Douglas J. Rhee, MD

86A. ARTIFICIAL TEARS , VISCOELASTICS , AND LUBRICATING OINTMENTSNotes: 1. Viscosity of water is 0.7 centistokes 12. Centistokes (cs) × density = centipoits (cp)3. Centipoits·seconds = cps4. Boric acid is a balanced salt solution used to equalize osmolarityPreservatives Legend:N = None 1 = Purite 2 = EDTA 3 = Benzalkonium chloride 4 = Chlorobutanol5 = Polyquad 6 = Sorbic acid 7 = Sodium perborate 8 = Methyl propylparbens 9 = Polyhexamethylene biguanideN/A = Not availableLow ViscosityLow viscosity lubricants are useful in mildly symptomatic dry eyes; they have a low tendency to blur vision but typically do not lastvery long.Trade Name Viscosity Osmolarity PreservativePreservative FreeBion Tears 5–15 cps 2 /4.5 cs 1 270–330 NCellufresh 3.2 cp 3 270–340 NDry Therapy 0.7 cs 1 N/A NHypotears PF