Abstract
Purpose :
Pseudoexfoliation syndrome (PEX) was historically described as responsible for an open angle type of glaucoma, recently, different frequencies of angle closure have been described in PEX. Angle closure prevalence varies a lot between ethnic groups. We hypothesized that if the difference in prevalence in angle closure between PEX populations is explained by the different prevalence of angle closure, the biometric characteristics will be similar between control and cases. We performed a prospective, cross-sectional, comparative, case-control study to compare anterior segment parameters of angle closure.
Methods :
We included 144 eyes of 72 patients; PEX with glaucoma (n=36): PEX with no glaucoma, PEG (n=23) and control (n=85). Male gender cases were 42%, 57% and 22% in PEX, PEG and controls respectably (p=0.002). Age (mean ± standard deviation, SD) was 76±7, 75±6 and 73±8 in PEX, PEG and control groups respectably (p=0.147). All eyes were evaluated with Pentacam HR (Oculus, Wetzlar, Germany), IOL Master version 4.08 (Carl Zeiss Meditec, Jena, Germany) and Visante AS-OCT (Visante, Carl Zeiss Meditec, Dublin, CA). Independent Student’s t-test, Pearson Chi2, ANOVA and Bonferroni tests were used for statistical analysis.
Results :
The anterior chamber depth ACD (mean±SD) of control/PEX showed no differences in Pentacam (2.55±0.39mm)/(2.37±0.22mm), IOL master (2.89±0.38mm)/(2.833±__mm) or Visante (2.65±0.33mm)/ (2.606±__mm). The iridocorneal angle ICA (mean±SD) of control/PEX was smaller in PEX by Pentacam (34.78±9.23)/(30.44±5.58) and Visante (30.48±10.4)/(25.58±5.25), with a statistically significant of p 0.016 and p 0.070 respectively. With Pentacam the anterior chamber volume ACV (mean±SD) for control/PEX was similar between groups (109.6 ±25.6mm3)/ (113.363±24.79mm3).
Conclusions :
We found a narrower ICA in PXF patients compare to healthy controls. However other biometric measures of the anterior chamber are similar between both groups. We hypothesized that the reason of conflicting findings between PXF biometry in different studies may be because angle closure in PXF patients is cause by different mechanism in different populations. In our study of northern Mexico we may have a mechanism that rely more in the forward movement of the iris in the periphery rather than in the central anterior chamber. One limitation of our study is the use patients with cataract as controls.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.