- Mannitol:
- 20%,
- given by intra-venous route;
- 1gm/kg–5ml/kg,
- Glycerol:
- 50%,
- given orally,
Mechanism Of Action :
Increase in plasma tonicity
↓
Increased formation of osmotic pressure gradient
↓
Blood draws sufficient water from vitreous
↓
Significant drop in IOP
Glycerol (ORAL)
- Dose : 5-3 ml /kg of 50% solution.
- It has intense sweet taste & is more palatable when given in iced unsweetened fruit juice or cola base to avoid vomiting/gastritis.
- Lowers IOP in 15-30 min, max effect in 60-120 min.
- Duration: 4-5 hours.
- It is metabolized to glucose – so not recommended for Diabetics.
Mannitol: (I.V.)
- 1-2 gm/kg of 20% solution i.e. 5-10 ml/kg.
- Lowers IOP in 15-30 min, max effect in 30-60 min.
- Duration: 6 hours
- Safer in diabetics but use cautiously in hypertensive patients.
SIDE EFFECTS:
- It increases blood volume – monitor B.P. continuously
- Renal failure is precipitated in kidney patients
INDICATIONS:
When acute fall in IOP is required : Acute Congestive Glaucoma
CONTRA-INDICATIONS :
- Acute tubular necrosis
- Anuria
- Pulmonary edema
- Acute LVF
- Cerebral hemorrhage
