Xanthopsia Due to Digoxin Toxicity as a Cause of Traffic Accidents: A Case Report.

BACKGROUND Manifestations of digoxin toxicity vary, such as cardiac disturbances and gastrointestinal symptoms, and most are not specific to digoxin toxicity. We report a case of xanthopsia (yellow vision), a rare and relatively specific manifestation of digoxin toxicity, causing traffic accidents. CASE REPORT A 76-year-old man was admitted to our hospital for treatment of heart failure. He reported that his digoxin dose had been increased from 0.125 mg daily to 0.25 mg daily 3 weeks before admission. His serum digoxin level was 7.3 ng/mL (therapeutic range 0.8 to 2.0). Additional history-taking revealed that he had xanthopsia several days before admission and stopped riding a motorbike because of two traffic accidents. On ophthalmological examination, he had decreased responses on flash, cone, and 30-Hz flicker electroretinograms in both eyes without visual field impairment. Intravenous hydration was initiated and digoxin was withdrawn. Xanthopsia gradually improved along with the decline of serum digoxin levels and disappeared within a week. One month after admission, electroretinography findings were normal. CONCLUSIONS Our case highlights the importance of acknowledging color vision deficiencies due to digoxin toxicity even in the modern era. This condition may increase risk of adverse events because affected patients are less likely to recognize color vision deficiencies.

Evaluation of pre- and post-surgery reading ability in patients with epiretinal membrane: a prospective observational study.

BACKGROUND: This study aimed to investigate the pre- and post-surgery reading ability in patients with idiopathic epiretinal membrane (ERM) to evaluate whether measurement of reading performance is a helpful test in addition to visual acuity (VA) as an assessment measure. METHODS: This prospective observational study involved 42 eyes of 40 patients with idiopathic ERM. Best-corrected visual acuity (BCVA), reading ability, and metamorphopsia score were evaluated at baseline and at 3, 6, and 12 months post-surgery. As the outcome measure, the reading ability of each patient (i.e., overall performance) was examined with MNREAD-J, the Japanese version of the MNREAD reading acuity (RA) charts, to determine RA, critical print size (CPS), and maximum reading speed (MRS). Generally, a difference of 0.2 logMAR or more is considered a significant change in BCVA. Thus, as a subgroup analysis, we additionally evaluated the BCVA and reading ability of the patients with a BCVA difference of 0.1 logMAR or less between at baseline and at 12 months post-surgery. RESULTS: Relative to their values at baseline, the subjects exhibited significantly improved BCVA, RA, and CPS throughout the post-surgery examination period (P < 0.001) and significantly improved MRS at 12 months post-surgery (P = 0.04). No significant change in the vertical metamorphopsia score was observed throughout the post-surgery follow-up period. However, and compared to the value at baseline, significant improvements in the horizontal metamorphopsia score were observed at 3, 6 (P < 0.05), and 12 months (P < 0.001) post-surgery. In the subgroup analysis of the 23 eyes that exhibited a BCVA improvement of 0.1 logMAR or less, the median BCVA did not change, but the median RA and CPS improved by 0.2 logMAR. CONCLUSIONS: Our findings showed that the surgical removal of ERM improves reading ability, even when the BCVA score does not improve. The measurement of reading performance appears to be a helpful test in addition to VA as a measure for assessing the surgical removal of ERM.