AIM: To compare the visual function of low-vision patients with primary retinal pigmentosa(RP)before and after wearing amber filter.

METHODS: Self-control before and after study. A total of 30 patients(60 eyes)with low vision who were diagnosed with primary RP in the ophthalmology clinic of Xi'an No.1 Hospital from August 2021 to March 2022 were collected. The uncorrected distance visual acuity(UCDVA), best-corrected distance visual acuity(BCDVA), uncorrected near visual acuity(UCNVA), best-corrected near visual acuity(BCNVA), visual field and Farnsworth-Munsell(FM)-100 color visions were recorded before and after wearing amber filter. The contrast sensitivity(CS)in three visual environments including bright room, darkroom and darkroom with glare was measured and recorded respectively, and the changes of those parameters were analyzed before and after wearing filter.

RESULTS: UCDVA and BCDVA after wearing the filter were better than those before wearing(t=-2.32, P<0.001; t=-6.77, P<0.001), while there was no statistically significant difference in UCNVA and BCNVA before and after wearing filter. The visual field index(VFI)after wearing filter was lower than that before wearing(t=8.62, P<0.001), and the mean defect(MD)of visual field was greater than that before wearing(t=7.73, P<0.001). FM100 color chess test showed that both total error score(TES)and partial error score(PES)in multiple regions were higher than those before wearing filter(P<0.001). After wearing, the CS of each frequency band in the environment of bright room and darkroom with glare was higher than that before wearing(P<0.001), and there was no statistically significant difference in each frequency band before and after wearing amber filter under the environment of darkroom without glare.

CONCLUSION: Patients with low vision of primary RP showed improved UCDVA and BCDVA, but unchanged UCNVA and BCNVA after wearing amber filter, while the visual field and color discrimination were worse than those before wearing filter. The CS of the bright room and darkroom with glare environment was improved than before wearing filter, while there were no significant changes in CS under darkroom without glare.