CAKE and PIE magazines’ Daily Congress News on the Anterior and Posterior Segments
Other new delivery systems on the block include the encapsulated cell technology (ECT) where cells genetically have been modified to produce a desired agent that are encapsulated in a semi-permeable hollow fiber membrane. It is retrievable when implanted in the vitreous. Another interesting drug delivery system is the Ophthalmic MicroPump™ (Replenish, Pasadena, California, USA) that delivers continuous drugs to the anterior and posterior segments, among other innovations. Dr. Mieler’s presentation’s co-author, Dr. Jennifer Kang-Mieler of the Illinois Institute of Technology in Chicago (USA) has invented the microspherethermo-responsive hydrogel drug delivery system (U.S. patents pending) which uses a biodegradeable thermo-responsive hydrogel in the in-vitro release.
Innovations in Retinal Pharmacology by Joanna Lee
Retinal pharmacology has come a long way ever since anti-VEGF drugs came onto the scene 15 years ago. Today, new delivery methods are being developed as the quest for more effective medicine continues.
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“nuanced approach” to assessing fluid is important,” Dr. Srinivas Sadda of the Doheny Eye Institute in Los Angeles, California (USA) said during his presentation on fluid management in neovascular age-related macular degeneration (nAMD) at the 37th World Ophthalmology Congres (WOC2020 Virtual®).
Review of literature Clinical trial data over the decades have shown that uncontrolled exudation in nAMD is bad for vision. He cited previously published studies like CATT1, IVAN2 and PIER3, among others, which demonstrated how intraretinal fluid, subretinal fluid and sub-RPE fluid, their absence or presence thereof, in exudative-based treatment approach influenced the visual outcome. For instance, the PIER study indicated that patients who had no residual fluid tend to have better visual outcomes compared to those who had fluid. However, the HARBOR study, of which Dr. Sadda
is a part of, showed that eyes with residual sub-retinal fluid only at 12 and 24 months experienced the greatest baseline characteristic visual acuity (BCVA) improvement. This led to his hypothesis that perhaps some residual SRF may be tolerated in the short-term. However, controlling exudation, in Dr. Srinivas’ estimation is still the key to achieving optimal visual outcomes in nAMD patients.
Drug delivery devices Providing an overview of retinal pharmacology, Dr. William Mieler of the The University of Illinois College of Medicine in Chicago (USA) noted that intravitreal injections (i.e. anti-VEGFs) and the use of sustained-release solid implant intravitreal devices are currently the most common methods used. However, the need for less invasive, safer and more effective drug delivery methods continues to drive innovation. Latest developments include microneedles, a micrometer-sized needle and injector which can deliver drug into suprachoroidal space (SC). There’s also the microcannula with (or without) light illumination for SC drug delivery as well as a microcatheter with potentials for stem cell delivery and delivery of corticosteroid.
Molecules and substances of note In another exciting development, Kyoto University’s Dr. Hanako Ikeda’s team found that VCP (valocin containing protein) ATPase inhibitors known as KUS121, KUS187 is shown to reduce death [Editor’s Note: KUS stands for ‘Kyoto University Substance’, developed by Prof. Kakizuka at the university.] KUS, a small-molecule compound, showed neuroprotective effects on the ganglion cells/photoreceptors in animal models of ocular diseases. These compounds show promising new avenues for glaucoma or retinal degeneration treatment using neuroprotective agents. The research team tested it on a small sample of patients with central vein artery occlusion (CRAO) in humans. The results demonstrated that KUS could prevent retinal ganglion cell (RGC) loss and improved visual acuity. Further tests after these two phases of study will be done in a larger scale in the future, Dr. Ikeda said. The chair of this session, Dr. Taiji Sakamoto from Kagoshima University in Japan, said: “So far, there’s been no drug to increase VA in CRAO so we’re looking forward to Phase 3 of this study.”
The role of imaging Further, Dr. Seung-Young Yu from Kyung Hee University in South Korea shared Cont. to Page 10 >>
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