Multimodal imaging of the macula in hereditary and acquired lack of macular pigment.

PURPOSE: Macular pigment (MP) deficit has been described in macular teleangiectasia type 2 (MTA; acquired MP loss) and in Sjögren-Larsson syndrome (SLS; hereditary MP deficiency). Central blue light-induced fundus autofluorescence (FAF) and blue light fundus reflectance (BLR) are thought to reflect MP distribution. This study was performed to describe the macular morphology in SLS and MTA by multimodal imaging to further investigate the causes of FAF and BLR changes in these disorders. METHODS: This was a single-centre, cross-sectional, retrospective, observational study on SLS and MTA patients treated at our institution. In a multimodal retinal imaging dataset, patterns of BLR and FAF changes were compared with the optical coherence tomography (OCT) and clinical appearance of the patients' retinas. RESULTS: Multimodal image sets of seven eyes of four patients with SLS and of 25 eyes of 15 patients with MTA were included in this study. In MTA, areas of focal FAF increase were mainly associated with retinal pseudocysts and photoreceptor loss and were co-located with regions of increased BLR. In SLS, areas of focally decreased FAF correlated with the typical intraretinal glistening dots. Frequently, a spot of focally increased FAF was visible at the fovea of SLS patients, often independent of the presence of pseudocysts or photoreceptor loss on OCT. CONCLUSION: In MTA and SLS different patterns of FAF alterations could be observed. The areas of increased BLR, which are thought to correlate with MP loss, appeared to have only restricted correlation with FAF appearance.

Effect of micellar lipids, dietary fiber and ß-carotene on lutein bioavailability in aged rats with lutein deficiency.

OBJECTIVE: To determine the effect of various dietary components on the intestinal uptake of lutein in aged rats. METHODS: This study determined the time-course (2, 4, 6, 8 h) plasma and tissue responses of a pharmacologic dose of lutein (200 µM) solubilized in mixed micelles with fat (3%, soybean oil), phosphatidylcholine (PC; 3 mM), lysophosphatidylcholine (lysoPC; 3 mM), dietary fiber (pectin, 1.25%), ß-carotene (200 µM), or micelles with no dietary components (control) in aged rats with lutein deficiency. RESULTS: No lutein was detected in the plasma of rats at 0 h indicating the deficiency. After gavages of lutein, the mean percent area under the curve (picomoles per milliliter per 8 h) of plasma lutein in the fat (91.4), PC (218.0), and lysoPC (94.1) groups were higher (P > 0.05), whereas its level in the dietary fiber and ß-carotene groups was lower than the control group. The liver and eye lutein levels of the PC (95.4, 38.67%) and fat (18.2, 143%) groups were significantly higher, whereas the lysoPC (9.6, 27.2%), ß-carotene (19.2, 35.4%), and dietary fiber (3.1, 88.4%) groups were lower than the control group. CONCLUSION: Results indicate that soybean oil and soy phospholipids greatly sway lutein absorption in aged rats with lutein deficiency. The results also suggest that ingestion of lutein with pectin and ß-carotene suppresses lutein absorption. Hence, to improve the absorption of lutein in older adults with macular pigment deficiency, foods with sufficient fat with low dietary fiber and ß-carotene may be suggested.

Consumption of 2 and 4 egg yolks/d for 5 wk increases macular pigment concentrations in older adults with low macular pigment taking cholesterol-lowering statins.

BACKGROUND: Lutein and zeaxanthin may reduce the risk of dry, age-related macular degeneration because of their photo-oxidative role as macular pigment. OBJECTIVE: The present study evaluated serum lutein, zeaxanthin, and macular pigment optical density (MPOD) responses at 0.25 degrees , 0.5 degrees , and 1 degree retinal eccentricities to the consumption of 2 and 4 egg yolks/d by older adults taking cholesterol-lowering medications. DESIGN: Subjects consumed foods containing 2 followed by 4 egg yolks/d for 5 wk each with a 4-wk egg-free period at baseline and between the 2 interventions. RESULTS: Changes in MPOD (n = 37) with egg yolk consumption were inversely associated (P < 0.05) with baseline MPOD. Subjects with low-baseline MPOD (defined as MPOD < or =0.5 at 0.25 degrees , < or =0.4 at 0.5 degrees , and < or =0.35 at 1 degrees ) showed increases of < or =50% (P < 0.05) with 4 egg yolks at the 3 retinal eccentricities. MPOD increased by 31% (P = 0.059) at 0.5 degrees with 2 egg yolks. Serum lutein increased by only 16% and 24% (P < 0.05) compared with increases of 36% and 82% (P < 0.001) in serum zeaxanthin (n = 52) after consumption of 2 and 4 egg yolks, respectively. Serum HDL cholesterol increased by 5% (P < 0.05) after consumption of 2 and 4 egg yolks. Serum LDL cholesterol did not change with either egg yolk treatment. CONCLUSIONS: Consumption of 4 egg yolks/d, and possibly of 2 egg yolks/d, for 5 wk benefited macular health in older adults with low MPOD. Serum HDL cholesterol increased without an increase in LDL cholesterol in this study population, most of whom were taking cholesterol-lowering statins.

For whales and seals the ocean is not blue: a visual pigment loss in marine mammals.

Most terrestrial mammals have colour vision based on two spectrally different visual pigments located in two types of retinal cone photoreceptors, i.e. they are cone dichromats with long-to-middle-wave-sensitive (commonly green) L-cones and short-wave-sensitive (commonly blue) S-cones. With visual pigment-specific antibodies, we here demonstrate an absence of S-cones in the retinae of all whales and seals studied. The sample includes seven species of toothed whales (Odontoceti) and five species of marine carnivores (eared and earless seals). These marine mammals have only L-cones (cone monochromacy) and hence are essentially colour-blind. For comparison, the study also includes the wolf, ferret and European river otter (Carnivora) as well as the mouflon and pygmy hippopotamus (Artiodactyla), close terrestrial relatives of the seals and whales, respectively. These have a normal complement of S-cones and L-cones. The S-cone loss in marine species from two distant mammalian orders strongly argues for convergent evolution and an adaptive advantage of that trait in the marine visual environment. To us this suggests that the S-cones may have been lost in all whales and seals. However, as the spectral composition of light in clear ocean waters is increasingly blue-shifted with depth, an S-cone loss would seem particularly disadvantageous. We discuss some hypotheses to explain this paradox.

Albinism in Nigeria with delineation of new recessive oculocutaneous type.

Seventy-nine Nigerian oculocutaneous albinos were investigated. Fifty-six had typical tyrosinase-positive albinism (TPA) and 23 had brown albinism (BA), a new oculocutaneous type. The TPA were characterized by localized but no generalized skin pigment, yellow hair, blue to brown irides, nystagmus, and reduced or absent retinal pigment. Localized skin pigment included freckles and lentigines. The iris and skin pigment were the result of the slow accumulation of pigment with age as both were found in older individuals. The most severe skin changes were premalignant keratoses and squamous cell carcinoma of the skin, and the skin malignancies were the major factor in limiting the lifespan for TPA. The BA were characterized by generalized light brown skin pigment, light brown hair, blue to brown irides, nystagmus, and reduced retinal pigment. There was little accumulation or change of pigment in the eyes or skin with age. The generalized light skin pigment was effective in reducing sensitivity to solar radiation and very few BA had premalignant keratoses. Pedigree analysis for BA suggested on autosomal recessive inheritance pattern.