Purpose: To evaluate quantitatively pattern of retinal nerve fiber
layer(RNFL(change
in eyes with normal-tension glaucoma(NTG)with hemifield dominant visual field
defects using scanning laser polarimetry (GDx: Laser Diagnostic Technologies,
San Diego, CA, USA)
Methods: Prospectively, Forty consecutive eyes from forty patients with
NTG and hemifield visual field defect based on the Humphrey visual field underwent RNFL
thickness measurements.Twenty normal eyes from twenty subjects matched in age and refractive error were
selected as a control group.
Results: Symmetry, calculated as the ratio of superior to inferior RNFL
thickness showed no statistical difference
between the study and control group(p=0.50). Affected ratio, calculated
as the ratio of RNFL thickness in the quadrant corresponding to hemifield of
visual field defect to that of temporal quadrant was statistically less than
that of control.(p=0.00). Similar finding was noted in the unaffected ratio.
However, overall, 27.5%(11/40 eyes) showed abnormal symmetry index that
indicated focal RNFL change.
Conclusion: Despite a mixture of both focal and diffuse RNFL changes,
symmetrical change in both upper and lower quadrants were prevalent. More sensitive
parameters may be needed to detect focal RNFL change with GDx NFA.