S. Collur et al., Human lens effect on in vivo scanning laser polarimetric measurements of retinal nerve fiber layer thickness, OPHTHAL SUR, 31(2), 2000, pp. 126-130
OBJECTIVE: To determine the effect of the human lens on retinal nerve fiber
layer measurements by scanning laser polarimetry. This technique uses the
form birefringence of the retinal nerve fiber layer to estimate its thickne
ss. The GDx Nerve Fiber Analyzer contains an optical retarder element to co
mpensate for the birefringence of the human cornea.
PATIENTS AND METHODS: Fourteen nonglaucomatous pseudophakic or aphakic eyes
were matched by age and race to 14 nonglaucomatous phakic eyes. Intraocula
r pressure, optic nerve head evaluation by slit lamp biomicroscopy and visu
al fields were performed to establish the absence of glaucoma. The nerve fi
ber layer thickness measurements by the GDx Nerve Fiber Analyzer were compa
red between the two groups.
RESULTS: The average nerve fiber layer thickness in the phakic group was 67
.2+/-11.3 mu m and in the nonphakic group was 66.1+/-11.8 mu m (P=0.80).
CONCLUSION: The human lens has negligible influence on in vivo nerve fiber
layer thickness measured by the GDx Nerve Fiber Analyzer.