Diabetic Retinopathy (DR)

Ayesha S Abdullah28.12.2012

Learning outcomes By the end of the lecture the students would

be able to;1. Describe the epidemiology of DR2. Correlate the pathogenesis of DR with the

clinical presentation 3. Identify signs of DR in a given fundus

photograph4. Identify the signs of proliferative DR and

high risk Non-proliferative DR on a given fundus photograph

5. Outline the management for DR

Diabetes Mellitus (DM) Metabolic syndrome characterized by

hyperglycaemia & insulin deficiency Type 1 and type 2 & Gestational Diabetes

Mellitus Type 2 is more common than type 1 A micro & macrovasculopathy

Epidemiology of DM and DR1. We are having a “global epidemic of DM”.2. The prevalence of DM is estimated to rise from 2.8%

(2000) to 4.4% (2030) 3. Most of this increase will occur as a result of a 150% rise

in developing countries. 4. The total number of people with diabetes is projected to

rise from 171 million in 2000 to 366 million in 2030. 5. The prevalence is estimated to be 10% in Pakistan6. With over 5.2 million people with DM , it is the 6th country

with the largest population of people with DM.7. With growing obesity, sedentary life style and increased

aging population, the prevalence is estimated to rise further.

Wild S, Roglic G, Green A, Sicree R, King H. Global Prevalence of Diabetes- Estimates for the year 2000 and projections for 2030. Diabetes Care 27:1047–1053, 2004

Diabetic retinopathy

Is a microvascular complication of DM The prevalence is highest among type 1

DM (40%) Patients with DR are 25% more likely to go

blind than non-diabetics In UK 1000 individuals are registered blind

each year due to diabetic eye disease It is the leading cause of blindness in 20-

64 year age group in USA

Pathogenesis of Diabetic Retinopathy

DR is a microangiopathy resulting in

Microvascular occlusion Microvascular leakage

Microvascular Occlusion

Factors responsible for occlusion 1. Thickening of capillary basement membrane2. Capillary endothelial cell damage and

proliferation 3. Changes in R.B.Cs 4. Increased stickiness and aggregation of

platelets

Neovascularization

Microvascular occlusion

Retinal capillary non-perfusion

Retinal ischaemia & Hypoxia, ischaemia of the nerve fibres- soft exudates

Arteriovenous shunts - IRMA(intra-retinal microvascualr abnormalities), venous changes, stagnation of blood and more hypoxia

Pathogenesis of Diabetic Retinopathy

Microvascular Leakage

Breakdown of inner blood-retinal barrier Retinal haemorrhages Retinal oedema

Diffuse edema Hard exudates

Microaneurysims

What is inner and outer blood-retinal

barrier?

Schematic of the retinal fundus illustrating the potential involvement of the components of the kallikrein–kinin system(KKS) found in the vitreous in diabetic retinopathy changes. Red lines indicate arteries and blue lines indicate veins. FXII, factor XII; FXIIa, factor XIIa; HK, high-molecular-weight kininogen; Kal, kallikrein; PK, prekallikrein; KKS, kallikrein–kinin system.

Classification of diabetic retinopathy

Non-proliferative (NPDR) Proliferative (PDR) Diabetic Maculopathy

Signs of DR

1. Microaneurysms (MA)2. Hard exudates (HE)3. Haemorrrhages (H)4. Retinal oedema- macular oedema(CSME)5. Cotton wool spots (CWS)6. Intra-retinal microvasuclar

abnormalities(IRMA)7. Venous changes8. Fibrovascualr proliferation –

Neovascularization

Microaneurysms & hard exudates

Haemorrhages and cotton wool spots

Neovasucalrization and fibrovasucalr proliferation

Diabetic macular oedema

Clinical presentation

Stages of DR

NPDR PDR

Stages of DR

Stages of DR1. Mild Nonproliferative Retinopathy Signs: MA & HE2. Moderate Nonproliferative Retinopathy Signs: Haemorrhages, microaneurysms, Soft exudates, IRMA3. Severe Nonproliferative Retinopathy.. Signs: Along with microaneurysms, haemorrhages, IRMA and

venous changes are also seen

4. Proliferative Retinopathy. Signs: NVE & NVD, vitreous haemorrhage, tractional RD

Management of DR

Indications PDR Clinically significant macular oedemaPrinciples & modes Metabolic control Control of risk factors Laser therapy- photocoagulation Anti-VEGF agents Vitreoretinal surgery

Recommended follow-up schedule

Normal or occasional MA Annually

Mild NPDR Every 09 monthsModerate NPDR Every 06 months Severe NPDR Every 04 months PDR Every 2-3 monthsCSME Every 2-4 months

Summary

Home workList the risk factors for DRHow does diabetic retinopathy

cause vision loss?msqheartline@hotmail.com