Table 1. Comparison of the features of the dynamic curves for PI fluorescence in ARPE-19 cultures illustrated in Figure 1 after pulse delivery of H₂O₂ or after enzymatic generation of H₂O₂ by glucose oxidase (GOx) addition.

Pulse delivery				Enzymatic generation
H2O2 (μM)	onset time (h±SD)	mean slope	peak intensity (AU±SD)	GOx (mU/ml)	onset time (h±SD)	mean slope	peak intensity (AU±SD)
0				0
400	15.6±1.3*	69*	681±99*	6	19.8±1.0*	56*	512±71*
600	13.2±1.5*	86*	931±153*	7	14.7±1.7*	97*	881±170*
700	10.2±0.8*	146*	1446±251*	8	11.7±0.4*	381*	1838±147*
800	10.0±0.8	213*	1653±215	9	10.5±0.6*	367	1911±149
1000	8.6±0.8*	329*	1987±179*	10	9.2±1.0*	442*	2165±240*
2000	6.5±0.4*	459*	2199±165*	12.5	8±0.4*	425	2155±74
				15	7.2±0.5*	628*	2248±112
				20	6±0.3*	573	1966±139*

Onset time is the time post-addition of H₂O₂ or GOx that PI fluorescence intensity increased by 5 standard deviations above baseline (defined as intensity at 2 h). The mean slope (M in the equation Mx+b) is for the line describing the increasing intensity during the linear phase of the rapid rise in fluorescence intensity as illustrated in Figure 1B (in green). The peak intensity (in arbitrary units [AU]) is the highest fluorescence intensity achieved during 20 h. Asterisks indicate where the outcome differs significantly (paired t test, p<0.02) from the outcome obtained for the same parameter in the next lower concentration of H₂O₂ or GOx.