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Assessment of night vision problems in patients with congenital stationary night blindness.

Bijveld MM, van Genderen MM, Hoeben FP, Katzin AA, van Nispen RM, Riemslag FC, Kappers AM - PLoS ONE (2013)

Bottom Line: The questionnaire showed that the CSNB2 patients hardly experienced any night vision problems, while all CSNB1 patients experienced some problems although they generally did not describe them as severe.The results from the "2D Light Lab" showed that all CSNB1 patients were blind at low intensities (equal to starlight), but quickly regained vision at higher intensities (full moonlight).From the results we conclude that night vision problems in CSNB, in contrast to what the name suggests, are not conspicuous and generally not disabling.

View Article: PubMed Central - PubMed

Affiliation: Bartiméus Institute for the Visually Impaired, Zeist, The Netherlands. mbijveld@bartimeus.nl

ABSTRACT
Congenital Stationary Night Blindness (CSNB) is a retinal disorder caused by a signal transmission defect between photoreceptors and bipolar cells. CSNB can be subdivided in CSNB2 (rod signal transmission reduced) and CSNB1 (rod signal transmission absent). The present study is the first in which night vision problems are assessed in CSNB patients in a systematic way, with the purpose of improving rehabilitation for these patients. We assessed the night vision problems of 13 CSNB2 patients and 9 CSNB1 patients by means of a questionnaire on low luminance situations. We furthermore investigated their dark adapted visual functions by the Goldmann Weekers dark adaptation curve, a dark adapted static visual field, and a two-dimensional version of the "Light Lab". In the latter test, a digital image of a living room with objects was projected on a screen. While increasing the luminance of the image, we asked the patients to report on detection and recognition of objects. The questionnaire showed that the CSNB2 patients hardly experienced any night vision problems, while all CSNB1 patients experienced some problems although they generally did not describe them as severe. The three scotopic tests showed minimally to moderately decreased dark adapted visual functions in the CSNB2 patients, with differences between patients. In contrast, the dark adapted visual functions of the CSNB1 patients were more severely affected, but showed almost no differences between patients. The results from the "2D Light Lab" showed that all CSNB1 patients were blind at low intensities (equal to starlight), but quickly regained vision at higher intensities (full moonlight). Just above their dark adapted thresholds both CSNB1 and CSNB2 patients had normal visual fields. From the results we conclude that night vision problems in CSNB, in contrast to what the name suggests, are not conspicuous and generally not disabling.

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Related in: MedlinePlus

2D Light Lab results of the normal subjects, the CSNB2 patients, and the CSNB1 patients.A: Three representative examples of the results from the 2D Light Lab. The figure shows the cumulative of the relative number of objects detected or recognized, the fit of the psychometric curve, and the crossmarks that indicate the intensity at which 50% of the objects were detected or recognized (i50d and i50r). B: The psychometric fit to the cumulative of objects detected at increasing light levels in the 2D Light Lab for each subject. The green dots (control subjects), black diamond (CSNB2 patients) and blue triangles (CSNB1 patients) in each fit indicate i50d and i50r. C: The parameters (slope, left) and (i50, right) of the psychometric fit to the 2D Light Lab results of all subjects. Overall we found equal slopes for detection and recognition in control subjects and in CSNB2. However, in the CSNB2 patients the curves were shifted toward higher intensities. The two curves of the CSNB1 patients were steeper, closer together and shifted towards higher intensities compared to control subjects.
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pone-0062927-g006: 2D Light Lab results of the normal subjects, the CSNB2 patients, and the CSNB1 patients.A: Three representative examples of the results from the 2D Light Lab. The figure shows the cumulative of the relative number of objects detected or recognized, the fit of the psychometric curve, and the crossmarks that indicate the intensity at which 50% of the objects were detected or recognized (i50d and i50r). B: The psychometric fit to the cumulative of objects detected at increasing light levels in the 2D Light Lab for each subject. The green dots (control subjects), black diamond (CSNB2 patients) and blue triangles (CSNB1 patients) in each fit indicate i50d and i50r. C: The parameters (slope, left) and (i50, right) of the psychometric fit to the 2D Light Lab results of all subjects. Overall we found equal slopes for detection and recognition in control subjects and in CSNB2. However, in the CSNB2 patients the curves were shifted toward higher intensities. The two curves of the CSNB1 patients were steeper, closer together and shifted towards higher intensities compared to control subjects.

Mentions: The 2D Light Lab results of a representative control subject, a CSNB2 patient, and a CSNB1 patient are given in Fig. 6A. It shows the cumulative number of objects detected (filled symbols) and recognized (open symbols), and the fit of the two psychometrical curves. The steepness of the two curves of the CSNB2 patients were almost equal to those of the control subjects, but the curves are shifted toward higher intensities. The two curves of the CSNB1 patients were also shifted towards higher intensities, and in addition steeper and closer together compared to control subjects.


Assessment of night vision problems in patients with congenital stationary night blindness.

Bijveld MM, van Genderen MM, Hoeben FP, Katzin AA, van Nispen RM, Riemslag FC, Kappers AM - PLoS ONE (2013)

2D Light Lab results of the normal subjects, the CSNB2 patients, and the CSNB1 patients.A: Three representative examples of the results from the 2D Light Lab. The figure shows the cumulative of the relative number of objects detected or recognized, the fit of the psychometric curve, and the crossmarks that indicate the intensity at which 50% of the objects were detected or recognized (i50d and i50r). B: The psychometric fit to the cumulative of objects detected at increasing light levels in the 2D Light Lab for each subject. The green dots (control subjects), black diamond (CSNB2 patients) and blue triangles (CSNB1 patients) in each fit indicate i50d and i50r. C: The parameters (slope, left) and (i50, right) of the psychometric fit to the 2D Light Lab results of all subjects. Overall we found equal slopes for detection and recognition in control subjects and in CSNB2. However, in the CSNB2 patients the curves were shifted toward higher intensities. The two curves of the CSNB1 patients were steeper, closer together and shifted towards higher intensities compared to control subjects.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3643903&req=5

pone-0062927-g006: 2D Light Lab results of the normal subjects, the CSNB2 patients, and the CSNB1 patients.A: Three representative examples of the results from the 2D Light Lab. The figure shows the cumulative of the relative number of objects detected or recognized, the fit of the psychometric curve, and the crossmarks that indicate the intensity at which 50% of the objects were detected or recognized (i50d and i50r). B: The psychometric fit to the cumulative of objects detected at increasing light levels in the 2D Light Lab for each subject. The green dots (control subjects), black diamond (CSNB2 patients) and blue triangles (CSNB1 patients) in each fit indicate i50d and i50r. C: The parameters (slope, left) and (i50, right) of the psychometric fit to the 2D Light Lab results of all subjects. Overall we found equal slopes for detection and recognition in control subjects and in CSNB2. However, in the CSNB2 patients the curves were shifted toward higher intensities. The two curves of the CSNB1 patients were steeper, closer together and shifted towards higher intensities compared to control subjects.
Mentions: The 2D Light Lab results of a representative control subject, a CSNB2 patient, and a CSNB1 patient are given in Fig. 6A. It shows the cumulative number of objects detected (filled symbols) and recognized (open symbols), and the fit of the two psychometrical curves. The steepness of the two curves of the CSNB2 patients were almost equal to those of the control subjects, but the curves are shifted toward higher intensities. The two curves of the CSNB1 patients were also shifted towards higher intensities, and in addition steeper and closer together compared to control subjects.

Bottom Line: The questionnaire showed that the CSNB2 patients hardly experienced any night vision problems, while all CSNB1 patients experienced some problems although they generally did not describe them as severe.The results from the "2D Light Lab" showed that all CSNB1 patients were blind at low intensities (equal to starlight), but quickly regained vision at higher intensities (full moonlight).From the results we conclude that night vision problems in CSNB, in contrast to what the name suggests, are not conspicuous and generally not disabling.

View Article: PubMed Central - PubMed

Affiliation: Bartiméus Institute for the Visually Impaired, Zeist, The Netherlands. mbijveld@bartimeus.nl

ABSTRACT
Congenital Stationary Night Blindness (CSNB) is a retinal disorder caused by a signal transmission defect between photoreceptors and bipolar cells. CSNB can be subdivided in CSNB2 (rod signal transmission reduced) and CSNB1 (rod signal transmission absent). The present study is the first in which night vision problems are assessed in CSNB patients in a systematic way, with the purpose of improving rehabilitation for these patients. We assessed the night vision problems of 13 CSNB2 patients and 9 CSNB1 patients by means of a questionnaire on low luminance situations. We furthermore investigated their dark adapted visual functions by the Goldmann Weekers dark adaptation curve, a dark adapted static visual field, and a two-dimensional version of the "Light Lab". In the latter test, a digital image of a living room with objects was projected on a screen. While increasing the luminance of the image, we asked the patients to report on detection and recognition of objects. The questionnaire showed that the CSNB2 patients hardly experienced any night vision problems, while all CSNB1 patients experienced some problems although they generally did not describe them as severe. The three scotopic tests showed minimally to moderately decreased dark adapted visual functions in the CSNB2 patients, with differences between patients. In contrast, the dark adapted visual functions of the CSNB1 patients were more severely affected, but showed almost no differences between patients. The results from the "2D Light Lab" showed that all CSNB1 patients were blind at low intensities (equal to starlight), but quickly regained vision at higher intensities (full moonlight). Just above their dark adapted thresholds both CSNB1 and CSNB2 patients had normal visual fields. From the results we conclude that night vision problems in CSNB, in contrast to what the name suggests, are not conspicuous and generally not disabling.

Show MeSH
Related in: MedlinePlus