Treatment of diseases of the posterior segment of the eye such as choroidal neovascularization presents a major challenge in ophthalmology. The posterior segment of the eye, including the retina, macula, and optic nerve, is difficult to access due to the recessed location within the orbital cavity.
Current drug delivery techniques to access the posterior segment of the eye include intra-vitreal injections, peri-ocular injections (i.e., subconjunctival, subtenon, or juxtascleral), and intra-vitreal implants. Drug delivery by injection into the suprachoroidal space is another technique that has recently been proposed in the treatment of posterior segment disease. The suprachoroidal space provides a potential route of access from the anterior region of the eye to the posterior region.
The iScience Surgical Ophthalmic Microcannula, or iTrack (iScience Surgical Corporation, Menlo Park, CA) is designed to access ocular structures such as schlemm's canal, subretinal space, vitreous cavity, and the suprachoroidal space. The iTrack received 510(k) clearance from the U.S. Food and Drug Administration on June 22, 2004 as a flexible microcannual for atraumatic cannulation of spaces in the eye such as the anterior chamber and posterior segment, for infusion and aspiration of fluids during surgery, including saline and viscoelastics. The microcannula incorporates an optical fiber to allow transmission of light to the microcannula tip for surgical illumination and guidance.
There is inadequate evidence regarding the clinical utility of supracoroidal injection of pharmacologic agents for the treatment of any ophthalmologic condition. Clinical outcome studies published in the peer-reviewed medical literature are needed to determine the value of this drug delivery method in the management of patients with diseases of the posterior segment of the eye.