Abstract
Purpose: :
Pseudoexfoliation (PEX) syndrome is a major risk factor for glaucoma and affected individuals have a higher rate of complications during cataract surgery. PEX material is mainly produced by the epithelial cells of the iris, lens and ciliary body. Variants of the lysyl oxidase-like 1 (LOXL1) - a gene involved in cross-linking elastin - are strongly associated with PEX syndrome. We aimed to evaluate the immunohistochemical expression of LOXL1 in lens capsule specimens of affected individuals.
Methods: :
Anterior lens capsule specimens were collected from routine phaco-emulsification cataract surgeries. Patients with PEX (n=15, mean age = 79.7 ± 7.2) and normal controls (n=24, mean age = 72.04 ± 5.9) were included in this study. PEX patients were determined by clinical slit lamp examination. Paraffin-embedded sections from all thirty-nine anterior lens capsules were immunostained with mouse anti-human LOXL1 polyclonal antibody (1:100, Abcam Inc., Cambridge, MA, USA) using the Ventana BenchMark fully automated machine.
Results: :
In the PEX group, 15 of 15 (100%) cases demonstrated immunopositivity for LOXL1 in the lens epithelial cells, while in the control group, only 1 of 24 (4%) cases were positive (p<0.0001). PEX material could be identified by light microscopy on the surface of the capsule in 7 of 15 (47%) capsules in the PEX group, of which all were positive for LOXL1.
Conclusions: :
The immunohistochemical approach in this report has led to the identification of LOXL1 as a major component of PEX fibers and is consistent with previous reports. The significant correlation between the expression of LOXL1 in epithelial lens cells and clinical PEX may indicate the involvement of LOXL1 in the formation of PEX material. Our results warrant further studies investigating the role of LOXL1 in early stages of PEX and possible therapeutic implications.
Keywords: immunohistochemistry • intraocular lens • candidate gene analysis