Intravital Staining of the Internal Limiting Membrane with a Novel Heavy Solution of Brilliant Blue G

Abstract

The aim of this study was to investigate the hydrodynamic properties and clinical efficacy of a novel heavier-than-water dye (BBG-D₂O) designed for staining of the internal limiting membrane (ILM) during vitreoretinal procedures, consisting of brilliant blue G (BBG, 0.25 mg/mL) with the addition of 13 % of deuterium oxide (D₂O). The gravity-related hydrodynamic distribution of BBG-D₂O was measured in 7 experiments using standard test cuvettes filled with balanced salt solution (BSS). BBG-D₂O was applied in 3 patients (2 × epiretinal membrane [ERM], 1 × vitreous traction and lamellar macular hole) for the staining of the ILM. Compared to standard solutions of BBG the heavy version of the dye (BBG-D₂O) presented a rapid flow towards the bottom of test cuvettes. After 15 seconds the concentration of BBG solutions in the lowest 25 % of the cuvette volumes was 4.2 ± 0.2 µg/mL (mean ± standard deviation) compared to 19.0 ± 2.6 µg/mL of BBG-D₂O (p < 0.0005). Clinically BBG-D₂O resulted in a strong staining effect of the ILM, comparable to conventional indocyanine green (ICG) solution and clearly more intensive than that of conventional BBG solution of the same concentration (0.25 mg/mL). The intensive staining effect of primary applied BBG-D₂O before epiretinal membrane removal allowed an en bloc peeling of ILM and ERM as a one-step procedure. No sign of any adverse effects related to the use of BBG-D₂O were observed. Heavy brilliant blue G (BBG-D₂O) provides a significantly improved staining effect of the ILM and by this makes ILM peeling more efficient, easier, faster and less traumatic.