The role of angle configuration in the risk of glaucoma in pseudoexfoliation (PEX) patients poses a challenge for most clinicians. Recently, researchers aimed to answer that question in a study comparing the anterior segment and angle parameters between PEX, pseudoexfoliation glaucoma (PXG) and normal control subjects by using anterior segment OCT (AS-OCT) imaging.
Data from 34 eyes with PEXG, 33 eyes with PEX and 31 eyes from a control group were analyzed.
The study shows that there is a progressive decrease in AS-OCT-measured angle parameters from the control group to PEX and to PXG, and PEXG eyes had significantly smaller measurements compared to the control group and PEX eyes. Shallow anterior chamber depth (ACD) in particular was noted as well.
“We found that lens vault was higher in PEX and PEXG eyes compared to the normal group,” the authors concluded in their study. “This finding combined with the smaller ACD in PEX and PEXG eyes supports the notion that the anterior shift of the lens secondary to the subclinical weakness of zonular fibers has a key role in the narrowing of anterior chamber angle in PEX, which is consistent with the previous UBM studies.”
The authors also observed that pupil size in dim illumination for the PEXG and PEX eyes were smaller than in control eyes. “Iris rigidity and insufficient mydriasis in these patients is associated with pseudoexfoliative material deposition in the stroma and muscle tissues, and the degenerative changes of the stroma including sphincter and dilator muscles,” the authors explained.
Additionally, PEXG eyes had significantly smaller measurements compared to the control group and PEX eyes. “This may reflect the chronicity of PEX condition in those patients that have developed glaucoma,” the authors noted. “On the other hand, this may raise the issue of the role of additional angle-closure mechanisms.”
Mohammadi M, Johari M, Eslami Y, et al. Evaluation of anterior segment parameters in pseudoexfoliation disease using anterior segment optical coherence tomography. American Journal of Ophthalmology. July 25, 2021. Epub ahead of print.