Abstract
Purpose: :
To evaluate objectively the effect of blue-light blocking filters (BLBF) on visual function of patients with age-related macular degeneration (AMD) by measuring contrast sensitivity (CS) and best-corrected visual acuity (BCVA).
Methods: :
Thirty seven patients with AMD and 8 age-matched subjects with normal vision (NV) were examined. We measured CS using a letter chart (Vector Vision) and BCVA before and after wearing BLBF (CCP; blocking <500 nm, CCP400; blocking <400 nm, TOKAI) or neutral density filters (NDF) of similar ND value, under conditions with or without glare. We compared changes of CS between (1) BLBF vs. NDF, (2) AMD group vs. NV group, (3) cataract group vs. intraocular lens (IOL) group in AMD. We measured BCVA with ETDRS chart.
Results: :
In patients with AMD, CS and BCVA improved by wearing BLBF under both with or without glare condition. The improvement in CS with CCP or CCP400 was significantly higher than with NDF in the condition without glare (ΔlogCS: 0.15 vs. 0.06 (CCP vs. NDF, p=0.03); 0.13 vs. 0.03 (CCP400 vs. NDF, p=0.008)). The improvement in CS and BCVA with CCP400 was significant (ΔlogCS: 0.23, p<0.001, ΔBCVA: 2.55, p=0.008) in AMD group but not in NV group (ΔlogCS: 0, ΔBCVA: 0.24, p=1.0)). Under glare condition the improvement in CS was not significant with BLBF or NDF. The improvement in CS was significantly higher in the AMD group than in the NV group using CCP (ΔlogCS: 0.35 vs. -0.14, P< 0.05).The improvement of CS in cataract group was significantly better than in IOL group (ΔlogCS: 0.15 vs. -0.11, p=0.01).
Conclusions: :
CS and BCVA can be used as objective parameters to evaluate the usefulness of BLBF. The results in this study suggest that BLBF improve the quality of vision in patients with AMD.
Keywords: age-related macular degeneration • contrast sensitivity • low vision