COMPARATIVE EVALUATION OF ACHROMATIC PERIMETRY AND FREQUENCY DOUBLING TECHNOLOGY AND CORRELATION WITH SCANNING LASER POLARIMETRY

Vikas Gulati

Abstract

PURPOSE. To evaluate the role of Frequency Doubling Technology (FDT) in early diagnosis of glaucoma as compared to standard achromatic perimetry (SAP) and to assess the correlation of the two methods of perimetry with anatomical damage detected on scanning laser polarimetry.

METHOD. In a cross-sectional study of 100 consecutive cases with elevated intraocular pressure (>21 mmHg), clinical glaucomatous optic nerve damage, and abnormal results on GDx nerve fiber layer analyzer,FDT and SAP was done for one randomly selected eye of each case in random order.FDT and SAP visual fields were compared for the degree of glaucomatous damage using Hodapp-Parrish-Anderson criteria for SAP and a modification of the same for FDT. Percentage field damage was calculated using a scoring system derived after Collaborative Initial Glaucoma Treatment Study. Percentage field damage on SAP and FDT was correlated to the results of scanning laser polarimetry.

RESULTS. FDP and SAP fields had 66% precise parity and 90% within one grade agreement (kappa=0.61). Linear regression analysis found a 10% additional damage on FDT. Percentage field loss on FDT had a statistically significant correlation with a greater number of GDx parameters than SAP.

CONCLUSIONS. FDT defects have a good clinical correlation with SAP defects. Visual field loss on FDT is more extensive and correlates better with nerve fiber layer damage detected on scanning laser polarimetry. FDT may detect functional damage at an earlier stage in glaucoma.

Details

Year: 2001

Program Number: 3:40 pm

Author Affiliation: All India Institute of Medical Sciences

Co-Authors: Ramanjit Sihota, Harish Agarwal, Rohit Saxena, Ajay Sharma

Co-Author Affiliation: All India Institute of Medical Sciences, All India Institute of Medical Sciences, All India Institute of Medical Sciences, All India Institute of Medical Sciences

Room: Room103