Estimations of Retinal Blue-Light Irradiance Values and Melatonin Suppression Indices Through Clear and Yellow-Tinted Intraocular Lenses.

Abstract

Spectral transmittance values in the wavelength range of 300 to 800 nanometers were measured using a spectrophotometer for 18 intraocular lenses (IOLs) including clear (ZCB00) and yellow-tinted (ZCB00V, both from AMO Japan) IOLs with three different lens powers. Also measured were the blue-light irradiance (BLI) values, which might reflect retinal damage caused by sunlight, and the melatonin suppression indices (MSIs), which might reflect the nonvisual photoreception function, through these IOLs. The BLIs (in mWcm-2) calculated were 7.62, 7.50, and 7.46 for the +10-diopter (D), +20-D, and +30-D ZCB00 IOLs, respectively; 4.10, 3.92, and 4.00 for the +10-D, +20-D, and +30-D ZCB00V IOLs, respectively; 5.76 for phakic eyes; and 15.00 for aphakic eyes. The MSIs (in mWcm-2sr-1) calculated were 1.18, 1.19, and 1.18 for the +10-D, +20-D, and +30-D ZCB00 IOLs, respectively; 0.98, 0.94, and 0.95 for the +10-D, +20-D, and +30-D ZCB00V IOLs, respectively; 1.03 for phakic eyes; and 1.21 for aphakic eyes. The data from the six clear IOLs (SA60AT, Alcon Japan; VA-60BBR, Hoya; AU6K, Kowa, N4-18B, Nidek; X-60, Santen; KS-3Ai, Staar Japan) and seven yellow-tinted IOLs (SN60AT; YA-60BBR, Hoya; AU6N, Kowa; N4-18YG, Nidek; NX-60, Santen; KS-AiN, Staar Japan; XY-1, Hoya) reported previously also were discussed. Compared to aphakic eyes, ZCB00 and ZCB00V IOLs reduce the BLI values by 49-50% and 73-74%, respectively; and currently available ultraviolet-blocking clear and yellow-tinted IOLs reduce the BLI values by 43-82%, respectively. Yellow-tinted IOLs absorb more circadian rhythm-associated light than clear IOLs. Although the data presented in this study cannot be applied directly to IOL implanted in patients, the balance between photoprotection and photoreception must be considered when using IOLs in a clinical setting.