Overall, mean scleral thickness was significantly less in the high
IOP–normal eyes (186 μm), compared with the low IOP–normal eyes
(204 μm;
Table 3 ). By region, scleral thickness was indistinguishable
in three of the four regions; however, in the foveal region, the sclera
was significantly thinner in the high IOP–normal eyes (265 μm),
compared with the low IOP–normal eyes (307 μm;
P <
0.0001, ANOVA). Within the four normal monkeys (monkeys 1, 2, 3, and 4)
considered individually, the mean posterior scleral thickness was
significantly greater in the normal eye fixed at low IOP than in the
contralateral normal eye fixed at high IOP in monkeys 1 and 2, but not
in monkeys 3 and 4 (data not shown). Finally, scleral thickness was
significantly less at 6 of the 15 measurement points in the high
IOP–normal treatment group, compared with the low IOP–normal group
(Fig. 4A) . Statistically significant differences in scleral thickness
between the low IOP–normal eyes and the contralateral high IOP–normal
eyes of monkeys 1 to 4 individually are shown for each measurement
point in
Figure 5A . Although the pooled data in
Figure 4A show a trend
toward posterior scleral thinning in the high IOP–normal treatment
group, the individual monkey data, as shown in
Figure 5A , are
equivocal.