Mechanism of action: Acetylcysteine is a mucolytic agent that acts by dissolving sulph-hydril bonds that are joining adjacent mucin molecules to form mucous plaques or strands. The eyedrops are not available commercially but can be easily prepared fresh.
The eyedrops not only dissolve mucous strands / plaques but it has a strong anti-inflammatory affect against ocular surface inflammation in a variety of conditions. Also, it has been found to promote corneal epithelium healing and prevent corneal stromal melting. Hence it can be used in a variety of ocular surface inflammatory conditions.
Indications: To dissolve mucous plaques in the following conditions:
- Filamentary Keratitis
- Chemical burns
- Non-healing corneal ulcer
- Necrotising Scleritis
Preparation of 0.5% eyedrops
Acetylcysteine is commercially available in sachets containing its powder that is water miscible (Mucolator 200 mg). Eyedrops are prepared by taking 75 mg in a bottle with 10 ml distilled water added to it. It is important that the pH of the preparation is kept alkaline and the osmolarity of the solution should be around 300 mosmoles/litre.
By this method, both these conditions are met with and the prepared drops are not only efficient, they do not cause stinging in the eyes and are well tolerated by the patients.
A concentration of 0.3% can also be prepared by dissolving 50mg powder into 10 mls of distilled water.