of hypertensive retinopathy in this setting.

The study was approved by the Ethics Committee of André Salifou University.

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