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Vision restoration therapy
Br. J. Ophthalmol.
doi:10.1136/bjo.2005.068163 Updated information and services can be found at: Rapid responses
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consent obtained by the prescribingprimary physician with explicit written documentation in the medical record;(2) detection and minimisation of toxi-city rather than prevention itself; (3) definition of high and low risk patients(see table 1); and (4) stratification of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
baseline eye examination is normal andthe Almonyetalreportinthisissueof electrophysiological testing might be recommendedscreeningintervalfollows scotomas. It is unlikely that this repre- tested with a ‘‘white on black’’ Amsler grid (AG), a ‘‘red on black’’ AG (RAG), did not have a baseline eye examination.
significant limiting factor for the TAG.
‘‘gold standard’’ for identification of no ‘‘gold standard’’ for HCQ retinopathy mentary changes and ‘‘bull’s eye macu- lopathy’’). Despite the recommendation of the AAO, it is not clear that a baseline location using another central field test 20 cases of toxicity at the ‘‘subthres- hold’’ dose of ,6.5 mg/kg/day. All of ment of renal and liver function, inquiry multifocal electroretinogram (MERG).
by the American Academy ofOphthalmology (AAO) Table 1 Criteria of low and higher risk for developing retinopathy (modified Baseline visual field testing (eg, Amsler orHumphrey 10–2) Optional colour vision testing (eg, screenfor pretreatment colour blindness) Optional specialised tests (eg, fluorescein subtle scotomas in patients taking HCQ.
measurement of visual acuity annually.
Correspondence to: Dr A G Lee, Departments Buckley et al in the April 2004 guidelines Neurosurgery, The University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA; leea@ 1 Maturi RK, Minzhou Y, Weleber RG. Multifocal electroretinographic evaluation of long-term hydroxychloroquine users. Arch Ophthalmol 2 Pluenneke AC, Blomquist PH. Utility of red amsler develop visual symptoms on treatment.
grid screening in a rheumatology clinic.
3 Marmor MF, Carr RE, Easterbrook M, et al.
Recommendation on screening for chloroquine and hydroxychloroquine retinopathy. A report by the American Academy of Ophthalmology.
4 Easterbrook M. Screening for antimalarial toxicity: current concepts. Can J Ophthalmol 5 Buckley R, Graham E, Jones S, et al. Ocular toxicity and hydroxychloroquine: guidelines for screening 2004. (www.rcophth.ac.uk/scientific/ docs/oculartoxicity2004.pdf, last accessed on 4 6 Samanta A, Goh L, Bawendi A. Are evidence- hydroxychloroquine? A nationwide survey ofpractice amongst consultant rheumatologists and implications for clinical governance.
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provement on these measures.4 Similarenlargement of the visual field after therapy has been demonstrated on‘‘standard clinical perimetry’’ by variousinvestigators and laboratories.5–9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
after therapy, probably reflects thecomparatively greater task difficulty ofthe SLO. It is well known that peri- We have followed with interest this methodology. An important point metric performance is task dependent, critically on stimulus characteristics.
alone, it would be ‘‘more compelling if Reinhard et al1 and collaborators on that perimeter.’’ Although not reported in patients had to respond to single stimuli ‘‘no therapeutic intervention … can correct effectively the underlying visual which perceptually flickers because it is could lead to incorrect conclusions.
to the vertical midline than the absolute Or take the patient shown in figure 1, inwhich the visual field defect shrank by shifting of the horizontal border withoutaffecting the vertical border, and thedeficit next to the fixation spot wasunchanged. If eye movement artefacts had occurred, the reverse would beexpected: a shift of the vertical borderand no change in the horizontal border.
Such border dynamics are incompatiblewith eye movement artefacts.
of placebo effects. However, the studyby Kasten et al6 described two indepen-dent clinical trials in which the placebo showed that the placebo treatment hadno effect in the post-chiasmatic groupand only a small effect in the optic nerve group. In this study6 and in others,5 7patients also reported subjective benefitsafter VRT, including improved visualfunction in reading, navigation, and Border position (° from vertical midline) further investigate VRT effects on stan-dardised functional measures of visual Figure 1 This graph (adapted from Sabel et al4) displays the visual field border position in the right eye as assessed by the three perimetric tests. (A) The results of patient CH where grey areas represent the area of the defect. A mismatch in perimetric fields was noted even before therapy.
After VRT, the HRP and TAP border shifted away from the vertical meridian whereas the SLO border remained roughly in the same position, exaggerating the border mismatch. (B) Shows the absolute visual field border for SLO, TAP, and HRP in the central 10˚ region in degrees of visual angle from the 0 vertical meridian before and after VRT (mean (SEM)). Whereas the SLO border was almost identical pre-VRT compared with post-VRT, the HRP and TAP borders were not only significantly different before VRT (mismatch), but also both shifted significantly after VRT, producing a visual standard in the field of rehabilitationmedicine. They are not limited to clarify this issue. First of all, most of the that ‘‘it remains possible that improve- learning,11 and there is an entire body of defects.’’3 This is indeed confirmed by neuroplasticity, such as studies on adult patients4: when ‘‘relative defects’’ in ‘‘relative’’ border was found to be is not purely ‘‘sensory.’’ It utilises many roughly identical to the SLO border.
ted that lack of a shift in the blind spot position is a good indicator that fixation tive to relative defects describing areas logical blind spot ‘‘filling in’’ and in the patients in the SLO study, the blind spot position remained identical after VRT.
other forms of perimetry either. Finally, yet defined. Horton believes that in pati- ‘‘no fringe of injured but salvageable the entire visual field border to shift. In tissue.’’ This assumption may be true in most patients this is not what is seen. A defect with computer-assisted training. RestorNeurol Neurosci 2003;21:19–28.
the damaged zones (‘‘relative defects’’).
6 Kasten E, Wu¨st S, Behrens-Baumann W, et al.
Computer-based training for the treatment of partial blindness. Nat Med 1998;4:1083–7.
7 Mueller I, Poggel DA, Kenkel S, et al. Vision restoration therapy (VRT) after brain damage: subjective improvements of activities of daily life and their relationship to visual field enlargements.
Visual Impairm Res 2003;5:157–78.
by surviving primary cortical afferents16 8 Poggel DA, Kasten E, Sabel BA. Attentional cueing improves vision restoration therapy in patients with visual field loss. Neurology2004;63:2069–76.
lus and pulvinar.18 19 This latter pathway 9 Zihl J, von Cramon D. Visual field recovery from scotoma in patients with postgeniculate damage.
those with partial deficits, benefit from A review of 55 cases. Brain 1985;108:335–65.
10 Trauzettel-Klosinski S, Reinhard J. The vertical field border in hemianopia and its significance for fixation and reading. Invest Ophthalmol Vis Sci 11 Gilbert CD, Sigman M, Crist RE. The neural basis Hortons group21: a direct projection from 12 Eysel T, Gonzalez-Aguilar F, Mayer U. A . . . . . . . . . . . . . . . . . . . . . .
functional sign of reorganization in the visualsystem of adult cats: lateral geniculate neurons with displaced receptive fields after lesions of the B A Sabel, S Kenkel, E Kasten, Institute of nasal retina. Brain Res 1980;181:285–300.
13 Chino YM, Smith EG 3rd, Kaas JH, et al.
Receptive-field properties of deafferentated visual cortical regions without involving V1.
role in VRT induced visual field enlarge- 14 Gilbert CD, Wiesel TN. Receptive field dynamics Correspondence to: Bernhard A Sabel, PhD, Institute of Medical Psychology, Otto-von- 15 Kaas JH, Krubitzer LA, Chino YM, et al.
Reorganization of retinotopic cortical maps in adult mammals after lesions of the retina. Science 16 Wu¨st S, Kasten E, Sabel BA. Blindsight after optic nerve injury indicates functionality of spared fibers. J Cogn Neurosci 2002;14:243–53.
analysis of the complete data in order to 17 Fendrich R, Wessinger CM Gazzaniga MS.
1 Reinhard J, Schreiber A, Schiefer U, et al. Does Residual vision in a scotoma: implications for visual restitution training change absolute that VRT does not assist all patients.
18 Po¨ppel E, Held R, Frost D. Residual visual controlled study. Br J Ophthalmol 2005;89:30–5.
functions after brain wounds involving the central NovaVision’s visual restoration therapy.
of the relative defect tends to correlate 19 Weiskrantz L, Warrington EK, Sanders MD, et al.
3 Plant GT. A workout for hemianopia.
Visual capacity in the hemianopic field following 4 Sabel BA, Kenkel S, Kasten E. Vision restoration 20 Cavanaugh J, Wurtz RH. Subcortical modulation comparative perimetric analysis and subjective of attention counters change blindness. J Neurosci 21 Sincich LC, Park KF, Wohlgemuth MJ, et al.
5 Julkunen L, Tenovuo O, Ja¨a¨skela¨inen S, et al.
Bypassing V1: a direct geniculate input to area Rehabilitation of chronic post-stroke visual field

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