Staining and peeling of the internal limiting membrane using a fluorescent dye (Rhodamine 6 G)

Area of Science:

• Ophthalmology
• Surgical Innovation
• Medical Imaging

Background:

• Internal limiting membrane (ILM) peeling is a crucial step in treating various vitreoretinal diseases.
• Visualizing the ILM can be challenging for surgeons, potentially leading to incomplete removal or retinal damage.
• Current visualization methods may have limitations in clarity or safety.

Purpose of the Study:

• To evaluate Rhodamine 6G as a fluorescent dye for enhancing visualization of the vitreous and ILM during ophthalmic surgery.
• To determine if low concentrations of Rhodamine 6G are detectable by the unaided human eye under standard surgical illumination.
• To assess the safety and efficacy of Rhodamine 6G for ILM peeling in a preclinical model.

Main Methods:

• Rhodamine 6G's spectral properties were analyzed and compared to Indocyanine Green (ICG).
• Pars plana vitrectomy was performed on rhesus monkey eyes using halogen illumination.
• Rhodamine 6G (0.1% in balanced salt solution) was applied, and its fluorescence was observed during ILM peeling.

Main Results:

• Rhodamine 6G exhibits absorption and emission spectra within human visual sensitivity.
• A distinct green fluorescence was observed in the vitreous cavity upon irrigation, aiding ILM identification and removal.
• Histological examination revealed successful ILM peeling with no signs of acute retinal toxicity.

Conclusions:

• Fluorescent dyes like Rhodamine 6G can significantly improve ILM visualization and facilitate safe peeling during vitreoretinal surgery.
• The study suggests that lower, less toxic concentrations of Rhodamine 6G may be feasible if the dye achieves sufficient fluorescence quantum yield upon binding to the ILM.
• Rhodamine 6G presents a promising tool for enhancing surgical precision and safety in ILM peeling procedures.