Typical slit-like retinal nerve fiber layer defect and corresponding scotoma
Iwata, K.; Nanba, K.; Abe, H.
Nippon Ganka Gakkai Zasshi 85(10): 1791-1803
1981
ISSN/ISBN: 0029-0203 PMID: 7337107 Document Number: 178266
The quantitative correlation between the slit-like retinal nerve fiber layer (NFL) defect and the sensitivity deterioration of scotoma in Bjerrum area was revealed. The localization of scotoma was also revealed. Seven cases with clear slit-like NFL defect in Bjerrum area were selected, in which 5 cases were non glaucomatous and 2 cases were early glaucomatous patients. Among the 5 non-glaucomatous cases, 2 had Behcet's desease, 1 had myocardial infarction and 2 had no apparent systemic or local abnormality. The visual field was measured by Goldmann perimeter and by Friedmann visual field analyzer Mark II (Friedmann MII), in which the threshold of each point was determined. When the width of slit-like NFL defect is narrower than 3 times greater the width of the retinal artery at a distance of 1 vertical disc diameter from the optic disc, the visual field impairment cannot be accurately identified by Goldmann perimetry. Using the Friedmann MII, abnormality of visual field can be accurately identified at the sensitivity reduction of -0.2 log to -0.6 log below circumferential sensitivity with extremely thin slit NFL defect are responsible for reductions of only -0.2 log, which is usually considered to be physiological variation, close correlation was observed between sensitivity reduction and the thickness of slit-like defect of NFL. The nucleus of the scotoma was usually localized at the temporal side from macula, where the NFL defect extended to the vertical line passing the fovea. When the NFL defect terminates at the nasal side from the vertical line, the nucleus of scotoma localizes also the same nasal side. Nerve fiber loss in slit-like defect is too little to change cup size and rim width. Apparently, the identification of NFL defect is the most sensitive method for giving evidence of visual damage in the slightest range; for the analysis of the quality of NFL defect is best provided by the grade of reduction in sensitivity and the size and the location of scotoma.