Viscocanalostomy and combined phacoemulsification with viscocanalostomy: A five-year follow-up.

PURPOSE: To assess the effectiveness and safety of viscocanalostomy (VC) and phaco-viscocanalostomy (PV) surgeries in eyes with a five-year follow-up. METHODS: Retrospective review of patients who underwent VC and PV between January 2010 and December 2012 in the Stanley Eye Unit Abergele, UK. Patients were included for the analysis if they had a full 5-year follow-up or required redo surgery in the 5-year period. Success was defined as an intraocular pressure (IOP) of <21 mmHg. The subanalysis included IOP <16 mmHg, IOP reduction >20%, and IOP reduction >30%, the complication rate, and the drop in the use of glaucoma medications post-surgery. RESULTS: A total of 370 eyes from 303 patients were included for the analysis. The mean preoperative IOP was 23 mmHg ± 5.3 mmHg with an average of 3.0 ± 0.1 medications. By year 5, this was reduced to 14.3 mmHg ± 6.5 mmHg with a mean of 1.0+/- 0.9 medications; 47.8% of the eyes had an IOP of <21 mmHg by year 5 without medication with a total of 92.6% of the eyes reaching this target with medication. The main complication in this group was the perforation of the Trabeculo Descemet's Window (TDW) but this was not associated with a poorer outcome. CONCLUSION: This large data set of eyes undergoing VC surgery demonstrates the effectiveness and safety of this technique over 5 years.

1 year posterior corneal changes after Bowman Layer Transplant for keratoconus.

INTRODUCTION: To report the posterior corneal changes after Bowman Layer Transplant for keratoconus in a tertiary hospital in the UK. METHODS: 5 eyes of 5 patients receiving Bowman Layer Transplant for advanced keratoconus in Royal Gwent Hospital (Newport, UK) were included. Pre and postoperative posterior corneal astigmatism, posterior Kmean, and back surface elevation were analysed. RESULTS: No significant changes were seen in the posterior corneal astigmatism, posterior Kmean, or back surface elevation between the pre- and postoperative period. CONCLUSION: This results would support the idea that the corneal changes seen after Bowman Layer Transplant are mainly in the anterior corneal surface.

On-chip electrochemical microsystems for measurements of copper and conductivity in artificial seawater.

The fabrication and characterisation of microelectrochemical sensors for Cu(2+) and conductivity suitable for operation in the marine environment are presented. The impact of the designs on sensor performance and their adequacy to operate in real conditions are discussed. The sensors, tailored to voltammetric and impedimetric measurements, are fabricated on silicon using photolithographic and thin film deposition techniques. The impedimetric sensor is made of Pt interdigitated electrodes which are used for the measurement of conductivity. The voltammetric sensors are based on a three electrode electrochemical cell with on-chip Ag|AgCl reference and Pt counter and working electrodes, used for detection of copper by underpotential deposition-stripping voltammetry at microelectrode array. The sensors operated in the Cu(2+) concentrations ranging from 0.48 to 3.97 µM with a limit of detection of 0.115 µM. The impact of the temperature, the pH and the salinity of the artificial seawater on the sensitivity for Cu(2+) detection are also considered. Measurements of copper concentration and conductivity are validated using certified reference materials and standard solutions.

Serum-protein effects on the detection of the beta-blocker propranolol by ion-transfer voltammetry at a micro-ITIES array.

In this work, the effect of the serum protein, bovine serum albumin (BSA), on the detection of propranolol in artificial serum by ion-transfer voltammetry at an array of micro-interfaces between two immiscible electrolyte solutions (microITIES) is presented. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and differential pulse stripping voltammetry (DPSV) were examined for the detection of low concentrations of propranolol. Both CV and DPV had an interference effect from BSA, manifested as lower currents in the presence of the protein. DPSV proved to be the most effective technique, enabling the detection of 0.05 microM propranolol in the presence of BSA. The DPSV method employed a preconditioning step as well as a preconcentration step followed by the analytical signal generation step. The latter was based on the back-transfer of the drug across the microITIES. The preconcentration step was crucial to prevention of the adverse effects of BSA on the voltammetric detection. These results demonstrate that serum-protein effects on drug detection at low concentrations can be eliminated by use of DPSV at arrays of microITIES. CVs of propranolol with increasing concentrations of BSA revealed the influence of the drug-protein binding interaction, with decreases in current but no change in transfer potential. Therapeutic concentrations of propranolol were detected, demonstrating the viability of this approach for bioanalytical investigations.