Posterior Drug Delivery Via Periocular route: Challenges and Opportunities

Abstract

Drug delivery to the posterior segment via the periocular route is a promising route for delivery of a range of formulations. In this review, we have highlighted the challenges and opportunities of posterior segment drug delivery via the periocular route. Consequently, we have discussed different types of periocular routes, physiological barriers that limit effective drug delivery, practical challenges regarding patient compliance and acceptability and recent advances in developing innovative strategies to enhance periocular drug delivery. We conclude with a perspective on how we envisage the importance of understanding complex barrier functions so as to continue to develop innovative drug-delivery systems.

Ophthalmic Drug Delivery Using Iontophoresis: Recent Clinical Applications

“…1 Alternate local delivery methods, including intravitreal and periocular injections, can be effective for delivery to posterior ocular tissues. 8,9 Direct injection of drug into the vitreous humor through the pars-plana achieves high drug concentrations in the vitreous and the retina with fewer systemic side effects than systemic administration. 8 However, the benefit of intravitreal injections is often limited by a short drug half-life, thus requiring frequent injections, which may lead to complications such as retinal detachment, retinal hemorrhage, endophthalmitis, cataract formation, and secondary glaucoma.…”

“…8,9 Direct injection of drug into the vitreous humor through the pars-plana achieves high drug concentrations in the vitreous and the retina with fewer systemic side effects than systemic administration. 8 However, the benefit of intravitreal injections is often limited by a short drug half-life, thus requiring frequent injections, which may lead to complications such as retinal detachment, retinal hemorrhage, endophthalmitis, cataract formation, and secondary glaucoma. 3,8,9 Periocular (peribulbar, posterior juxtascleral, retrobulbar, sub-Tenon, and subconjunctival) injection can also deliver significant drug levels to the anterior and posterior segments, 8 is less invasive than intravitreal injections, and carries less risk of endophthalmitis, retinal detachment, and increased ocular pressure than intravitreal injection.…”

“…8 However, the benefit of intravitreal injections is often limited by a short drug half-life, thus requiring frequent injections, which may lead to complications such as retinal detachment, retinal hemorrhage, endophthalmitis, cataract formation, and secondary glaucoma. 3,8,9 Periocular (peribulbar, posterior juxtascleral, retrobulbar, sub-Tenon, and subconjunctival) injection can also deliver significant drug levels to the anterior and posterior segments, 8 is less invasive than intravitreal injections, and carries less risk of endophthalmitis, retinal detachment, and increased ocular pressure than intravitreal injection. 3,8 However, complications with periocular injection can include periorbital hemorrhage and globe perforation, orbital fat prolapse with trans-septal installation, and blepharoptosis with superotemporal sub-Tenon injection.…”

“…3,8,9 Periocular (peribulbar, posterior juxtascleral, retrobulbar, sub-Tenon, and subconjunctival) injection can also deliver significant drug levels to the anterior and posterior segments, 8 is less invasive than intravitreal injections, and carries less risk of endophthalmitis, retinal detachment, and increased ocular pressure than intravitreal injection. 3,8 However, complications with periocular injection can include periorbital hemorrhage and globe perforation, orbital fat prolapse with trans-septal installation, and blepharoptosis with superotemporal sub-Tenon injection. 9 Novel delivery systems continue to be investigated with the aim of developing new safe and effective ways of improving drug delivery to the eye.…”

Principles of pharmacology in the eye

“…All measurements for quality of life, such as disability‐adjusted life‐years, confirm that visual impairment is a highly ranked burden in all countries (Chiang et al, ). The leading causes of visual impairment and irreversible blindness are posterior segment‐related diseases (Pascolini and Mariotti, ), which include glaucoma, age‐related macular degeneration (AMD), macular oedema secondary to retinal vein occlusion (RVO), cytomegalovirus (CMV) retinitis, posterior uveitis, diabetic retinopathy (DR) and retinitis pigmentosa (RP) (Thrimawithana et al, ; del Amo et al, ; Waite et al, ).…”