ABSTRACT
Introduction: Patients suffering from visual field defects caused by optic nerve or postchiasmatic injury commonly experience many limitations in their daily activities. The generally accepted paradigm that nothing can be done leaves little hope for such patients as restoration was once considered impossible. In recent years, however, a paradigm shift has taken place. Through high-resolution perimetry (HRP), areas of residual vision can now be identified where training visual functions help to restore some of the lost vision and there is now a growing body of evidence that the visual system possesses a high degree of plasticity. Clinical Picture: A retrospective case review of 3 patients who suffered post-chiasmatic visual field loss and underwent 6 modules of vision restoration therapy (VRT). Their HRP results were compared before and after therapy. Treatment: All 3 patients underwent 6 modules of VRT. Each module consisted of twice daily 30 minutes of visual stimulation consisting of 500 randomly placed supra-threshold visual stimuli in a central 540 by 430 dark monitor screen. Outcome: All 3 patients experienced an improvement in their confidence in mobility as well as bumping less into objects in their peripheral fields. In Case 1, pre-VRT HRP showed a stimulus detection accuracy of 55.34%. After 6 modules of VRT there was an impressive increase to 90.23%. In Case 2, pre-VRT HRP showed a left incomplete homonymous hemianopia with a stimulus detection accuracy of 70.32% that improved to 98.10%. In Case 3, pre-VRT HRP revealed a left superior quadrantanopia with a stimulus detection accuracy of 57.03% that increased to 73.42%. Conclusions: Although VRT is in its early stages in Singapore, the results from these 3 patients are promising and this can become one of the new modalities in the provision of an all-rounded neuro-rehabilitation programme for our patients with post-chiasmatic visual field loss.
Patients suffering from visual field defects caused by optic nerve or post-chiasmatic injury commonly experience many limitations in their daily activities. The generally accepted paradigm that nothing can be done leaves little hope for such patients as restoration was once considered impossible.
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