Therapeutic implications of nanomedicine for ocular drug delivery

•Ocular nanomedicine with great clinical translational potential.•Nanomedicine can be used for treating anterior and posterior eye diseases.•The principles of nanomedicine for targeted and sustained ocular drug delivery.•The perspectives of ocular nanomedicine include scale-up manufacturing and safety profiles. Delivering therapeutics to the eye is challenging on multiple levels: rapid clearance of eyedrops from the ocular surface requires frequent instillation, which is difficult for patients; transport of drugs across the blood–retinal barrier when drugs are administered systemically, and the cornea when drugs are administered topically, is difficult to achieve; limited drug penetration to the back of the eye owing to the cornea, conjunctiva, sclera and vitreous barriers. Nanomedicine offers many advantages over conventional ophthalmic medications for effective ocular drug delivery because nanomedicine can increase the therapeutic index by overcoming ocular barriers, improving drug-release profiles and reducing potential drug toxicity. In this review, we highlight the therapeutic implications of nanomedicine for ocular drug delivery. Ocular nanomedicine poses a promising therapeutic potential and offers many advantages over conventional ophthalmic medications for effective ocular drug delivery; because nanomedicine can overcome ocular barriers, improve drug-release profiles and reduce potential drug toxicity.