VFDs were tested in 38 patients after epilepsy surgery to the temporal lobe.
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A VFD in the upper quadrant was demonstrated with HFA in 76% of patients.
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Subjective symptoms and bedside VFD testing are insensitive to detect even a severe VFD.
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Web-based VFD testing was sensitive to detect severe but not moderate VFDs.
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Patients consider post-surgical VFD testing as mandatory.
Abstract
Purpose
To determine visual field defects (VFDs) using methods of varying complexity and compare results with subjective symptoms in a population of newly operated temporal lobe epilepsy patients.
Methods
Forty patients were included in the study. Two patients failed to perform VFD testing. Humphrey Field Analyzer (HFA) perimetry was used as the gold standard test to detect VFDs. All patients performed a web-based visual field test called Damato Multifixation Campimetry Online (DMCO). A bedside confrontation visual field examination ad modum Donders was extracted from the medical records in 27/38 patients. All participants had a consultation by an ophthalmologist. A questionnaire described the subjective complaints.
Reults
A VFD in the upper quadrant was demonstrated with HFA in 29 (76%) of the 38 patients after surgery. In 27 patients tested ad modum Donders, the sensitivity of detecting a VFD was 13%. Eight patients (21%) had a severe VFD similar to a quadrant anopia, thus, questioning their permission to drive a car. In this group of patients, a VFD was demonstrated in one of five (sensitivity = 20%) ad modum Donders and in seven of eight (sensitivity = 88%) with DMCO. Subjective symptoms were only reported by 28% of the patients with a VFD and in two of eight (sensitivity = 25%) with a severe VFD. Most patients (86%) considered VFD information mandatory.
Conclusion
VFD continue to be a frequent adverse event after epilepsy surgery in the medial temporal lobe and may affect the permission to drive a car in at least one in five patients. Subjective symptoms and bedside visual field testing ad modum Donders are not sensitive to detect even a severe VFD. Newly developed web-based visual field test methods appear sensitive to detect a severe VFD but perimetry remains the golden standard for determining if visual standards for driving is fulfilled. Patients consider VFD information as mandatory.
Part of this work has been previously presented at the following congresses: European Association for Vision and Eye Research (EVER), Nice, France, October 2015. European Academy of Neurology (EAN), Copenhagen, Denmark, May 2016. European Congress of Epileptology (ECE), Prague, Czech Republic, September 2016.
