Detection of Early Normal-Tension Glaucoma without Visual Field Defects

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In this project, four types of laser scanning ophthalmoscopes were evaluated with regard to their usefulness in assessing abnormalities of the optic nerve head due to glaucoma. The scanning laser tomograph had the advantage of enabling the examiner to evaluate the three-dimensional appearance of the optic nerve head and to detect abnormalities in the nerve fiber layr along the disc margin. Detailed assessment of nerve fiber layr defects in the macular region was possible using the laser scanning ophthalmoscope with an argon-blue laser. The scanning laser polarimeter allows the examiner to estimate the size of nerve fiber layr defects from the thickness of the nerve fiber layr as shown on the topographic map of the eye. Finally, use of the scanning laser Doppler flowmeter to examine eyes with advanced visual field defects showed that blood flow to the optic nerve head may be decreased with advanced visual field defects showed that blood flow to the optic nerve head may be decreased in t … More hese eyes. These results indicated that to use these scanning laser devices is useful to early detection of glaucoma as well as visual field testing.In addition to using optic disc parameters and retinal nerve fiber layr findings for diagnosing early glaucoma, to identify presence of peripapillary atrophy or splinter hemorrhage has been revealed to be another important landmarks. On the other hand, in normal-tension glaucoma patients with only superior or inferior hemifield dominant defects, the relation between visual field indices, obtained by automated perimetry, and optic disc parameters determined via confocal laser scanning tomography and retinal nerve fiber layr thickness determined via scanning laser polarimetry was assessed. We found that even in the optic tic parameters or nerve fiber layr thickness corresponding to the unaffected hemifield, there were statistically, significant worsening in these parameters. It was concluded that the optic nerve head or nerve fiber layr abnormalities may be detectable in areas of apparently normal visual field in normal-tension glaucoma. Less