PARAFOVEAL SCANNING LASER POLARIMETRY FOR DETECTION OF GLAUCOMA CHANGES

S. Kogure, H. Iijima and S. Tsukahara

Department of Ophthalmology, Yamanashi Medical University, Japan

Purpose: To determine whether scanning laser polarimetry could detect the glaucomatous changes of nerve fiber thickness in the parafoveal area.

Methods: Enrolled in this study were 14 eyes with glaucoma showing at least a point with 6 dB or more decrease in pattern deviation within central-10-degree-visual field in the central 30-2 program of Humphrey Field Analyzer (HFA), along with 14 normal control eyes. Averaged mean deviation and corrected pattern standard deviation were -3.74+-2.72dB (ranging from +0.53dB to -7.45dB) and 5.17+-3.07dB (ranging from 0.55dB to 10.43 dB) respectively in glaucoma eyes. The fundus images centered on the fovea were taken three times for each eye using Nerve Fiber Analyzer II (NFA II). The nerve fiber layer thickness was measured along a circle of 90 pixels in diameter around the fovea with 5-pixel width. The measured ring was divided into 12 sectors. The nerve fiber thickness of each of the six sectors in the superior hemisphere was compared with that of the sector opposite to the fovea and the ratio of them was evaluated.

Results: The ratio of the three upper temporal sectors in eyes with glaucoma was significantly different from that in normal eyes, indicating asymmetrical nerve fiber thickness in the sectors on the opposite side of the fovea in eyes with glaucoma.

Conclusions: Glaucomatous changes of nerve fiber thickness could be detected in the parafoveal area with scanning laser polarimetry.