Diabetes mellitus is a global epidemic. It is estimated that
171 million people are suffering from this disease throughout the world which
is increasing in number every year. Diabetic retinopathy (DR) is one of its
frequent and serious complications and is among the leading causes of blindness
worldwide. A patient can be suffering from type 2 diabetes mellitus well before
clinical diagnosis and usually has diabetic retinopathy at the time of his
diagnosis.
Diabetic retinopathy (DR) is defined as damage to retinal
microvascular system due to prolonged hyperglycemia. Major risk factors are
duration of diabetes, degree of glycemic control and hyperlipidemia. In type 2
diabetic subjects diabetic retinopathy has been associated with increase in
arterial stiffness and thickness of the intima-media suggesting that a common
pathophysiology might be leading to diabetic microangiopathy1.
Diabetics are 25 times more likely to become blind than non-diabetics
due to diabetic retinopathy. For this it is vital to increase the awareness
about the complications of diabetic retinopathy by educating the patients
through the health care professionals and public seminars3.
Over
the past 20 years, eight population-based studies have suggested that the
prevalence of diabetic retinopathy is close to 28.7% in diabetic patients2.
A study conducted in Karachi among the newly diagnosed cases of type 2 diabetes
mellitus reported 15% of the patients had diabetic retinopathy4. We
conducted a similar study to determine the frequency of retinopathy in newly
diagnosed diabetic type 2 patients in order to see the magnitude of the problem
in local population compared to the available statistics. By doing so one would
be able to suggest more meticulous primary and secondary preventive strategies
that would ultimately decrease the morbidity of such patients.
MATERIAL AND
METHODS
After the approval of the hospital ethical committee and
informed verbal consent of the patients the study was conducted in the medical
out patients departments of DHQ Hospital, Faisalabad. The purpose of research
was explained to the patients. All patients of either sex (Non-probability
consecutive sampling) were included, who were diagnosed within two months as
type 2 diabetes. Diagnosis of Diabetes was done by reports of > 200 mg/dl on
two consecutive base line random blood sugar (RBS), fasting blood sugar (FBS)
and Glycosylated hemoglobin (HBA1c) on the following set criteria as defined by
world health organization (WHO) in 1999 and revised in 20065. Patients
having associated hypertension, renal disease, corneal opacity, mature
cataract, hazy vitreous and or uncooperative due to any reason, were excluded
from study. The pupil was dilated after instillation of one drop of tropicamide
in each eye. All the patients underwent dilated retina examination with +90
Diopter lens on biomicroscopic slit lamp for the presence of diabetic
retinopathy. The patients requiring further evaluation or treatment were referred
to the Ophthalmology department after entering the data into a proforma.
The
data was analyzed by using SPPS 11. Descriptive statistics were calculated
for all the variables. Mean and standard deviation was calculated for the
quantitative variables that is age in years. Frequency and percentage were
calculated for the qualitative variables that is genders, presence and type of
retinopathy.
RESULTS
The
study was completed in a period of 7 months from Sep 2010 to March 2011. A
total of 196 patients fulfilling the criteria were included. (As calculated by
WHO sample size calculator by keeping p = 15%4, margin of error = 5%
and confidence interval = 95%). Age range was 31 to 60 years; majority of them
belonged to 4th decade (Table 1) with a mean age of 50.95 ± 10.12 years. 64.28%
patients were males and 35.71% were females (Table 2). Diabetic retinopathy was
observed in 25 (12.75%) patients with newly diagnosed type 2 diabetes mellitus.
Out of these, 15 were males and 10 were females (Table 3). 16 (8.16%) patients
among 12.75% were found to have background retinopathy, 6(3%) had pre proliferative
and 3 (1.53%) had proliferative retinopathy (Fig. 1). The HbA1C (%) was found
to be 9.5 ± 1.6 in the patients with diabetic retinopathy and 7.4 ± 2.5 in
patients without diabetic retinopathy (Table 4).
Out
of the 16 patients with background retinopathy, 10 were males and 6 were
females, whereas 4 males and 2 females had preproliferative retinopathy and 2
males and 1 female had proliferative retinopathy (Table 5).
Fig. 1: Types
of Retinopathy in Study Group: n = 196.
DISCUSSION
Diabetes mellitus is the most common endocrine metabolic
disorder. The true frequency of patients having diabetes mellitus is difficult
to ascertain because of differing standards of diagnosis but various studies
have reported that prevalence of diabetes mellitus in Pakistan is around 5 7%6.
Similarly it was estimated that in Pakistan the prevalence of diabetic
retinopathy (DR) in diabetic patients is 12%7 whereas others have
reported the rates to be as high as 15%8 to 19.9%9. DR is
a major cause of blindness in those suffering from type 2 Diabetes. It is
assumed globally that Diabetic retinopathy (DR) will be one of the most
important causes of blindness in the future.
We conducted a prospective study among the newly diagnosed
patients of type 2 diabetes mellitus and found that the diabetic retinopathy
was present among 12.75% of the patients. A study done in southern parts of
Pakistan showed 15% of newly diagnosed diabetics had retinopathy at the time of
diagnosis4. Similarly a study from India reported this figure to be
10.2%10 whereas in United Kingdom the prevalence of diagnosed
retinopathy was reported to be 19%11. These differences could
probably be because of ethnic variations, different gender and age groups
presentations. This is evident by comparing our results with a similar study
done in abbottabad12. They found the frequency to be 17% while their
study group was with mean age of 45.1 ± 3.2 years consisting of predominantly
females whereas in our settings the mean age was 50.95 ± 10.12 years and was
predominantly male.
We found retinopathy predominantly to be background (8.16%),
then pre-proliferative (3%) and proliferative (1.53%). These results are
comparable to the findings of Hayat et al.12
In our study group HbA1C (%) was found to be 9.5 ± 1.6 and
the fasting plasma glucose level was 221 ± 35.6 in the patients with diabetic
retinopathy. These findings augment the association of HbA1c and fasting plasma
glucose in patients with retinopathy as suggested by Abdollahi A13 and
Rema M et al10. Denmark14 also
suggested a strong correspondence of period of diabetes, HbA1c levels and
systolic blood pressure with the severity of retinopathy.
The
importance of eye examination of all diabetic patients at the time of diagnosis
in preventing the blinding complications of DR. It further shows that age, gender, and
glycemic control are associated with the onset and progression of DR.
CONCLUSION
The
frequency of retinopathy in newly diagnosed patients of type 2 diabetes
mellitus is 12.75% and stress the value of in depth ophthalmic assessment of
every patient of diabetes at the time of diagnosis.
Authors Affiliation
Dr. Kashif
Jamil
Department of
Medicine
Punjab
Medical College
Unit IV DHQ Hospital, Faisalabad
Dr. Yasir
Iqbal
Asst. Prof.
Ophthalmology
IIMC-T Pakistan Railways Hospital, Rawalpindi
Dr. Sohail
Zia
Asst. Prof.
Ophthalmology
IIMC-T Pakistan Railways Hospital, Rawalpindi
Dr. Qaim Ali
Khan
Asst. Prof.
Ophthalmology
Poonch
Medical College, Rawalakot, AJK.
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