The Effects of Hyaluronate and Its Interaction With Ascorbate on Aqueous Humour Dynamics: A Clinical and Laboratory Study

Karditsas, Stilianos D (1993) The Effects of Hyaluronate and Its Interaction With Ascorbate on Aqueous Humour Dynamics: A Clinical and Laboratory Study. PhD thesis, University of Glasgow.

Abstract

Purpose. Healon (sodium hyaluronate 1%), a viscoelastic material widely used in ophthalmic surgery, may exacerbate the potentially harmful early intraocular pressure (10P) rise observed postoperatively in cataract surgery. The results of in vitro studies demonstrate that such 10P elevations may be due to obstruction of the aqueous humour outflow pathways. Therefore Healon- induced 1013 rises might be preventable if this biopolymer could be depolymerized into smaller molecules which could be easily cleared by the outflow pathways. Ascorbic acid (AA) depolymerizes hyaluronic acid in vitro in a concentration-dependent manner at concentrations of AA which are normally present in the aqueous humour. In the early postoperative period, aqueous AA levels are probably decreased due to damaging effects of surgical trauma on the blood-aqueous barrier (BAB). Furthermore, recent reports suggest that Healon exacerbates the postsurgical BAB breakdown. Collectively, these results suggest that the BAB breakdown occurring during surgery may result in a drop in the concentrations of aqueous humour ascorbate to levels too low to effectively depolymerize Healon. This suggests that if physiological levels of ascorbate could be maintained the postoperative Healon-induced IOP rise would be attenuated. The purpose of this study was to investigate if Healon-induced 10P rises can be attenuated by increasing aqueous AA levels in the aqueous humour in the immediate postoperative period.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: W S Wilson
• Keywords: Medicine, Ophthalmology
• Date of Award: 1993
• Depositing User: Enlighten Team
• Unique ID: glathesis:1993-74581
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 27 Sep 2019 17:41
• Last Modified: 27 Sep 2019 17:41
• URI: https://theses.gla.ac.uk/id/eprint/74581