Ac Bird

Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes

BACKGROUND It has been suggested that eating green leafy vegetables, which are rich in lutein and zeaxanthin, may decrease the risk for age related macular degeneration. The goal of this study was to analyse various fruits and vegetables to establish which ones contain lutein and/or zeaxanthin and can serve as possible dietary supplements for these carotenoids. METHODS Homogenates of 33 fruits and vegetables, two fruit juices, and egg yolk were used for extraction of the carotenoids with hexane. Measurement of the different carotenoids and their isomers was carried out by high performance liquid chromatography using a single column with an isocratic run, and a diode array detector. RESULTS Egg yolk and maize (corn) contained the highest mole percentage (% of total) of lutein and zeaxanthin (more than 85% of the total carotenoids). Maize was the vegetable with the highest quantity of lutein (60% of total) and orange pepper was the vegetable with the highest amount of zeaxanthin (37% of total). Substantial amounts of lutein and zeaxanthin (30–50%) were also present in kiwi fruit, grapes, spinach, orange juice, zucchini (or vegetable marrow), and different kinds of squash. The results show that there are fruits and vegetables of various colours with a relatively high content of lutein and zeaxanthin. CONCLUSIONS Most of the dark green leafy vegetables, previously recommended for a higher intake of lutein and zeaxanthin, have 15–47% of lutein, but a very low content (0–3%) of zeaxanthin. Our study shows that fruits and vegetables of various colours can be consumed to increase dietary intake of lutein and zeaxanthin.

Smoking and age related macular degeneration: the number of pack years of cigarette smoking is a major determinant of risk for both geographic atrophy and choroidal neovascularisation

Background/aims: There is evidence that smoking is a risk factor for age related macular degeneration (AMD). However, not all studies have demonstrated this association and several key questions about the role of smoking in AMD have still to be determined. The aim of this study was to further investigate this relation for both choroidal neovascularisation (CNV) and geographic atrophy (GA). Methods: To investigate the relation between smoking and the risk of developing age related macular degeneration (AMD) in white people, 435 cases with end stage AMD were compared with 280 controls. All subjects had graded stereoscopic colour fundus photography and AMD was defined as the presence of GA or CNV. Smoking history was assessed using multiple parameters in a detailed questionnaire. Results: Comparison of current and former smokers with non-smokers was consistent with smoking being a risk factor for AMD but did not reach statistical significance. There was a strong association between AMD and pack years of cigarette smoking (p = 0.002), the odds ratio increasing with the amount smoked; for subjects with more than 40 pack years of smoking the odds ratio was 2.75 (95% CI 1.22 to 6.20) compared with non-smokers. Both types of AMD showed a similar relation; smoking more than 40 pack years of cigarettes was associated with an odds ratio of 3.43 (95% CI 1.28 to 9.20) for GA and 2.49 (95% CI 1.06 to 5.82) for CNV. Stopping smoking was associated with reduced odds of AMD and the risk in those who had not smoked for over 20 years was comparable to non-smokers. The risk profile was similar for males and females. Passive smoking exposure was associated with an increased risk of AMD (OR 1.87; 95% CI 1.03 to 3.40) in non-smokers. Conclusions: The authors have demonstrated a strong association between the risk of both GA and CNV and pack years of cigarette smoking. This provides support for a causal relation between smoking and AMD. They also show an increased risk for AMD in non-smokers exposed to passive smoking. Stopping smoking appears to reduce the risk of developing AMD.

Autosomal dominant retinitis pigmentosa: four new mutations in rhodopsin, one of them in the retinal attachment site

Several mutations in the rhodopsin gene in patients affected by autosomal dominant retinitis pigmentosa (ADRP) have recently been described. We report four new rhodopsin mutations in ADRP families, initially identified as hetero-duplexed PCR fragments on hydrolink gels. One is an in-frame 12-bp deletion of codons 68 to 71. The other three are point mutations involving codons 190, 211, and 296. Each alters the amino acid encoded. The codon 190 mutation has been detected in 2 from a panel of 34 ADRP families, while the remaining mutations were seen in single families. This suggests that, consistent with a dominant condition, no single mutation will account for a large fraction of ADRP cases. The base substitution in codon 296 alters the lysine residue that functions as the attachment site for 11-cis-retinal, mutating it to glutamic acid. This mutation occurs in a family with an unusually severe phenotype, resulting in early onset of disease and cataracts in the third or fourth decade of life. This result demonstrates a correlation between the location of the mutation and the severity of phenotype in rhodopsin RP.

Symptomatic abnormalities of dark adaptation in patients with age-related Bruch's membrane change.

Some patients with age-related changes at the level of Bruchs membrane and good visual acuity report poor vision in dim light, fading vision in bright light, and a central scotoma noticeable in the dark. Ophthalmic examination, scotopic thresholds, and dark adaptation kinetics were recorded in 12 eyes of 12 patients with such symptoms. All had macular drusen which were hypofluorescent on fluorescein angiography in nine subjects, and six had evidence of prolonged choroidal filling on fluorescein angiography. Scotopic thresholds were depressed in six patients who all experienced a central scotoma in the dark or poor night vision. The kinetics of dark adaptation were abnormal in all 10 patients in whom reliable measurements were possible. The findings suggest that visual symptoms reflect abnormality of both scotopic sensitivity and the time course of dark adaptation in patients with age-related Bruchs membrane change.

RPGR mutation associated with retinitis pigmentosa, impaired hearing, and sinorespiratory infections

Retinitis pigmentosa (RP) is a progressive retinal degeneration that affects about 1 in 4000 of the population.1 Approximately 15–30% of patients with RP have X linked retinitis pigmentosa (XLRP), which is the most severe form of RP consistently manifesting early in life.2,3 Night blindness is usually present in early childhood with loss of peripheral visual fields and ultimately central vision, resulting in registered blindness by the end of the third decade. Female carriers display a broad spectrum of fundus appearances ranging from normal to extensive retinal degeneration.4–6 XLRP is genetically heterogeneous with two major loci, RP2 (Xp11.23) and RP3 (Xp21.1). Both disease genes have now been identified (respectively RP2 7 and RPGR 8–10) with RP2 mutations causing disease in approximately 15% of XLRP families,11,12 while RPGR mutations are reportedly more common, accounting for up to 75% of XLRP.10 Two other rare loci for XLRP have also been described on Xp22 and Xq26–27.13,141 Hong et al 15 described the phenotype and pathology of an RPGR knockout mouse model. They showed the subcellular localisation of RPGR to the photoreceptor connecting cilia, and in the absence of RPGR partial mislocalisation of essential outer segment proteins. These data suggest a putative role for RPGR in the retina, controlling movement of essential proteins from the inner to the outer segment of photoreceptors via the connecting cilia. Several groups have recently identified a retina specific RPGR interacting protein (RPGRIP1).16–18 This protein also localises to the photoreceptor connecting cilium and is thought to be a structural component of the ciliary axoneme.18 Subsequent mutation screening in patients suffering from retinal diseases has identified mutations in RPGRIP1 as a cause of Leber congenital amaurosis.19,20 In this report, we present the phenotype of …

Functional characterisation and serial imaging of abnormal fundus autofluorescence in patients with retinitis pigmentosa and normal visual acuity.

Aim: To characterise and monitor abnormal fundus autofluorescence (AF) in patients with retinitis pigmentosa (RP) who have good visual acuity. Methods: 21 patients with a clinical diagnosis of RP were examined. All had rod-cone dystrophy (ISCEV standard electroretinograms (ERGs)), visual acuity of 6/9 or better, and manifested a parafoveal ring of high density fundus AF. Repeat AF imaging was performed after periods of between 2 years and 5 years in 12 patients. Pattern ERG (PERG) and multifocal ERG (mfERG) were performed in 20 cases. Visual fields (VF), photopic and scotopic fine matrix mapping and small field PERGs were performed in representative cases. Results: The rings of high density AF varied in size between patients (from 4°–16° diameter). MfERGs showed relative preservation over the central macular area, correlating with the size of AF ring and with PERG and psychophysical data. Progressive constriction of the AF ring was demonstrated at follow up in three patients. Serial PERG, mfERG, and VFs, performed in one of these cases, showed evidence of deterioration concordant with ring constriction. Conclusions: High density rings of AF, seen in some patients with RP with good visual acuity, demarcate areas of preserved central photopic function. MfERGs correlate with the area encircled by high density AF and the PERG data. The size of the ring of AF can show progressive constriction accompanied by increasing macular dysfunction.

Abnormal dark adaptation kinetics in autosomal dominant sector retinitis pigmentosa due to rod opsin mutation.

The time course of dark adaptation was measured in 10 subjects from three families with autosomal dominant sector retinitis pigmentosa (RP) due to mutations in the first exon of the rod opsin gene. In each subject cone adaptation and the early part of the recovery of rod sensitivity followed the normal time course, but the later phase of rod adaptation was markedly prolonged. The recovery of rod sensitivity is much slower than that reported in any other outer retinal dystrophy. Using a model based upon primate data of rod outer segment length and turnover, we have calculated that the delayed phase of the recovery of rod sensitivity in the RP patients tested following strong light adaptation could be due in part to formation of new disc membrane with its normal concentration of rhodopsin rather than in situ regeneration of photopigment.

Mutations in a protein target of the Pim-1 kinase associated with the RP9 form of autosomal dominant retinitis pigmentosa

The RP9 form of autosomal dominant retinitis pigmentosa (adRP) maps to a locus on human chromosome 7p14. We now report two different disease associated mutations in a previously unidentified human gene, the mouse orthologue of which has been characterised by its interaction with the Pim-1 oncogene. In the original linked family we identified the missense mutation H137L. A second missense mutation, D170G, was found in a single RP patient. The putative RP9 gene appears to be expressed in a wide range of tissues, but its function is unknown and a pathogenic mechanism remains to be determined.

Acute zonal occult outer retinopathy: towards a set of diagnostic criteria

Background: Individuals with acute zonal occult outer retinopathy (AZOOR) present with initially progressive scotomata and photopsia. Characteristically, the extent of the visual field defect is unexplained by fundal examination, but there is marked retinal dysfunction evident electrophysiologically. It is the authors’ experience that a group of patients exhibit characteristic clinical and electrophysiological abnormalities, which serve as criteria for a working diagnosis. Methods: A retrospective observational case series of 28 patients were identified with the clinical diagnosis of AZOOR who shared similar abnormal electrophysiology. Details of the history and ophthalmic findings were obtained from the case notes. Results: Electrophysiology demonstrated a consistent pattern of dysfunction both at the photoreceptor/retinal pigment epithelial complex but also at inner retinal levels, essentially comprising a delayed 30 Hz flicker ERG and a reduction in the EOG light rise. Conclusion: This study determines diagnostic criteria applicable to a group of patients with AZOOR, typically those with classic symptomatology. Electrophysiological testing can help avoid lengthy, costly, and potentially invasive investigations, and the unnecessary use of immunosuppressive therapy.

Age related macular degeneration and sun exposure, iris colour, and skin sensitivity to sunlight

Background/aim: It has been suggested that sun exposure may be a risk factor for age related macular degeneration (AMD) and that skin sensitivity to sunlight and iris colour could be confounding factors. The aim was to investigate this further in the white population. Methods: 446 cases with end stage AMD were compared with 283 spouse controls. Data on sun exposure, places of residence, iris colour, subjective assessment of change in iris colour, hair colour at age 20, and skin sensitivity were obtained using a questionnaire. Iris colour was graded clinically by comparison with standard photographs. AMD was graded using stereoscopic colour fundus photographs as well as clinical examination and was defined as the presence of geographic atrophy or choroidal neovascularisation. All variables were included in a multiple logistic regression model including age, sex, and smoking. Results: There was no association between AMD and sun exposure or related factors except for the suggestion of an association between sunburn prone skin type and geographic atrophy which reached borderline significance. Conclusions: No significant association between AMD and sun exposure, iris colour, change in iris colour, or hair colour was demonstrated.