Table 2.

A summary of using chitosan for ophthalmology.

Property of Chitosan	Action	Application	References
High molecular weight Concentration of polysaccharides Non-irritant nature	To stop the lachrymal flow, thicken the solution and interact with the mucus’ negative charges. Increase ocular tolerability and precorneal residency time duration	Ocular carrier for topical administration of required medicament.	[133]
High tolerance	Longer contact time with ointments and ease of administration with accuracy and repeatability of the dose Ocular in situ gels are an effective substitute for traditional eye drops that have drawbacks such as rapid and thorough removal from the eye, which results in significant medication loss.	Ocular wound repair and increased permeability	[134]
Encapsulation effectiveness and particle size shape of nanoparticles Non-irritating	Release with controlled diffusion Drug-loaded nanoparticles keep their drug’s original crystallinity since the drug and polymer don’t interact.	Ocular delivery	[69]
Characteristics of mucoadhesion Crosslinking is intense in chitosan nanoparticles. Biocompatible and biodegradable	Enhances the drugs’ bioavailability and helps them penetrate the eye. Enhancements in the delivery site’s chitosan nanoparticle absorption, accumulation, and clearance	Creation of a formulation for a continuous medication releaseTreatment for glaucoma, age-related macular degeneration, viral and bacterial infections, and diabetic retinopathy	[132]
Exceptional mucoadhesive properties	While precorneal residency is prolonged, precorneal clearance could be hindered. Enhance distribution to the posterior eye segment by increasing the chance of adherence to corneal and conjunctival surfaces.	Age-related macular degeneration (AMD) and diabetic retinopathy (DR),Posterior eye drug delivery	[64]
Mucoadhesive, muco-penetration, and controlled release properties	Lower intraocular pressure in glaucomatous rabbits	Topical ophthalmic controlled drug deliveryTreatment of glaucoma	[66]
Charge-based nature and mucoadhesive qualities	Keep the anti-inflammatory diclofenac release under control while preserving or enhancing the lens’s physical characteristics	Increase the ocular bioavailability of diclofenac sodium already available	[65]
Low toxicity and good ocular tolerance Bioadhesion- and permeability-enhancing properties	Extending and improving medication retention on the surface of the eye. Serve as transmucosal drug transporters, allowing either the buildup of medicines in the corneal or conjunctival epithelia or the transportation of pharmaceuticals to the inner eye.	Ocular drug delivery	[135]
Penetration Enhancement	Enhance the drug’s concentration and its duration in the body to improve the accuracy of instilled drop solutions and dosing consistency.	Ocular Delivery Formulations, ocular inflammation	[134]