The effect of a Computer Lens Filter on visual performance in subjects with retinitis pigmentosa

Abstract Background： Retinitis pigmentosa (RP) patients usually complain about nyctalopia and reduced dark adaptation which cause their visual discomfort. In this study we aimed to explore the effects of a UV reduction Computer Lens Filter (CLF) on contrast sensitivity (CS), reading speed for computer screen text and visual comfort in subjects with retinitis pigmentosa (RP) to find if a CLF is helpful for RP patients . Method: Twenty-two subjects diagnosed with binocular RP participated. Bright CS using the Mars test and reading speed for screen text were measured both with and without CLF wear. Subjective estimates of computer screen brightness and visual comfort were evaluated by Linkert self-report estimates. These functions were compared for the two conditions of filter wear and non-wear. Result ： Mean subject age was 38.2±7.5 years and mean logMAR VA was 0.505± 0.324. Wearing a CLF did not improve bright CS ( t = 0.680, P=0.504 ) or increase reading speed ( t =-0.223, P = 0.826 ). CLF wear was judged to reduce screen brightness ( t = -5.412, P<0.0001 ) and improve visual comfort ( t = 6.897, P<0.0001 ). Conclusion ： CLF wear did not improve RP subjects’ CS or reading speed for screen text, but did reduce the appearance of screen brightness and improve subjects’ reported visual comfort. Improvement in comfort alone may be sufficient justification for filter use as a vision aid for RP patients during vision rehabilitation.