Protective effect of glycine in streptozotocin-induced diabetic cataract through aldose reductase inhibitory activity.

Glycine is a proteinogenic amino acid that serves as a precursor for several proteins. The anti-cataract effects of lysine and other amino acid mixtures in animal models have been reported. Normal rats were administered saline and formed the normal control group (group I). Diabetic rats were administered streptozotocin and were the diabetic control group (group II). Rats were administered glycine (250 mg and 500 mg/kg of body weight) formed groups III and IV, respectively. Diabetic rats were administered sorbinil and were served as positive control (group V). The body weight changes, serum glucose, plasma insulin, total protein, glutathione (GSH) content, and mRNA and protein levels of aldose reductase were determined. Glycine treatment increased body weight gain, reduced blood glucose, and increased plasma insulin levels compared to diabetic control rats, and also increased GSH content and decreased mRNA and protein levels of aldose reductase compared to their respective controls. In summary, glycine supplementation effectively inhibited aldose reductase enzyme activity in experimental diabetic rats.

Serum selenium levels are associated with age-related cataract.

OBJECTIVE: The aim of the study is to analyse correlations between age-related cataract (ARC), serum selenium levels and glutathione peroxidase gene 1 and 4 (GPX-1 and GPX-4). MATERIAL AND METHODS: A total sample of 275 participants were enrolled into the study: group A, 94 subjects elligible for ARC surgery, and group B, 181 volunteers without ocular symptoms, gender-, age-, and smoking- status and volume-matched at 1:2 with subjects in group A. All participants (n=275) were divided according to the Lens Opacities Classification System III (LOCS III) into: 1) study group (subjects with clinically significant cataract; N≥3 or C≥3 or P≥2), 2) control group (controls with clinically non-significant cataract; N<3 and C<3 and P<2). The single nucleotide polymorphisms of GPX-1 and GPX-4 were assessed using Real Time PCR. Serum selenium levels were assayed using Inductively Coupled Plasma Mass Spectrometry. RESULTS: Low selenium levels significantly predicted any age-related cataract (OR 7.969; p<.01), nuclear cataract (OR 12.823; p<.01) and cortical cataract (OR 3.31; p<.01). There was no significant effect of gender, age, SNP GPX-1 and SNP GPX-4 on the prevalence of age-related nuclear, cortical and posterior sub-capsular cataract. Serum selenium levels of 75-85 µg/L were associated with the lowest prevalence of ARC. CONCLUSIONS: Due to a confirmed association between serum selenium levels and age-related cataract, low serum selenium levels may constitute a potential risk factor of age-related cataract.

Fatty acids modulate the efficacy of lutein in cataract prevention: Assessment of oxidative and inflammatory parameters in rats.

BACKGROUND: Effects of lutein (L) and fatty acids [linoleic acid (LA), eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) and oleic acid (OA)] on oxidative stress and inflammation in cataract were assessed. METHODS: Cataract was induced in male Wistar rat pups (11 days old) by giving a single dose of sodium selenite (25 µM/kg body weight) by IP. Lutein (1.3 µmol/kg body weight) was given one day before and five days after selenite injection as a micelle with 7.5 mM LA, or 7.5 mM EPA + DHA or 7.5 mM OA. Serum and lens oxidative stress and inflammatory parameters having a bearing cataract were assessed. RESULTS: Serum and lens nitric oxide, MDA and protein carbonyls were significantly (p < 0.05) increased in cataract compared to control and experimental groups. Catalase, SOD, glutathione peroxidase and glutathione transferase activity and glutathione level in serum and lens of cataract group were significantly (p < 0.05) decreased. Serum eicosanoids (PGE2, LTB4, and LTC4) and cytokines (CRP, TNF-α, IL1-ß, and MCP-1) were significantly (p < 0.05) increased in cataract. The activity of cPLA2 and Cox-2 in cataract lens was higher (p < 0.05) compared to other groups. EP-1, NOS-2 and NF-kB expression were higher (p < 0.05) in cataract. The ratio of water insoluble to water soluble protein was increased in cataract lens. Group administered with L + EPA + DHA exhibited highest cataract prevention compared to L + LA and L + OA. Pups given lutein with EPA + DHA had the highest amount of lutein in the lens. CONCLUSIONS: The anti-cataract activity of lutein was influenced by fatty acids and found to be highest with EPA + DHA compared to LA or OA.

Delayed progression of diabetic cataractogenesis and retinopathy by Litchi chinensis in STZ-induced diabetic rats.

CONTEXT: The study was carried out to evaluate the effect of the aqueous fruit pericarp extract of Litchi chinensis (APLC) on parameters which leads to diabetic cataractogenesis and retinopathy in the streptozotocin-induced diabetic rats. OBJECTIVE: The objective of the study is to evaluate the APLC for in vivo antioxidant activity and its role in inhibiting the polyol pathway and formation of advanced glycation end products (AGEs). MATERIALS AND METHODS: The diabetic animals were treated with L. chinensis for a period of 12 weeks. At the end of 12 weeks, the animals were killed and the biochemical pathways involved in the pathogenesis of cataract such as oxidative stress by protein content, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and polyolpathway by aldose reductase (AR) in lens homogenates, alterations in protein carbonyl content (PCO) and AGEs in both serum and lens the APLC-treated diabetic rats were compared against diabetic control rats. Cataract progression due to hyperglycemia was monitored by slit lamp bio microscope and classified into four stages. Fundoscope test and retinal histopathology were done for assessing retinopathy. RESULTS: Statistically significant reduction in glucose, and elevation of protein content, SOD, CAT, and GSH levels and decreased levels of AR and PCO in lens homogenate and significant reduction in AGEs serum and lens homogenate were observed. Slit lamp examination, fundoscope, and histopathology showed improvement in retinal changes in APLC-treated rats compared to diabetic control animals. CONCLUSION: The treatment with APLC found to delay the progression of diabetic cataractogenesis and retinopathy, which might be due to its antioxidant activity, because of the presence of active phytochemicals in APLC.

Magnesium taurate prevents cataractogenesis via restoration of lenticular oxidative damage and ATPase function in cadmium chloride-induced hypertensive experimental animals.

Previously we found that hypertension potentiates the risk the cataractogenesis. In the present study, we investigated the protective effects of magnesium taurate (MgT) on hypertension and associated lenticular damages against cadmium chloride (CdCl2)-induced hypertensive animals. Male Sprague-Dawley albino rats (150-180g) were assigned to five experimental groups (n=6). Among the five groups, normal group received 0.3% carboxymethyl cellulose (10ml/kg/day, p.o.). Hypertension control group received CdCl2 (0.5mg/kg/day, i.p.). Tests and standard groups received MgT (3 and 6mg/kg/day, p.o.) and amlodipine (3mg/kg/day, p.o.) concurrently with CdCl2 respectively, for six consecutive weeks. Blood pressure, heart rate, and eyes were examined biweekly, and pathophysiological parameters in serum and eye lenses were evaluated after six weeks of the experimental protocol. The chronic administration of MgT concurrently with CdCl2 significantly restored the blood pressure, serum and lens antioxidants (CAT, SOD, GPx, and GSH), MDA level, and ions (Na+, K+, and Ca2+). Additionally, MgT treatment led to significant increase in the lens proteins (total and soluble), Ca2+ ATPase, and Na+K+ ATPase activity as compared to hypertension control group. Ophthalmoscope observations indicated that MgT treatments delayed the progression of cataract against the hypertensive state. The study shows that MgT prevents the progression of cataractogenesis via restoration of blood pressure, lenticular oxidative damages, and lens ATPase functions in the hypertensive state. The results suggest that MgT supplement may play a beneficial role to manage hypertension and associated cataractogenesis.

Protective effect of Tephrosia purpurea in diabetic cataract through aldose reductase inhibitory activity.

PURPOSE: Tephrosia purpurea (T. purpurea) has been reported to prevent cataract formation in senile cataract model as well as proven effective in STZ induced type 1 diabetes. Aldose reductase (AR) is a key enzyme in the intracellular polyol pathway responsible for the development of diabetic cataract. OBJECTIVE: To investigate the effects of T. purpurea in the light of inhibition of aldose reductase enzyme in polyol pathway. METHODS: We studied the effects of alcoholic extract and flavonoid fraction of T. purpurea in streptozotocin (STZ, 45mg/kg, i.v.)-induced type I diabetic cataract in rats. The animals were divided into five groups as control, control treated with alcoholic and flavonoid fraction, diabetic control and diabetic treated with alcoholic and flavonoid fraction. In-vitro aldose reductase inhibitory activity was also evaluated. Further, molecular docking study was performed with crystal structure of aldose reductase and its known chemical constituents of the plant. RESULTS: The IC50 value of alcoholic extract for aldose reductase inhibition was found to be 209.13µg/ml, and that of flavonoid fraction was found to be 46.73µg/ml. Administration of STZ produced significantly abnormal levels of serum glucose, serum insulin, soluble protein and antioxidants in the lens homogenate. Treatment with alcoholic extract and flavonoid fraction of T. purpurea were able to normalize these levels. Some of the active constituents of T. purpurea showed significant interactions with aldose reductase enzyme in molecular docking studies. CONCLUSIONS: Our data suggested that both the extracts might be helpful in delaying the development of diabetic cataract due to the presence of rutin and quercetin. This beneficial effect may be due to its significant inhibition of aldose reductase enzyme and anti-oxidant activity.

Hypercholesterolemia-induced ocular disorder: Ameliorating role of phytotherapy.

The ocular region is a complex structure that allows conscious light perception and vision. It is of ecto-mesodermal origin. Cholesterol and polyunsaturated fatty acids are involved in retinal cell function; however, hypercholesterolemia and diabetes impair its function. Retinal damage, neovascularization, and cataracts are the main complications of cholesterol overload. Dietary supplementation of selected plant products can lead to the scavenging of free reactive oxygen species, thereby protecting the ocular regions from the damage of hypercholesterolemia. This review illustrates the dramatic effects of increased cholesterol levels on the ocular regions. The effect of phytotherapy is discussed in relation to the different regions of the eye, including the retina, cornea, and lens.

Vitamin E and risk of age-related cataract: a meta-analysis.

OBJECTIVE: We conducted a meta-analysis to evaluate the relationship between vitamin E and age-related cataract (ARC). DESIGN: The fixed- or random-effect model was selected based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Begg's test. The dose-response relationship was assessed by a restricted cubic spline model. SETTING: Relevant studies were identified by a search of PubMed and the Cochrane Library to May 2014, without language restrictions. SUBJECTS: Studies involved samples of people of all ages. RESULTS: Dietary vitamin E intake, dietary and supplemental vitamin E intake, and high serum tocopherol levels were significantly associated with decreased risk of ARC, the pooled relative risk was 0·73 (95% CI 0·58, 0·92), 0·86 (95% CI 0·75, 0·99) and 0·77 (95% CI 0·66, 0·91), respectively. Supplemental vitamin E intake was non-significantly associated with ARC risk (relative risk=0·92; 95% CI 0·78, 1·07). The findings from dose-response analysis showed evidence of a non-linear association between dietary vitamin E intake and ARC. The risk of ARC decreased with dietary vitamin E intake from 7 mg/d (relative risk=0·94; 95% CI 0·90, 0·97). CONCLUSIONS: The findings of the meta-analysis indicated that dietary vitamin E intake, dietary and supplemental vitamin E intake, and high level of serum tocopherol might be significantly associated with reduced ARC risk.

Serum free fatty acids level in senile cataract.

PURPOSE: To evaluate and compare the levels of free fatty acids between senile cataract patients and normal controls. METHODS: Fifty consecutive patients with newly diagnosed senile cataract and 50 age- and gender-matched controls were evaluated. Subjects/patients were randomized according to selection criteria. The levels of free fatty acids (FFAs) in serum were measured by gas chromatography-mass spectrometry (GC-MS). Sixteen fatty acids from 14:0 to 24:1 were identified. The values were compared between cataract and control groups by parametric independent sample test and Mann-Whitney U tests. RESULTS: A significant decrease was observed in arachidonic acid (C20:4n-6, ARA), cis-4,7,10,13,16,19-docosahexaenoic acid (C22:6n-3, DHA), tetracosanoic acid (C24: 0), cis-7,10,13,16,19-docosapentaenoic acid (C22:5n-6, DPA), total n-3 long-chain polyunsaturated fatty acids (LC-PUFAs), total n-6 LC-PUFAs, total fatty acids, unsaturated fatty acids (USFAs), polyunsaturated fatty acids (PUFAs), and nonessential fatty acid levels in patients with senile cataract in comparison with healthy persons (p < 0.05). CONCLUSIONS: The levels of FFA including DPA, tetracosanoic acid, ARA, and DHA were significantly lower in the senile cataract group compared to that in the normal controls. FFA may be helpful in preventing senile cataract.

Efficacy of biodegradable curcumin nanoparticles in delaying cataract in diabetic rat model.

Curcumin, the active principle present in the yellow spice turmeric, has been shown to exhibit various pharmacological actions such as antioxidant, anti-inflammatory, antimicrobial, and anti-carcinogenic activities. Previously we have reported that dietary curcumin delays diabetes-induced cataract in rats. However, low peroral bioavailability is a major limiting factor for the success of clinical utilization of curcumin. In this study, we have administered curcumin encapsulated nanoparticles in streptozotocin (STZ) induced diabetic cataract model. Oral administration of 2 mg/day nanocurcumin was significantly more effective than curcumin in delaying diabetic cataracts in rats. The significant delay in progression of diabetic cataract by nanocurcumin is attributed to its ability to intervene the biochemical pathways of disease progression such as protein insolubilization, polyol pathway, protein glycation, crystallin distribution and oxidative stress. The enhanced performance of nanocurcumin can be attributed probably to its improved oral bioavailability. Together, the results of the present study demonstrate the potential of nanocurcumin in managing diabetic cataract.

Association of blood antioxidants and vitamins with risk of age-related cataract: a meta-analysis of observational studies.

BACKGROUND: Observational studies have been inconsistent regarding the association between blood antioxidants or vitamins and risk of age-related cataract. OBJECTIVE: We performed a meta-analysis to determine whether an association exists between blood levels of antioxidants or vitamins and age-related cataract in observational studies. DESIGN: We searched PubMed, EMBASE, and the Web of Science for relevant studies from inception to October 2012. Study-specific risk estimates were combined by using a random-effects model. RESULTS: A total of 13 studies with 18,999 participants were involved in this meta-analysis. A pooled estimate showed vitamin E (OR: 0.75; 95% CI: 0.58, 0.96), α-carotene (OR: 0.72; 95% CI: 0.59, 0.88), lutein (OR: 0.75; 95% CI: 0.65, 0.87), and zeaxanthin (OR: 0.70; 95% CI: 0.60, 0.82) were inversely associated with age-related cataract. Vitamins A (OR: 0.69; 95% CI: 0.58, 0.83) and C (OR: 0.67; 95% CI: 0.57, 0.78) were inversely associated with age-related cataract in Asian populations but not in Western populations. ß-Carotene (OR: 0.90; 95% CI: 0.78, 1.05), lycopene (OR: 0.86; 95% CI: 0.65, 1.15), and ß-cryptoxanthin (OR: 0.83; 95% CI: 0.68, 1.02) had no significant association with risk of cataract. CONCLUSIONS: This meta-analysis provides additional evidence supporting the view that blood levels of certain antioxidants are inversely associated with risk of age-related cataract. However, the role of antioxidant or vitamin supplement intake in preventing cataract should be further investigated in interventional studies.

[Hereditary hyperferritinemia cataract syndrome]. / Das hereditäre Hyperferritinämie-Katarakt-Syndrom.

HISTORY: A 42-year-old man was found to have a four to six fold increase in the level of plasma ferritin since four years. In the age of 10 he had undergone unilateral resection of a dysplastic kidney associated with systemic hypertension. He had also developed recurrent venous thromboses caused by atresia of the inferior vena cava with azygos continuation, known since 23 years. Iron overload or hemochromatosis had been excluded, but despite numerous investigations the exact cause of the hyperferritinemia had not been elucidated. The patient, his grandfather, his mother and a brother had undergone cataract surgeries in both eyes. He presented at admission with prominent veins over the abdomen a postthrombotic syndrome. INVESTIGATION: Laboratory tests revealed a ferritin level 6 times above the upper limit of normal, but iron, transferrin saturation, and transferrin levels were normal. The patient was on oral anticoagulation (INR 2.2). Molecular genetic tests revealed heterozygous mutation IRE+ 32 G > T. DIAGNOSIS, TREATMENT AND COURSE: The findings indicated a hereditary hyperferritinemia cataract syndrome with an autosomal dominant trait. As functions of other organs are not affected, bilateral cataract surgery is "curative". CONCLUSION: Early and correct diagnosis avoids unnecessary diagnostic and therapeutic interventions, such as extended and repeated laboratory tests, liver biopsies, phlebotomies and chelation therapy.

Total antioxidant capacity in Eales' disease, uveitis & cataract.

BACKGROUND & OBJECTIVES: The human system possesses antioxidants that act harmoniously to neutralize the harmful oxidants. This study was aimed to evaluate the serum total antioxidant capacity (TAC) as a single parameter in Eales' disease (ED) and in an acute inflammatory condition such as uveitis and in cataract which is chronic, compared to healthy controls. METHODS: The TAC assay was done spectrophotometrically in the serum of Eales' disease cases (n=20) as well as in other ocular pathologies involving oxidative stress namely, uveitis and cataract (n=20 each). The oxidative stress measured in terms of TBARS, was correlated with the TAC. Individual antioxidants namely vitamin C, E and glutathione were also estimated and correlated with TAC. RESULTS: TAC was found to be significantly lower in Eales' disease with active vasculitis (0.28 ± 0.09 mM, P<0.001), Eales' disease with healed vasculitis (0.67 ± 0.09 mM), uveitis (0.46 ± 0.09 mM, P<0.001) and cataract (0.53 ± 0.1 mM, P=0.001) compared to the healthy controls, with a TAC level of 0.77 ± 0.09 mM. The TAC was found to correlate positively with vitamin E levels (P=0.05), GSH (P=0.02) but not with vitamin C, as seen in ED cases. In ED cases supplemented with vitamin E and C, there was a significant increase in the TAC level (P=0.02). INTERPRETATION & CONCLUSIONS: The TAC measurement provided a comprehensive assay for establishing a link between the antioxidant capacity and the risk of disease as well as monitoring antioxidant therapy. This method is a good substitute for assay of individual antioxidants as it clearly gives the status of the oxidative stress in the disease process.

Selenium and pseudoexfoliation syndrome.

PURPOSE: To investigate the levels of selenium (Se), an essential trace element, in aqueous humor, conjunctival specimens, and serum of patients with pseudoexfoliation (PEX) syndrome and control subjects; and to determine the role of Se in the development and pathogenesis of PEX syndrome. DESIGN: A prospective case-control study. METHODS: Twenty-seven cataract patients with PEX syndrome and 20 age-matched cataract patients without PEX syndrome were enrolled in this institutional study. Patients with ophthalmic conditions other than PEX and conditions that may influence Se levels were excluded. During cataract surgeries, aqueous humor, conjunctival specimens, and serum were collected in both groups. Selenium levels of all samples were measured by using atomic absorption spectrophotometer. RESULTS: The mean Se levels in aqueous humor of patients with PEX syndrome (50.96 ± 23.79 µg/L) were significantly lower than the control group (77.85 ± 19.21 µg/L) (P < .001). The mean Se levels in conjunctival specimens of patients with PEX syndrome (4.04 ± 1.44 µg/mg) were significantly lower than the control group (7.19 ± 2.00 µg/mg) (P < .001), as well. The mean Se levels in serum of patients with PEX syndrome (115.25 ± 25.20 µg/L) were lower than the control group (124.25 ± 14.40 µg/L), but this was not statistically significant (P = .325). CONCLUSION: Reduced levels of Se in aqueous humor, conjunctival specimens, and serum of patients with PEX may support the role of impairment in antioxidant defense system in the pathogenesis of PEX syndrome.

Antiglycating potential of Zingiber officinalis and delay of diabetic cataract in rats.

PURPOSE: Advanced glycation end products (AGE) are associated in the development of several pathophysiologies including diabetic cataract. Earlier we have reported that some common dietary agents have antiglycating activity and ginger (Zingiber officinalis) was one of the few prominent agents that effectively prevented AGE formation in vitro. In this study we investigated the potential of ginger to prevent diabetic cataract in rats. METHODS: Diabetes was induced in Wistar-NIN rats by intraperitoneal injection of streptozotocin (35 mg/kg bodyweight) and the control rats received vehicle alone. While a set of diabetic animals received AIN-93 diet, another set received either 0.5 or 3% ginger in their diet for a period of two months. Cataract progression was monitored by slit-lamp biomicroscope. At the end of two months, the animals were sacrificed to evaluate non-enzymatic glycation and osmotic stress in the eye lens. RESULTS: Slit-lamp examination revealed that feeding of ginger not only delayed the onset but also the progression of cataract in rats. Molecular analyses indicated that feeding of ginger significantly inhibited the formation of various AGE products including carboxymethyl lysine in the eye lens. In addition, ginger also countered hyperglycemia-induced osmotic stress in the lens. CONCLUSIONS: The results indicated that ginger was effective against the development of diabetic cataract in rats mainly through its antiglycating potential and to a lesser extent by inhibition of the polyol pathway. Thus, ingredients of dietary sources, such as ginger, may be explored for the prevention or delay of diabetic complications.

Gains in statistical power from using a dietary biomarker in combination with self-reported intake to strengthen the analysis of a diet-disease association: an example from CAREDS.

A major problem in detecting diet-disease associations in nutritional cohort studies is measurement error in self-reported intakes, which causes loss of statistical power. The authors propose using biomarkers correlated with dietary intake to strengthen analyses of diet-disease hypotheses and to increase statistical power. They consider combining self-reported intakes and biomarker levels using principal components or a sum of ranks and relating the combined measure to disease in conventional regression analyses. They illustrate their method in a study of the inverse association of dietary lutein plus zeaxanthin with nuclear cataracts, using serum lutein plus zeaxanthin as the biomarker, with data from the Carotenoids in Age-Related Eye Disease Study (United States, 2001-2004). This example demonstrates that the combined measure provides higher statistical significance than the dietary measure or the serum measure alone, and it potentially provides sample savings of 8%-53% over analysis with dietary intake alone and of 6%-48% over analysis with serum level alone, depending on the definition of the outcome variable and the choice of confounders entered into the regression model. The authors conclude that combining appropriate biomarkers with dietary data in a cohort can strengthen the investigation of diet-disease associations by increasing the statistical power to detect them.

[Prevalence of diabetic retinopathy. Check-up program of a public health insurance company in Germany 2002-2004]. / Prävalenz der diabetischen Retinopathie. Studie bei Versicherten der Deutschen Betriebskrankenkasse 2002-2004.

OBJECTIVES: Population based studies have reported a prevalence of diabetic retinopathy (DR) at the time of diagnosis in up to 30% of the patients. In the context of a general diabetes check-up program (so called "Diabetes-TUV"), the prevalence of diabetic retinopathy in Germany was examined in all diabetes patients insured in a public health insurance company. METHODS: Patients were screened in the offices of 181 ophthalmologists according to a standardized protocol formulated by Prof. Kroll, Marburg. A total of 6,500 sheets were analysed out of which 14.5% were multiply documented. The latest protocols of 5,596 patients were evaluated; the mean age was 64.7 years with an average duration of diabetes of 10.2 years. RESULTS: Some 86.3% of the eyes examined had no DR, in 3.1% no evaluation was possible. Of the patients checked, 10.6% had DR. Mild/moderate DR was reported in 8.3%, severe non-proliferative DR in 1.7% and proliferative DR in 0.5%. Macular edema was reported in 0.85% of cases, vitreous hemorrhage in 0.2%. There was 0.1% iris neovascularisation and 0.1% retinal detachment. Visual impairment due to cataract or secondary cataract was found in 25.2% of patients with an 8.3% pseudophakia rate. CONCLUSION: Documentation of the eye examination in the diabetes check-up program was good. The 10.6% prevalence of DR in Germany, even after long standing diabetes, seems to be lower than in earlier population based studies in the US or UK. The data reported here could be an indication of better diabetes care in Germany. However, not all patients were examined with dilated pupils, and in the case of severe changes, the ophthalmologist might have decided not to fill in the report form and to have chosen another form of communication.

Delay of cataract development in the Shumiya cataract rat by the administration of drinking water containing high concentration of magnesium ion.

We discovered that the cataract development in the Shumiya cataract rat (SCR) can be prevented by the administration of deep-sea drinking water (DDW). A standard diet based on the American Institute of Nutrition guidelines (AIN-76) and DDW containing a high mineral concentration such as low, medium and high Mg2+ content (50, 200 and 1000 mg of Mg2+/l, respectively) were used in this study. SCRs were freely fed with combinations of the standard diet and purified water or DDW during 5-15 weeks of age. The opacities of SCR lenses were documented by anterior eye segment analysis system EAS-1000. The onset of opacification of cataractous SCR lenses administered a combination of standard diet and purified water started at 11 weeks of age, and mature cataracts had formed at 13 weeks of age. However, the supplementation of Mg2+ by administration with medium DDW showed the greatest effect of delay of cataract onset in SCR. In addition, even cataractous SCR lenses at 14 weeks of age showed differences in opacity level. The opacification and Ca2+ of the lenses in cataractous SCR administered medium DDW were lower than those administered purified water. In conclusion, the present study demonstrates that administration of DDW potently delays cataract development in SCR, and this may be caused by inhibiting the increase in Ca2+ levels in the lens.