- Twice daily 4% Sodium Cromoglycate vs. 2% Sodium Cromoglycate used four times daily in seasonal (grass pollen) allergic conjunctivitis. Collum, L.M., Fitzsimon, S., Hillery, M., Collum, A., Power, W.J., Pelikan, Z., Jenson, J.B. Documenta ophthalmologica. Advances in ophthalmology. (1992)