EPIDEMIOLOGICAL CORRELATES OF DIABETIC RETINOPATHY- A STUDY FROM DEHRADUN

Dr Megha Luthra*, Dr Saurabh Luthra**, Dr Gaurav Luthra** & Dr M C Luthra***SGRRIM&HS, Dehradun**Drishti Eye Centre, Dehradun

BACKGROUND

Diabetes mellitus is a major cause of avoidable blindness in both developing and developed countries. Patients with diabetic retinopathy (DR) are 25 times more likely to become blind than non-diabetics (1).

India has 31.7 million diabetics (2). In the Andhra Pradesh Eye Disease Study (APEDS) of self-reported diabetics, the prevalence of DR was 22.4% (3). In the Chennai Urban Rural Epidemiology Study (CURES), the overall prevalence of DR as 17.6% (4).

After several years of diabetes nearly 100% of IDDM patients and 60% of NIDDM patients develop retinopathy. Average expectancy of a diabetic (40-50 years) is gradually increasing with improved care (5).

OBJECTIVES OF THIS STUDY

To find out the prevalence of Diabetes and Diabetic Retinopathy among patients attending retina service in Drishti Eye Centre, Dehradun.

To study epidemiological factors associated with DR.

METHODOLOGY

This is a clinic-based cross-sectional study All patients attending the retina service of

Drishti Eye Centre, Dehradun from July to October 2010 were included.

Diabetic patients were interviewed, examined and investigated for correlates of DR.

Data was analyzed with help of spss 10.0 software.

Statistical Methods used were percentages and Chi Square Test.

RESULT

A total of 732 patients attended the retina service from 16th July to 21st October 2010

149 patients (20.3%) had known diabetes out of which 100 (67.1%) showed signs of diabetic retinopathy

Variables that are significantly associated with DR include age (4th and 5th decades of life), female sex, very low and very high income, no or high education, high BP, high Cholesterol, longer duration of diabetes (> 5 years), use of insulin, irregular eye screening and unknown glycosylated hemoglobin (HbA1c)

RESULT

TABLE I

Variable GroupsPatients with DR

(number)

Patients with DR

(percentage)

Patients with no

DR (number)

Patients with no DR

(percentage)ψ² d.f. p value

Age (in years)

<= 49 20 74.1 7 25.96.75 3 <0.05

50-59 29 76.3 9 23.7

60-69 41 66.1 21 33.9

>=70 10 45.5 12 54.5

Total 100 67.1 49 32.9

SexFemale 43 71.7 17 28.3

0.94 1 <0.05

Male 57 64 32 36

Total 100 67.1 49 32.9

Monthly Income (in

Rupees)

Nil 42 72.4 16 27.67.25 2 <0.05

<=15000 31 54.4 26 45.6

>15000 27 79.4 7 20.6

Total 100 67.1 49 32.9

RESULT

TABLE II

Variable GroupsPatients with DR

(number)

Patients with DR

(percentage)

Patients with no

DR (number)

Patients with no DR

(percentage)

ψ² d.f. p value

Education Below matric 31 83.8 6 16.2

6.43 2 <0.05

Matric 12 57.1 9 42.9 Above Matric 57 62.6 34 37.4

Total 100 67.1 49 32.9High Blood

Pressure Yes 64 68.1 30 31.90.11 1 <0.05

No 36 65.5 19 34.5

Total 100 67.1 49 32.9High

Cholesterol Yes 13 60.7 11 39.30.64 1 <0.05

No 83 68.6 38 31.4

Total 100 67.1 49 32.9

RESULTTABLE III

Variable GroupsPatients with DR

(number)

Patients with DR

(percentage)

Patients with no

DR (number)

Patients with no DR

(percentage)

ψ² d.f. p value

Duration of Diabetes (in

years) 1 to 5 26 53.1 23 46.9

6.77 2 <0.05

5 to 10 21 77.8 6 22.2>=10 53 72.6 20 27.4Total 100 67.1 49 32.9

Insulin Yes 34 70.8 14 29.2 0.44 1 <0.05No 66 65.3 35 34.7

Total 100 67.1 49 32.9Regular

Screening Yes 56 67.5 27 32.50.01 1 <0.05

No 44 66.7 22 33.3

Total 100 67.1 49 32.9HbA1c

Normal 13 72.2 5 27.89.6 2 <0.05

High 37 84.1 7 15.9

Not Done 50 57.5 37 42.5

Total 100 67.1 49 32.9

DISCUSSION Hypertension increases the risk and progression of DR. Tight control of

blood pressure results in 34% reduction in progression of retinopathy (5).

The prevalence and severity of DR increases with increasing age in type 1 DM but not in type 2 DM. There is a direct correlation between the frequency and severity of DR and the duration of DM (6).

Decrease in glycosylated hemoglobin levels was associated with a significant decrease in the progression of DR as well as the incidence of PDR.Intensive diabetic control leads to reduction in the development and progression of all diabetic complications (7,8).

A positive correlation exists between serum lipids and risk of DR in type 2 DM. Recently, Gupta et al. have reported reduction in severity by using atorvastatin as an adjunct to macular photocoagulation (9).

Although educational attainment was inversely associated with retinopathy in women in the Wisconsin Epidemiological Study of Diabetic Retinopathy (WESDR), socioeconomic status was not associated with increased risk of worsening of retinopathy. Once the level of glycemia is accounted for, social factors have little or no influence on this complication of diabetes (10).

CONCLUSION

The main predictors for DR as affirmed by this study are high BP, high cholesterol, longer duration of disease, use of insulin, irregular eye screenings of diabetics and poor glycaemic control.

This provides the major thrust areas for physicians and not just ophthalmologists for prevention of DM

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