Parafoveal vision impairments and their influence on reading performance and self-evaluated reading abilities
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Background and purpose
Patients with homonymous hemianopic field defects (HFD) after postchiasmatic cerebral brain injuries often complain about impairments in daily life activities, particularly problems in reading, and show considerable reductions of vision-related quality of life (QoL). This study aimed to assess the relation of “objective” reading performance and self-reported “subjective” reading abilities; it was further investigated whether parafoveal HFD characteristics have an impact on both parameters.
In postchiasmatic-lesioned subjects with HFD (n = 43), “objective” reading performance was measured with Radner-Reading-Charts (reading speed, reading acuity). Vision-related QoL was assessed by the National-Eye-Institute-Visual-Function-Questionnaire (NEI-VFQ). Four reading-relevant NEI-VFQ items that assessed “subjective” reading abilities were separately analyzed. Macular sparing measures were derived from campimetry (±16° vertical, ±21.5° horizontal); i.e., the vertical HFD border between ±2° and the proportion of intact parafoveal visual field within the “reading window”. Since macular sparing may be a perimetric artefact, eye movements during campimetry were recorded in 26 subjects.
Mean reading speed of the total sample (90.72 ± 33.96 words per minute) was considerably reduced, as was the patients' vision-related QoL, which was revealed by diminished NEI-VFQ scores. Reading acuity was 0.12 ± 0.13 LogRAD (0.81 ± 0.26 according to the decimal system). There were significant but weak correlations between reading acuity and speed with all reading-relevant NEI-VFQ-items (r-range, reading acuity: −0.57 to −0.38, reading speed: 0.33 to 0.43) and 7/12 NEI-VFQ-subscales (r-range, reading acuity: −0.47 to −0.33, reading speed: 0.31 to 0.40). The intact parafoveal visual field correlated significantly with 2/4 reading-related NEI-VFQ-items and with 4/12 NEI-VFQ-subscales (r-range 0.31 to 0.52). Reading acuity and mean reading speed were both correlated with fixation accuracy during campimetry (r = −0.38 and 0.45). Correlations of spared areas between +2° to −2° and the relative and absolute defect HFD border with reading speed, but not reading acuity, tended to significance. Subjects deviated from the campimetric fixation mark in a SD-range of ±5.2° vertically and ±6.5° horizontally but eye movement ranges were not correlated with macular sparing measures.
Patients with HFD showed severely reduced reading speed, which was reflected in subjectively diminished reading performance, and reduced reading-related QoL parameters. Larger areas of functionally intact parafoveal vision were associated with better reading performance. Although eye movements occurred during campimetry, these did not seem to constitute an artificially enlarged area of parafoveal intact vision.
KeywordsHemianopia Reading Visual field border Macular sparing Eye movements Quality of life
We thank Nicole Mäter and Sandra Heinrich (both Institute of Medical Psychology, Magdeburg, Germany) for their support in data-collection and data-handling as well as Jürgen Köhler, PhD for his support in statistical analyses (University of Applied Sciences, Magdeburg-Stendal, Section of Statistics, Magdeburg, Germany). The study was funded by the Otto-von-Guericke University, Magdeburg.
- 1.Ciuffreda KJ (1994) Reading eye movements in subjects with oculomotor disturbances. In: Ygge J, Lennerstrand G (eds) Eye movements in reading. Alden Press, Oxford, pp 163–186Google Scholar
- 2.Faul F, Erdfelder E, Lang AG, Buchner A (2007) G*Power3: a flexible statistical power analysis program for the social, behavioural and biomedical sciences. Behav Res Meth 39:175–191Google Scholar
- 4.Franke GH, Mähner N, Reimer J, Voigtländer-Fleiß A, Esser J (2003) Ein psychodiagnostischer Zugang zur Erfassung der Einbußen an gesundheitsbezogener Lebensqualität bei verringerter Sehkraft. Zeitschrift für Medizinische Psychologie 12:57–62Google Scholar
- 6.Gall C, Mueller I, Gudlin J, Lindig A, Schlueter D, Jobke S, Franke GH, Sabel BA (2008) Vision- and health-related quality of life before and after vision restoration training in cerebrally damaged subjects. Restor Neurol Neurosci 26:1–13Google Scholar
- 7.Gall C, Lucklum J, Sabel BA, Franke GH (2009) Vision- and health-related quality of life in subjects with visual field loss after postchiasmatic lesions. Invest Ophthalmol Vis Sci 50:2765–2776Google Scholar
- 14.McConkie GW, Rayner K (1975) The span of the effective stimulus during a fixation in reading. Percept Psychophys 17:578–586Google Scholar
- 15.McConkie GW, Rayner K (1976) Asymmetry of the perceptual span in reading. Bull Psychonomic Soc 8:365–368Google Scholar
- 22.Posner MI, Nissen MJ, Ogden WC (1978) Attended and unattended processing modes: the role of set for spatial location. In: Pick HL Jr, Saltzman E (eds) Modes of perceiving and processing information. Erlbaum, Hillsdale: NY, pp 137–157Google Scholar
- 31.Wilson B, Cockburn J, Halligan P (1987) Development of a behavioral test of visuospatial neglect. Am J Phys Med Rehabil 68:98–101Google Scholar
- 32.Zihl J (1989) Cerebral disturbances of elementary visual functions. In: Brown JW (ed) Neuropsychology of visual perceptions. Lawrence Erlbaum, Hillsdale (NJ), pp 35–58Google Scholar