1. OPHTHALMOLOGY DIABETES
MBChB 4
Prof P Roux
2012

2. 3. Background diabetic retinopathy
1. Adverse risk factors
2. Pathogenesis
3. Background diabetic retinopathy
4. Diabetic maculopathies
Focal
Diffuse
Ischaemic
5. Clinically significant macular oedema
6. Preproliferative diabetic retinopathy
7. Proliferative diabetic retinopathy

3. Adverse Risk Factors 1. Long duration of diabetes
2. Poor metabolic control
3. Pregnancy
4. Hypertension
5. Renal disease
6. Other
Obesity
Hyperlipidaemia
Smoking
Anaemia

4. Pathogenesis of diabetic retinopathy

5. Consequences of retinal ischaemia

6. Consequences of chronic leakage

7. Location of lesions in background
diabetic retinopathy

8. Signs of background diabetic retinopathy
Microaneurysms usually
temporal to fovea
Intraretinal dot and
blot haemorrhages
Hard exudates frequently
arranged in clumps or rings
Retinal oedema seen as
thickening on biomicroscopy

9. Focal diabetic maculopathy
Circumscribed retinal thickening
Focal leakage on FA
Focal photocoagulation
Associated complete or incomplete
circinate hard exudates
Good prognosis

10. Diffuse diabetic maculopathy
Diffuse retinal thickening
Generalized leakage on FA
Frequent cystoid macular oedema
Grid photocoagulation
Guarded prognosis
Variable impairment of visual acuity

11. Ischaemic diabetic maculopathy
Macula appears relatively normal
Capillary non-perfusion on FA
Poor visual acuity
Treatment not appropriate

12. Clinically significant macular oedema
Hard exudates
within 500 m
of centre of
fovea with adjacent
oedema which may
be outside 500 m
limit
Retinal oedema
within 500 m
of centre of fovea
Retinal oedema one disc area or larger any
part of which is within one disc diameter
(1500 m) of centre of fovea

13. Treatment of clinically significant
macular oedema
Grid treatment
Focal treatment
For diffuse retinal thickening located more
than 500 m from centre of fovea and
500 m from temporal margin of disc
For microaneurysms in centre of hard
exudate rings located m
from centre of fovea
Gentle whitening or darkening of
microaneurysm ( m, 0.10 sec)
Gentle burns ( m, 0.10 sec),
one burn width apart

14. Preproliferative diabetic retinopathy
Signs
Cotton-wool spots
Venous irregularities
Dark blot haemorrhages
Intraretinal microvascular
abnormalities (IRMA)
Treatment - not required but watch for proliferative disease

15. Proliferative diabetic retinopathy
Affects 5-10% of diabetics
IDD at increased risk (60% after 30 years)
Neovascularization
Flat or elevated
Severity determined by comparing with area of disc
Neovascularization of disc = NVD
Neovascularization elsewhere = NVE

16. Indications for treatment of proliferative
diabetic retinopathy
NVD > 1/3 disc in area
Less extensive NVD
+ haemorrhage
NVE > 1/2 disc in area
+ haemorrhage

17. Laser panretinal photocoagulation
Initial treatment is burns
Area covered by complete PRP
Spot size ( m) depends
on contact lens magnification
Follow-up 4 to 8 weeks
Gentle intensity burn ( sec)

18. Assessment after photocoagulation
Poor involution
Good involution
Persistent neovascularization
Regression of neovascularization
Haemorrhage
Residual ‘ghost’ vessels or
fibrous tissue
Re-treatment required
Disc pallor

19. Indications for vitreoretinal surgery
Severe persistent vitreous
haemorrhage
Dense, persistent premacular
haemorrhage
Progressive proliferation
despite laser therapy
Retinal detachment involving
macula