Smell Sensitivity in Primary Open-angle Glaucoma and Pseudoexfoliation Glaucoma.

Area of Science:

• Ophthalmology
• Neurology
• Sensory Science

Background:

• Glaucoma, a leading cause of irreversible blindness, encompasses various subtypes.
• Exfoliation syndrome (XFS) and exfoliative glaucoma (XFG) are characterized by the deposition of fibrillar material.
• Olfactory dysfunction has been increasingly recognized as a potential indicator of neurological changes.

Purpose of the Study:

• To compare smell sensitivity, identification, and differentiation abilities in patients with primary open-angle glaucoma (POAG), exfoliative glaucoma (XFG), and exfoliation syndrome (XFS).
• To evaluate these olfactory functions against a control group of healthy individuals.

Main Methods:

• A cross-sectional study involving 20 patients each of POAG, XFG, and XFS, alongside 20 healthy controls.
• The Sniffin' Sticks test was employed to assess smell threshold, identification, and differentiation.
• Statistical analysis included one-way ANOVA and Tukey's post hoc test.

Main Results:

• Significant differences in odor discrimination, identification, and threshold were observed across all groups (P<0.001).
• The XFG group demonstrated significantly lower smell identification scores compared to POAG, XFS, and control groups.
• Smell sensitivity was reduced in XFG and XFS patients relative to POAG and control groups.

Conclusions:

• Exfoliative glaucoma and exfoliation syndrome are associated with impaired smell identification and sensitivity.
• These findings highlight potential neural degeneration mechanisms common to pseudoexfoliation and glaucoma.
• Olfactory testing may offer insights into the broader systemic implications of certain glaucoma types.