Social determinants of diabetic retinopathy and impact of sight-threatening diabetic retinopathy: A study from Pune, India

Abstract

Purpose:

Diabetes-related retinopathy is the leading cause of blindness in India. The study was carried out with the purpose of studying the association of sight-threatening diabetic retinopathy (STDR) with socioeconomic factors and demonstrating the impact of STDR on the affected individual.

Methods:

A mixed methods (quantitative and qualitative) research design was used. The study participants were divided into two groups for quantitative analysis. The control group consisted of non–sight-threatening diabetic retinopathy, whereas the study group consisted of sight-threatening diabetic retinopathy. Apart from demographics, data on comorbidities, type and duration of diabetes mellitus (DM), health insurance status, and socioeconomic data were collected from each individual. A statistical test (Chi-square) was performed to study the association between socioeconomic (SE) classes and STDR. For the qualitative part, a few people were chosen. Face-to-face interviews were conducted in depth.

Results:

A total of 207 individuals, were recruited, of which 69 had STDR and the remaining 138 had non-STDR. The incidence of STDR was high among patients with lower socioeconomic class (SEC) (upper lower and lower), and univariate analysis revealed a strong association between STDR and SEC, the presence of comorbidities, presence of health insurance, type and duration of DM, and P value <0.05. SEC, in contrast, emerged as an independent risk factor for STDR in multivariate analysis. STDR had a devastating effect on all patients interviewed. The financial impact was most likely the most severe.

Conclusion:

People with lower SEC are more likely to suffer from STDR-related vision loss. The impact of such vision loss on individuals is multifaceted, including a negative impact on social and work life, psychological well-being, and, most importantly, a significant financial impact.

India is home to over 74 million diabetics, and the number is estimated to exceed 123 million by 2040.[1] Increasing longevity, changing lifestyles, and dietary habits contribute to the increasing prevalence of diabetes mellitus (DM) in India and all over the world.[2] The largest increase in the disease burden (among all non-communicable diseases) between 1996 and 2016 was noted for DM at 80%.[3] Diabetes and its complications are now an area of focus for the prevention of mortality and morbidity. The absence of acute symptoms and lack of awareness are the main barriers to the detection of DM and its complications.[4,5] The prevalence of DM in India has been reported to be between 10.2% and 36% in various population-based surveys.[6-9] In a study conducted in Pune it was reported that DM affects over a fifth of persons above 50 years of age. Nearly a seventh of the diabetics in this study had diabetic retinopathy (DR); however, the coverage of screening was poor.[10] The rising trend of DM among other non-communicable diseases (NCD) means that the prevalence of DR-related visual impairment and blindness will become a major public health issue in the future. There is a plethora of literature that suggests the association between the severity of DR and duration of DM, poor glycemic control, high serum lipid levels, anemia, pregnancy, and pre-existing comorbidities such as hypertension and nephropathy, all of which contribute to the pathophysiology of DR.[11] There is little evidence in the literature to suggest an association between socioeconomic class (SEC) and sight-threatening diabetic retinopathy (STDR). The relation between lower socioeconomic status and higher blindness rate is unambiguous.[12] This is clearly indicated by the higher prevalence of blindness in the poorer countries of the world compared with the developed countries. In addition, data suggest that within a particular country those with lower socioeconomic status are more likely to suffer from blindness around the world.[13] The contributions to this phenomenon seem to include a higher prevalence of blinding conditions in those with lower socioeconomic status, less access to health services, lack of awareness, financial barriers for the treatable, and preventable causes of blindness, and questionable quality of health services available to those with lower socioeconomic status.[14] How SE factors, such as low education levels and low-income levels, can increase the risk of vision loss from DR, as a result of lack of accessibility to services, expensive services, or any other factor remains to be explored. This study investigates the various social factors that influence vision loss due to DR. Furthermore, the goal of this study was to demonstrate the impact of STDR on an individual.

Methods

This mixed methods (quantitative + qualitative) research was approved by the Institutional Ethics Committee and abided by the tenets of the Helsinki protocol, was carried out in a tertiary eye care center in Pune, Maharashtra, between October 2020 and June 2021. All patients with DM were enrolled, exclusion criteria were patients below 30 years of age, conditions that can affect the occurrence of and impede the assessment of diabetic retinopathy (advanced cataract, high myopia, retinal degenerative diseases, uveitis, etc.), any other disability where the patient is not in a position to understand or communicate and people not willing to participate in the study. Cases were defined as subjects with STDR (proliferative diabetic retinopathy [PDR], diabetic macular edema [DME]) and control were individuals with non-STDR or no DR. The ratio of the case: control was 1:2. Data were collected on demographics such as age, address, occupation, and availability of health insurance and previous medical records, type of DM, duration of DM, type of treatment. The status of glycemic control was determined by the latest HbA1C records, where a value of >7% was considered poor glycemic control. For the purpose of the study, STDR was defined as PDR or diabetic macular edema (DME), whereas NSTDR was defined as non-proliferative diabetic retinopathy (NPDR) with no DME or no DR. Subjects were broadly divided into cases and controls. To establish their SEC, the modified Kuppuswamy scale 2020 was used.[15] For this, the data on education, occupation, and monthly family income were collected, and a score was given for each answer. Scores of 26–29, 16–25, 11–15, 5–10, and <5, were considered as upper, upper middle, lower middle, upper lower, and lower respectively. With the assumption that the top two SEC persons were likely to have better health-seeking behavior and for the purpose of analysis, these categories were clubbed together to form two broad categories-upper (upper and upper middle), lower (lower middle, upper lower and lower) SEC. Statistical analysis was conducted to study any association between socioeconomic class and STDR using the SPSS (IBM) software.

Some of the STDR cases with severe visual impairment (SVI) or blindness were purposely selected for face-to-face interviews for the purpose of qualitative components. The interview topic guide was developed by a team of public health specialists and ophthalmologists using the World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF)[16] framework. This considers various aspects of disability including structure, function, and impact on participation as well as on personal factors. The questionnaire was pre-tested. A qualified ophthalmologist took interviews in the presence of a medical social worker (MSW). The MSW took field notes during the interview (such as emotional reactions and body language) and provided support to the interviewee if needed.

These interviews were audio recorded, and the resulting textual data were transcripted and translated before being organized, categorized, and analyzed with analysis software such as (NVivo).

Results

A total of 207 people were enrolled in the study, with 69 in the study/cases group having STDR and 138 in the control group having no DR and NSTDR. Table 1 shows the characteristics of the study population. The mean age of patients enrolled in the study was 58.52 ± 8.34 years, with the majority being less than 60 years and a male-to-female ratio of 1.7: 1. According to the Kuppuswamy Socioeconomic Status Scale 2020, the majority (55.5%) of patients enrolled belonged to the upper class, followed by those belonging to the lower class (40%). Type 2 diabetes mellitus was the most common type of diabetes in 81.15% of patients, with Type 1 diabetes mellitus accounting for 18.84%. More than 71% of patients had poorly controlled diabetes as detected from their medical records. The majority of patients, i.e., more than two-thirds had diabetes for more than 5 years. Almost two-thirds of the patients (66.18%) had comorbidities such as hypertension, chronic kidney disease, and neuropathy. Nearly 38% were never screened for DR before. The majority of patients (80.67%) were started on oral hypoglycemic agents, followed by those on insulin (18.64%). The mean BVCA among all enrolled patients was 0.74 ± 0.98 (6/30 to 6/48). Almost 58% had a moderate-to-severe visual impairment or worse. Multiple regression analysis revealed that patients’ low socioeconomic status was significantly associated with STDR. Sight-threatening diabetic retinopathy was seen significantly higher among lower- or upper lower-class patients. Table 2 shows the distribution of factors such as SEC and visual impairment level by the status of DR. Multiple regression analysis showed that lack of insurance, lower SE classes, and the presence of comorbidities were strongly associated with STDR.

Table 1.

Characteristics of the study population

Age		Gender		Residence		SEC		Type of DM
<60	≥60	Male	Female	Urban	Rural	Upper	Lower	Type I	Type II
121 (58.45%)	86 (41.54%)	130 (62.8%)	77 (37.17%)	181 (87.43%)	26 (12.56%)	125 (60.38%)	82 (39.61%)	168 (81.15%)	39 (18.84%)

Table 2.

Association between diabetic retinopathy and other risk factors

Variables (n=207)	Total (n)	Grades of DR		P	Odds ratio (95 CI)
Type of DM
NIDDM	168	132	36	<0.0001	5.1 (2.4 to 10.7)
IDDM	39	6	33
Duration of DM
<10 years	119	69	8	<0.0001	1.7 (1.4 to 2.0)
>10 years	88	69	61
Co-morbidities
No	71	58	13	0.001	1.3 (1.1 to 1.7)
Yes	136	80	56
Visual Impairment
No or mild VI	87	85	2	<0.0001	2.2 (1.8 to 2.7)
Moderate/worst	120	53	67
Health Insurance
Yes	114	88	26	<0.0001	1.8 (1.5 to 2.3
No	93	50	43
Variables	Total (n)	No DR/STDR (n=138)	STDR (n=69)	P	Odds ratio (95 CI)
Socio economic class
Upper	81	69	12	<0.0001	1.6 (1.3 to 1.7)
Lower	126	69	57	<0.0001	0.6 (0.4 to 0.7)

Qualitative results

The second component of this study was a qualitative evaluation to determine the impact of STDR on individuals. Twenty-one participants with STDR-related blindness or SVI were purposefully chosen. The sample was chosen to ensure a balanced distribution of age and gender distribution. The impact on various aspects of life was studied. Activity: almost all participants experienced difficulty in carrying out day-to-day activities such as going to the office, doing household work, traveling, reading the newspaper, and watching television. “Yes indeed because of low eyesight and because of weakness, I feel so lethargic all the time. I was very active as a person before getting diabetes, it had made me very weak. (Feels sad).” (9.1.10.7) (48 years, male) Participation: Several participants significant restrictions on their social/work life. One of the participants, a 39-year-old male was a working professional for an MNC whereas the rest of the employed had to lose their jobs due to low vision. “I have stopped socializing completely. Being an analysis engineer in an MNC, we have our parties in five-star hotels, and resorts. I had to cut down since last 2 years.” (14.1.15.22) (39 years, male) “I have stopped working since last 6 years due to low vision. I was very active as an auto driver.” (starts weeping). (9.9.1.15) (54 years, male) “I loved cooking for my children. From last 1 year, I have stopped cooking. I feel God is punishing me for my previous sins.” (starts weeping) (9.5.2.11) (60 years, female) Relationships: Many patients had stopped interacting with people in the social circle. Some even reported a negative impact on family dynamics. “There is a lot of stress and tension in the family. My wife and children get irritated very often with me. The family has to suffer because of me.” (becomes sad) (16.1.11.24) (65 years, male). This particular patient had extreme guilt for being the reason for the problems that his family faced due to his loss of vision. Personal life (emotions and self-esteem). Negative thoughts were recurring in patients. Patients tried to cope with negative inner thoughts on a daily basis. “I get immense negative thoughts about my future, every morning I get up with the fear that my eyesight will drop further and I will become completely blind.” (has a very worrisome face) (17.1.19.25) (64 years, female) “Yes, I have bouts of negativity and depressions. Once I had tried to commit suicide by hanging myself to the ceiling fan.” (starts sobbing) (17.1.1.25) (54 years, male). This patient was referred to the psychotherapist. Finance: Diabetic care (medicine, surgery, laser, and injections) had a drastic impact on the patient’s personal and family finances. Less than one-third were insured, whereas the rest had to pay all the expenses for diabetes care, which added to the financial burden on the family. “All the medicines, travel expenses, cost of surgery is very high. A poor gardener like me cannot afford all this. I have to spend around 2000 rupees every month.” (10.1.21.18) (55 years, male).

Discussion

India is one of the top two countries with a high number of persons with DM.[1] Patients with DR are 25 times more likely to become blind than non-diabetics.[17] Good glycemic control arrests the development and progression of DR and decreases the risk of visual loss. Blindness prevention strategies from DR have already been identified by the WHO (screening and early treatment).[18] However, screening coverage is low, and treatment uptake is low, especially in Asian countries.[10] The mean age of patients enrolled in our study was 58.8 years. Almost 58% were less than 60 years. The working age group may add to the financial woes of the family. This shows that the working age group affected with DM is on the high rise. Although DR is known to affect both genders equally. It is the health-seeking behavior that might differ between males and females. There have been reports showing the role of gender bias in affecting the health outcomes of women.[19,20] Diabetes had been present in nearly half of the patients for more than 10 years. For the glycemic controls, 8 of the 10 patients had non–insulin-dependent diabetes mellitus and were taking oral hypoglycemic agents. Every 8 out of 10 STDR patients had hypertension. Hypertension is known to contribute to the pathophysiology of DR. Almost half of the patients were covered by government or private insurance. Access to health insurance has likely improved as a result of improved finance and the launch of the Pradhan Mantri Jan Arogya Yojana.[21] This is an attempt to transition from a sectoral and segmented approach to healthcare delivery to a comprehensive, need-based approach. Nearly two-thirds of the patients were aware of the disease, its treatment, complications, and the need for follow-up. According to the results of a rapid assessment of avoidable blindness survey conducted by the same institute in Pune, nearly 70% of the general population has never been screened for DR.[10] This high proportion of previously screened DR in the current study could be attributed to previously diagnosed DR status, as well as pre-existing vision-related problems that influenced patients’ health-seeking behavior. Such patients are more likely to seek medical attention. One-third of the patients had moderate visual impairment (Snellen visual acuity 6/18–6/60), whereas nearly one-fifth had SVI or blindness (>6/60–no PL). Despite the fact that many were literate (basic primary education), more than one-third of the patients enrolled were not in a position to work. This high rate of unemployment was primarily due to poor vision. The majority of those in the study belonged to the middle SEC, which included upper middle and lower middle. Furthermore, only a few of them were from the upper class. Maharashtra is a wealthier and more developed state in India, with Pune being one of the most developed among Maharashtra’s cities. The proportion of STDR was high among patients with lower SEC, and univariate analysis revealed a strong association between STDR and lower SEC, presence of comorbidities, lack of health insurance, type, and duration of DM, and P value <0.05. Lower SEC, in contrast, emerged as an independent risk factor for STDR in the multivariate analysis. The various ways in which socioeconomic deprivation manifests itself in STDR include a lack of education, a lack of awareness, poverty with a lack of compliance, and a lack of access to healthcare facilities. Measures to provide timely health check-ups, such as DR screening through opportunistic and systematic screening, and prompt referral from rural areas to tertiary ophthalmic centers with advanced facilities, are urgently needed. Health expenses for diabetics may be multiple, such as for eye care as well as the treatment of DM and other associated heart, kidneys, and other diseases. There is a need for increased financial support as well as improved screening for DR. Our study’s strength is that it elucidates the impact of STDR on an individual’s life in a qualitative manner. The type of impact on life could be complex and intertwined with multiple domains. STDR had a devastating effect on all patients interviewed. The financial impact was most likely the most severe. In such a case, despite being aware of the risk of blindness, a person may choose not to seek treatment. The majority of patients reported severe limitations in their daily mobility and the inability to move independently due to vision loss. Dependence on others for daily activities may also result in a severely reduced income opportunity for a family member. This could push a family deeper into poverty. Such vision loss can have an impact not only on a person’s relationships with others but also on one’s self-esteem and lead to depression. This type of psychological impact cannot be measured quantitively. Given India’s average life expectancy of 70 years, more than half of them had at least 20 more years to live. Such high ‘disability-adjusted life years’ (DALYs)[22] make a compelling case for DR blindness prevention. As a result, we recommend that a sustained campaign to raise awareness about DR and improve screening coverage through the use of various cost-effective screening models is required. There should be a health financing mechanism available for the general population so that they are aware of it and can be treated as soon as possible. There should be a greater emphasis on psychological counseling for diabetic patients, particularly those who have complications from the disease. Similar studies in other parts of India or countries with a high prevalence of diabetes could raise different issues. There are several limitations to this study. Because the rural population is underrepresented, the challenges they face may have gone unnoticed. This study was conducted during the corona pandemic outbreak. Transportation was severely impacted during this time period, which may have resulted in an underrepresentation of rural populations in our study. Aside from this, the rural population is likely to face additional barriers such as distance, cost, lack of awareness about services, and so on. Similarly, the high proportion of males may imply that some unique challenges faced by females have been overlooked. Because this was a hospital-based study, the findings cannot be generalized to the Maharashtra or Indian populations.

Conclusion

People with lower SEC are more likely to suffer from STDR vision loss. The impact of STDR on individuals would be multifaceted, including a negative impact on social and work life, psychological well-being, and, most importantly, significant financial difficulties.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.