Introduction and Background – Dry Eye is a multifactorial disease of the tear film and the ocular surface which may be due to reduced tear production or excessive tear evaporation resulting in discomfort, visual disturbance, and tear film instability with a potential damage to the ocular surface. Advantages of certain Excipients in an eye drop formulations of artificial tears are sometimes not fully appreciated. Glycerin is an excellent humectant and hygroscopic agent. It helps in maintaining moisture for a long time. Glycerin also acts as a lubricant because of its viscous nature. Glycerin at the concentration less than 1 % is devoid of its irritant potential. Balanced Electrolytes makes the solution isotonic and stable.

Objective – The purpose of this study was to compare the Efficacy of ophthalmic solution containing Sodium CMC 0.5% with Glycerin 0.9% and Balanced Electrolytes as excipient vs Plain Sodium CMC 0.5%.

Methodology – This was a two-arm, open label, parallel design study conducted in 52 subjects with the symptoms of dry eyes (irritation, light sensitivity, pain or blurred vision). Schirmer's test was conducted on the subjects giving informed consent. This gives the baseline value of moisture in both the eyes of the volunteer. One drop of the artificial tears containing Carboxy Methyl Cellulose (CMC) 0.5% eye drop with Glycerin 0.9% and Balanced Electrolytes as excipients was instilled in the right eye and one drop of the artificial tears containing plain CMC eye was instilled into the left eye. Schirmer's test was repeated on these subjects at 1 hour and 3 hour after instillation of the drops in each eye.

Results – The baseline Schirmer’s test reading in both the eyes was similar. On repeating the Schirmer’s test after instilling the artificial tear eye drops in both the eyes, mean reading was 19.42 mm in the right eye and 15.76 mm in the left eye, at the end of one hour. The mean Schirmer’s test reading was 19.38 mm in the right eye and 15.34 mm in the left eye, at the end of three hours.  At one and three hours, the difference was statistically significant (p<0.05) in both the eyes with the difference of 3.65mm i.e. 23 % and 4.03 i.e. 26 % respectively. Thus the eye which received Sodium CMC 0.5% with Glycerin 0.9% and Balanced Electrolytes was better lubricated than the eye which received Plain CMC.

Conclusion – In the present study, better and prolonged efficacy of Carboxy Methyl Cellulose with Glycerin and Balanced Electrolytes as excipients is demonstrated as compared to Plain Carboxy Methyl Cellulose in keeping the ocular surface moist.