INFLUENCE OF AXIAL LENGTH ON VISUAL-FIELD DEFECTS IN PRIMARY OPEN-ANGLE GLAUCOMA

With the high Frequency of myopia in Taiwan, potential complications o r associated conditions, such as glaucoma, are of great concern. To in vestigate the role of axial length in glaucoma, we enrolled 307 primar y open-angle glaucoma (POAG) patients from 1986 through 1996. For the control group, 124 persons were recruited from a survey of a non-glauc oma population and the Ophthalmology Out-patient Department of the Nat ional Taiwan University Hospital. Routine eye examination, stereophoto graphy of the optic disc, automated visual field tests, and A-scan ult rasonography were performed on each patient. The Glaucoma Hemifield te st was used for analysis of visual field results. The mean axial lengt h was longer in the POAG group than in the control group, especially i n the younger age groups (40-59 yr). The POAG group was divided into a short-axial-length (SAL, axial length < 26 mm) group and a long-axial -length (LAL, axial length greater than or equal to 26 mm) group. Both subgroups had the deepest visual field defects in the upper and lower nasal areas. The LAL. group had deeper visual field defects and the d efects were more frequently involved in all sectors analyzed than the SU group defects. The upper visual field had deteriorated more in the SAL group, whereas dhe depth of scotoma was similar in the upper and l ower hemifields in the LAL group. Our results support the idea that gl aucoma patients have a longer axial length than people without glaucom a, and that visual held defects are more pronounced in patients with L AL than in those with SAL.