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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

Results of Parts 4 to 7 of the questionnaire.Top: answers of CSNB2 patients. Bottom: answers of CSNB1 patients. The black horizontal lines indicate the medians. The grey vertical lines extend from the first quartile to the third quartile and thus indicate the range of the mid 50% ranked answers. A black dot is used when the mid 50% ranked date contained one answer only.
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pone-0062927-g003: Results of Parts 4 to 7 of the questionnaire.Top: answers of CSNB2 patients. Bottom: answers of CSNB1 patients. The black horizontal lines indicate the medians. The grey vertical lines extend from the first quartile to the third quartile and thus indicate the range of the mid 50% ranked answers. A black dot is used when the mid 50% ranked date contained one answer only.

Mentions: Fig. 3 shows the first quartile, the median and the third quartile of ranked response options the patients gave to Parts 4 to 7 of the questionnaire, dealing with assistance or devices, outdoor problems, indoor problems, and general problems. The results show that CSNB2 patients answered most questions about problems with “never” or “sometimes”, while CSNB1 patients experienced problems more frequently. None of the CSNB2 and CSNB1 patients used a cane when walking in the dark (Q10), but CSNB1 patients sometimes used other aids (Q11–13). One CSNB1 patient described that he sometimes used his phone as a flashlight (Q14), and one CSNB2 patient described to always seek for the best illuminated areas (Q15). Both CSNB2 and CSNB1 patients experienced less problems moving about or finding their way in a familiar environment (Q17,18) compared to an unfamiliar environment (Q19,20). None of the CSNB2 patients and only two of the CSNB1 patients reported going out less often than they wanted because of their vision at night (Q27). Both CSNB2 and CSNB1 patients reported more problems in Part 6 (Indoor problems like recognizing faces or reading a book) compared to Parts 4, 5 and 7. Finally, CSNB1 patients felt blind at night (Q36), insecure at a social event (Q37), restricted because of their vision at night (Q38) and dependent on others in dark circumstances (Q39), but at different frequencies. CSNB2 patients mostly reported “never” or “sometimes” to these questions.


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)

Results of Parts 4 to 7 of the questionnaire.Top: answers of CSNB2 patients. Bottom: answers of CSNB1 patients. The black horizontal lines indicate the medians. The grey vertical lines extend from the first quartile to the third quartile and thus indicate the range of the mid 50% ranked answers. A black dot is used when the mid 50% ranked date contained one answer only.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0062927-g003: Results of Parts 4 to 7 of the questionnaire.Top: answers of CSNB2 patients. Bottom: answers of CSNB1 patients. The black horizontal lines indicate the medians. The grey vertical lines extend from the first quartile to the third quartile and thus indicate the range of the mid 50% ranked answers. A black dot is used when the mid 50% ranked date contained one answer only.
Mentions: Fig. 3 shows the first quartile, the median and the third quartile of ranked response options the patients gave to Parts 4 to 7 of the questionnaire, dealing with assistance or devices, outdoor problems, indoor problems, and general problems. The results show that CSNB2 patients answered most questions about problems with “never” or “sometimes”, while CSNB1 patients experienced problems more frequently. None of the CSNB2 and CSNB1 patients used a cane when walking in the dark (Q10), but CSNB1 patients sometimes used other aids (Q11–13). One CSNB1 patient described that he sometimes used his phone as a flashlight (Q14), and one CSNB2 patient described to always seek for the best illuminated areas (Q15). Both CSNB2 and CSNB1 patients experienced less problems moving about or finding their way in a familiar environment (Q17,18) compared to an unfamiliar environment (Q19,20). None of the CSNB2 patients and only two of the CSNB1 patients reported going out less often than they wanted because of their vision at night (Q27). Both CSNB2 and CSNB1 patients reported more problems in Part 6 (Indoor problems like recognizing faces or reading a book) compared to Parts 4, 5 and 7. Finally, CSNB1 patients felt blind at night (Q36), insecure at a social event (Q37), restricted because of their vision at night (Q38) and dependent on others in dark circumstances (Q39), but at different frequencies. CSNB2 patients mostly reported “never” or “sometimes” to these questions.

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