Abstract
Purpose: :
Energy transmission of the transscleral cyclophotocoagulation (TSCPC) G-probe is maintained after repeated use, however such use can lead to contamination. In this study we evaluated the mechanical stability and clinical efficacy of a disposable 250µ polyurethane and hydrogel glue laminate sterile cover for the G-probe.
Methods: :
Diode laser output with and without the G-probe cover both before and after TSCPC (18 shots at 2000 mW for 2000mS) on cadaver eyes was measured with a Nova 2 (Ophir Optronics Ltd., Jerusalem, Israel) laser output meter (5 shots at 2000 mW for 9000mS). Qualitative analyses of the laser aiming beam were made prior to each trial in the covered and uncovered state and photographs were taken. After each treatment the G-probe cover was examined for microperforations and the footplate for debris and/or damage. Twenty cycles were performed. Microbiology was taken on the cadaver eye and the probe footplate prior to and after the treatment cycles, microbial profiles were compared. Histological analysis post G-probe covered TSCPC was performed on a cadaver eye. Laser output data was analyzed with repeated measures ANOVA.
Results: :
Qualitatively, laser focus dispersion was minimized by the G-probe cover. The mean (95% CI) laser output was measured as 1.248 (1.198-1.299), 1.595 (1.511-1.680), 1.494 (1.372-1.616) for the uncovered, covered pre-TSCPC and covered post-TSCPC respectively. This difference was significant (F = 26.5, df = 1, p<0.001). No perforations in the G-probe cover were evident on any trial and no debris or damage was detected on the G-probe. Ciliary body pathology was consistent with previous reports of TSCPC in cadaver eyes. Microbial segregation of the cadaver eye and the G-probe footplate was maintained by the cover.
Conclusions: :
The G-probe cover is an effective and robust barrier to both patient and probe contamination with multiple use cycles. Although energy levels may be slightly higher in covered probes, histological differences were not evident and the clinical significance of this finding is likely limited.
Keywords: laser • ciliary body • bacterial disease