European Journal of Cardiovascular Medicine

Age-related cataracts are one of the most prevalent causes of visual impairment and blindness worldwide, affecting millions and posing substantial public health and socioeconomic challenges¹. Cataracts develop as proteins in the eye's lens begin to clump, leading to clouding and vision impairment². The risk of cataract formation increases significantly with age, particularly among adults over 60 years, with common risk factors including genetics, ultraviolet (UV) exposure, smoking, diabetes, and dietary influences^3,4. Recently, oxidative stress has emerged as a critical component in cataractogenesis, drawing attention to biochemical markers such as serum uric acid, which may contribute to lens opacity⁵.

Serum uric acid, primarily a product of purine metabolism, is an antioxidant at physiological levels⁶. However, elevated uric acid levels have been linked to oxidative stress and inflammation, conditions associated with increased cataract risk⁷. While uric acid can act as a scavenger of reactive oxygen species (ROS), excess levels may paradoxically promote oxidative stress, potentially accelerating cellular aging and increasing cataract susceptibility. Despite these indications, the association between serum uric acid levels and cataract formation is not well-established, with only limited observational studies addressing the relationship.

This study aims to explore the association between serum uric acid levels and age-related cataract formation in a sample of older adults. By examining the correlation between serum uric acid and cataract prevalence, this study seeks to determine whether serum uric acid could serve as a predictive marker for cataract risk, providing insights into potential preventive measures. Additionally, the findings could contribute to the broader understanding of oxidative stress in age-related ocular disorders, helping to inform future research and clinical strategies for cataract prevention

Study Design and Setting

This observational, cross-sectional study was conducted at Government Medical College (GMC) Suryapet, Telangana, India. The study spanned one year, from February 2023 to January 2024, providing a comprehensive examination of serum uric acid levels and their association with age-related cataract formation among the participants.

Sample Size and Selection

A total of 100 participants aged 50 and above were enrolled in the study. Inclusion criteria included adults with no prior cataract surgery and no known systemic diseases affecting uric acid levels, such as gout or chronic kidney disease. Participants with a history of intraocular surgeries or known ocular diseases apart from cataracts were excluded. Participants were recruited from GMC Suryapet’s ophthalmology outpatient department and provided informed consent prior to enrollment.

Data Collection

Demographic data, including age, gender, and relevant medical history, were collected through structured interviews. Blood samples were drawn from each participant after a 12-hour fasting period to ensure accurate serum uric acid measurement. Serum uric acid levels were analyzed using an enzymatic colorimetric method at the GMC Suryapet laboratory, and values were recorded in mg/dL.

Cataract Assessment

Ophthalmologists performed a slit-lamp examination to diagnose cataract presence and categorize the type of cataract (nuclear, cortical, posterior subcapsular, or mixed). Age-related cataract presence was documented for further statistical analysis.

Statistical Analysis

Data were analyzed using SPSS software. Descriptive statistics were employed to summarize demographic data, serum uric acid levels, and cataract prevalence by age group. Pearson’s correlation coefficient was used to assess the correlation between serum uric acid levels and cataract formation. Logistic regression analysis was performed to adjust for confounding variables such as age and gender, examining the risk of cataract formation per unit increase in serum uric acid. Statistical significance was set at p < 0.05.

Ethical Considerations

The study was approved by the Institutional Ethics Committee of GMC Suryapet. All participants were informed about the study's purpose, and written consent was obtained. Participants’ data were anonymized to ensure confidentiality.

The study included a sample of 100 participants, with an average age of 65.3 ± 8.4 years. Gender distribution showed a slightly higher proportion of females (55%) than males (45%) (Table 1). The mean serum uric acid level for the entire sample was 5.8 ± 1.5 mg/dL, which served as the baseline for comparing participants with and without cataracts

Table 1: Sample Demographics

Age Distribution and Cataract Prevalence

Participants were grouped into four age categories: 50–59, 60–69, 70–79, and 80+. The distribution across age groups showed a greater prevalence of cataracts among older participants, with 32% of those aged 50-59 and 80% of those aged 80+ having cataracts. Overall, 58% of the sample presented with cataracts, and the age-specific distribution indicated an increase in cataract prevalence with age (Table 2 and Table 3).

Table 2: Age Distribution of Participants

Table 3: Cataract Presence by Age Group

Serum Uric Acid Levels and Cataract Presence

When analyzing serum uric acid levels by cataract status, those with cataracts had a higher mean serum uric acid level (6.1 ± 1.3 mg/dL) compared to those without cataracts (5.4 ± 1.4 mg/dL) (Table 4). This difference was statistically significant (p < 0.05), suggesting an association between elevated serum uric acid levels and cataract formation.

Table 4: Serum Uric Acid Levels by Cataract Status

Correlation Analysis

Pearson correlation analysis revealed a significant positive association between serum uric acid levels and the presence of cataracts (r = 0.42, p < 0.05), indicating a moderate positive correlation. Age also showed a significant correlation with cataract presence (r = 0.51, p < 0.01), highlighting age as an influential factor in cataract formation (Table 5).

Table 5: Correlation Analysis

Logistic Regression

A logistic regression model, adjusting for age and gender, demonstrated that each 1 mg/dL increase in serum uric acid levels corresponded to a 1.2-fold increased risk of developing cataracts (OR = 1.2, 95% CI: 1.1–1.5, p < 0.05) (Table 6). This analysis confirmed serum uric acid as a significant predictor of cataract formation even when controlling for age, reinforcing its potential role as a risk factor.

Table 6: Logistic Regression Analysis

This study aimed to explore the association between serum uric acid levels and age-related cataract formation in adults aged 50 and above at GMC Suryapet. The results revealed a significant association between elevated serum uric acid levels and cataract presence, suggesting that higher uric acid may be a risk factor for cataract development. This finding is consistent with prior research highlighting aging as a primary contributor to cataractogenesis (Mukesh et al10., 2006)iation Between Serum Uric Acid Levels and

Cataract Formation

Our findings indicated that participants with cataracts had significantly higher mean serum uric acid levels than those without cataracts. Previous studies have shown similar results, suggesting that while uric acid serves as an antioxidant under normal physiological conditions, at elevated levels it may contribute to oxidative stress, which can affect lens proteins (Qin et al13., 2020) . Oxidatis recognized as a key factor in lens opacity and cataract formation, where uric acid, although protective initially, may at high levels exacerbate oxidative damage, accelerating cataract formation (Luo et al8., 2017) .

Comparison wit Studies

The positive association between serum uric acid levels and cataract presence observed in this study is in line with previous findings that emphasize uric acid’s complex role in oxidative stress. Studies like those by Luo et al8. (2017) and Mohammadi et al12. (2023) demonstrate comparable associations in other ocular conditions, indicating that hyperuricemia could be a modifiable risk factor for age-related eye disorders (Luo et al8., 2017; Mohammadi et al12., 2023) . However, some studies prenderscoring the need for further research to clarify this association across diverse demographics (Tarwadi & Agte9, 2011) .

Age as a Predictor of Cataract Formationcted, cataract prevalence in our study increased with age, with the highest rates observed among participants aged 80 and above. This trend is well-supported by the cumulative exposure to oxidative stress, UV light, and metabolic changes over time, contributing to lens opacity (Huang et al14., 2022) . Age remains a strong and unmodifiable risk factor, witons for public health strategies aimed at addressing age-related visual impairments (Mukesh et al10., 2006) .

Potential Clinical Implications

Our findings suggest that serum uric acid levels may help identify individuals at higher risk for age-related cataracts. Reducing serum uric acid levels through lifestyle changes or pharmacological interventions, typically recommended for hyperuricemia, could potentially benefit patients at risk for cataracts, as proposed by studies on uric acid’s systemic impact (Hamling et al11., 2008) . Considering that cataracts are a leading cause of preventable blindness wodressing this modifiable risk factor could be particularly valuable in populations with limited access to surgical treatments (Tarwadi & Agte9, 2011) .

Study Limitations

This study’s observational nature limits the ability to infer causation between elevated serum uric acid and cataract formation. The relatively small sample size and the focus on a single geographic region may restrict the generalizability of these findings. Additionally, potential confounders such as dietary patterns, genetic predisposition, and other comorbidities affecting uric acid levels were not comprehensively controlled.

Future Directions

Further research is warranted to examine the role of serum uric acid in cataractogenesis across larger, more diverse populations. Longitudinal studies could help clarify whether reducing serum uric acid levels delays cataract onset or progression. Additionally, exploring the underlying mechanisms of how uric acid influences oxidative stress in the lens may contribute to targeted therapies aimed at preserving lens clarity.

Our study demonstrates a significant association between elevated serum uric acid levels and age-related cataract formation among adults aged 50 and above. Participants with cataracts had higher mean serum uric acid levels, and each 1 mg/dL increase in uric acid was associated with a 1.2-fold increased risk of cataract development. Additionally, cataract prevalence rose with age, confirming age as a primary risk factor. These findings suggest that elevated serum uric acid could be a modifiable risk factor for cataracts, underscoring the potential benefit of monitoring and managing uric acid levels to reduce cataract risk in aging populations.

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