Disclosed herein is an ophthalmic formulation comprising a compound of formula (I) wherein R1 is a linear or branched C9-C33 alkyl or a linear or branched C9-C33 alkenyl with 1 to 4 double bonds; R2 is a linear or branched C9-C19 alkyl or a linear or branched C9-C19 alkenyl with 1 to 4 double bonds; and an ophthalmologically acceptable carrier.
