SCIENTIFIC POSTER_Mafalda Figueiredo

Purpose:

To investigate the efficacy and safety of novel dyes composed of lutein in association with brilliant blue for staining the vitreous and the internal limiting membrane (ILM) during vitreoretinal surgery in pre-clinical and clinical human models.

Methods:

The preclinical efficacy of lutein-based dyes (Retidyne and Retidyne Plus) was tested in sixty human cadaveric eyes undergoing vitreoretinal surgery. The various dye solutions were in contact with intraocular tissues for 1 minute and then removed by mechanical aspiration or membrane peeling initiated and completed with an intraocular forceps. The specimens were examined by light and electron transmission microscopy. These products were also tested in eighteen and twelve patients, using Retidyne and Retidyne Plus, respectively, that underwent pars plana vitrectomy. A post-surgery questionnaire was completed and follow up examinations were performed including best corrected visual acuity (BCVA), optical coherence tomography, fluorescein angiogram, autofluorescence imaging and visual field testing.

Results:

In the preclinical study contact between the lutein-based dyes and the retina, lens and vitreous surface resulted in orange staining of the vitreous and greenish blue staining of the ILM, which facilitated surgical steps in all eyes with no histologic signs of toxicity. In the clinical study we observed that both dyes were deposited on the posterior pole by gravity. Vigorous dye flushing into the vitreous cavity was unnecessary. Retidyne facilitated the ILM removal in all eyes, and Retidyne Plus stained both the internal limiting membrane as well as the posterior hyaloid and vitreous base by deposition onto the vitreous gel. BCVA improved in all eyes without clinical adverse effects and no signs of toxicity by as revealed by fundus imaging and visual field testing. Histology showed effective removal of the ILM in all eyes.

Conclusion:

The natural dye solutions based on lutein combined with brilliant blue efficiently stained the vitreous and ILM in human cadaveric eyes. In clinical use the new dyes were effective to intraoperatively identify the ILM, posterior hyaloid and vitreous base. No dye-related adverse events were detected for any of the patients confirming the excellent safety profile observed in previous rabbit model studies.