Rat eyes with high IOP and normalized IOP progress toward glaucomatous
RGC loss. A, mean IOP values ± S.D., n =
4–6 eyes/group. At day 0 eyes were surgically cauterized or were left
normal. At days 3 or 10 post-cautery the indicated groups were treated with
β-blocker (betaxolol 0.5%, Alcon Labs), the other groups were untreated.
Daily treatment with β-blocker continued until day 28. Within 3 days of
β-blocker treatment, cauterized eyes experienced a significant reduction
of high IOP and their IOPs were not different from non-cauterized eyes as long
as betaxolol was applied. B, progressive loss of RGCs triggered by
short-term ocular hypertension. Mean RGC loss ± S.E., n = 6
retinas/group/experiment, from 3 independent experiments. Normalization of IOP
with betaxolol (from day ∼7 onwards) reduces the rate of RGC loss, but
does not prevent it. When betaxolol was used successful normalization of IOP
were verified, but is not shown here for clarity. Normal non-cauterized eyes
were obtained from 3 rats. In the test groups 6 rats for each time point had
both eyes cauterized to elevate pressure, and one eye was treated with
betaxolol to lower pressure. *, significant RGC loss compared
versus normal non-cauterized retinas (p ≤ 0.01).
**, significantly higher RGC loss in cauterized eyes compared
versus cauterized eyes treated with betaxolol (p ≤
0.01).