The Effects of Superior and Inferior Visual Field Defects on Reading Ability

<p>[Purpose] People with a superior or inferior visual field defect (SVFD, IVFD) sometimes experience difficulty in daily life even when their visual acuity (VA) is relatively good. In this study, we investigated the difficulties in patient's daily life with a focus on the reading ability between those with SVFD and IVFD.</p><p>[Subjects and Methods] Subjects were 18 patients with SVFD or IVFD and VA of > 0.4 in the fellow eye who visited the Department of Ophthalmology Outpatient Clinic at Osaka Medical College Hospital between September 2015 and June 2016, and 20 healthy controls. The subjects' age ranged from 50 to 89 years. The VF was evaluated with Goldmann perimetry and the Humphrey Field Analyzer (HFA) 10-2. Reading speed (letters per minute) was measured using vertical writing (VW), horizontal writing (HW), and horizontally aligned vertical writing (HAVW). Reading performance was compared between the patients and controls. In addition, the patients with SVFD and IVFD filled out a questionnaire about the difficulties in their daily life and any differences between these two groups of patients were investigated. </p><p>[Results] The respective VW, HW, and HAVW reading speeds were 356 ± 84, 246 ± 48, and 290 ± 54 for the patients with SVFD, 333 ± 87, 219 ± 75, and 260 ± 91 for the patients with IVFD, and 345 ± 55, 259 ± 66, and 240 ± 103 for the controls. The patients with SVFD and IVFD had a lower reading speed than the controls. The reading speed with HAVW was significantly higher than the speed with VW in the patients with SVFD. The patients with IVFD tended to read faster with HW than with VW. The subjects with IVFD who showed a very low VW reading speed had higher HW and HAVW reading speeds. The central VF evaluated by the HFA 10-2 was found to have a connection with reading speed. The questionnaire results indicated that the patients with IVFD had more difficulty in mobility in daily life. </p><p>[Conclusions] For the subjects with IVFD who had difficulty in reading VW, re-arranging the direction of the writing from vertical to horizontal appeared to be effective. The HFA 10-2 was useful for evaluating the central VF that affects patient's reading performance. Patients' difficulties in mobility and daily life activity had a close connection with their IVFD, and the inferior peripheral VF was found to be especially important for mobility.</p>