Role of Vital Dyes in Chromovitrectomy.

ABSTRACT: Chromovitrectomy, the intraocular application of dyes to assist visualization of preretinal tissues during vitreoretinal surgery, was introduced to avoid ocular complications related to internal limiting membrane peeling, inadequate removal of the vitreous, and incomplete removal of epiretinal membranes. Since 2000, chromovitrectomy has become a popular approach among vitreoretinal specialists. The first vital dye used in chromovitrectomy, indocyanine green, facilitated identification of the fine and transparent internal limiting membrane. Following indocyanine green, trypan blue was introduced to identify epiretinal membranes, and triamcinolone acetonide stained the vitreous well. Recently, additional natural dyes such as lutein and anthocyanin from the açaí fruit have been proposed for intraocular application during vitrectomy. The main goal of this review was to study the role of vital stains in chromovitrectomy and report the latest findings in the literature.

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.

Effect of lens status in the surgical success of 23-gauge primary vitrectomy for the management of rhegmatogenous retinal detachment: the Pan American Collaborative Retina Study (PACORES) group results.

PURPOSE: To determine the effects of lens status on the success rate of primary pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment using either perfluoropropane gas (C3F8) or silicone oil (SO) tamponade. METHODS: A retrospective chart analysis was made of 97 eyes from 92 patients with rhegmatogenous retinal detachment with no proliferative vitreoretinopathy that were treated with primary 23-gauge PPV. Eyes included in this were phakic (n = 28), pseudophakic (n = 41), or phakic eyes subject to simultaneous phacoemulsification, intraocular lens implantation, and PPV during primary rhegmatogenous retinal detachment repair (n = 28). Tamponade at the end of PPV was with either C3F8 (n = 65) or SO (n = 32). Success was defined as retinal reattachment at 1 year follow-up after a single procedure in eyes submitted to C3F8 injection; in eyes treated with SO injection, the success rate was defined as retina reattached 1 year after oil removal. Statistical comparisons were made between groups using chi-square, Fisher's exact test, Kruskal-Wallis, Mann-Whitney, and multivariate analysis. All eyes were operated by 2 experienced retina surgeons and had a minimum follow-up of 12 months. RESULTS: The vitreoretinal redetachment rate in eyes subjected to C3F8 tamponade was significantly higher (28.6%) for phakic eyes (P = 0.011) compared with pseudophakic or phakic eyes that underwent to phacoemulsification and intraocular lens implantation (4.5%). Eyes in which SO was used at the end of the surgical procedure demonstrated a similar trend of higher reoperation rates in phakic eyes (28.6%) compared with pseudophakic or phakic eyes (8%) subjected to phacoemulsification and intraocular lens implantation; however, no statistically significant difference was observed (P = 0.201). No statistically significant differences were found between groups in relation to the number of tears (P = 0.863) and their location (inferior: P = 0.189, superior: P = 0.708, nasal: P = 0.756, and temporal: P = 0.08). CONCLUSION: The success rates of primary 23-gauge PPV with either C3F8 or SO tamponade in pseudophakic eyes with rhegmatogenous retinal detachment was higher than the same procedure performed in phakic eyes. Still, the retrospective and limited data presented is too preliminary to suggest or recommend that practitioners perform simultaneous combined cataract surgery with retinal detachment and requires further studies in a larger and prospective design to confirm these present findings.