Figure 1. Temporal loss of
photoreceptors after light exposure in hematoxylin and
eosin–stained retinal cross sections. Graph showing the number
of nuclei rows (±standard deviation [SD]) present in the outer
nuclear layer (ONL) of six control and six experimental retinas
(three right and three left retinas from three animals) at
different times after light exposure (ALE) in eight equidistant
retinal locations (four dorsal, four ventral). The animals
analyzed were chosen randomly from the control and the
experimental animals that had been processed to obtain
hematoxylin and eosin–stained cross sections. The distance from
the optic disc to the retinal location analyzed is shown in the
x-axis. Photoreceptor loss was more severe in the dorsal than in
the ventral retina. Photoreceptor loss in the dorsal retina was
significant at 1 day ALE at all retinal locations (Mann–Whitney
test, p<0.001), except at 3.6 mm, where this loss was
significant only from 3 days ALE (p<0.001). Photoreceptor
loss in the ventral retina was significant at 1 day ALE only at
the 0.9 and 1.8 mm locations (p<0.001 and p=0.002,
respectively), and at the 2.7 and 3.6 distances, loss was
significant from days 3 and 7 ALE, respectively (p<0.001).
Photoreceptor loss did not seem to progress from 3 months on
(there were no significant differences between the numbers of
photoreceptors found 3 or 6 months ALE at any retinal location).