1. Background diabetic retinopathy

Clinical signs

A. Microaneurisms (tiny, round, red dots)
B. Hard exudates (waxy, yellowish lesions with distinct margins)
C. Retinal oedema (retinal thickening seen with stereoscopic view)
D. Haemorrhages (dot-blot and flame-shaped)

Investigations

Fluorescein angiography

A. Hyperfluorescent dots (microaneurisms)
B. Diffuse hyperfluorescence (retinal capillary leakage)
C. Hypofluorescence (hard exudates, haemorrhages)

Management

A. Optimal control of diabetes
B. Annual follow up

2. Preproliferative diabetic retinopathy

Clinical signs

A. See clinical signs in background retinopathy
B. Cotton wool spots (whitish, fluffy lesions)
C. Venous beading and loops
D. Intraretinal microvascular abnormalities (IRMA) –shunts that run from arterioles to venules

Investigations

Fluorescein angiography
A. See background retinopathy
B. Hypofluorescence due to capillary non perfusion
C. Areas of hyperfluorescence (IRMA) adjacent to areas of capillary non perfusion

Management

C. Optimal control of diabetes
D. Control of blood pressure
E. 2-4 months follow up

3. Proliferative diabetic retinopathy

Clinical signs

A. See clinical signs in background and preproliferative retinopathy
B. Neovascularisation on or within one optic disc diameter
C. Neovascularisation elsewhere on the retina
D. Neovascularisation of the iris
E. Fibrovascular tissue along the posterior surface of the vitreous
F. Fibrovascular tissue extending into the vitreous and adherent to the retina
G. Traction retinal detachment
H. Vitreous haemorrhage

Investigations

Fluorescein angiography

A. See background and preprolifirative retinopathy
B. Highlights the neovascularisation
C. Hyperfluorescence due to leakage from neovascular tissue

Management

A. Laser treatment depends on localisation and the area covered new vessels
B. Surgical treatment of retinal detachment
C. Pars plana vitrectomy in vitreous haemorrhage
D. Follow up every 4 weeks

4. Diabetic maculopathy

A. May be present and include signs of any of the stages listed
B. Well-circumscribed or diffuse retinal thickening
C. Complete or incomplete rings of perifoveal hard exudates
D. Dark-blot haemorrhages

Investigations

Fluorescein angiography
A. Ischemic-capillary non-perfusion at the fovea
B. Diffuse exudative – late diffuse hypefluorescence due to leakage
C. Focal exudative – focal hyperfluorescence, good macular perfusion

Management

A. Laser treatment depends on severity of changes and presence of clinically significant macular oedema (CSMO)