All measurements considered, the number of drusen increased
significantly (
P = 0.007) with increasing age.
Comparing the glaucomatous group (40 eyes) with the age-matched
nonglaucomatous control group (43 eyes), no significant
(
P ≥ 0.30) differences were detected in total drusen
count, drusen count in the foveal and extrafoveal regions, total drusen
area, drusen area in the foveal region, or drusen area in the
extrafoveal region
(Table 2) . In the follow-up examination, when the
photographs taken at baseline and the end of the study were compared,
the increase in total drusen count, foveal drusen count, and
extrafoveal drusen count in the total drusen, foveal drusen, and
extrafoveal drusen areas did not vary statistically (
P > 0.40) between the glaucomatous group and the nonglaucomatous
age-matched control group
(Table 3) .
In the whole study group, at baseline and the end of the study,
respectively, total drusen count (P = 0.75 and P = 0.28, respectively), foveal drusen count
(P = 0.26 and P = 0.95, respectively),
extrafoveal drusen count (P = 0.26 and P = 0.08, respectively), total drusen area
(P = 0.28 and P = 0.35, respectively),
foveal drusen area (P = 0.42 and P =
0.77, respectively), and extrafoveal drusen area (P =
0.22 and P = 0.28, respectively) were statistically
independent of neuroretinal rim area. The same held true if only the
eyes of the glaucomatous group were taken into account
(P > 0.25). Neuroretinal rim area decreased
significantly (P < 0.001) during the period of
elevation of intraocular pressure within the glaucomatous group. Within
the glaucomatous group, number and area of drusen at end of the study,
and the change in number and area of drusen during the period of
elevation of intraocular pressure were statistically (P > 0.30) independent of the decrease in neuroretinal rim area. When the
glaucomatous group was compared with the nonglaucomatous age-matched
control group, neuroretinal rim area was significantly
(P < 0.001) smaller in the glaucomatous group. In the
normal eyes, neuroretinal rim area was independent (P =
0.96) of age.
In the entire study group, size of beta and alpha zones of
parapapillary atrophy were statistically independent of total drusen
count (P = 0.28 and P = 0.94,
respectively), foveal drusen count (P = 0.98 and P = 0.33, respectively), extrafoveal drusen count
(P = 0.76 and P = 0.33, respectively),
total drusen area (P = 0.70 and P =
0.63, respectively), foveal drusen area (P = 0.95 and P = 0.23, respectively), and extrafoveal drusen area
(P = 0.61 and P = 0.95, respectively).
The same result was found when the glaucomatous group
(P > 0.25) and the nonglaucomatous age-matched control
group (P > 0.20) were analyzed separately. Within the
glaucomatous group, number and area of drusen at the end of the study,
and the change in number and area of drusen during the period of
elevation of intraocular pressure were statistically (P > 0.30) independent of the development and enlargement of the beta
zone and alpha zones of parapapillary atrophy.
In the entire study group and in each of the subgroups, total drusen
count (P = 0.40), foveal drusen count
(P = 0.65), extrafoveal drusen count (P = 0.35), total drusen area (P = 0.13), foveal drusen
area (P = 0.15), and extrafoveal drusen area
(P = 0.19) were statistically (P >
0.30) independent of the visibility of the retinal nerve fiber layer,
with squared correlation coefficients lower than 0.04. Visibility of
the retinal nerve fiber layer decreased significantly
(P < 0.001) during the period of elevation of
intraocular pressure within the glaucomatous group. When the
glaucomatous group and the nonglaucomatous age-matched control group
were compared, visibility of the retinal nerve fiber layer was
significantly (P < 0.001) lower in the glaucomatous
group.
If in the statistical analysis the total study group was divided into
monkeys with and without arterial hypertension–atherosclerosis, count
and size of macular drusen were not significantly (P >
0.10) correlated with any of the parameters: neuroretinal rim area,
size of alpha and beta zones of parapapillary atrophy, and retinal
nerve fiber layer visibility. Correspondingly, the differences in size
and count of macular drusen between the glaucomatous eyes and the
nonglaucomatous eyes were not statistically significant
(P > 0.20).
The coefficient of variation for the reassessment of the number of
drusen in the foveal region was 0.189, and for the count of the drusen
in the extrafoveal region, it was 0.174.