Purpose: In pigmentary glaucoma (PG), reverse pupillary block
is one mechanism presumed possible for backward bowing of the iris leading to
iris-zonular rubbing. The concept of treatment in PG includes the elimination
of iris concavity via laser iridotomy or miosis. The purpose of this study was
to evaluate the intraocular pressure control in patients with PG after LI or
low dose pilocarpine treatment.
Methods: In this prospective study we enrolled 23 patients
with clinically diagnosed pigmentary glaucoma in both eyes. The patients were
randomly assigned to receive in one eye YAG laser iridotomy (LI-group) while
the fellow eye was treated with pilocarpine 2% drops one or two times daily
(pilo-group). In 6 patients UBM study was available for pre- and post-treatment
evaluation. All patients provided informed consent to the treatment procedure.
Results: Follow-up ranged from 6 to 23 months. There were 17
men and 6 women with a mean age of 28 years (range 20 to 45 years). Patients’
refraction ranged from 0.00 to –7.00 diopters (mean = -2,89 +/- 2,18). There
was no statistically significant difference in the preoperative mean IOP
between the two eyes (p=0.09). Additional treatment was necessary (IOP > 21
mmHg) in 19 out the 23 LI-group eyes and in 11out of the 23 pilo-group eyes (p
< 0.05). Post-treatment UBM examination revealed an almost planar iris
configuration in all 6 LI-group eyes, while in the 6 pilo-group eyes a more
concave configuration was noted compared to the pre-treatment configuration.
Conclusion: Our results indicate that in patients with PG low
dose pilocarpine treatment has a better control in IOP than LI, keeping the
pupil in constriction and eliminating the iris concavity responsible for the
release of pigment. Although the concave iris contour in PG reverted to a
planar configuration after laser iridotomy, patients IOP remained at the high
twenties after treatment, confirming the opinion that it is not yet appropriate
to apply laser iridotomy as a treatment in PG.