Patterns of Binocular Visual Field Loss Derived from Large-Scale Patient Data from Glaucoma Clinics

Abstract

To estimate prevalence of visual field (VF) loss in superior and inferior hemifields in binocular VFs in a large sample of patients with bilateral glaucoma. Retrospective cohort study. Glaucoma patients and suspects attending 4 regionally different secondary-care eye clinics in the United Kingdom. Binocular integrated visual fields (IVFs) using a best location method were constructed for 16 642 patients with bilateral VF loss. A significant VF defect was defined as 3 or more VF locations less than a certain sensitivity threshold, such as 20 dB. Patients were classified as having a VF defect in the inferior hemifield, superior hemifield, both hemifields, or neither hemifield. The criteria for number of locations and sensitivity threshold (in decibels) were varied across a large range of values. In addition, factor analysis was applied to the sensitivity values (in decibels) of the IVFs to determine common defect patterns in an automated fashion. Ratio of patients with binocular VF defects in the superior compared with the inferior areas of the IVF. Estimates of the ratio of patients having binocular VF defects in the superior compared with the inferior region of the IVF ranged from 2.1 (95% confidence interval, 2.1-2.4) to as high as 5.1 (95% confidence interval, 4.7-5.5), depending on the defect criteria used. Fewer than 10% of those patients exhibiting relatively early binocular VF loss had a defect confined to the inferior region only. Common patterns of binocular VF loss were dominated chiefly by superior hemifield defects. In a clinical population of patients with measurable VF loss in both eyes, superior-only binocular VF loss is more common than inferior-only loss. These estimates, derived from large collections of electronic medical records, are useful for interpreting findings about location of binocular VF loss impacting everyday activities and examining visual disability in glaucoma.