Abstract
Purpose: :
During vitreoretinal surgery dyes are used to stain the inner limiting membrane (ILM) thus helping surgeons to identify anatomical structures. Brilliant blue (BBG) is an intraocular dye that was approved for intraocular use. Using 0.05 ml of 40% Glucose, surgeons tried to facilitate staining of the ILM, although Glucose at this concentration demonstrated toxic effects on cell cultures. It was our purpose to examine the effect of 0.4 ml BBG (Brilliant PeelTM 0.25 mg/ml, Fluoron, Ulm, Germany) mixed with 0.05 ml/ 0.1 ml/ 0.15 ml of 40% Glucose on retinal function measured by the electroretinogram (ERG).
Methods: :
Bovine eyes were enucleated directly post mortem and retinas were prepared, isolated and perfused with an oxygen saturated nutrient solution, and the ERG was recorded. At stable ERG amplitudes the perfusion was stopped and BBG mixed with 0.05 ml/0.1 ml/ 0.15 ml Glucose was applied epiretinally. Perfusion was started again after 60 seconds and the ERG-recovery was followed up for 75 minutes. 1 mM Aspartate was added to the nutrient solution to obtain a-wave amplitudes. After measuring stable a-wave amplitudes the perfusion was stopped and proceded likewise.
Results: :
After application of BBG/0.05 ml 40% Glucose, an initial increase in the b-wave amplitude of 1.86% was recorded that was not significant (p>0.05). At the end of the washout phase we recorded a decrease of 11.2% (p>0.05). Using BBG/0.1ml 40% Glucose we noticed an initial decrease by 19.1% (p>0.05), followed by a significant decrease of 23.40% (p=0.0039). For BBG/1.5 ml 40% Glucose an initial increase of 14% (p>0.05), followed by a significant decrease of 26% (p=0.0039) was recorded. The photoreceptor potential showed at a concentration of 0.4 ml BBG/ 0.05ml 40% Glucose an increase of 23.5% (p>0.05). At the end of the washout we detected a reduction of the a-wave amplitude by 2.0% (p>0.05). During staining with BBG/0,1ml 40% Glucose an initial increase by 21.73% (p>0.05) followed by decrease of 4.36% (p>0.05) was recorded. For BBG/1.5 ml 40% Glucose, we recorded an initial increase of the a-wave amplitude by 70% (p=0.0022) followed by a decrease of 8% (p>0.05)
Conclusions: :
We did not find any toxic effect at a concentration of 0.05ml 40% Glucose. We found a significant dose-dependent negative effect on the retinal network at a concentration of 1.0 ml/1.5 ml 40% Glucose. Therefore we do not consider using 40% Glucose the safest option. Further investigation is needed.
Keywords: electrophysiology: clinical • retinal culture • vitreoretinal surgery