Changes of trabecular meshwork pigmentation in patients with pigment dispersion syndrome

Abstract

To report the changes of trabecular meshwork (TM) pigmentation and clinical outcomes of patients with pigment dispersion syndrome (PDS) after resolution of reverse pupillary block.Twenty one eyes of 11 PDS patients were followed up periodically for 15 years after resolution of reverse pupillary block with either Nd: YAG laser peripheral iridotomy (LPI) or trabeculectomy. Visual acuity (VA), best-corrected visual acuity (BCVA), slit lamp examination, intraocular pressure (IOP), Humphrey visual field analysis (VFA), gonioscopy and stereoscopic funduscopy were performed on admission and every 6 months postoperatively. TM pigmentation was quantitatively evaluated and graded every 5 years after the treatment, in which the circumference of anterior chamber angle was divided into 4 quadrants: superior, inferior, nasal and temporal. Postoperative IOP, VA, BCVA, VFA, TM pigmentation and adjunctive anti-glaucoma medications were main outcome measurements and compared with baseline.Eleven patients (9 males, 2 females) were identified as PDS according to the diagnostic criteria, with average age of 38.25 ± 6.93 years (range, 31-55 years) at initial diagnosis. The mean IOP level was 33.1 ± 9.8 mmHg (range, 22-56 mmHg) at diagnosis. Ten PDS eyes received LPI, and the other eleven eyes underwent uneventful trabeculectomy. The median TM pigmentation score of the 21 PDS eyes was 16 (interquartile range [IQR], 15-16) on admission, which changed to 14 (IQR,(13)(14)(15) 13 (IQR,(12)(13)(14) 12(IQR, at 5-, 10-, 15-year follow-up visits respectively. The decrease rate of TM pigmentation was 37% in inferior quadrant, while in nasal, temporal, and superior quadrant the reduction rate was 28%, 23%, and 18%, respectively, at the last follow-up visit. Majority of these enrolled eyes (19/21) had stable VA and BCVA with average endpoint IOP of 15.1 ± 3.4 mmHg.TM pigmentation in PDS patients attenuates with time after reverse pupillary block was resolved, in which the inferior quadrant seems faster than the other quadrants. Abbreviations: AC = anterior chamber, BCVA = best-corrected visual acuity, IOP = intraocular pressure, IPE = iris pigment epithelium, IQR = interquartile range, LPI = laser peripheral iridotomy, PDS = pigment dispersion syndrome, PG = pigmentary glaucoma, TM = trabecular meshwork, VA = visual acuity, VFA = Humphrey visual field analysis.

Pilot report: objective quantification of trabecular meshwork pigmentation using densitometry and the NIDEK GS-1 gonioscope in glaucoma patients

“…This case series shows how patients with heavier pigment density in the trabecular meshwork may be correlated with elevated IOP and glaucoma. The current understanding of pigment dispersion syndrome is that it is a disease that predominantly affects Caucasian men ( 6 , 7 ). In practice, many patients of Latin American and African descent can be observed to have high levels of pigment in the Trabecular meshwork (TM).…”