Slides current until 2008 Diabetic retinopathy. Curriculum Module III-7a – Diabetic retinopathy Slide 2 of 39 Slides current until 2008 Diabetic eye disease

Slides current until 2008

Diabetic retinopathy

Diabetic retinopathyCurriculum Module III-7a – Diabetic retinopathy

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Diabetic eye disease

• Diabetic retinopathy

• Diabetic cataract:– early senile– true diabetic (Snowflake)

• Recurrent iritis


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• A silent complication with no initial symptoms

• When symptoms occur, treatment is more complicated and often impossible

• Screening for retinopathy is of the utmost importance


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When to screen for retinopathy

• Type 1 diabetes: within 5 years of diagnosis

• Type 2 diabetes: at time of diagnosis

Thereafter, every 1 to 2 years, depending on the status of the retina


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Diabetic eye disease

• Blurred vision: common symptom of hyperglycaemia

• Epidemiology:– any retinopathy: 21-36%– vision-threatening retinopathy:

6-13%


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Risk factors

• Poor glycaemic control

• Long duration

• Hypertension

• Dyslipidemia

• Nephropathy

• Pregnancy


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Intensive therapy

DCCT – type 1 diabetes:

• Primary prevention cohort: reduced risk of developing retinopathy by 76%

• Secondary intervention cohort: reduced risk of progression of retinopathy by 54%

DCCT 1993


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Intensive therapy

UKPDS – type 2 diabetes:

• Good glycaemic control: reduced progression of retinopathy by 20-30%

• Tight blood pressure control: reduced progression of retinopathy by 34%

UKPDS 1998


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Screening tests

• Visual acuity

• Direct fundoscopy (through dilated pupils)

• Indirect fundoscopy

• Retinal photography

• Testing intra-ocular pressure


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• Non-proliferative diabetic retinopathy: minimal, mild, moderate, severe

• Proliferative Diabetic Retinopathy (PDR): high-risk PDR, advanced PDR

• Macular oedema, clinically significant macular oedema


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Normal retina

Macula

Optic disc


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Non-proliferative diabetic retinopathy

Hard exudates


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Severe non-proliferative retinopathy

Haemorrhage

Cotton wool spot


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Classifications

• Proliferative retinopathy: new vessels


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Proliferative retinopathy

New vessels

Pre-retinal haemorrhage


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Advanced proliferative retinopathy

Scar tissue


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Vitreous haemorrhage

• See a black mark across the vision

• Some blood will be reabsorbed

• Vitrectomy may be necessary


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Early macular oedema


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Investigations

• Fluorescein angiogram: provides more detailed information


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Fluorescein leakage

Dot haemorrhage

Blot haemorrhage


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Fluorescein leakage


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Clinical trials

DRS Diabetic Retinopathy

ETDRS Early Treatment Diabetic Retinopathy Study

WESDR Wisconsin Epidemiology Study of Diabetic Retinopathy


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Treatment

• Laser therapy:– Pan-retinal for proliferative

retinopathy– Focal or grid for macular

oedema


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Pan-bombing for proliferative retinopathy


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Pan-retinal laser bombing


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Grid laser for macular oedema


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Laser therapy

Side effects

• Loss of peripheral vision, tunnel vision, night blindness

• Colour blindness

• Vision can get worse but “laser saves sight” in long term


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Treatment

• Blood pressure: reduces macular oedema

• Blood glucose control: slows progression

• Control lipids

• Use of aspirin


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Pregnancy

• Pregnancy can cause transient deterioration of diabetic retinopathy but generally not permanent damage

• Baseline retinal assessment should be performed before pregnancy

• Retinopathy is not a problem in gestational diabetes


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In the older person

• Presence of cataract makes visualisation of fundi more difficult

• Cataract surgery may cause macular oedema

• NPDR with macular oedema is the main cause of visual loss


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Summary

• 100% of people with diabetes will develop some retinopathy

• The higher the blood glucose level the greater the risk

• Different grades of retinopathy• Laser therapy saves sight• Timely treatment is most effective• Regular screening is a must


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Review question

1. What is the defining characteristic of proliferative retinopathy?

a. Numerous microaneurysmsb. Large amount of exudatesc. Destruction of retinal capillariesd. Formation of new blood vessels


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Review question

2. A young woman with type 1 diabetes has been told by an eye specialist that she has microaneurysms in her eyes. Which of the following would be an appropriate answer to her concerns about losing her vision?

a. Microaneurysms in the eye can suddenly bleed causing temporary or permanent loss of vision

b. You will soon require laser therapy that may prevent the number of microaneurysms from increasing and delay vision loss

c. You may not experience vision loss but the condition could gradually worsen

d. Microaneurysms are of no significance and are often found in people who do not have diabetes


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Review question

3. Which of the following activities would probably be ill-advised in a person with type 1 diabetes and severe proliferative retinopathy?

a. Walking on a treadmillb. Jogging on the spotc. Riding a stationary bicycled. Swimming


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Review question

4. Which of the following changes is most likely to increase the severity of existing mild non-proliferative retinopathy?

a. Pregnancyb. Weight gainc. Weight lossd. Increased exercise


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Review question

5. A woman with type 1 diabetes has been diagnosed with mild non-proliferative retinopathy. What information should she receive regarding laser therapy?

a. Laser therapy is not often used in type 1 diabetes

b. Laser therapy is not considered necessary at your early stage of retinopathy

c. The eye specialist may choose to delay laser therapy until there is visual impairment

d. There are new therapies available for retinopathy that your eye specialist may be planning to use


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Answers

1. d

2. c

3. b

4. a

5. b


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References

1. DCCT Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complication in insulin-dependent diabetes mellitus. N Engl J Med 1993; 329: 977-86.

2. UK prospective Diabetes Study Group. Tight blood pressure control and risk of macrovascular and microvascular complications in type 2 diabetes. UKPDS 38. BMJ 1998; 317: 708-13.

3. Effect of intensive diabetes treatment on development and progression of complications in adolescents with insulin dependent diabetes mellitus: DCCT. Journal of Pediatrics 1994; 125: 177-88.

4. Klein R, Klein B, Moss SE, Linton KL. The Beaver Dam Eye Study in adults with newly discovered and previously diagnosed diabetes mellitus. Ophthalmology 1992; 99(1): 58-62.

5. Nathan DM. The pathophysiology of diabetic complications: how much does the glucose hypothesis explain? Ann Intern Med 1996; 124(1Pt2): 86-9.

6. Ohkubo Y, Kishikawa H, Araki E, Miyata T, Isami S, Motoyoshi S, Kojima Y, Furuyoshi N, Shichiri M. Intensive insulin therapy prevents the progression of diabetic microvascular complications in Japanese patients with non-insulin diabetes mellitus. A randomised prospective 6 year study. Diabetes Res Clin Pract 1995; 28: 103-17.


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References

7. Mitchell P. Development and progression of diabetic eye disease in Newcastle 1977 to 1984: rates and risk factors. Aust NZ J Ophthalmol 1985; 13: 39-44.

8. The Diabetic Retinopathy Study Research Group. Preliminary report on the effects of photocoagulation therapy. Am J Ophthalmol 1976; 81(4): 383-96.

9. The Diabetic Retinopathy Study Research Group. Photocoagulation treatment of proliferative diabetic retinopathy. Clinical application of Diabetic Retinopathy Study (DRS) findings, DRS Report Number 8. Ophthalmology 1981; 88(7): 583-600.

10. Klein R, Klein BEK, Moss SE, Davis MD, et al. The Wisconsin Epidemiologic study of diabetes retinoapthy III. Prevalence and risk of diabetic retinopathy when age at diagnosis more than 30 years. Arch Ophthalmol 1984; 182: 527-32.

11. UK Prospective Diabetes Study Group. Tight blood pressure control and risk of macro and microvascular complications in type 2 diabetes. UKPDS 38. BMJ 1998; 317: 703-13.

Documents

Slides current until 2008 Diabetic retinopathy. Curriculum Module III-7a – Diabetic retinopathy Slide 2 of 39 Slides current until 2008 Diabetic eye disease