Analysis of peripapillary nerve fiber layer thickness measured by Scanning Laser Polarimetry with variable corneal compensation in glaucoma

Objective To evaluate the ability of Scanning Laser Polarimetry(SLP)with variable corneal compensation(VCC)to discriminate normal controls from patients with glaucoma.Methods A total of 36 healthy subjects and 91 patients with glaucoma was included.According to the predefined types of visual field defect,glaucomatous eyes were divided into three groups:glaucomatous eyes with normal visual field,with early visual field defects and with moderate and advanced visual visual field defects.Scanning Laser Polarimetry was performed.TSNIT average,superior average,inferior average,TSNIT standard deviation and NFI were measured.Analysis of variance(ANOVA)was used to compare different value among the groups.Results All parameters measured showed statistically significant difference between normal control and glaucoma patients with visual field defects( P 0.001).About TSNIT average and superior average,there were statistically significant differences between normal control and glaucoma patients with normal visual field( P =0.009 and P =0.005).Conclusions Assessments of nerve fiber layer thickness as determined by Scanning Laser Polarimetry with variable corneal compensation can differentiate patients with glaucoma from normal subjects.Decrease of NFL can be found before visual field defect.