Prevalence of diabetic
retinopathy in patients in a tertiary hospital in south India
T. Jayalekshmi 1, K.P.
Poulose 2
1Dr T Jayalekshmi, Associate professor, SUT Academy of medical
sciences, Vattappara, Trivandrum, Kerala, India, 2Prof K P Poulose,
Professor emeritus of medicine, SUT Academy of medical sciences,
Vattappara, Trivandrum, Kerala, India
Address for
correspondence: Dr T Jayalekshmi, Email:
t_jayalekshmi@yahoo.com
Abstract
Aims: To
estimate the prevalence of Retinopathy in patients attending a diabetic
clinic and to evaluate the risk factors underlying its development. Methods: 750
diabetic patients who reported for executive check up in a preventive
clinic were evaluated for absence or presence of retinopathy. Diabetic
Retinopathy (DR) present was graded as non proliferative diabetic
retinopathy (NPDR) and proliferative diabetic retinopathy (PDR). Risk
factors were then evaluated in order to delineate those related to
retinopathy. Investigations included complete blood count, blood sugar,
serum lipids, ECG, Renal function tests and complete clinical
examination. Results:
DR was detected in 111 patients (14.8 %) with NPDR in 106 patients
(14.1%) and PDR in 5 patients (0.7%). Factors related to the incidence
of retinopathy were duration of diabetes, presence of hypertension,
high blood sugar level and hyperlipidemia. It was found that duration
of diabetes, level of glycemic control and high levels of cholesterol
were statistically significant for the occurrence of retinopathy. Conclusion: In
addition to glycemic control, lowering of serum lipids may be effective
in lowering the incidence of retinopathy in diabetic patients
.Hypertension was not related to the occurrence of retinopathy.
Keywords:
Diabetic Retinopathy, Prevalence, Risk factors
Manuscript received:
20th September 2016,
Reviewed: 30th September 2016
Author Corrected:
09th October 2016,
Accepted for Publication: 18th October 2016
Introduction
Diabetic Retinopathy is the leading cause of blindness in middle aged
adults [1]. According to WHO 70 million people were affected by
diabetes in India in the year 2015 and the figure is estimated to rise
to 79.4 million by 2030[2]. It is estimated that the global magnitude
of DR will increase from 126.6 million in 2010 to 191 million by 2030.
Present review shows that prevalence of DR in India and China is
significantly lower [3]. The reported prevalence of DR in India ranges
from 17.6% to 28.2% [4]. A recent Meta analysis of 35 population based
studies of Diabetes worldwide indicated that about one third of
diabetic individuals had some degree of DR, and fewer than 10% had
either diabetic macular oedema (DME) or PDR. This means that a
substantial number of individuals with underlying diabetes do not
progress to overt vision threatening DR if managed properly. However
these are at a risk of conversion and need regular follow up [4].
Materials
and Methods
750 diabetic patients who reported for executive check up over a period
of 2 years were examined in ophthalmology department of Sut hospital
for the presence or absence of DR. A full medical history was taken
including age of patient, duration of diabetes, treatment details,
history of hypertension, and hyperlipidemia. Fasting blood glucose of
each patient was estimated after an overnight fast. Diabetic control
was graded as Normal (<100 mg/dl), Moderate control (100-126
mg/dl), and High (>126 mg/dl). Glycosylated hemoglobin assay was
not done in all cases and hence not included in this study.
Hypertension was deemed to be present when the systolic blood pressure
was >140 mm Hg or when diastolic blood pressure was >90
mm Hg or when patient gave history of hypertension controlled with
medications. Hyperlipidemia was graded as present when total
cholesterol was >200 mg/dl or when patient was on medication for
hyperlipidemia. The pupil of each eye was dilated using Tropicamide 1%
and phenylephrine 10% eye drops followed by detailed fundus examination
with direct and indirect ophthalmoscopy. DR patients were classified
according to the grading in the worse eye.
Statistical Analysis-
Quantitative variables were expressed in mean +/- standard deviation
(SD) and categorical variables expressed in percentage. Association of
retinopathy with selected variables was carried out using chi-square
test. SPSS 17.0 version was used for analysis. P value less than 0.05
was considered statistically significant.
Results
Of the 750 diabetic patients, 567(75.6%) were males and 183(24.4%) were
females. The mean age of those examined was +/-SD 53.9 +/-9.1[Table 1].
Table-1: Percentage
distribution of the sample according to age
|
Age
|
Count
|
Percent
|
|
31 - 40
|
50
|
6.7
|
|
41 - 50
|
219
|
29.2
|
|
51 - 60
|
295
|
39.3
|
|
61 - 70
|
158
|
21.1
|
|
71 - 80
|
28
|
3.7
|
|
Mean ± SD
|
53.9 ± 9.1
|
Family history of diabetes was present in 551 patients (73.5%) with
higher incidence in mother 340(45.3%) and siblings 370(49.3%) and lower
incidence in father 255(34.0 %). [Table 2]. DR was detected in
111(14.8%) patients. Of this Non proliferative DR (NPDR) was present in
106 (14.1%) and Proliferative DR (PDR) in 5 (0.7%) [Table 3]
Table-2: Percentage
distribution of the sample according to family history
|
Family
history
|
Count
|
Percent
|
|
Father
|
255
|
34.0
|
|
Mother
|
340
|
45.3
|
|
Siblings
|
370
|
49.3
|
|
Both parents
|
151
|
20.1
|
|
Parents + siblings
|
119
|
15.9
|
Table-3: Percentage
distribution of the sample according to associated retinopathy
|
Associated
retinopathy
|
Count
|
Percent
|
|
Normal
|
639
|
85.2
|
|
NPDR
|
106
|
14.1
|
|
PDR
|
5
|
0.7
|
Overall, retinopathy was more prevalent in patients with Insulin
requiring diabetes 39(52.6%) compared to patients not requiring insulin
72(11.8%). [Table 4].
Table 4: Comparison of
treatment based on retinopathy
|
Treatment
|
Retinopathy
|
c2
|
p
|
|
Normal
|
Abnormal
|
|
Count
|
Percent
|
Count
|
Percent
|
|
OHA
|
536
|
88.2
|
72
|
11.8
|
23.15**
|
0.001
|
|
Insulin only
|
33
|
76.7
|
10
|
23.3
|
|
OHA+Insulin
|
70
|
70.7
|
29
|
29.3
|
The highest risk for development of DR was in those patients having
diabetes for >10 years. There was significant association
between duration of diabetes and DR. [Table 5].
Table-5: Comparison of
retinopathy based on duration
|
Duration
|
Retinopathy
|
c2
|
p
|
|
Normal
|
Abnormal
|
|
Count
|
Percent
|
Count
|
Percent
|
|
0 - 5
|
288
|
94.7
|
16
|
5.3
|
55.27**
|
p<0.01
|
|
6 - 10
|
174
|
84.1
|
33
|
15.9
|
|
11 - 15
|
85
|
78.0
|
24
|
22.0
|
|
16 - 20
|
55
|
64.7
|
30
|
35.3
|
|
>20
|
37
|
82.2
|
8
|
17.8
|
A total of 349(46.5%) with diabetes had associated hypertension and of
this 52(14.9%) patients had DR. There was no significant association
between DR and hypertension in this study [Table 6].
Table-6: Comparison of HT
based on retinopathy
|
HT
|
Retinopathy
|
c2
|
p
|
|
Normal
|
Abnormal
|
|
Count
|
Percent
|
Count
|
Percent
|
|
Yes
|
297
|
85.1
|
52
|
14.9
|
0.01
|
0.943
|
|
No
|
342
|
85.3
|
59
|
14.7
|
Of the total diabetics 52 (6.9%) had hyperlipidemia. .Of this 14(26.9%)
patients had DR. There was significant association between
hyperlipidemia and DR.[Table7].
Table-7: Comparison of
hyperlipidemia based on retinopathy
|
Hyperlipidemia
|
Retinopathy
|
c2
|
p
|
|
Normal
|
Abnormal
|
|
Count
|
Percent
|
Count
|
Percent
|
|
Yes
|
38
|
73.1
|
14
|
26.9
|
6.51*
|
0.011
|
|
No
|
601
|
86.1
|
97
|
13.9
|
The incidence of DR was more in uncontrolled diabetics which was
significant association at 0.05 level. [Table 8].
Table-8: Comparison of
FBS based on retinopathy
|
FBS
|
Retinopathy
|
c2
|
p
|
|
Normal
|
Abnormal
|
|
Count
|
Percent
|
Count
|
Percent
|
|
Normal
|
112
|
90.3
|
12
|
9.7
|
6.59*
|
0.037
|
|
Moderate control
|
171
|
88.1
|
23
|
11.9
|
|
High
|
356
|
82.4
|
76
|
17.6
|
Discussion
DR is one of the few ophthalmic diseases that have a defined preventive
measure to delay progression of the disease and consequent visual loss.
The reported prevalence of DR varies in different studies. In the
Indian scenario ,JS Jain et al at PGI Chandigarh diabetic clinic
reported a prevalence rate of 42.9%. Two other south Indian studies
have shown prevalence rate of 34.1% and 37% respectively. In the Andhra
Pradesh Eye disease study (APEDS) the prevalence rate for DR is 26.2%.
The Chennai Urban Rural Epidemiology study (CURES 1) reported a
prevalence rate of 17.6% which is much lower than in other groups [5,
6]. In a study in south India the prevalence of DR in type 2 diabetics
in urban India was 10.84% [7].
In the present study DR was present in 14.8% of the 750 patients
referred for evaluation which is lower compared to most studies. It may
be due to racial and demographic factors. However, the methods of
detecting retinopathy used in different studies may be the most
important reason [8].
Specificity of direct and indirect ophthalmoscopy used in this study to
detect retinopathy is high but sensitivity is low (34-50 %)
particularly for early retinopathy. Systematic screening for
retinopathy using automated retinal image analysis is emerging as an
important screening tool for early detection of DR [9].
In this study a number of risk factors were investigated and it was
found that many were significantly related to retinopathy. These
included duration of diabetes, hypertension, hyperlipidemia and
increased level of fasting blood sugar.
Duration of diabetes and retinopathy are closely associated and this
has been proved in a number of previous studies.In the present study
the incidence of retinopathy showed a steady increase after 6 years to
20 years (15.9% to 35.3%) and a reduction in incidence after 20 years
duration (17.8%). In clinical practice some patients seem to be having
a protection against retinopathy despite having multiple risk factors
[10]. It is probable that both genetic and environmental factors play a
role in the expression of DR [11, 15, 16.].
In this study there was no significant association of hypertension with
retinopathy (14.9%). A number of studies suggest that diastolic blood
pressure was related more to the progression than to the occurrence of
retinopathy [12]. Studies such as Wisconsin Epidemiological study of
diabetic retinopathy (WESDR) and United Kingdom Prospective Diabetes
Study (UKPDS) suggest that hypertension increases the risk and
progression of DR [11]. This difference in our study may be probably
due to good control of hypertension.
The degree of glycemic control proved to be a significant factor in the
study (p value 0.037) consistent with other studies. Glycemic control
has been clearly highlighted as a major modifiable risk factor for DR.
Our study showed significant association of hyperlipidemia (Total
cholesterol) and retinopathy which is consistent with some studies. In
the Chennai urban rural epidemiological study, serum lipids were higher
in patients with DR than those without retinopathy [13, 16]. There are
conflicting reports in the literature regarding the effect of lipid
profile on retinopathy. Weber et al found that serum triglycerides were
strongly associated with degree of retinopathy [14].
Conclusion
More effort should be given to determine more risk factors for the
occurrence of DR in patients with diabetes. Although the present study
was able to define many of these factors, much still needs to be done.
Awareness about retinopathy, good control of blood sugar, cholesterol
and high blood pressure will decrease the incidence of DR.
Funding:
Nil, Conflict of
interest: None initiated.
Permission from IRB:
Yes
References
1. Das A. Diabetic retinopathy: Battling the global epidemic. Indian J
Ophthalmol. 2016 Jan;64(1):2-3. doi: 10.4103/0301-4738.178155. [PubMed]
2. Gadkari SS, Maskati QB, Nayak BK. Prevalence of diabetic retinopathy
in India: The All India Ophthalmological Society Diabetic Retinopathy
Eye Screening Study 2014. Indian J Ophthalmol. 2016 Jan;64(1):38-44.
doi: 10.4103/0301-4738.178144.
3. Murthy GV, Das T. Diabetic care initiatives to prevent blindness
from diabetic retinopathy in India. Indian J Ophthalmol. 2016
Jan;64(1):50-4. doi: 10.4103/0301-4738.178152. [PubMed]
4. Das T Aurora,Chhablani J . Giridhar A,Kumar A, Raman R et
al.Evidence based review of diabetic macular oedema
management.Consensus statement on Indian treatment guidelines.Indian J
Ophthalmol 2016; 64:14-25.
5. M Chakrabarti et al-An effective model for counselling in
diabetic patients. Kerala J Ophthalmol 2008; 3:248-251.
6. Dr Jay J Meyer et al-Diabetic Retinopathy in Asia
:Illumination.Journal of Aravind Eye Care System.Vol V11 No.1
Jan-Mar.2007:15-17.
7. Namperumalsamy P et al. Prevalence and risk factors for diabetic
retinopathy in the population of over 30 years of age in Theni district
of South India. Br J Ophthalmol.1999 Aug; 83(8):937-40.
8. Valverde C, Garcia M, Hornero R, Lopez-Galvez MI. Automated
detection of diabetic retinopathy in retinal images. Indian J
Ophthalmol. 2016 Jan;64(1):26-32. doi:
10.4103/0301-4738.178140. [PubMed]
9. Raman R, Gella L, Srinivasan S, Sharma T. Diabetic retinopathy: An
epidemic at home and around the world. Indian J Ophthalmol. 2016
Jan;64(1):69-75. doi: 10.4103/0301-4738.178150. [PubMed]
10. Singh R, Ramasamy K, Abraham C, Gupta V, Gupta A. Diabetic
retinopathy: an update. Indian J Ophthalmol. 2008 May-Jun;56(3):178-88.
[PubMed]
11. el Haddad OA, Saad MK. Prevalence and risk factors for diabetic
retinopathy among Omani diabetics. Br J Ophthalmol. 1998
Aug;82(8):901-6. [PubMed]
12. Cetin EN, Bulgu Y, Ozdemir S, Topsakal S, Akın F, Aybek H, Yıldırım
C. Association of serum lipid levels with diabetic retinopathy. Int J
Ophthalmol. 2013 Jun
18;6(3):346-9. doi: 10.3980/j.issn.2222-3959.2013.03.17. Print 2013. [PubMed]
13. Lill.Inger Larsson, Albert Alm,Folke Lithner, Gosta Dahlen and
Reinhold Bergstrom:The association of hyperlipidemia with retinopathy
in diabetic patients aged 15-50 years in the county of Umea:Acta
ophthalmol.scand. 1999;77:585-591.
14. Mishra B, Swaroop A, Kandpal RP. Genetic components in diabetic
retinopathy. Indian J Ophthalmol. 2016 Jan;64(1):55-61. doi:
10.4103/0301-4738.178153. [PubMed]
15. Radha V, Rema M, Mohan V. Genes and diabetic retinopathy. Indian J
Ophthalmol. 2002 Mar;50(1):5-11. [PubMed]
16. Kaur P,BBS ,Kaur I,Singh G,Singh B.Correlation of severity of
Diabetic Retinopathy with various risk factors.Int J Res Health
Sci(internet).2014 Apr 30;2(2):473-9.
How to cite this article?
T. Jayalekshmi, K.P. Poulose. Prevalence of diabetic retinopathy in
patients in a tertiary hospital in south India. Int J Med Res Rev
2016;4(10):1802-1806.doi:10.17511/ijmrr. 2016.i10.16.