I’m currently on Restasis for dry eye. Can sterile castor oil be used as well?

Castor oil has good lubricating products but it is not currently available for placement in the eye as an FDA-approved product. Gum cellulose has similar lubricating properties and can be purchased for use in dry eyes from certain compounding pharmacies (a specialized type of pharmacy that makes custom prescriptions). Restasis does have the ability to increase tear production, decrease swelling and irritation, and strengthen the tear layer. Neither castor oil nor gum cellulose shares these properties.