Pharmaceutics (May 2022)

Melatonin-Eluting Contact Lenses Effect on Tear Volume: In Vitro and In Vivo Experiments

  • María Serramito,
  • Ana F. Pereira-da-Mota,
  • Carlos Carpena-Torres,
  • Fernando Huete-Toral,
  • Carmen Alvarez-Lorenzo,
  • Gonzalo Carracedo

DOI
https://doi.org/10.3390/pharmaceutics14051019
Journal volume & issue
Vol. 14, no. 5
p. 1019

Abstract

Read online

(1) Background: The purpose of this study was to synthesize melatonin-eluting contact lenses (CLs) and evaluate both the ocular kinetics of the released melatonin and its effect on tear volume and intraocular pressure. (2) Methods: In vitro, melatonin-eluting CLs were synthesized by using non-functionalized (HEMA) and functionalized (HEMA/APMA) monomers. In vivo, a short-term prospective and randomized study was performed on 15 rabbits divided into two groups: 12 rabbits wearing functionalized CLs and 3 rabbits without CLs as a control. The melatonin levels in tears, aqueous humor, vitreous body and retina, tear volume, and intraocular pressure were measured for 8 h. (3) Results: In vitro, both monomers did not show differences in terms of melatonin loading and release (p ≥ 0.05). In vivo, the melatonin concentration was elevated in tears and aqueous humor after 2 and 4 h of wearing CLs, respectively (p p < 0.05). (4) Conclusions: The melatonin-eluting CLs released their content over the ocular surface for at least 2 h, which was associated with a secretagogue effect on tear volume. However, the increased amount of melatonin found in the aqueous humor had no effect on intraocular pressure.

Keywords