We have followed with interest the discussion ignited by the paper by Reinhard et al¹ by way of editorial comments from Horton² and Plant.³ As co-authors of the paper by Reinhard et al¹ and collaborators on that study, we have no objections to the data as presented. However, Horton’s interpretation that these data indicate that “no therapeutic intervention … can correct effectively the underlying visual field deficit” after post-chiasmatic injury is not supported by current scientific evidence. On the contrary, a comprehensive and critical review of the literature reveals that there is a sound scientific basis for recommending vision restoration therapy (VRT) for some patients with hemianopia.

The Reinhard study¹ used scanning laser ophthalmoscopy (SLO) to evaluate visual fields before and after a 6 month course of VRT and found no change in the size of the blind field detected by this methodology. An important point well taken by Horton is that rather than relying on the VRT computer based tests alone, it would be “more compelling if visual field improvements could be demonstrated with any standard clinical perimeter.” Although not reported in the Reinhard article, the same patients were also tested by two other perimetric methods: the Tübingen automated perimeter (TAP) and high resolution perimetry (HRP, which is a campimetric visual field test).⁴ We acknowledge that Horton did not have access to this important information which was in press at the time. We believe that not considering these other perimetric data could lead to incorrect conclusions. Even before VRT began, the SLO border was already located significantly closer to the vertical midline than the absolute TAP and HRP borders (fig 1). After VRT, the SLO border was unchanged, but the absolute TAP and HRP borders had significantly shifted, confirming improvement …