Diabetic Retinopathy (DR) Ayesha S Abdullah

Learning outcomes By the end of the lecture the students would be able to; 1.Describe the epidemiology of DR 2.Correlate the pathogenesis of DR with the clinical presentation 3.Identify signs of DR in a given fundus photograph 4.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 DR 1.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 The prevalence is estimated to be 10% in Pakistan 6.With over 5.2 million people with DM, it is the 6 th 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 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 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 membrane 2. 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 changes 8. Fibrovascualr proliferation – Neovascularization

Microaneurysms & hard exudates

Haemorrhages and cotton wool spots

Neovasucalrization and fibrovasucalr proliferation

Diabetic macular oedema

Clinical presentation

Stages of DR NPDRPDR

Stages of DR

1. Mild Nonproliferative Retinopathy Signs: MA & HE 2. Moderate Nonproliferative Retinopathy Signs: Haemorrhages, microaneurysms, Soft exudates, IRMA 3. 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 oedema Principles & modes  Metabolic control  Control of risk factors  Laser therapy- photocoagulation  Anti-VEGF agents  Vitreoretinal surgery

Recommended follow-up schedule Normal or occasional MAAnnually Mild NPDREvery 09 months Moderate NPDREvery 06 months Severe NPDREvery 04 months PDREvery 2-3 months CSMEEvery 2-4 months

Summary Home work List the risk factors for DR How does diabetic retinopathy cause vision loss?