The blood-retinal barrier in Berlin's edema

The pathogenesis of Berlin's edema is uncertain; but one possible factor is breakdown of the blood-retinal barrier. The authors evaluated 10 affected patients with the use of vitreous fluorophotometry and fluorescein angiography. The aqueous humor dye concentration was elevated in the affected eye, compared with the unaffected eye. The means and standard deviations of the posterior vitreous penetration ratios of the involved and uninvolved eyes were 1.36 ± 0.66 and 1.45 ± 0.67 x 10^-6 min^-1, respectively; there was no statistically significant difference. The angiograms showed no leakage in either eye. It seems unlikely that disruption of the blood-retinal barrier could be a major pathophysiologic factor in this condition without leading to abnormalities on either test. The authors recommend using the term 'commotio retinae' until there is more conclusive evidence that the blood-retinal barrier is abnormal.