Transmission spectrums and retinal blue-light irradiance values of untinted and yellow-tinted intraocular lenses.

PURPOSE

To record and compare the spectral transmission characteristics of foldable untinted and yellow-tinted intraocular lenses (IOLs) and evaluate the protective effects against retinal damage by sunlight.

SETTING

Shimane University Faculty of Medicine, Izumo, Japan.

METHODS

The study evaluated 3 untinted IOLs (SA60AT, VA-60BBR, AU6 K) and 3 yellow-tinted IOLs (SN60AT, YA-60BBR, AU6 N) of 3 lens powers (+10.0 diopters [D], +20.0 D, and +30.0 D). Spectral transmittance in the wavelength range of 300 to 800 nm was measured using a spectrophotometer through 2.5 mm and 4.5 mm diameter apertures. Retinal hazard indices, including blue-light irradiance and maximum permissible exposure duration per day (t(max)) for viewing sunlight, were calculated.

RESULTS

The untinted IOLs completely absorbed ultraviolet (UV) light and nearly completely absorbed transmitted visible light at wavelengths longer than 440 nm. Yellow-tinted IOLs absorbed more in the blue-light range (400 to 500 nm) than untinted IOLs. The blue-light irradiance was 34.2% to 56.0% lower with the SN60AT IOL than with the SA60AT IOL, 35.2% to 48.4% lower with the YA-60BBR IOL than with the VA-60BBR IOL, and 16.8% to 22.9% lower with the AU6 N IOL than with the AU6 K IOL. Blue-light irradiance values of SN60AT and YA-60BBR IOLs decreased as the lens power increased.

CONCLUSIONS

Compared with aphakic eyes, UV-blocking untinted IOLs reduced the blue-light irradiance value by 60%; yellow-tinted IOLs conferred an additional 17% to 56% reduction. The difference in lens power was significantly related to the blue-light irradiance value of some yellow-tinted IOLs. .