A new dye based on anthocyanins from the acai fruit (Euterpe oleracea) for chromovitrectomy in humans: clinical trial results.

PURPOSE: To test the applicability of the acai dye at a 25% concentration for identifying the posterior hyaloids and internal limiting membranes (ILMs) during pars plana vitrectomy (PPV) in human eyes with macular holes (MHs). METHODS: This study included 25 patients with chronic idiopathic MHs. The exclusion criteria included glaucoma, previous significant ocular conditions, and previous ocular surgeries except uncomplicated cataract. Ten surgeons performed 23-gauge four-port PPV, phacoemulsification, posterior hyaloid detachment, ILM peeling guided by dye staining, and perfluoropropane injection. The patients remained prone for 5 days postoperatively. The patients were evaluated postoperatively after 1, 30, and 180 days. The surgeons completed a questionnaire regarding the dye's staining abilities. RESULTS: The posterior hyaloids and ILMs stained purple in all eyes. The final best-corrected visual acuity improved significantly (p < 0.001) from preoperatively (1.37 ± 0.29) to 180 days postoperatively (1.05 ± 0.43). The MHs closed in 76% of eyes. CONCLUSION: The acai dye at a 25% concentration identified posterior hyaloids and ILMs during PPVs in humans. Dye toxicity was unlikely.

Analysis of Anthocyanins Extracted from the Acai Fruit (Euterpe oleracea): A Potential Novel Vital Dye for Chromovitrectomy.

PURPOSE: To classify and quantify anthocyanins in a vital dye extracted from the acai fruit (Euterpe oleracea), adjust pH and osmolarity, and perform lyophilization to develop a new chromovitrectomy dye. METHODS: Three dye concentrations 10%, 25%, and 35% (equivalent to 100, 250, and 350 mg of lyophilized acai fruit pulp extract samples) were evaluated when diluted in 1 ml of phosphate-buffered solution (pH 7 and 300 mOsm). The dye was analyzed by mass spectrometry and high-performance liquid chromatography (HPLC) to identify and quantify anthocyanins molecules. RESULTS: The pH and osmolarity correction and lyophilization were performed without damaging the anthocyanin molecular structure. Mass spectrometry confirmed the presence of five anthocyanins in the three concentrations of the dye. Cyanidin-3-O-glucoside was the major anthocyanin found. HPLC showed that the concentration of anthocyanin was similar, independent of the dye concentration tested. CONCLUSIONS: Lyophilization and the correction of pH and osmolarity (7.00 and 300 mOsm, resp.) were performed successfully. Five anthocyanins are present in the dye from the acai fruit. The major anthocyanin is cyanidin-3-O-glucoside. Independent of the dye concentration tested, the anthocyanin concentration was similar. Standardized chemical characteristics of this new dye may allow its use during chromovitrectomy in humans.

Retinal Toxicity of Acai Fruit (Euterpe Oleracea) Dye Concentrations in Rabbits: Basic Principles of a New Dye for Chromovitrectomy in Humans.

PURPOSE: Evaluate toxicity of acai fruit (Euterpe oleracea) dye concentrations in a rabbit model. METHODS: Rabbits were injected intravitreously with 10%, 25%, and 35% acai dye concentrations. Control eyes received balanced salt solution (BSS). Electroretinogram (ERG), fundus imaging, fluorescein angiography (FA), optical coherence tomography (OCT), and light and transmission electron microscopy (LM/TEM) were performed. RESULTS: Fundus imaging showed increased vitreous opacity with increased dye concentrations. FA and OCT showed normality with all concentrations. Comparisons between BSS and dye concentrations were analyzed using Kruskal-Wallis and Mood's median test (p < 0.05). At 24 h, ERGs showed reduced amplitudes from baseline in all eyes. Median b-wave amplitudes nonsignificantly decreased and latency increased with 10% and 25%; findings were significant (p < 0.05) for 35%. LM and TEM showed no abnormalities for 10% and 25%. With 35%, TEM showed ganglion cell edema at 24 h that resolved after 7 days. Vacuolization, multilamellar bodies, and nerve bundle damage occurred at 24 h/7 days in the inner nuclear layer. Mitochondrial cristae disruption occurred in the inner photoreceptor segment at 24 h that decreased by 7 days. CONCLUSION: Ten and twenty-five percent concentrations were safe and may improve identification of the posterior hyaloid and internal limiting membrane during chromovitrectomy in humans.

Color variation assay of the anthocyanins from Açai Fruit (Euterpe oleracea): a potential new dye for vitreoretinal surgery.

AIM: The goals of this study were to determine the potential for use of the natural anthocyanins from the açai fruit (Euterpe oleracea) during vitreoretinal surgery and the ideal physicochemical properties of the dye. METHODS: We evaluated the color variations of the dye at different pHs and osmolarities with or without the use of mordants as a potential new tool for internal limiting membrane peeling. The extracts of anthocyanin from the açai fruit were analyzed by spectrophotometry to determine the degree of color variations associated with various pHs and osmolarities. The experiments were conducted in test tubes filled with tryptophan soya media and Petri dishes prepared with agar media. RESULTS: We observed various shades of green, red, and purple in the extracts of the anthocyanin dye at different pHs and osmolarities. The assay to adjust the anthocyanin solution similar to the physiologic retinal environment (osmolarity, 300 mOsm; pH, 7.00) resulted in a shade of purple that may be useful to stain the intraocular microstructures during vitreoretinal surgery. The physicochemical property of the purple anthocyanin solutions from the açai fruit was observed at physiologic pH and osmolarity. CONCLUSION: Anthocyanins from the açai fruit may be useful to enhance visualization of the intraocular microstructures during vitreoretinal surgery.

Posterior hyaloid detachment and internal limiting membrane peeling assisted by anthocyanins from acai fruit (Euterpe oleracea) and 10 other natural vital dyes: experimental study in cadaveric eyes.

PURPOSE: The purpose of this study was to determine whether natural dyes facilitate posterior hyaloid detachment (posterior vitreous detachment [PVD]) and retinal internal limiting membrane (ILM) peeling in human eyes. METHODS: Open-sky vitrectomy with posterior hyaloid and ILM removal was performed in 86 human cadaveric eyes. After core vitrectomy, 11 different dyes were injected into the vitreous cavity to aid hyaloid detachment and ILM removal. The dyes were allowed to settle on the macula for 5 minutes after PVD and were removed by mechanical aspiration. Intraocular forceps were used for ILM peeling, which was confirmed by light microscopy of the peeled tissue. Acai fruit (Euterpe oleracea) extract and 10 additional dyes from plants or animal sources were tested: pomegranate (Punica granatum), logwood (Haematoxylum campechianum), chlorophyll extract from alfalfa (Medicago sativa), cochineal (Dactylopius coccus), hibiscus (Hibiscus rosa-sinensis), indigo (Indigofera tinctoria), paprika (Capiscum annuum), turmeric (Curcuma longa), old fustic (Maclura tinctoria), and grape (Vitis vinifera). RESULTS: The dyes facilitated PVD and ILM peeling. Acai fruit (E. oleracea) extract, logwood (H. campechianum), cochineal (D. coccus), and old fustic (M. tinctoria) facilitated PVD in all cases; dye-assisted PVD was compared with triamcinolone-assisted PVD performed previously in a comparative model. Acai fruit (E. oleracea) extract, cochineal (D. coccus), and chlorophyll extract from alfalfa (M. sativa) showed the best capability for ILM staining; dye-assisted ILM removal was compared with the ILM peeling guided by indocyanine green staining performed previously in a comparative model. Light microscopy confirmed the ILM removal in all cases. CONCLUSION: Anthocyanin dye of the acai fruit (E. oleracea) and the dyes from cochineal (D. coccus) and chlorophyll extract from alfalfa (M. sativa) resulted in the best capability for posterior hyaloid and ILM staining in human cadaveric eyes and may be a useful tool for vitreoretinal surgery.