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Objective: To determine the relationship of objective and subjective outcome measures of Vision Restoration Training (VRT) for visual field recovery in partially blind patients. This is of interest because the patient's subjective improvement cannot be inferred from objective changes in visual field charts. Design: Nineteen patients with visual system lesions underwent visual field tests (objective measure) before and after six months of VRT. Subjective outcome was determined by pre-and post-training interviews (open narration, questions on activities of daily living, ratings). Interview content was quantified by determining the response frequency for relevant content categories. Drawings of perceived visual field size were used as a subjective topographical measure. Subjective training results were compared to objective visual field size (perimetry). Results: Visual field size increased significantly over the training period. Patients' subjective evaluations depended on the size and location of regained areas, but also on specific evaluation of safe navigation, mobility, reading, and communication. Patients with objective increase of visual field size also reported subjective improvements in daily life. Conclusions: Computer-based training can improve visual field size as well as subjective visual performance. The patients' subjective experience should be included in treatment evaluation to ensure the meaningfulness of training beyond perimetric measures.

Visual field deficits in patients have long been considered to be nontreatable, but in previous studies we have found an enlargement of the intact visual field following vision restoration therapy (VRT). In the present pilot study, we wished to determine whether a double-stimulation approach would facilitate visual field enlargements beyond those achieved by the single-stimulus paradigm used in standard VRT. This was motivated by the findings that following visual cortex injury in animals, the size of receptive fields could be enlarged by systematic costimulation, where two stimuli were used to excite visual cortex neurons (Eysel, Eyding, & Schweigart, 1998). Patients (n = 23) with stable homonymous field deficits after trauma, cerebral ischemia, or hemorrhage (lesion age > 6 months) carried out either (a) standard VRT with a single stimulation (n = 9), or vision therapy with (b) a parallel costimulation (n = 7) or (c) a moving costimulation paradigm (n = 7). Training was carried out twice daily for 30 min over a 3-month period. Before and after therapy, visual fields were tested with 30 degrees and 90 degrees Tübinger automatic perimetry (TAP) and with high-resolution perimetry (HRP). Eye movements were recorded with an eye tracking system. When data of all three types of visual field training were pooled, we found significant improvements of stimulus detection in HRP (4.2%) and fewer misses within the central 30 degrees perimetrically (-3.7% right eye, OD, or -4.4% left eye, OS). However, the type of training did not make any difference such that the three training groups profited equally. A more detailed analysis of trained versus untrained visual field areas in 16 patients revealed a superiority of the trained area of only 1.1% in HRP and between 3.5% (OS) and 4.4% (OD) in TAP. Spatial attention and alertness improved significantly in all three groups and correlated significantly with visual field enlargements. While vision training had no influence on the patient's testimonials concerning their visual abilities, the patients significantly improved in a practical paper-and-pencil number tracking task (Zahlen-Verbindungs Test; ZVT). Visual field enlargement does not benefit from a double-stimulation paradigm, but visual attention seems to play an important role in vision restoration. The improvements in trained as well as in untrained areas are explained by top-down attentional control mechanisms interacting with local visual cortex plasticity.

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