Diabetic retinopathy

1. Look specifically for dot, blot haemorrhages, hard exudates, cotonwool spots this tells you it is diabetic retinopathy. If no other features then this is background retinopathy.
2. Look at macula (‘look into the light’; temporal to disk) if this is involved then ‘diabetic maculopathy’
3. Look around disk – is there new vessel formation if so then ‘proliferative retinopathy’
4. Look for any haemorrhages, evidence of panretinal photocoagulation

Hypertensive retinopathy

1. Look for AV nipping – this is quite easy to see. I cannot see arteriolar narrowing. These features alone suggest grade I-II hypertensive retinopathy.
2. Look for flame haemorrhages, cotton wool spots if present then grade III hypertensive retinopathy.
3. If papilloedema then grade IV.

Old Choroidoretinitis

Patch of white / yellow with pigmented patches due to proliferation of retinal pigment epithelium.

Causes
Unknown (most cases)
Toxoplasma
Sarcoidosis
Toxocara

Retinitis pigmentosa

Causes

• Idiopathic
• Refsums
• Laurence-Moon-Biedl
• Mitochondrial e.g. Kearns-Sayre
• Abetalipoproteinaemia (disease of childhood; unlikely PACES)

Extensions

• Look for bilateral hearing aids – suggests Refsums / LMB / Abetalipoproteinaemia
• Look for polydactyly = LMB
• Check for finger nose ataxia – cerebellar signs in Refsums
• ‘Do any of your relatives have similar problem’ – multiple possible inheritance patterns. Also need to rule out consanguity.

Notes
Differential diagnosis: Panretinal photocoagulation, scars tend to be rounded with smooth edges compared to irregular scars in RP. Note that the signs of diabetic retinopathy can sometimes be not very obvious after panretinal photocoagulation. Very advanced angioid streaks e.g. in PXE can also look similar. If macula is involved in the pigmentation this makes panretinal photocoagulation highly unlikely – ophthalmologist will not laser retina!