Recent advances in intraocular and novel drug delivery systems for the treatment of diabetic retinopathy

ABSTRACT

Introduction: Diabetic retinopathy (DR) is associated with damage to the retinal blood vessels that lead eventually to vision loss. The existing treatments of DR are invasive, expensive, and cumbersome. To overcome challenges associated with existing therapies, various intraocular sustained release and novel drug delivery systems (NDDS) have been explored.

Areas covered: The review discusses recently developed intraocular devices for sustained release of drugs as well as novel noninvasive drug delivery systems that have met a varying degree of success in local delivery of drugs to retinal circulation.

Expert opinion: The intraocular devices have got very good success in providing sustained release of drugs in patients. The development of NDDS and their application through the ocular route has certainly provided an edge to treat DR over existing therapies such as anti-VEGF administration but their success rate is quite low. Moreover, most of them have proved to be effective only in animal models. In addition, the extent of targeting the drug to the retina still remains variable and unpredictable. The toxicity aspect of the NDDS has generally been neglected. In order to have successful commercialization of nanotechnology-based innovations well-designed clinical research studies need to be conducted to evaluate their clinical superiority over that of the existing formulations.

KEYWORDS:

• Diabetic retinopathy
• intraocular devices
• novel drug delivery system
• vascular endothelial growth factor

Article Highlights

• Diabetic retinopathy is one of the complications among people suffering from DM

• Diabetic retinopathy occurs due to high blood glucose level, activation of chronic, low-grade inflammatory signals, and metabolic dysfunction

• Advent of intravitreal anti-VEGF agents has provided better management of DR but gained limited clinical success

• The available intravitreal injections are costly, painful and require skilled person for its administration

• Novel drug delivery systems (NDDS) have been successful in pre-clinical studies due to their non-invasiveness, cost effectiveness and ability to target the drug to retina through ocular route

• Clinical translation of these NDDS of drugs used for treatment of diabetic retinopathy is yet to materialize

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.