This study aimed to assess the prevalence of hypertension and diabetes mellitus in cataract patients from low-income backgrounds. A total of 100 patients were selected based on specific criteria from the department of ophthalmology at Shadan Institute of Medical Sciences over six months. The study evaluated the presence of diabetes, hypertension, both conditions, or neither. Results indicated that 34% of patients had no comorbidities, while 31% had both hypertension and diabetes, identifying these as significant risk factors for cataract development. Hypertension was more prevalent (25%) than diabetes mellitus (10%). Females appeared to be at a slightly higher risk for cataract, both with and without comorbidities, compared to males. The age group most affected was 45-50 years. The findings suggest that coexisting hypertension and diabetes significantly contribute to cataract risk, especially among women. Therefore, managing these conditions may be crucial in reducing cataract incidence in this demographic.

Cataract, Prevalence, Hypertension, Diabetes mellitus, Ophthalmology, Gender, Age.

Cataracts continue to be the leading cause of blindness in many nations due to insufficient surgical services. According to a report by the WHO (World Health Organization) and NPCB (National Programme for Control of Blindness), there are currently 12 million blind people and over 22 million blind eyes in India, 80.1% of whom are blind due to cataract. In India, there are over 3.8 million cataract-related blindness cases every year. The current yearly performance level is in the range of 1.6-1.9 million cataract surgeries. One of the major causes of cataract is diabetes mellitus and hypertension. Patients having diabetes are up to five times more likely to develop cataracts at an earlier age [1]. Aldose reductase (AR) is an enzyme that catalyses the conversion of glucose to sorbitol via the polyol pathway, a mechanism linked to the development of diabetic cataract. It has been established that the sorbitol build-up inside the cells results in osmotic changes that weaken hydropic lens fibers. Diabetes-induced lens oxidative stress has been linked to the polyol pathway as its principal mediator. The main location of protein synthesis, i.e., the endoplasmic reticulum (ER), experiences osmotic stress brought on by the accumulation of sorbitol, which eventually causes the generation of free radicals and cataract onset [2,3]. On the other hand, hypertension seems to be present in two-thirds of patients undergoing cataract surgery. Hypertension is thought to contribute to increases in inflammatory cytokines, including interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha). A person’s BP has also been linked to an increase in C-reactive protein (CRP) levels. Given that systemic inflammation is closely associated with cataract, hypertension contributes to the degenerative process of cataract production via a mechanism of inflammation [4,5]. 

Currently, there is a growing body of research exploring the relationship between diabetes mellitus, hypertension, and the formation of cataracts. While some studies suggest that these conditions significantly contribute to the development of cataracts, others indicate that their impact may not be as substantial. The varying conclusions drawn from different research efforts highlight the complexity of this issue. Some studies emphasize the role of diabetes mellitus, while others focus on hypertension as a more significant factor in the early onset of cataracts. These conflicting findings underscore the need for more comprehensive and in-depth studies, particularly in diverse population groups with various ethnic backgrounds, to better understand the factors at play. This study specifically aims to evaluate the prevalence of diabetes mellitus and hypertension in cataract patients from economically disadvantaged backgrounds. By focusing on this demographic, the research seeks to shed light on the extent to which these conditions contribute to cataract formation in poorer populations, ultimately providing insights that could inform targeted interventions and healthcare strategies. 

A 6-month prospective cross-sectional study was conducted at the Department of Ophthalmology, Shadan Teaching Hospital and Research Centre, involving 100 diabetic and hypertensive cataract patients, aged 45 years and above. The study included patients of both genders aged 45 and above, diagnosed with cataract, having hypertension, diabetes, or both. Those who’ve had cataract surgery and consent to sharing information are included. Patients below 45, pregnant or lactating women, and those unwilling to share health information are excluded. Data for the study were sourced from patient information collected through forms completed by patients. The data collection form was designed to comprehensively document various aspects, including patient demographics, cataract details, medical history, vital signs, and co-morbidities like diabetes and hypertension, along with associated factors and contact information. The collected data encompassed a range of information relevant to the study’s objectives. Prior to commencing the study, the approval of the ethical committee was obtained from Shadan Teaching Hospital and Research Centre. A group of 100 cataract-diagnosed patients (59 females and 41 males) from the ophthalmology inpatient and outpatient departments were enrolled after taking informed consent. Participant information, including demographic data, medical history, and medication details, was collected using a performa and subsequently analysed. Patients were also counselled on post-op complications and care.

During the six-month study period, data were meticulously collected from a total of 100 cataract patients, comprising 59 females and 41 males. The study assessed six specific parameters, which are detailed as follows:

Gender: Having both hypertension and diabetes (n=31) was proven to be a major risk factor for cataract development as compared to having only hypertension (HTN) or only diabetes (DM). Female patients seem to be at a slightly higher risk in all groups (Table 1).

Table 1: Patient distribution according to gender based on comorbidities 

Age: The 45-50 yrs age group exhibited the highest patient count across all categories, some having prior ocular trauma; while our study found HTN to be a more significant risk factor than DM for cataract formation across all ages, the combination of HTN and DM posed a considerable risk for early cataract development (table 2)

Table 2: Patient distribution according to age based on comorbidities 

Addictions: 52 out of 100 patients had no addictions; most cataract cases were observed among patients without addictions and with hypertension, although smokers, alcoholics, and tobacco chewers primarily exhibited both hypertension and a higher risk for early-age cataract development.

Table 3: Patient distribution according to addictions based on co-morbidities.

Use of supplements: 68% of cataract patients had not used any supplements. 32% of patients used various dietary supplements, which were irrelevant to the study. 

Insulin-dependent and non-insulin-dependent diabetes mellitus: 57% of patients were not insulin dependent, while 43% of patients were insulin dependent. Use of insulin in diabetics did not show an increase in the risk of early cataract formation, as patients were distributed among all age groups. 

In our study, 25% of the patients were found to have only hypertension, and 10% had only diabetes mellitus. This finding aligns with the research conducted by Ioanna Mylona et al [6], who published a study titled “Hypertension is the Prominent Risk Factor in Cataract Patients.” Their study highlighted that hypertension, rather than diabetes, is the more significant single risk factor contributing to the development of cataracts. According to their research, diabetes alone did not demonstrate a substantial effect on cataract formation, while hypertension was clearly identified as a prominent risk factor in cataract patients. 

The study found that the highest prevalence of cataracts, at 31%, occurred in patients suffering from both hypertension and diabetes. This finding aligns with research published by Jin-Jin Li [7] in the article titled “Hypertension and Diabetes Synergistically Strengthen the Association with Cataract.” According to this study, the presence of both hypertension and diabetes significantly increases the risk of developing cataracts. This correlation emphasizes the critical need for managing these conditions together, as their combined effects can greatly amplify the likelihood of cataract formation, making early detection and treatment crucial for affected individuals. 

Women were found to have a significantly higher risk of developing cataracts, regardless of the presence of co-morbidities. This finding supports the research published by Madeleine Zetterberg et al [8], titled “Gender and Cataract—The Role of Estrogen.” The study highlights that numerous population-based studies have observed lens opacities to be more prevalent in women than in men, with these differences being unrelated to lifestyle factors. Consequently, the development of cataracts in women may be linked to elevated levels of estrogen, suggesting a gender-specific risk factor in the pathogenesis of cataracts. 

In our study, the duration of diabetes varied across all age groups, and we did not find a significant link between long-standing diabetes and cataract formation. This contrasts with the findings of Seong II Kim et al [9] in their study titled “Prevalence and Risk Factors for Cataracts in Persons with Type 2 Diabetes Mellitus,” which identified the duration of diabetes as the most prominent risk factor for cataracts. Our results suggest that factors other than the length of time with diabetes might play a more crucial role in cataract development in patients with type 2 diabetes. 

In our study, men who got cataract at a relatively early age (45-55 years) were exposed to direct sunlight on a regular basis due to their occupation (farmer, labour, coolie, watchman, truck driver etc.) whereas majority of females who got cataract at an early age were housewives who did a lot of cooking. The continuous exposure to smoke from stoves might be a risk factor for cataract development in women, which is consistent with the study published by Amod K Pokhrel et al [10] on “Case-control study of indoor cooking smoke exposure and cataract in Nepal and India”. It stated that a lack of kitchen ventilation could cause cataracts, especially when using wood and dung as solid fuels for cooking. 

Patients who followed a vegetarian diet were found to have cataracts diagnosed at a relatively earlier age compared to those who followed a mixed diet or a diet high in meat. This finding aligns with the study conducted by Braxton D. Mitchell and James M. Lepkowski [11] titled “The Epidemiology of Cataract in Nepal.” Their research highlighted that vegetarianism was one of the parameters showing a positive association with the development of cataracts. The study suggests that certain nutritional deficiencies commonly associated with vegetarian diets might contribute to this earlier onset. Therefore, it is crucial for hypertensive and diabetic patients, who are already at higher risk for cataracts, to be particularly mindful of their diet. They should be advised to maintain a balanced diet that ensures they receive all necessary nutrients to avoid potential deficiencies that could contribute to cataract formation. Ensuring a diet that includes a variety of foods from all major food groups, including adequate protein, vitamins, and minerals, is essential in mitigating the risk of early cataract development. This highlights the importance of dietary counselling and regular monitoring of nutritional intake, especially in patients with existing health conditions such as hypertension and diabetes. 

Investigating the correlation between nuclear, cortical, and posterior subcapsular cataracts was the objective of the Blue Mountains Eye Study [12]. The investigation corroborated the results of prior studies, but also established a correlation between posterior subcapsular cataracts and diabetes mellitus.  

An investigation conducted in Barbados examined the correlation between diabetes and lens opacities in a sample of 4314 black individuals [13]. An 18% prevalence of a history of DM was found to be associated with all lens changes, particularly at younger ages. A separate investigation conducted by Srinivasan et al [14] revealed that the overall occurrence of cataracts is far greater among diabetics compared to the likelihood of their progression. The researchers also noted that age is the primary risk factor for the cumulative occurrence and advancement of most forms of cataract, with older patients having higher rates of both. 

A total of 61 cataract patients included in this study were of all genders. In these cases, the frequency of patients who presented only with hypertension was 5 (29.4%). A posterior subcapsular cataract was replaced with a nuclear cataract in 4 cases (14.3%). Type II diabetes mellitus in isolation exhibited extremely low frequencies in all categories; indeed, 1 case (1.6%) with cortical cataract, 3 cases (4.9%) with posterior subcapsular cataract, 2 cases (3.3%) diagnosed with nuclear cataract and mixed cataract procedures. Individuals diagnosed with diabetes have a higher propensity to develop cataracts compared to those without diabetes, and chronic cataracts tend to advance at a faster rate in diabetic patients [15].  

A comprehensive epidemiological study carried out in Korea, including 11,591 participants, revealed that hypercholesterolemia, diabetes mellitus, age, education level, and lower monthly family income were individually identified as risk factors for the development of pure cortical cataracts. The present study investigated the association between pure nuclear cataracts and independent risk factors for diabetes, metabolic syndrome, aging, and low educational attainment. Furthermore, age and diabetes mellitus were identified as independent risk factors for the development of posterior subcapsular cataracts. The findings of this study suggest that there are specific risks linked to the development of mixed cataracts, such as diabetes mellitus, advancing age, reduced monthly household income, and lower levels of education [16].  

The analytical sample for the cross-sectional study consisted of 31,464 persons aged 60 and older. The variation in the occurrence of cataracts and glaucoma among individuals with diabetes mellitus, considering their socio-economic and demographic characteristics, was analyzed using bivariate cross-tabulation and chi-square test. Cataracts impact over 20% of the elderly population, in contrast to glaucoma, which affects only 2% of this group. Prevalence rates for cataract and glaucoma are 29% among older adults with diabetes, compared to 22% among those without diabetes. In relation to gender, the occurrence of cataracts is relatively greater among females (25%) compared to males (21%). Importantly, after accounting for socio-economic and demographic factors, older persons with diabetes have a significantly higher likelihood of cataract (Adjusted odds ratios [AOR] 1.495 and p-value < 0.01) and glaucoma (AOR 1.554 and p-value < 0.01) compared to their counterparts [17].

Female patients appear to be at a slightly higher risk of developing cataracts, both with and without comorbid conditions, compared to male patients. This suggests that gender may play a role in the susceptibility to cataract formation. Among the various patient groups, those suffering from both hypertension and diabetes mellitus showed the highest prevalence of cataracts, with a significant 31% of these patients affected. This indicates a strong correlation between these comorbidities and the development of cataracts. Furthermore, the age group of 45-50 years had the most significant number of patients across all groups, highlighting that middle-aged individuals may be particularly vulnerable to cataracts, especially when compounded by other health issues. In conclusion, the overall prevalence of hypertension among the studied population was found to be 25%, while diabetes mellitus affected 10% of the patients. This data underscores that hypertension, with a prevalence rate of 25%, is more common in this patient population compared to diabetes mellitus. The findings emphasize the importance of managing these chronic conditions, particularly in middle-aged and older adults, to potentially reduce the risk of cataract development and improve overall eye health outcomes.

We would like to thank ophthalmologist Dr. Kaneez Fatima, Associate Professor, Department of Ophthalmology, Shadan Institute of Medical Sciences, for her guidance & staff members for their support.

Not reported

Corresponding Author: 
Syeda Khadija Tazeen
Department of Ophthalmology
Shadan Teaching Hospital and Research Centre, Hyderabad
Email: tazeensyed105@gmail.com

Co-Authors:
Kaneez Fatima
Department of Ophthalmology
Shadan Institute of Medical Sciences, Hyderabad
Email: kaneezfatima237@gmail.com

Mobin Fatima
Department of Ophthalmology
Shadan College of Pharmacy, Hyderabad
Email: quamermobin21@gmail.com 

Umme Kulsum Hafsa
Department of Ophthalmology
Shadan Teaching Hospital and Research Centre, Hyderabad
Email: hafsa7kulsum@gmail.com 

Saifa Mansur Shah
Department of Ophthalmology
Shadan Teaching Hospital and Research Centre, Hyderabad
Email: ayeshamansur03@gmail.com 

M A Shoeb Malik
Department of Ophthalmology
Shadan Teaching Hospital and Research Centre, Hyderabad
Email: shoebmsm21@gmail.com 

Hannan Ahmed Sharaf
Department of Ophthalmology
Shadan Teaching Hospital and Research Centre, Hyderabad
Email: sharafahmed171@gmail.com

All authors contributed to the conceptualization, investigation, and data curation by acquiring and critically reviewing the selected articles. They were collectively involved in the writing – original draft preparation, and writing – review & editing to refine the manuscript. Additionally, all authors participated in the supervision of the work, ensuring accuracy and completeness. The final manuscript was approved by all named authors for submission to the journal.

Not reported

The authors declare no conflicts of interest.

None

https://doi.org/10.63096/medtigo3062248

Syeda Khadija T, Kaneez F, Mobin F, et al. Prevalence of Type 2 Diabetes Mellitus and Hypertension in Cataract Patients: A Prospective Study at a Tertiary Care Hospital. medtigo J Med. 2024;2(3):e3062248. doi:10.63096/medtigo3062248 Crossref