Related Cataract Research Articles

Protective role of C-phycocyanin against secondary changes during sodium selenite mediated cataractogenesis.

Age related cataract is the leading cause of blindness associated with accumulation of oxidative stress in the eye lens. The present investigation reveals the rational of the beneficial effects of the natural compound C-phycocyanin (C-PC) is beneficial when administered to rat pups to protect against the secondary effects of sodium selenite induced cataractogenesis. A single subcutaneous dose of sodium selenite (19 μmol/kg body weight) on the 10th day of postpartum is adequate to induce cataract in rat pups. Serum biochemical parameters, such as the level of electrolytes, mean activities of anti-oxidant enzymes i.e. superoxide dismutase, catalase and reduced glutathione were observed to be significantly altered during selenite induced cataractogenic process. Histopathological examination revealed signs of degradation of normal cell architecture in the liver, kidney and eye lens. Interestingly, the deleterious effects of sodium selenite toxicity were restored with the simultaneous treatment with C-PC. The results suggest that an administration of 200 mg/kg body weight of C-PC has the ability to prevent/alter the secondary changes reflected in the serum biochemical and histological modifications in rats exposed to sodium selenite. These results complement the beneficial role of C-PC of cyanobacterial origin as a efficacious anti-cataractogenic agent against sodium selenite toxicity.

Made of the Mist: Nineteenth-Century British and American Views of Niagara II

Writing within the conventions of the European sublime was often problematic for 19th-century travel writers who found Niagara had no Old World precedent. Frances and Anthony Trollope, Dickens, Hawthorne, Margaret Fuller, Twain, and Henry James all made important contributions to the literary development of the Fall's treatment in the 19th century, when they first became widely written upon, painted, and commodified after the 1825 completion of the Erie Canal. This article explores the importance of these authors' points of view of the cataract in relation to silence, guidebook empiricism, guidebook Romanticism, irreverence, and the problematic prospect of coming to terms with the Falls as a commercial and tourist destination.

Grape seed extract and zinc containing nutritional food supplement prevents onset and progression of age-related cataract in wistar rats.

To study possible inhibition of oxidative stress and cataract formation by single combined formulation of grape seed extract and Zincovit tablets against sodium selenite-induced age-related cataract in Wistar rat pups. Oxidative stress and consequent cataract formation was induced by subcutaneous administration of a single dose of sodium selenite (10 µmoles/kg) to Wistar rat pups on day 7 post-natally. In experiments designed to inhibit such cataract formation, the pups were pretreated subcutaneously with combined formulation of grape seed extract and Zincovit tablets (40, 80 and 160 mg/kg), one day prior to the administration of selenite and continuing such treatment till day 20, when the experiments were terminated. The extent of tissue damage caused by the selenite was assessed biochemically by measurements of the levels of reduced glutathione, glutathione peroxidase, glucose-6-phosphate dehydrogenase, protein thiol, catalase, superoxide dismutase, malondialdehyde, aldose reductase, sorbitol dehydrogenase and adenosine triphosphate in the isolated lenses. Cataract formation and its prevention were monitored by examining the eye with pen light illumination and subsequent photography of the isolated lenses. Injection of selenite led to a significant loss of lens clarity due to cataract formation. In the group treated with combined formulation of grape seed extract and Zincovit tablets, the formation of cataract was significantly prevented. In the normal and selenite induced senile cataract control group, the levels of lens oxidative stress markers, G6PD and ATP were substantially lower than in the grape seed extract with Zincovit tablets treated group (p < 0.05). Over all, the results suggest that single combined formulation of grape seed extract and Zincovit tablets may offer a prophylactic measure against onset and progression of age- related cataract of human subjects as nutritional food supplement.

Small Incision Cataract Surgery (SICS) with Clear Corneal Incision and SICS with Scleral Incision – A Comparative Study

Background: Age related cataract is the leading cause of blindness and visual impairment throughout the world. With the advent of microsurgical facilities simple cataract extraction surgery has been replaced by small incision cataract surgery (SICS) with posterior chamber intra ocular lens implant, which can be done either with clear corneal incision or scleral incision. Objective: To compare the post operative visual outcome in these two procedures of cataract surgery. Materials and method: This comparative study was carried out in the department of Ophthalmology, Delta Medical College &amp; Hospital, Dhaka, Bangladesh, during the period of January 2010 to December 2012. Total 60 subjects indicated for age related cataract surgery irrespective of sex with the age range of 40-80 years with predefined inclusion and exclusion criteria were enrolled in the study. Subjects were randomly and equally distributed in 2 groups; Group A for SICS with clear corneal incision and group B for SICS with scleral incision. Post operative visual out come was evaluated by determining visual acuity and astigmatism in different occasions and was compared between groups. Statistical analysis was done by SPSS for windows version12. Results: The highest age incidence (43.3%) was found between 61 to 70 years of age group. Among study subjects 40 were male and 20 were female. Preoperative visual acuity and astigmatism were evenly distributed between groups. Regarding postoperative unaided visual outcome, 6/12 or better visual acuity was found in 19.98% cases in group A and 39.6% cases in group B at 1st week. At 6th week 6/6 vision was found in 36.3% in Group A and 56.1% in Group B and 46.2% in group A and 66% in group B without and with correction respectively. With refractive correction, 6/6 vision was attained in 60% subjects of group A and 86.67% of group B at 8th week. Post operative visual acuity was statistically significant in all occasions. Postoperative astigmatism of &gt;0.50D was in 82.5% subjects of group A and 52.8% subjects of group B at 1st week. At 6th week postoperative astigmatism of less than 1D was in 79.95% subjects of Group A and 83.34% subjects of Group B. About 20% subjects in Group A and only 3.3% in Group B showed astigmatism of more than 1D and these differences on both the occasions were statistically significant. Conclusion: The post operative visual outcome was better in SICS with scleral incision (group B) than in SICS with clear corneal incision (Group-A). DOI: http://dx.doi.org/10.3329/dmcj.v2i1.17793 Delta Med Col J. Jan 2014; 2(1): 22-27

Cataract in 50 Plus Population: Prevalence &amp; Perception of Symptoms in a Rural Block of Cuttack District of Odisha

Background : With the increase in life expectancy, the degenerative disorders are increasing day by day. Age related cataract is one among those and it is the commonest type of acquired cataract affecting persons usually above the age of 50 years. Most eye diseases in their initial stages tend to be ignored by many a people as common and trivial. Objectives : 1. To know the prevalence of cataract in 50+ population. 2. To know the perception of symptoms due to cataract. Method : It was a community based cross-sectional study conducted in two villages in a rural block of Odisha. The villages were selected by multistage random sampling. Sample size calculated was 266. The study respondents were interviewed and clinically examined by door to door visit. Data analysis was done with SPSS(11.0).Chi-square test was used as required. Results : A total of 274 individuals of 50+ age were enrolled in the study. The prevalence of cataract among the study subjects was 70% (68% in males and 72% in females). It was higher in BPL(Below poverty line) subjects. Significant difference (p<0.001)was observed in prevalence of cataract between perceivers and non-perceivers of eye problems. 97% of the cases of blindness was due to cataract. Conclusion : The study concludes that there is high prevalence of age related cataract in rural area of Odisha and also gives idea how rural people perceive the symptoms related to cataract.

To Study and Compare the Incidence of Posterior Capsule Opacification Depending on the Type of Materials used in Different Intraocular Lenses

We present a study which compare the incidence of posterior capsule opacification on type of materials used in different intraocular lenses i.e. Poly Methyl Meth Acrylic IOL, Hydrophilic IOL,Hydrophobic IOL in patients visiting eye O.P.D. of E.S.I.H., Basaidarapur, New Delhi. The target population was patients visiting ophthalmology department of E.S.I. Hospital, Basaidarapur for treatment of visually significant age related cataract. 60 eyes of 60 patients were enrolled in the study and were randomly divided in 3 groups with 20 eyes in each group. All eyes underwent cataract surgery by phaco emulsification technique by one surgeon.

Surgical outcomes after intraocular lens implantation for posterior lenticonus–related cataract according to preoperative lens status

To address the surgical outcomes of pediatric patients with cataracts associated with posterior lenticonus who required cataract extraction and intraocular lens (IOL) implantation according to preoperative lens status. Department of Ophthalmology, Seoul National University Children's Hospital, Seoul, South Korea. Comparative case series. Patients who had cataract extraction and IOL implantation for posterior lenticonus were divided into 2 groups according to the preoperative lens status. Clinical features and visual outcomes in both groups were comparatively analyzed. Forty-seven eyes of 43 patients were studied. Thirty-five eyes had lens opacities localized to the posterior pole, and 12 eyes presented with total opacity of the lens. Preexisting posterior capsule defect was identified intraoperatively in 11 eyes with total lens opacity. Eyes with preexisting posterior capsule defects more frequently required ciliary sulcus fixation of the IOL (P=.01). The mean follow-up after cataract extraction was 66.9 months ± 35.9 (SD). The mean final corrected distance visual acuity of patients with total opacity (0.37 ± 0.57 logMAR) was better than that of patients with posterior polar opacity (0.56 ± 0.50 logMAR), with borderline significance (P=.05). A preexisting posterior capsule defect, found most often in eyes that presented with total lens opacity, could be an obstacle to capsular bag fixation of the IOL. Posterior lenticonus patients with total lens opacity had marginally significantly better visual outcomes than patients with posterior polar opacity. No author has a financial or proprietary interest in any material or method mentioned.

Prevalence of Pre-Existing Corneal Astigmatism in Age Related Cataract Patient

Cataract surgery is no more a blind rehabilitation surgery, it absolutely gives normal vision. In the era of modern cataract surgery patients expectations are also high about visual outcome. This prospective study was carried out to investigate the magnitude and pattern of pre-existing corneal astigmatism in age related cataract patient at Faridpur Medical College Hospital, Faridpur and Agha Yusuf Adhunik Hospital, Kustia, from July 2009 to June 2012. We examined 850 eyes of 730 patients who underwent cataract surgery. The mean age at the time of surgery was 61.9±8.1 (40 to 70) years. Corneal astigmatism was measured by Auto Refracto Keratometer at least two times for each patient. Astigmatism was calculated from diopteric difference of vertical reading from horizontal reading. With the rule (WTR) astigmatism was considered when steep meridian at 90°± 20°. Against the rule (ATR) astigmatism was considered when steep meridian at 180°±20°. Astigmatism is in other direction is defined as oblique. On keratometry, when vertical reading (k1) was found greater than horizontal (k2) was considered WTR astigmatism and the reverse reading for ATR astigmatism. The percentage of corneal astigmatism was 1D or less was 69.6%, more than 1D and less than 1.5D, 27.6% and more than 1.5D and less then 2D 2.8%. Prevalence of ATR astigmatism was more than WTR astigmatism and prevalence of ATR astigmatism increases significantly with age. Approximately two third of pre-operative patient had 1D or less astigmatism and one third had more than 1D corneal astigmatism. DOI: http://dx.doi.org/10.3329/fmcj.v8i1.16887 Faridpur Med. Coll. J. 2013;8(1): 02-04

Antioxidant delivery to the lens nucleus: A strategy to delay age related nuclear cataract

AbstractAge related nuclear (ARN) cataract is associated with the accumulative effects of oxidative damage to proteins in the lens nucleus. Since it is preceded by a loss of the key lens antioxidant GSH specifically in the lens centre, but not the lens periphery or cortex, ARN cataract is thought to be due to a failure to deliver GSH to the nucleus. Due to its large size, the avascular lens cannot rely on passive diffusion alone to deliver GSH to deeper lying fiber cells. Instead it has been proposed that the lens operates an internal microcirculation system which delivers nutrients to the lens nucleus faster than would occur by passive diffusion alone. Consistent with this model, our group has used MRI and confocal microscopy to visualize this microcirculation and have revealed that the lens sutures serve as an extracellular pathway to deliver molecules to the lens nucleus. Furthermore, we have shown that cells in the nucleus express transporters that are potentially capable of accumulating the GSH and glucose convected to them via the microcirculation system. These results suggest that harnessing the circulation system to deliver antioxidants to the lens nucleus is a potential strategy to delay the onset of ARN cataract.

Comparison of the New Biometer OA-1000 with IOLMaster and Tomey AL-3000

Background: The OA-1000 (Tomey, Japan) is a new optical biometer, which allows measurements of axial length (AL), anterior chamber depth (ACD) and corneal thickness (CT) due to partial coherence interferometry (PCI) technology. The aim of this study was to compare the OA-1000 results with those obtained with the IOLMaster and contact applanation A-scan ultrasonography.Methods: We examined 133 eyes of 75 patients with age related cataract. Mean age was 72.0 ± 9.5 years. Biometry measurements of AL and ACD were performed with the Tomey OA-1000 based on PCI, the IOLMaster based on PCI (AL) and slit projection (ACD), and the Tomey AL-3000 based on contact applanation A-scan ultrasonography.Results: Mean AL using the IOLMaster was 23.21 ± 1.08 mm, using the AL-3000 was 22.79 ± 1.04 mm, using the OA-1000 it was 22.97 ± 1.1 mm. Mean ACD using the IOLMaster was 2.99 ± 0.41 mm, using the OA-1000 3.40 ± 0.46 mm, using the Tomey AL-3000 it was 2.93 ± 0.43 mm. Mean difference between the AL and ACD measured with the OA-1000 and the IOLMaster was 0.22 ± 0.047 mm and 0.40 ± 0.33 mm, between OA-1000 and the AL-3000 it was 0.19 ± 0.23 mm and 0.47 ± 0.33 mm, and between IOLMaster and AL-3000 it was 0.42 ± 0.23 and 0.09 ± 0.36 mm. For AL the correlation coefficient R between IOLMaster and OA-1000 was 0.999, between IOLMaster and AL-3000 it was 0.976, between AL-3000 and OA-1000 it was 0.977. For ACD R between IOLMaster and OA-1000 was 0.735, between IOLMaster and AL-3000 it was 0.822, between AL-3000 and OA-1000 it was 0.716 (all p < 0.001).Conclusions: Compared with other used clinical instruments the OA-1000 generates accurate results. Although differences were found, the OA-1000 provided results that correlated well with the values of IOLMaster and AL-3000.

A fraction of stem bark extract of Entada africana suppresses lipopolysaccharide-induced inflammation in RAW 264.7 cells

Ethnopharmacological relevanceEntada africana is a plant used in African traditional medicine for the treatment of stomachache, fever, liver related diseases, wound healing, cataract and dysentery. Aims of the studyThis study aimed at evaluating the anti-inflammatory activity of fractions of the stem bark extract of the plant using lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages model. Materials and methodsThe crude extract was prepared using the mixture CH2Cl2/MeOH (1:1, v/v) and fractionated by flash chromatography using solvents of increasing polarity to obtain five different fractions. The effects of the fractions on the cells viability were studied by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and their inhibitory activity against LPS-induced nitric oxide (NO) production screened by Griess test. The most active fraction was further investigated for its effects on reactive oxygen species (ROS) production using flux cytometry, the expression of inducible nitric oxide synthase (iNOS), pro-and anti-inflammatory cytokines (IL1β, TNFα, IL6, IL10 and IL13) by RT-PCR, and the activity of the enzyme p38 MAPK kinase by enzyme-linked immunosorbent assay (ELISA). ResultsThe fractions presented no significant effect on the viability of macrophages at 100μg/ml after 24h incubation. The CH2Cl2/MeOH 5% (Ea5) fraction was found to be the most potent in inhibiting NO production with a half inhibition concentration (IC50)=18.36μg/ml, and showed the highest inhibition percentage (89.068%) in comparison with Baicalin (63.34%), an external standard at 50μg/ml. Ea5, as well as Baicalin significantly (P<0.05) inhibited the expression of TNFα, IL6 and IL1β mRNA, attenuated mRNA expression of inducible NO synthase in a concentration-dependent manner, stimulated the expression of anti-inflammatory cytokines (IL10 and IL13), and showed a 30% inhibition of the activity of p38 MAPK kinase. ConclusionThe results of the present study indicate that the fraction Ea5 of Entada africana possesses most potent in vitro anti-inflammatory activity and may contain compounds useful as a therapeutic agent in the treatment of inflammatory related diseases cause by over-activation of macrophages.

Barriers to cataract surgical uptake in central ethiopia

Purpose:The aim of this study was to assess the factors that delay surgical intervention in patients suffering from age related mature cataract in Ethiopia.Materials and Methods:A short term descriptive study was performed that evaluated patients with mature cataract presenting to outreach eye care clinics in rural central Ethiopia. Patients were interviewed to determine the reasons for delay in their cataract surgeries.Result:A total of 146 subjects (57 male and 89 females) with operable age related cataract were evaluated at 31 outreach clinics. Over 86% of the respondents were above 55 years of age, (range, 45–78 years). The male to female ratio was 1:1.5 and 30.2% of the subjects were blind bilaterally (best corrected visual acuity <3/60). The majority of the respondents were farmers (53.4%) and 86.3% were illiterate. The major factors that delayed cataract surgery included: Cost of surgery (91.8%), insufficient family income (78.1%), good vision in the fellow (unaffected) eye (39.7%), and the distance to hospital from their village (47.9%).Conclusion:Surgical cost, insufficient family income, and the distance to an eye care centre were the major factors delaying cataract surgery in rural Ethiopia.

Lipid peroxidation and the total antioxidant status in the pathogenesis of age related and diabetic cataracts: a study on the lens and blood.

Cataract is one of the major causes of a visual impairment, which eventually leads to blindness. An oxidative damage to the lens proteins is a major factor which leads to cataract formation. Therefore, we intended to study the relationship between the biochemical markers of oxidative stress and various forms of cataracts. We examined the lenses and the sera of 120 subjects who were aged 50 to 80 years, who were distributed in two groups, viz. the study group (90 patients) and the control group (30 subjects). The oxidative stress was assessed by estimating the lipid peroxidation product in the form of thiobarbituric acid reactive substances (TBARS), the antioxidant status by measuring the levels of vitamin E and the total antioxidant capacity (TAC). The study group patients were further divided into those with nuclear cataracts (30 patients), cortical cataracts (30 patients), and diabetic cataracts (30 patients). In this study, it was found that the levels of TBARS in the study group were significantly high (p<0.001), whereas the TAC (p<0.001) and the vitamin E (p<0.001) levels were significantly low, both in the lenses and the blood of the study group as compared to those of the control group. Thus, the present study suggests that an imbalance between the oxygen free radicals and the antioxidants may lead to lipid peroxidation in the lens. Also, the elevated levels of glucose in the diabetic cataracts lead to the auto-oxidation of glucose and a non-enzymatic glycation of the lens protein. Thereby, the high molecular weight proteins aggregate in the cataract.

Causes of visual impairment and blindness in Kaduna State Special Education School

Aims and Objectives: To identify the causes of visual impairment and blindness in students of Kaduna State Special Education School (KASSES) and make recommendations for the planning of eye care, including prevention and management of the avoidable causes of childhood blindness in our environment. Background: Childhood blindness is one of the priorities of vision 2020: The Right to sight. The attributable to childhood is comparable to that of age related cataract (the commonest cause of blindness worldwide). Significant proportions of the causes of childhood blindness are avoidable and can be identified after a screening exercise and treated. Periodic screening will also provide current data for planning and implementation of childhood blindness prevention programmes. Materials and Methods: All the students of the blind section of KASSES who were present during the study were examined and the Georgia Project's screening protocol for visual impairment in children was completed for each of them. The data was analyzed using Analyze-it V2.22 (2010) statistical software. Results: A total of 71 students were examined. M:F ratio was 1.7:1. The age range was between 6-29 years but 76% were within the bracket of 10-19 years. Seventy percent were blind, 21% had severe visual impairment, and 9% had moderate visual impairment. Cataract was the commonest cause of blindness (25.3%), followed by trauma (16.9%), optic atrophy, buphthalmos, and retinitis pigmentosa (12.7% each). Others were corneal scarring/staphyloma (9.9%), Rubella (7.0%), and a case each of bilateral ankyloblepharon and uveitis (1.4%). Conclusion: The causes of visual impairment in KASSES are largely avoidable. Incorporation of Primary Eye Care (PEC) into Primary Health Care (PHC) will drastically reduce needless blindness, especially in childhood and the morbidity and mortality associated with the blind years. Early identification of students with treatable causes such as cataract should also be encouraged through regular school screening and health education.

Screening and structural evaluation of deleterious Non-Synonymous SNPs of ePHA2 gene involved in susceptibility to cataract formation.

Age-related cataract is clinically and genetically heterogeneous disorder affecting the ocular lens, and the leading cause of vision loss and blindness worldwide. Here we screened nonsynonymous single nucleotide polymorphisms (nsSNPs) of a novel gene, EPHA2 responsible for age related cataracts. The SNPs were retrieved from dbSNP. Using I-Mutant, protein stability change was calculated. The potentially functional nsSNPs and their effect on protein was predicted by PolyPhen and SIFT respectively. FASTSNP was used for functional analysis and estimation of risk score. The functional impact on the EPHA2 protein was evaluated by using SWISSPDB viewer and NOMAD-Ref server. Our analysis revealed 16 SNPs as nonsynonymous out of which 6 nsSNPs, namely rs11543934, rs2291806, rs1058371, rs1058370, rs79100278 and rs113882203 were found to be least stable by I-Mutant 2.0 with DDG value of > −1.0. nsSNPs, namely rs35903225, rs2291806, rs1058372, rs1058370, rs79100278 and rs113882203 showed a highly deleterious tolerance index score of 0.00 by SIFT server. Four nsSNPs namely rs11543934, rs2291806, rs1058370 and rs113882203 were found to be probably damaging with PSIC score of ≥ 2. 0 by Polyp hen server. Three nsSNPs namely, rs11543934, rs2291806 and rs1058370 were found to be highly polymorphic with a risk score of 3-4 with a possible effect of Non-conservative change and splicing regulation by FASTSNP. The total energy and RMSD value was higher for the mutant-type structure compared to the native type structure. We concluded that the nsSNP namely rs2291806 as the potential functional polymorphic that is likely to have functional impact on the EPHA2 gene.

Corticosteroid Use for Diabetic Macular Edema: Old Fad or New Trend?

Diabetic retinopathy is the leading cause of blindness in working age individuals in developed countries. Most cases of diabetes related vision loss result from breakdown of the blood-retinal barrier with resultant diabetic macular edema (DME). For over 30 years, laser photocoagulation has been the standard therapy for DME, but most eyes do not experience significant improvements in visual acuity. Intravitreal injections of drugs that inhibit the action of vascular endothelial growth factor (VEGF) lead to gains in vision, but can be expensive and need to be repeated frequently. In addition to VEGF-mediated breakdown of the blood-retinal barrier, recent evidence suggests that inflammation plays an important role in the development of DME. Recognizing this, physicians have injected steroids into the vitreous and developers have created sustained release implants. Intravitreal injections of triamcinolone acetonide lead to rapid resolution of macular edema and significant short-term improvements in visual acuity, but unfortunately, visual acuities diminish when treatment is continued through 2 years. However, intravitreal triamcinolone remains an attractive treatment option for eyes that are pseudophakic, scheduled to undergo cataract surgery, resistant to laser photocoagulation, or require urgent panretinal photocoagulation for proliferative retinopathy. In controlled trials, intraocular implants that slowly release dexamethasone and fluocinolone show promise in reducing macular edema and improving visual acuity. The high incidences of drug related cataracts and glaucoma, however, require that corticosteroids be used cautiously and that patients be selected carefully. The increasing number of patients with DME, the burgeoning cost of medical care and the continuing development of intravitreal steroids suggest that the use of these agents will likely increase in coming years.

Lutein: More than just a filter for blue light

Lutein is concentrated in the primate retina, where together with zeaxanthin it forms the macular pigment. Traditionally lutein is characterized by its blue light filtering and anti-oxidant properties. Eliminating lutein from the diet of experimental animals results in early degenerative signs in the retina while patients with an acquired condition of macular pigment loss (Macular Telangiectasia) show serious visual handicap indicating the importance of macular pigment. Whether lutein intake reduces the risk of age related macular degeneration (AMD) or cataract formation is currently a strong matter of debate and abundant research is carried out to unravel the biological properties of the lutein molecule. SR-B1 has recently been identified as a lutein binding protein in the retina and this same receptor plays a role in the selective uptake in the gut. In the blood lutein is transported via high-density lipoproteins (HDL). Genes controlling SR-B1 and HDL levels predispose to AMD which supports the involvement of cholesterol/lutein transport pathways. Apart from beneficial effects of lutein intake on various visual function tests, recent findings show that lutein can affect immune responses and inflammation. Lutein diminishes the expression of various ocular inflammation models including endotoxin induced uveitis, laser induced choroidal neovascularization, streptozotocin induced diabetes and experimental retinal ischemia and reperfusion. In vitro studies show that lutein suppresses NF kappa-B activation as well as the expression of iNOS and COX-2. Since AMD has features of a chronic low-grade systemic inflammatory response, attention to the exact role of lutein in this disease has shifted from a local effect in the eye towards a possible systemic anti-inflammatory function.

Total activity of glutathione-S-transferase (GST) and polymorphisms of GSTM1 and GSTT1 genes conferring risk for the development of age related cataracts

The pathogenesis of cataract is influenced by a number of factors including oxidative stress. Glutathione-S-transferase (GST) catalyses the nucleophilic addition of the thiol of GSH to electrophilic acceptors. It is important for detoxification of xenobiotics in order to protect tissues from oxidative damage. In humans, GSTT1 and GSTM1 deletion genotypes are associated with a variety of pathological conditions including certain ophthalmic diseases. In the present study, it is aimed to determine the risk of genetic polymorphisms of GSTM1 and GSTT1 isoforms of GST for developing of age related cataracts (ARCs). We compared the prevalence of GSTT1 and GSTM1 deletion genotypes, which were determined by multiplex polymerase chain reaction, in 455 patients with ARCs (108 with nuclear (NC), 105 with cortical (CC), 96 with posterior subcapsular, (PSC) and 146 with mixed type (MT)) and 205 age and sex matched controls. The GST activity in erythrocytes (RBC) and cataractous lenses was measured spectrophotometrically using 1-chloro-2,4-dinitrobenzene (CDNB) as substrate. The frequency of GSTM1 positive individuals was significantly higher in MT cataracts followed by NC, CC and PSC types with corresponding decrease in the GSTM1 null genotypes as compared to controls. Considering the GSTT1 locus, GSTT1 null genotypes showed high frequency in patients in general as compared to controls with corresponding reduction in the GSTT1 positive genotype. The activity of GST in RBC was higher in all the types of cataracts as compared to that in controls and in cataractous lenses the mean values were slightly higher in cases of NC cataracts as compared to CC, PSC and MT. The data suggests that GSTM1 positive, GSTT1 null and double null (GSTM1 null and GSTT1 null) genotypes may confer risk for the development of ARC. The increased activity of GST found in the present study could be due to a compensatory mechanism operating in response to increased oxidative stress.

Importance of multi-modal approaches to effectively identify cataract cases from electronic health records

There is increasing interest in using electronic health records (EHRs) to identify subjects for genomic association studies, due in part to the availability of large amounts of clinical data and the expected cost efficiencies of subject identification. We describe the construction and validation of an EHR-based algorithm to identify subjects with age-related cataracts. We used a multi-modal strategy consisting of structured database querying, natural language processing on free-text documents, and optical character recognition on scanned clinical images to identify cataract subjects and related cataract attributes. Extensive validation on 3657 subjects compared the multi-modal results to manual chart review. The algorithm was also implemented at participating electronic MEdical Records and GEnomics (eMERGE) institutions. An EHR-based cataract phenotyping algorithm was successfully developed and validated, resulting in positive predictive values (PPVs) >95%. The multi-modal approach increased the identification of cataract subject attributes by a factor of three compared to single-mode approaches while maintaining high PPV. Components of the cataract algorithm were successfully deployed at three other institutions with similar accuracy. A multi-modal strategy incorporating optical character recognition and natural language processing may increase the number of cases identified while maintaining similar PPVs. Such algorithms, however, require that the needed information be embedded within clinical documents. We have demonstrated that algorithms to identify and characterize cataracts can be developed utilizing data collected via the EHR. These algorithms provide a high level of accuracy even when implemented across multiple EHRs and institutional boundaries.

Blindness and visual impairment in Remo, Ogun State, Nigeria: A hospital-based study

This study was conducted to determine the magnitude and causes of blindness and visual impairment in Remo, Ogun State, Nigeria. A retrospective clinic based study to analyse the cases of patients with blindness in general hospitals of Iperu and Isara areas of Ogun state between May 2005 and December 2005. The data of demographic characteristics and diagnosis were retrieved from the outpatient cards. Three hundred and sixty-nine cases registered in the eye clinic during the period of the study and were examined. 177 were males and 190 were females. The age range of patients seen was between 17 days and 89years with a mean age of 43.3 years, ± 23.62(SD). 116 patients were aged 70years and above while 13 patients were less than 10years. 29.5% of the clinic attendance were uniocularly blind, 21.1% were bilaterally blind while 25 2% were visually impaired. 55.1% of the bilateral blindness was in males. 30.8% cases of the bilaterally blind were from age related cataract, 23.1% from glaucoma, 6 cases were due to Retinitis Pigmentosa and 3 from pterygium, Cataract followed by glaucoma was the leading cause of uniocular blindness. Cataract was responsible for 66.7% of visually impairment. Blindness and visual impairment is a public health problem in Remo Ogun State, Nigeria; cataract, glaucoma and pterygium were the important causes of blindness and visual impairment. The major causes of blindness in this part of Ogun state are preventable.