Researchers at CEU Cardenal Herrera University in Spain have demonstrated, for the first time, that topical administration of progesterone in the eye is viable to slow the degenerative process characteristic of retinitis pigmentosa (RP).1
Noting recent research into the role of hormones, particularly progesterone, in preventing cell death due to oxidative stress, CEU’s UCH Drug Delivery Systems (DDS) research group successfully developed and tested a range of methods of delivery of this hormone into the eye. The group showed that progesterone can be delivered in various forms, such as eyedrops, micelles and inserts, in sufficient quantity to penetrate the surface of the eye and reach the neuroretina without causing significant toxicity or irritation.
“The use of ocular inserts enables progesterone to be delivered in greater quantities than when aqueous solutions are used. Although we saw that aqueous solutions can also permeate the sclera and the cornea, inserts performed best in our tests, as they liberate progesterone for absorption by the neuroretina over a sustained period and in greater quantity,” reported Dr Adrian Alambiaga who detailed the findings in his doctoral thesis.
The group’s lead researcher, Professor Alicia López Castellano, said the research opens possible new therapeutic strategies for retinitis pigmentosa patients, and by extension for patients with other eye conditions in which oxidative stress is a risk factor, such as glaucoma, age-related macular degeneration, macular oedema due to retinal vein occlusion, cytomegalovirus retinitis, posterior uveitis, and diabetic retinopathy.
Alambiaga-Caravaca, A.M., et al. (2022) Topical Ocular Administration of Progesterone Decreases Photoreceptor Cell Death in Retinal Degeneration Slow (rds) Mice. Pharmaceuticals. doi.org/10.3390/ph15030328.