Abstract
Purpose:
The pathophysiology of silicone oil related visual loss is still unknown. This study tested the hypothesis that intraocular silicone oil results in insufficient potassium buffering which in turn may lead to retinal damage.
Methods:
Analysis of retro-oil fluid or vitreous humor and serum obtained from patients undergoing removal of silicone oil (n=11) or primary vitrectomy for macular hole (n=14) or floaters (n=6). Sodium, potassium, magnesium, chloride and glucose levels were analyzed by ion-selective electrodes in these samples.
Results:
Potassium levels were not increased in retro-oil fluid (4.36 mmol/L, interquartile range (IQR) 0.57) compared to vitreous humor (4.70 mmol/L, IQR 0.37). The median level of magnesium (0.65 mmol/L, IQR 0.08) in the retro-oil fluid was lower compared to vitreous humor levels (0.80 mmol/L, IQR 0.11) (p<0.001). Also, the ratio of magnesium in retro-oil fluid and serum was different from vitreous humor and serum (p<0.05). Serum levels of all electrolytes and glucose did not differ between the groups.
Conclusions:
Potassium levels are not increased in retro-oil fluid. Magnesium levels are lower in retro-oil fluid than in vitreous humor and serum. The clinical consequences of this finding have to be determined.