FN: Diabetic retinopathy (the eye in DM) Flashcards
the problem
- DM is leading cause of blindness up to 60yrs
- 30% have occular problems @ presentation
- BP
Pathogenesis 2 disease processess name
Cataract
Retinopathy
Cataract in DM
DM accelerates cataract formation
Lens absorbs glucose which is converted to sorbitol by aldose reductase
Retinopathy
- Microangiography - occlusion
- Occlusion leads to ischaemia and new vessel formation in retina
- Occlusion also causes cotton wool spots (ischaemia)
- Vascular leakage leads to oedema and lipid exudates
- Rupture of microaneuryms causes blot haemorrhages
Complications of neovascularisation
Bleed - vitreous haemorrhage
Carry fibrous tissue with them and can lead to retinal detachment
Screening
- All diabetcs should be screened annually
- Fundus photography
- Refer those with maculopathy, NPDR and PDR to opthalmologist - 30% NPDR develop PDR in 1yr
Investigation
Flourescein angiography
Management
- Good BP and glycaemic control
- Rx concurrent disease: HTN, dyslipidaemia, renal disease, smoking, anaemia
- Laser photocoagulation
Laser photocoagulation
- Maculopathy: focal or grid
- Proliferative disease: pan-retinal (macula spared)
CN palsies
CNIII and VI palsies may occur
In diabetic CNIII palsy the pupil may be spared as its nerve fibres run peripherally and receive blood from pial vessels
Fundoscopy findings 4 types
- Background retinopathy: Leakage
- Pre-proliferative Retinopathy: Ischaemia
- Proliferative retinopathy
- MAculopathy
Background retinopathy: Leakage
- Dots: microaneury,s
- Blots haemorrhages
- Hard exudates: yellow lipid patches
Pre-proliferative Retinopathy: Ischaemia
Cotton wool spots (infarcts)
Venous bleeding
Dark haemorrhages
Intra-retinal microvascular abnormalities
Maculopathy
Caused by macular oedema
reduced acuity may be only sign
Hard exudates w/i one disc width of macula
Proliferative retinopathy
New vessels
Pre-retinal or vitreous haemorrhage
Retinal detachment
