Macular pigment changes in pseudophakic eyes quantified with resonance Raman spectroscopy

We examined changes in macular pigment optical density (MPOD) levels after cataract surgery and compared the MPOD between eyes with clear intraocular lenses (IOLs) and yellow-tinted IOLs.

Prospective, comparative case series.

The MPOD levels were measured in 480 eyes of 337 patients after cataract surgery. Among them, the data from 259 eyes (clear IOL group, 121 eyes; yellow-tinted IOL group, 138 eyes) of 259 Japanese patients were selected for statistical analyses on the basis of the inclusion criteria: a postoperative visual acuity (VA) of ≥0.8 and no fundus diseases. Only 1 eye of each patient was enrolled. Patients provided informed consent to participate in this study on the basis of the approval of the institutional review board before surgery.

The patients selected the type of IOL to be implanted. The MPOD levels were measured using resonance Raman spectroscopy on day 1 (baseline value); months 1, 3, and 6; and years 1 and 2 postoperatively.

The difference in MPOD levels between the IOL groups was analyzed by unpaired t tests. The following parameters were analyzed by multiple regression analysis: age, gender, body mass index (BMI), smoking history, glaucoma, diabetes, preoperative VA, preoperative refractive error, and IOL power and type.

We found no significant differences in the baseline characteristics between the 2 groups. Until 6 months postoperatively, the MPOD levels did not differ significantly between the groups. However, from 1 year onward, the levels were significantly higher in the yellow-tinted IOL group compared with the clear IOL group. By multiple regression analysis, 1 day postoperatively, older age and diabetes were correlated with lower MPOD levels; 1 year postoperatively and thereafter, however, lower MPOD levels were correlated with clear IOLs.

Cataract surgery with clear IOLs induced a greater decrease in macular pigment levels compared with yellow-tinted IOLs during a longer follow-up period. These findings agreed with observations that excessive light exposure is associated inversely with MPOD, because clear IOLs transmit higher intensities of blue light than yellow-tinted IOLs.