Abstract
Purpose: :
It has been reported that visual field defects in myopic glaucoma are more likely to be closure to fixation point or to involve the fixation area. We evaluate clinical features in myopic glaucomatous eyes with scotoma threatening central visual field.
Methods: :
One hundred fifty eight eyes of 158 patients were compiled with spherical equivalent from -0.5 to -10 diopters. Heidelberg Retina Tomogragh (HRT) and fundus photography were conducted to calculate optic disc ovality and eyes with optic disc ovality ≤ 0.8 were selected on the ratio of horizontal to vertical diameter. Visual field was examined using Goldmann perimeter and Octopus 101 (program M2). We divided scotomas into three types, simple, complex and fusional.
Results: :
Increased optic disc ovality was associated with higher myopia. Scotomas were detected in 42 eyes for simple type, 59 eyes for complex type and 57 eyes for fusional type. According to M2 program, simple scotoma was observed around central area from 5 to 10 degrees, and high frequency on upper nasal area. Appearance of complex and fusional scotoma was in more advanced stage of field changes and in some scotomas decrease of sensitivity was observed within central 5 degrees area.
Conclusions: :
This study suggested that at the beginning of visual field defects, fixation area within central 5 degrees was not involved and after progression of glaucomatous optic disc changes fixation area might be involved from 5 to 10 degrees, so called Bjerrum area.
Keywords: optic disc • visual fields • myopia