Macular pigment changes after cataract surgery with yellow-tinted intraocular lens implantation

Abstract

Purpose: We previously reported that macular pigment optical density (MPOD) levels decreased during a long follow-up period after clear intraocular lens (IOL) implant surgery presumably due to excessive light exposure. We examined changes in MPOD levels in the eyes that received yellow-tinted IOL implant surgery.

Subjects and methods: This was a prospective, observational study. Fifty-five eyes of 35 patients were studied. MPOD levels were measured with a dual-wavelength autofluorescence technique on day 4; months 1, 3, and 6; and years 1 and 2 postoperatively. The average optical densities at 0°- 2° eccentricities (local MPODs) and total volumes of MPOD (MPOVs) in the area within 1.5° and 9° eccentricities were analyzed.

Results: The mean local MPOD at baseline (on day 4) was 0.79 at 0°, 0.71 at 0.5°, 0.68 at 0.9°, and 0.32 at 2°. The mean MPOV within 1.5° and 9° at baseline was 2950 and 18,897, respectively. Local MPOD at 0.9° and 2° and MPOVs were slightly decreased at month 1 and increased after that. The increase reached statistical significance in local MPOD at 0.5° and 2° and MPOVs (Tukey-Kramer test). The changes in MPOV within 9° at year 2 [(MPOV on year 2 - MPOV on day 4) / MPOV on day 4] were from -0.21 to 1.18 (mean and standard deviation: 1.14 ± 0.28). The MPOV of 15 eyes increased more than 10% from the initial value, was maintained within 10% in 21 eyes, and deteriorated more than 10% in only 3 eyes.

Conclusions: Local MPOD and MPOV tended to slightly decrease month 1 postoperatively and gradually increased after that, but the rates of increases in MPOD levels were small. Yellow-tinted IOLs that have a lower transmittance of blue light might be preferable for preserving MPOD levels after surgery.

Fig 1

A. Transmission of human crystalline lens with age ranged 10 to 70 years old. The data is a personal gift from Okuno T. Transmission shows a monotonous decrease in blue range with age. B. Transmission curves of +20 diopter clear intraocular lens (IOL, SA60AT, Alcon Inc.) and yellow-tinted intraocular lenses (SN60AT). Yellow-tinted IOL blocks blue light. Dotted line indicates the maximum absorption wavelength of macular pigment (460 nm). The data is a personal gift from Tanito M.

Fig 2. A change in the mean local macular pigment optical density (MPOD) levels in the eyes that had all measurement data during a postoperative follow-up period of 2 years (35 eyes of 22 subjects).

Asterisks indicate a significant difference (p < 0.05) in local MPOD levels between two time points.

Fig 3. A change in macular pigment optical density volume (MPOV) within 1.5° eccentricity in the eyes that had all measurement data during a postoperative follow-up period of 2 years (35 eyes of 22 subjects).

Asterisks indicate a significant difference (p < 0.05) in MPOV between two time points.

Fig 4. A change in macular pigment optical density volume (MPOV) within 9° eccentricity in the eyes that had all measurement data during a postoperative follow-up period of 2 years (35 eyes of 22 subjects).

Asterisks indicate a significant difference (p < 0.05) in MPOV between two time points.