Clinical features and Classification of Diabetic Retinopathy

1. Clinical features and Classification of Diabetic Retinopathy Dr. Dan Bwonya, Mengo Hospital

2. History of disease Type of DM Duration of Diabetes Control of Diabetes Endogenous / Exogenous insulin

3. Other systemic factors: • Hypertension • Nephropathy & proteinuria • Serum lipids • Puberty • Pregnancy

4. Social factors: Socio-economic status Smoking Alcohol Exercise

5. Ocular history: • Visual symptoms • History of glaucoma • Using any ocular medication • History any previous treatment • History of any previous surgery

6. Ocular examination: Best corrected visual acuity Ocular motility Slit lamp examination for Cataract/endophthalmitis Glaucoma Retina / photography

7. Vision assessment Loss of visual function is usually a late presentation of diabetic retinopathy Loss of vision in DR: • Diabetic macular edema • Vitreous hemorrhage • Tractional Retinal detachment • Neovascular glaucoma

8. Moderate visual loss • Drop of 3 or more lines of snellen equivalent • Drop of 15 or more letters on the ETDRS visual acuity charts

9. Severe visual loss • Loss of 6 or more lines of vision on the vision chart

10. Retina evaluation (slit lamp or fundus photography) Microaneurysms Dot and blot haemorrhages Hard ( intra-retinal ) exudates Cotton-wool spots Venous beading and loops Intraretinal microvascular abnormalities ( IRMA ) Neovascularization of the retina, optic disc or iris Fibrous tissue adherent to vitreous face of retina Retinal detachment Vitreous haemorrhage Pre retinal haemorrhage

11. Microaneurysm Small deep red dots (out pouches) of damaged /week capillary wall • Seen as red, round intra retinal lesions • Black dots on red free (green) examination • May surround CWS / circinate ring of HE • Fundoscopy visible when larger than 30 microns • Upper limit – 125 microns • Seen more on FFA than clinically

12. Haemorrhages Intraretinal bleeding, dot, blot or flame shaped • Shape depends on the location within retinal layer • Dot & blot hges. – Between outer plexiform and inner nuclear layer • Flame shaped hges. – Superficial nerve fibre layer

13. Hard exudates • Collection of lipids adjacent to microvascular leakage • Appear as creamy yellow plaques, flecks or dots • Arranged in individual streaks, clusters or circinate pattern • Affinity for posterior pole

14. Soft exudates Greyish white fluffy patches of discolouration in nerve fibre • Cotton wool spots • Small infarcts of the nerve fibre layers • Appear as fluffy white or yellow white spots, marked by striations of the nerve fibre layer

15. Vascular changes • Venous changes – generalized dilatation, beading, looping, sausage like segmentation • Arterioles may be narrowed

16. IRMA • Intra retinal microvascular abnormalities • Seen adjacent to areas of capillary closure • Focal areas of flat neovascularization • Intra retinal in location • Absence of leakage on FFA • Do not cross major retinal blood vessel

17. Neovascularization • NVD– Fine loops of vessels lying on the surface of disc or bridging across the cup • NVE – wheel like network of vessels radiating like spokes from the central and circumferential vessel bounding the periphery • NVE complexes are usually irregular in shape without a distinct margin

18. Hemorrhage • Sub internal limiting hge. • Sub hyaloid hge. • Intragel hge.

19. Classification Of DR & DME Aims of classification • Documentation of the disease • Plan of management • Monitor Progression of disease • Follow up of patient

20. Classification of DR 1.Hirschberg’s classification – first attempt 1890 2. Ballantye and Michaelson – the sequence of changes. 3. Michalaelson – pathological classification 4. Scott – variation in retinopathy features 5. Alaerts and Slosse – seperated progression of vascular and exudative lesions 6. Lee et al – lesions graded by severity 7. Duke – Elder’s 1960 – staging into simple and proliferative DR

21. 8. O’ Hare grading system – devised by a committee to devise a treatment plan 9. Hammersmith grading system – comparison with standard photographs 10. Vahex classification – purely ophthalmoscopic 11. Airlie House of classification 1968 – Basis of modern ETDRS classification Recent classifications: 12. Kanski’s classification 13. Modified ETDRS classification 1970 14. International clinical disease severity scale of DR 15. ICO classification

22. Kanski’s classifiation Popular & widely accepted classification Basically a treatment oriented ophthalmoscopic classification: • BDR • PPDR • PDR • Diabetic maculopathy

23. Diabetic maculopathy • Focal • Diffuse • Ischaemic • Mixed • CSME

24. BDR Microaneurysm Hemorrhages Hard exudates Retinal edema

25. PPDR • Vascular changes: venous beading, looping or sausaging, arteriolar narrowing, sometimes obliteration • Dark blot hges – hemorrhagic retinal infarcts • Cotton wool spots • IRMA

26. PDR • Neovascularization - NVD - NVE • Vitreous detachment • Hemorrhage - SHH - VH

27. Focal maculopathy • Well circumscribed leaking areas, with complete / incomplete rings of hard exudates. • FFA shows focal leakage

28. Diffuse maculopathy • Generalized leakage with CME • More evident on FFA

29. Ischemic maculopathy • Relatively normal appearance of macula, FFA delineates the extent • Clinically presented as reduced vision • No direct correlation with severity of ischemia and vision loss • FAZ > 1000 microns suggestive of visual loss

30. Mixed maculopathy • Combination of diffuse macular edema and ischemia

31. CSME • Clinically significant macular edema • Clinical finding • FFA to delineate the extent of involvement • Indication for treatment

32. 1. Retinal edema that is one disc area (1500 microns) or larger any part of which is within one disc diameter of the centre of the fovea 2. Hard exudates within 500 microns of the fovea, if associated with adjacent retinal thickening (may be outside 500 microns of fovea) 3. Retinal edema within 500 microns of the centre of fovea

33. Modified ETDRS classification • NPDR • PDR

34. Mild NPDR • Atleast one microaneurysm • Not as severe as moderate

35. Moderate NPDR • Extensive micro aneurysm • & / or cotton wool spots, venous beading, IRMA (not as severe as severe type)

36. Severe NPDR 4 – 2 – 1 rule: Presence of any one of the following: • Intra retinal hges. in all 4 quadrants • Venous beading in 2 quadrants • Severe IRMA in one quadrant

37. Very severe NPDR • Any two or more characteristics of severe NPDR

38. Cotton wool spots less helpful in predicting progression Presence suggest that a careful search for features predicting progression to PDR Features suggestive of risk to progression of PDR: • IRMA • Multiple retinal hges. • Venous beading & looping • Widespread capillary non perfusion • Widespread leakage on FFA

39. Early PDR One of the following: • NVE < 1/2 DD • NVD < 1/2 DD • NVE < 1/3 with VH / preretinal hge.

40. High risk PDR One of the following: • NVD > 1/3 DD • NVD with VH / pre retinal hge. • NVE > 1/2 DD with VH / pre retinal hge.

41. High risk PDR Any 3 combination: • Presence of VH or pre retinal hge. • Presence of new vessels • Location of new vessels on / near the disc • Moderate to severe extent of new vessels

42. Advanced PDR • High risk characteristics with TRD involving macula • VH obscuring view of retina

43. ICO classification of DR This classification links each stage of disease to clinical management Non sight threatening disease No apparent DR: No detectable DR on ophthalmoscopy Mild NPDR: Microaneurysm only Moderate NPDR: Microaneurysm, with dot, blot Hges, Hard exudates & CWS Severe NPDR:Any of the following: • More than 20 intraretinal hges. In each of the four quadrants • Venous beading in 2 quadrants • IRMA in one quadrant • No evidence of PDR Mild NPDR Moderate NPDR Severe NPDR

44. Sight threaning disease PDR: Clinical signs: Severe NPDR and One or more of the following: • Neovascularization. • Vitreous / preretinal hge. • Previous laser treatment • Low risk if NVE, flat new vessels not at disk • High risk NV, at disk

45. Diabetic macular edema • Retinal thickening of the macula and Hard exudates are signs of current or previous DME • Non-Central involved DME l : • Retinal thickening in the macula that does not involve the central subfield zone of 1mm diameter • Central-involved DME: • Retinal thickening in the macula that does involve the central subfield zone of 1mm diameter • Moderate DME:Retinal thickening or hard exudates approaching the center of the macula but not involving the center • Severe DME:Retinal thickening or hard exudates involving the center of the macula mild moderate severe

46. Complications of PDR Persistent intragel VH Tractional RD Opaque membranes Burnt out / involutional stage Rubeosis Iridis / neovascular glaucoma

47. Diabetic papillopathy • Usually bilateral (80%) • Good prognosis for central vsion • Characterized by transient hyperemic disc edema without neovascularization • Not related to diabetic retinopathy • Usually self limiting, resolves in 2 - 10 months • Complcations: Mild optic atrophy AION

48. Featureless retinopathy • Silent DR • Clinically no / minimal evidence of previous retinopathy • Stage between BDR & PPDR • More evident with hypertensive features • FFA confirms the actual status of retinopathy

49. Thanks