Table 3.

Ocular Routes of Administration

Type		Advantages	Limitations	Examples
Noninvasive	Topical (e.g. eye drops, contact lenses)	No physical disturbance to eye Easy administration	Reduced bioavailability Increased clearance	Latanoprost for glaucoma
	Systemic	No physical disturbance to eye Easy administration	Reduced bioavailability Off-target effects	Vitamin regimens for ocular diseases
Invasive	Subtenon	Can avoid complications from needle injections by using a cannula	Causes physical damage to eye structures Increase in ocular pressure	Steroid injection to treat chronic uveitis in the posterior segment
	Subconjunctival	Improved bioavailability over topical methods Good for anterior and posterior portions of the eye	Variable absorption Systemic absorption may occur	Antibiotic or corticosteroids to treat lesions in the anterior segment
	Ocular implants	Extended release of product Can be biodegradable	Nonbiodegradable implants must be surgically removed	Ozurdex (dexamethasone) to treat retinal vein occlusion
	Subretinal	Direct delivery to retinal cells	Requires trained surgeons	Luxturna
	Intravitreal	Less invasive than subretinal Easy surgery Widespread distribution	May have reduced transduction of retina and RPE Potential for particles or floaters	Anti-VEGF treatments for AMD
	Suprachoroidal	Does not require retrobulbar anesthesia in an operating room Better bioavailability than intravitreal	Requires trained surgeons Procedure-related complications Faster clearance	Xipere for macular edema secondary to posterior uveitis