Purchase this article with an account.
E. d. Costa, E. B. Rodrigues, E. Dib, F. M. Penha, B. A. Furlani, O. Magalhaes, Jr., M. Maia, C. H. Meyer, A. de Miranda, M. E. Farah; Vital Dyes and Light Sources for Chromovitrectomy: Comparative Assessment of Osmolarity, Ph, and Spectrophotometry. Invest. Ophthalmol. Vis. Sci. 2008;49(13):5598. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate in-vitro the pH, osmolarity, spectrophotometry, and photostability proprieties of nine vital dyes for vitreoretinal surgery.
Detailed evaluation of the pH and osmolarity of nine vital dyes was performed: indocyanine green (ICG), trypan blue (TB), brilliant blue (BriB), bromophenol blue (BroB), congo red (CR), light green (LG), fast green (FG), indigo carmine (IC), evans blue (EB) for chromovitrectomy diluted in four solvents (BSS, glucose 5%, water, and viscoelastic). Spectrophotometry was utilized to examine the absorbance of nine novel dyes in three different solutions (BSS, glucose 5% and water). The absorbance was matched with irradiance emission of seven endoillumination light sources and fiberoptics: Alcon Xenon, Alcon Accurus H3, Grieshaber GLS, B&L Millenium, DORC Metal Halide, Synergetics Photon, and Synergetics Photon 2. Photostability measurements were obtained; thereafter pH, osmolarity, and spectrophotometry were reassessed.
Osmolarity of the dyes in three solvents and the pH in four solvents ranged within the following values: FG 290-344 mOsm, pH 3.82-7.12; CR 291-385 mOsm, pH 6.74-9.85; LG 288-325 mOsm, pH 3.4-6.92; EB 291-345 mOsm, pH 4.7-9.32; ICG 288-338 mOsm, pH 3.88-7.48; TB 287-332 mOsm, pH 4.12-8.37; IC 291-333 mOsm, pH 3.3-7.17; BroB 257-329 mOsm, pH 2.6-6.71; BriB 267-350 mOsm, pH 5.15-7.12. Osmolarity of all nine dyes decreased to very low value diluted in water ranging from 0 to 54 mOsm, while BSS and glucose promoted small but clinically relevant changes in osmolarity and pH. ICG, LG, TB, BroB, CR, and IC demonstrated different absorbance according to the solvent, while BriB or FG showed similar absorbance curves when diluted in glucose, BSS, or water. Spectrophometry analysis revealed that most vital dyes except ICG have remarkable overlap with every available vitrectomy light source at absorbance from 550nm to 680nm. Overlap of irradiance of endoillumination fiberoptics and absorbance of vital dyes was greater in Grieshaber GLS and Alcon Accurus H3. Photon 2 had the lower overlap area among all light sources.
Vital dyes possess much variable properties in osmolarity and pH depending on solvents. Intra-operative light exposure should be minimized since overlap between the absorbance curves of vital dyes and endoillumination fiberoptics could promote retina toxicity.
This PDF is available to Subscribers Only