Recent progress in the use of thermogelling polymers for treatment of ophthalmic conditions

Ocular diseases have serious implications on patients' lives, with the majority causing blindness if left untreated. In 2020 it was estimated that 43 million people were blind worldwide which is expected to increase to 61 million by 2050. Due to the eye's complex structure and defence mechanisms, there has been an ongoing challenge to deliver drugs which can penetrate the eyes' barrier and reside at the site of action. Recent advances focus on the use of hydrogels, in particular temperature-responsive hydrogels, 'thermogels', to improve the properties of current therapies. Formulating a hydrogel-based system has shown to increase the bioavailability and biodegradability, provide a sustained release profile, enhance the drug permeation and residence time, as well as reduce the frequency of applications. This article provides a review of progress made over the past 5 years (2017-2021) using 'thermogels' for the treatment of some common or life-threatening ophthalmic conditions.