A method of cross-linking collagen present in a collagenous tissue comprising contacting the collagenous tissue with an amount of a formaldehyde releasing agent effective to crosslink the collagen is provided. A method of inhibiting loss of structural integrity of a collagenous tissue during transplantation-related transport comprising contacting the collagenous tissue with an amount of a formaldehyde releasing agent effective to inhibit loss of structural integrity of the collagenous tissue is also provided. A composition for ophthalmic administration comprising a formaldehyde releasing agent, sodium bicarbonate, and ophthalmically suitable carriers or excipients is also provided. Finally, a method of altering the refractive power of a cornea comprising contacting the cornea with a formaldehyde releasing agent so as to effect cross-linking in the cornea and thereby alter the refractive power of the cornea is provided.
