Automated static perimetry: The influence of myopia and its method of correction

Objectives To determine how the magnitude of myopia and its method of corre ction influence visual field testing. Design: Prospective observational case series, including comparison of spec tacles and contact lenses. Participants: One hundred forty-six ophthalmologically normal males 19 to 2 4 years of age with myopia (spherical equivalent from -0.50 to -14.0 diopte rs). Methods: Participants performed automated static threshold perimetry. Refra ctive errors were corrected using trial lenses and soft contact lenses. Sub jects were tested with both methods of correction, the order of which was r andomized. Main Outcome Measures: Threshold sensitivity and global indexes. Results: Only one subject (0.7%) had a significant reproducible visual fiel d defect on both methods of correction. Six subjects (4.1%) had a focal vis ual field defect on one method of correction but not the other. For myopia greater than -4.0 diopters, the mean defect decreased significantly as axia l length and degree of myopia increased (P < 0.01). Similar results were ob tained with either method of correction. Conclusions: Threshold sensitivity is reduced in moderate and high myopia, regardless of the method of correction. The surprisingly low prevalence of visual field defects in this myopic population disputes the widely held vie w that myopia is associated commonly with visual field abnormalities. if fi eld defects are found in myopes on automated perimetry, it is advisable to repeat the test with another method of optical correction to check that suc h defects are genuine and not related to the method of refractive correctio n. Ophthalmology 2001;108: 290-295 (C) 2001 by the American Academy of Opht halmology.