Methylcellulose,* which has been included as a vehicle in many ophthalmic preparations since 1945, is a water-soluble cellulose ether with a high degree of purity and uniformity. Solutions of methylcellulose have cohesive and emollient properties, considerable clarity, and a refractive index similar to that of the cornea. Such solutions are stable in a pH range which is tolerated by the eye and are unaffected by light or aging. When ophthalmic drugs contain methylcellulose, their activity is increased and their action prolonged.1,2
In 1945, Swan3 studied the effects of methylcellulose on the ocular tissues of rabbit eyes. There was no biomicroscopic or histologic evidence of injury. Animal experiments also failed to reveal any inflammatory reaction after subconjunctival injections. However, after intraocular injections, Swan found that 0.1 ml. of a 1.0% solution of methylcellulose produced a mild iridocyclitis.
The present paper is a report of further studies of methylcellulose in