Incorporation of radiolabeled sulfate (cpm/mg dry tissue weight) was
reduced in the anterior (−20% ± 3%) and posterior (−36% ± 7%)
sclera of the myopic eye in 5 day MD animals (
P < 0.01
anterior and posterior sclera;
Fig. 2A ) compared with contralateral control eyes (paired
t-test)
and the eyes of normal animals (ANOVA). Sulfate incorporation was also
significantly reduced in the posterior (−42% ± 4%) sclera of the
myopic eyes of lens-defocus animals (
P < 0.001) when
compared with contralateral control and normal eyes. There was no
significant difference between sulfate incorporation into posterior
scleral samples from myopic eyes of 5 day form-deprived animals and
lens-defocus animals. If incorporation of radiolabeled sulfate was
expressed per microgram of DNA (cpm/μg DNA), instead of per milligram
of dry tissue weight, the findings were essentially identical (see
Figs. 2A 2B ). There was found to be no significant difference in
levels of sulfate incorporation (cpm/mg) between normal eyes
(
n = 10) and contralateral control eyes
(
n = 10) of 5 day MD and lens-defocus animals for
either anterior or posterior sclera (
P = 0.66 anterior;
P = 0.89 posterior). There was no correlation between
the interocular reduction in GAG synthesis and either the interocular
difference in refractive error (
P = 0.77) or VCD
(
P = 0.99), indicating that the level of scleral GAG
synthesis was not a good predictor of the degree of refractive error or
ocular elongation.