Pigment Dispersion Syndrome Progression to Pigmentary Glaucoma in a Latin American Population

Abstract

Objective: To determine the progression of pigment dispersion syndrome (PDS) into pigmentary glaucoma (PG) in a population at the Central Military Hospital in Bogotá, Colombia.Materials and methods: A retrospective study was conducted, based on a review of medical records of patients with PDS evaluated in the Glaucoma Clinic. Data were collected in a database in excel and subsequently analyzed with the software Statistical Package for the Social Sciences (SPSS), performing Chi-square test analysis and Spearman’s rho test.Results: Forty-eight eyes of 24 patients were included. Forty-two percent were women and 58% were men. Pigmentation of the trabecular meshwork was the most frequent clinical sign (100%), followed by Krukenberg’s spindle (91.7%), the least frequent were the iris concavity and iris heterochromia (4.2%), the average of the spherical equivalent was of - 1.33 (SD 2.07).The rate of conversion of PDS to PG was 37.5%, after an average follow-up of 50.7 months. Having an intraocular pressure (IOP) greater than 21 mm Hg was statistically the only significant risk factor for conversion.Conclusion: We found several differences in frequency and clinical signs in these patients in contrast to previous data, probably due to different racial characteristics.The rate of progression is similar to previous reports despite of heterogeneity of these. Having IOP > 21 mm Hg was the only risk factor associated with progression in this sample.How to cite this article: Gomez Goyeneche HF, Hernandez-Mendieta DP, Rodriguez DA, Sepulveda AI, Toledo JD. Pigment Dispersion Syndrome Progression to Pigmentary Glaucoma in a Latin American Population. J Curr Glaucoma Pract 2015;9(3):69-72.

Molecular Genetics of Pigment Dispersion Syndrome and Pigmentary Glaucoma: New Insights into Mechanisms

“…However, in another study which evaluated conversion over time, the conversion rate was estimated at 10% at 5 years and 15% at 15 years [ 5 ]. In a Latin American cohort, the conversion rate was observed to be 37.5% at 50 months which is in good agreement with US studies [ 45 ]. However, in a Pakistani cohort, the observed conversion rate was only 4% at 15 years which may support ethnicity as a risk factor for conversion [ 47 ].…”

“…Rigorous exercise has been shown to induce pigment dispersion, enhance posterior iris bending, and increase IOP which all contribute to conversion risk [ 41 – 44 ]. IOP is a major risk factor for PDS to PG conversion, with the increase in risk being proportional to the increase in IOP [ 5 , 45 ]. The actual rate of conversion is highly variable between studies and seems to in part depend on the ethnic background of patients.…”

A porcine ex vivo model of pigmentary glaucoma

“…Compared to human PG, the IOP elevation was relatively acute and took two days from pigment exposure to ocular hypertension. In contrast, development of high IOP in human patients can take years 76,77 . Debris clearing by macrophages, in addition to TM cell phagocytosis, is a more effective process in vivo than ex vivo 66,67 .…”

A porcine ex vivo model of pigmentary glaucoma

“…However, this model also has several limitations: compared with human PG, the IOP elevation seen here was relatively acute and took only 2 days from the time of pigment exposure to onset of ocular hypertension. Yet, although pigment showers can cause IOP spikes, consistently high IOP in human patients can take years to develop 80 , 81 . In vivo , clearing of debris by macrophages, in addition to the phagocytosis by TM cells, is more effective 64 , 65 .…”