EPIDEMIOLOGY AND NATURAL HISTORY OF DIABETIC RETINOPATHY

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EPIDEMIOLOGY AND NATURAL HISTORY OF DIABETIC
RETINOPATHY

• Tatiana Segato
• University of Padova

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• EPIDEMIOLOGIC DATA ABOUT
• DIABETIC RETINOPATHY ARE USEFUL
• IN DEVELOPING STRATEGIES
• TO PREVENT OR REDUCE
• ITS OCCURRENCE OR PROGRESSION

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• A large number of epidemiologic studies about
  prevalence and incidence of diabetic retinopathy
  have been performed during last years
• In the next two slides are summarized some
  limitations of the studies and the major risk
  factors.

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Epidemiologic studies limitations

• sample size
• duration
• type of patients
• methods to quantify retinopathy
• definition of hypertension
• data analysis

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Risk Factors

• duration of diabetes
• metabolic control
• blood pressure
• elevated lipids
• type of treatment (BISED)

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Metabolic Control and Diabetic Retinopathy
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DCCT metabolic control and Diabetic
retinopathy in type 1 diabetes (1441 patients
follow up 6,5 years)

• PATIENTS WITH NO DR
• reduction by 76 of the adjusted mean risk for
  the development of DR

2. PATIENTS WITH DR reduction by 54 of the
progression of DR
reduction by 47 of the development of severe
NPDR or PDR
reduction by 56 of laser treatment need
DCCT N Engl J Med 1993
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DCCT / EDIC 4 years follow-up

• Conventional therapy HbA1 8.2
  Intensive therapy HbA1 7.9

EDIC Epidemiology of Diabetes Interventions and
Complications study
New Eng J Med 2000
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Intensive blood-glucose control with
sulphonylureas or insulin compared with
conventional treatment and risk of
complications in patients with tipe 2 diabetes
(UKPDS 33)
The Lancet, 1998
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Metabolic control and retinopathy progression gt
2 levels in type 2 diabetes
UKPDS, 33 The Lancet, 1998
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The intensive treatment group had a substantial
25 reduction in the risk Of microvascular
endpoints
UKPDS, 33 The Lancet, 1998
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Hypertension Control and Diabetic Retinopathy
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EUCLID
EFFECT OF LISINOPRIL ON PROGRESSION OF
RETINOPATHY IN NORMOTENSIVE PEOPLE WITH
TYPE 1 DIABETES.
Two year randomised double-blind
placebo-controlled trial with lisinopril in
normotensive ( lt155/90 mmHg ) type 1 diabetic
patients.
Lancet, 1998
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Lisinopril halves the progression of retinopathy
in IDDM over 2 yrs period (plt0.02) Progression
to proliferative retinopathy is significantly
reduced (plt0.03) Incidence of new retinopathy is
reduced by 30 (n.s.)
The effect of Lisinopril on retinopathy in people
with IDDM (EUCLID)
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Tight blood pressure control and risk of
macrovascular and microvascular complications in
type 2 diabetes
UKPDS Br Med J 1998
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Blood Pressure Tight
Less Tight Control
vs
cohort, median values
Less tight control 154/87
Tight control 144/82
UKPDS Br Med J 1998
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Cumulative event rate ()
Proportion of two step progressionof DR at
various intervals in UKPDS vs hypertension
controls (Risk reduction 34)
UKPDS Br Med J 1998
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UKPDS Br Med J 1998
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Similar proportion of patiens in the two groups
showed deterioration in retinopathy by two
grades after nine years. CAPTOPRIL 31 ATENOL
OL 37
UKPDS 39 Br Med J 1998
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EFFECTS OF AGGRESSIVE BLOOD PRESSURE CONTROL IN
NORMOTENSIVE TYPE 2 DIABETIC PATIENTS ON
ALBUMINURIA, RETINOPATHY AND STROKES. ABCD The
Appropriate Blood Pressure Control in Diabetes
Robert W. Schrier et al.
Kidney International 2002
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ABCD TRIAL PROGRESSION OF DR (? 2 STEPS)
BP 128/75
BP 137/81
follow up INTENSIVE MODERATE 2
yrs 13 21 plt0,05 5 yrs 34 46 plt0,02 Enalap
ril 38 Nisoldipine 30
pn.s.
INCIDENCE 39 42
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SERUM LIPIDS AND DIABETIC RETINOPATHY
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• Cusik et al Ophth 2003
• The regression of hard exudates is most
  likely due to agressive lipid lowering
• Klein et al Ophth 2002
• Plasma lipids are associated with the
  presence of hard exudate
• Klein et al Brit J Oph 2002
• Association of elevated plasma LDL
  cholesterol with diabetic retinopathy
• Kaushik et al Diab Res 2001
• Simvastatin retards progression of
  retinopathy in diabetic patients with
  hypercholesterolemia

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• THE RESULTS OF THESE STUDIES HIGHLIGHT
  BENEFITS OF LIPID-LOWERING THERAPY IN DIABETIC
  RETINOPATHY
• BUT
• THEY NEED FURTHER DATA BY INCORPORATING LARGER
  NUMBER OF PATIENTS AND BY INCREASING THE DURATION
  OF EACH TRIAL

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Fundus examination

• Direct ophthalmoscopy
• Indirect ophthalmoscopy
• Biomicroscopy
• Fundus photography
• Fluorescein Angiography

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Fluorescein angiography is not needed to
diagnose CSME or PDR, both of which are diagnosed
by means of the clinical exam. However, it is an
extremely valuable test for selected patients
with DR, and is commonly used in the following
ways
American Academy of Ophthalmology, preferred
practice patterns, 1993
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• FLUORESCEIN ANGIOGRAPHY (FA) IS GENERALLY USED
  FOR TREATMENT PLANNING.
• THE MAJOR ADVANTAGE OF FA OVER FUNDUS
  PHOTOGRAPHY IS ITS ABILITY TO DETECT MACULAR
  ISCHEMIA DENOTED BY NONPERFUSION OF THE RETINAL
  CAPILLARIES AND TO DETECT SUBTLE DME AS EVIDENCED
  BY FLUORESCEIN LEAKAGE FROM THE CAPILLARIES.

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DIABETIC RETINOPATHY LESIONS

• Microaneurysm
• Hemorrhages
• Hard exudates
• cotton wool spot
• IRMA
• Venous abnormalities
• New vessels
• papillary and/or elsewhere
• Vitreous/Preretinal hemorrhages

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The ETDRS severity scale has been widely applied
in research settings, publications, and in
meetings of retina subspecialty groups, and it
has shown satisfactory reproducibility and
validity.Although it is recognized as the gold
standard for grading the severity of diabetic
retinopathy in clinical trials, its use in
everyday clinical practice has not proven to be
easy or practical.
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INTERNATIONAL CLINICAL DIABETIC RETINOPATHY
DISEASE SEVERITY SCALE
Ophthalmology 2003
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(No Transcript)
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INTERNATIONAL CLINICAL DIABETIC MACULAR EDEMA
DISEASE SEVERITY SCALE
Ophthalmology 2003
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(No Transcript)
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If diabetic macular edema is present, it can be
categorized as follows
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Advanced Diabetic Eye Disease
Tractional retinal detachment Rubeosis
iridis Neovascular glaucoma
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THE NEED TO SCREEN FOR DIABETIC RETINOPATHY IS
UNCONTROVERSIAL.

• Detection of sight threatening retinopathy and
  treatment by laser therapy has been shown to be
  effective in preventing the onset of visual
  impairment.
• Data from epidemiologic studies strongly support
  the implementation of intensive therapy to
  normalize blood glucose, blood pressure and lipid
  levels resulting in an even greater reduction in
  the risk of diabetic retinopathy and laser
  treatment.