Abstract
Purpose: :
To evaluate the potential of Typan blue (TB) for intra-operative staining of the internal limiting membrane (ILM) and epiretinal membranes (ERM) with respect to perceivable contrast.
Methods: :
In a retrospective clinical case-series we analyzed 44 consecutive chromovitrectomy interventions in 44 patients with macular holes (MH), epiretinal fibrosis (ERF), vitreoretinal traction syndromes (VRTS) or persistent macular edema (PME). Of the 44 enrolled subjects, 15 underwent TB, 14 Indocyanine green (ICG) and 15 Brilliant blue G (BBG) chromovitrectomy. Main outcome measure was the color contrast between stained ILM or ERM and the underlying unstained tissue as it is perceived by the human eye. Perceived contrasts were determined in the CIE 1976 (L*, a*, b*) color space by means of objective, quantitative video-based semi-automated chromaticity difference measurements. This color space is conceptually uniform and changes of the same visual importance result in the same difference (Euclidean distance) in the color space.
Results: :
Euclidian distances produced by TB were significantly higher for ERM (7.67) than for the ILM (5.85, p=0.01793). Euclidian distances for the ILM were similar with the use of both TB (5.85) and BBG (6.11, p=0.7164) but significantly higher after the application of ICG (16.35, p=2.2e-16).
Conclusions: :
TB has an affinity to both the ILM and ERM, where it stains ERM significantly better than the ILM. TB staining capacity for the ILM is equivalent to that of Brilliant blue G (BBG), but significantly inferior to the contrast provided by Indocyanine green (ICG).
Keywords: vitreoretinal surgery