[A comparative study of visual field defects between primary open-angle and low tension glaucoma]

Area of Science:

• Ophthalmology
• Visual Neuroscience

Background:

• Glaucoma encompasses a group of optic neuropathies characterized by progressive visual field loss.
• Primary open-angle glaucoma (POAG) and low-tension glaucoma (LTG) are distinct subtypes with varying intraocular pressure profiles.
• Understanding early visual field defects is crucial for timely diagnosis and intervention.

Purpose of the Study:

• To characterize and compare the early visual field defects in primary open-angle glaucoma (POAG) and low-tension glaucoma (LTG).

Main Methods:

• Quantitative perimetry using QZS-2 automated perimetry (full threshold program) was performed on 41 eyes with early POAG and 15 eyes with early LTG.
• Statistical analysis compared visual field parameters, including mean light sensitivity and short-term fluctuation, between glaucoma groups and a normal control group.

Main Results:

• Early visual field defects in both POAG and LTG predominantly manifested as localized decreases in light sensitivity, with some cases showing diffuse defects.
• Defects were primarily observed in the central visual field, occasionally extending to the peripheral nasal field.
• Statistically significant differences in mean light sensitivity and short-term fluctuation were found in the central field between early glaucoma groups and controls (P < 0.05).

Conclusions:

• The characteristics of early visual field defects are indistinguishable between primary open-angle glaucoma and low-tension glaucoma.
• Both POAG and LTG exhibit similar patterns of damage and affected areas in their early stages.