Tinted IOL hinders transmission of low-wavelength laser beam

Acta Ophthalmol. 2011;89(1):37-39.

Short-wavelength laser beams used for photocoagulation diminished when directed through yellow-tinted IOLs as opposed to clear lenses, a study found.

"Tinted IOLs have many benefits and may gradually replace clear IOLs," the study authors said. "The decrease in the transmittance ratio for the tinted IOL when a short-wavelength laser beam of 488 + 514 nm is used can be adjusted by increasing the setting power of the beam."

Investigators compared the transmittance ratios of various laser wavelengths through tinted and non-tinted IOLs of various dioptric powers. The yellow-tinted AcrySof SN60AT IOL and the clear AcrySof SA60AT IOL (both Alcon) with powers of +10 D, +20 D and +30 D were used. Wavelengths of 488 + 514 nm, 514 nm, 521 nm, 568 nm and 647 nm were used.

A power meter was used to measure the power of the laser beam passing through each IOL.

Results showed no discernable differences in transmittance values between the tinted and clear IOLs at laser wavelengths of 521 nm, 568 nm and 647 nm. However, the ratios decreased when laser beam wavelengths of 488 + 514 nm and 514 nm were applied through tinted IOLs.

Transmittance ratios also decreased in relation to the power of tinted IOLs. The ratio was 91.9% with a +10 D lens, 86.7% with a +20 D lens and 82.2% with a +30 D lens at a laser wavelength of 488 + 514 nm, the authors reported.

The wavelength of 488 + 514 nm correlates to the blue-green beam of the argon laser photocoagulator, the authors said.