Although ERG data (Figure 4) may indicate that digoxin application resulted in a condition resembling retinal ischemia, we did not detect increased HIF1A levels shortly after treatment presumably because digoxin can inhibit HIF1A, as reported by others.31, 32 Only after clearance of digoxin, HIF1A levels may increase and reach the levels detected between 2 and 10 days. This evidence concerns the gene HIF1A and retinal ischemia.