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Siddiqui What is risk of pigmentary glaucoma from pigment dispersion syndrome?
78% were male, and 75% were myopic, with a mean myopic correction slightly higher
than the group that did not develop glaucoma (4.3
± 4.0 vs 3.9 ± 2.6 diopters,
difference not statistically significant: p=0.48). The mean age of patients who converted
was slightly higher than the non-conversion group, but the difference was not statistically
significant (45
± 15 years vs 40 ± 11 years; p=0.21).
The greatest risk factor for predicting conversion to pigmentary glaucoma was
IOP at initial examination (24.0
± 3.0 vs 18.0 ± 3.8 mm Hg for non-conversion group,
p=0.001). Patients with initial IOP of 21 mm Hg or higher had a 46% chance of
converting to glaucoma, while those with IOP less than 21 had only a 2% chance of
conversion by 15 years (p<0.001; Figure 4). Each 1 mm Hg increase in IOP in pigment
dispersion syndrome patients increased the risk of conversion to pigmentary glaucoma
1.4 times (95% CI 1.2-1.6). This odds ratio was not calculated on a linear scale, but
followed the formula: odds ratio=e
(x*0..3365)
, where x = increase in IOP. Thus, a 2 mm
increase in IOP increased the odds ratio to 1.96. Age, refractive error, and family history
of glaucoma were not associated with an increased conversion risk.
4) Characteristics of pigmentary glaucoma patients: For the 23 patients found to
have pigmentary glaucoma on initial examination, the mean age was 42 ± 12; 78% were
male. The mean IOP at diagnosis was 29.0
± 5.0 mm Hg. A positive family history for
glaucoma was recorded in 48%, none of the family members were known to have
pigment dispersion syndrome or pigmentary glaucoma. The mean myopic refractive error
was -3.9 ± 1.8 diopters (range: -0.1 to 6.0 diopters). The range of follow-up times was
1.4 to 23 years, with a mean of 11
± 7 years (median: 9 years).
