Etiology Of Cataract Research Articles

Multi-tissue transcriptome-wide association study identifies novel candidate susceptibility genes for cataract.

Cataract is the leading cause of blindness among the elderly worldwide. Twin and family studies support an important role for genetic factors in cataract susceptibility with heritability estimates up to 58%. To date, 55 loci for cataract have been identified by genome-wide association studies (GWAS), however, much work remains to identify the causal genes. Here, we conducted a transcriptome-wide association study (TWAS) of cataract to prioritize causal genes and identify novel ones, and examine the impact of their expression. We performed tissue-specific and multi-tissue TWAS analyses to assess associations between imputed gene expression from 54 tissues (including 49 from the Genotype Tissue Expression (GTEx) Project v8) with cataract using FUSION software. Meta-analyzed GWAS summary statistics from 59,944 cataract cases and 478,571 controls, all of European ancestry and from two cohorts (GERA and UK Biobank) were used. We then examined the expression of the novel genes in the lens tissue using the iSyTE database. Across tissue-specific and multi-tissue analyses, we identified 99 genes for which genetically predicted gene expression was associated with cataract after correcting for multiple testing. Of these 99 genes, 20 (AC007773.1, ANKH, ASIP, ATP13A2, CAPZB, CEP95, COQ6, CREB1, CROCC, DDX5, EFEMP1, EIF2S2, ESRRB, GOSR2, HERC4, INSRR, NIPSNAP2, PICALM, SENP3, and SH3YL1) did not overlap with previously reported cataract-associated loci. Tissue-specific analysis identified 202 significant gene-tissue associations for cataract, of which 166 (82.2%), representing 9 unique genes, were attributed to the previously reported 11q13.3 locus. Tissue-enrichment analysis revealed that gastrointestinal tissues represented one of the highest proportions of the Bonferroni-significant gene-tissue associations (21.3%). Moreover, this gastrointestinal tissue type was the only anatomical category significantly enriched in our results, after correcting for the number of tissue donors and imputable genes for each reference panel. Finally, most of the novel cataract genes (e.g., Capzb) were robustly expressed in iSyTE lens data. Our results provide evidence of the utility of imputation-based TWAS approaches to characterize known GWAS risk loci and identify novel candidate genes that may increase our understanding of cataract etiology. Our findings also highlight the fact that expression of genes associated with cataract susceptibility is not necessarily restricted to lens tissue.

Investigating Post-Operative Refractive Outcomes in Patients Undergoing Cataract Surgery to Assess the Potential Impact of a Concurrent Diagnosis of Dry Eye Disease (DED)

Cataract surgery is one of the most performed surgical procedures in the world. A cataract is defined as opaqueness in the interior of the ocular lens2. The exact etiology of cataracts is multifactorial ranging from environmental conditions to biochemical changes induced by aging3. The Intraocular lens (IOL) power calculation is an essential part of the pre-operative planning for cataract surgery as it determines the specific IOL that should be utilized for a patient. Keratometry measurements are required for this IOL power calculation, however, DED has been shown to cause inaccurate keratometry measurements4,5. We hypothesize that patients with DED undergoing cataract surgery will have a larger deviation from the predicted spherical equivalent (SE) post-operatively.
 Patients who were over the age of 18 and underwent cataract surgery were included. Patients who had a diagnosis of glaucoma, Herpes Simplex Keratitis, punctual plugs, undergone Laser-Assisted in Situ Keratomileusis (LASIK) surgery, Radial Keratometry, or any form of corneal scarring were excluded from this study as they can negatively impact keratometry measurements.
 The DED sample had a statistically significant larger SE deviation from the predicted SE compared to the healthy sample (p=0.037). The DED sample also had a statistically significant larger percentage of patients with an SE deviation of 0.50 D or greater (p=0.002). Finally, the DED had a statistically significant older age than the healthy group (p=0.028).
 The significant difference in age between the healthy sample and the DED sample confirms the significant correlation between age and prevalence of DED the literature has described6. The statistically significant increased post-operative SE deviation from predicted SE within the DED sample can be the result of the increased variability in the tear film associated with DED. This can lead to inaccurate keratometry measurements, thus leading to incorrect IOL power calculations.

Involvement of increased endoplasmic reticulum stress in the development of cataracts in BALB.NCT-Cpoxnct mice

The BALB.NCT-Cpoxnct is a mutant mouse model for hereditary cataracts. We previously uncovered that the primary cause of the cataracts of BALB.NCT-Cpoxnct is a mutation in the coproporphyrinogen oxidase (Cpox) gene. Because of the mutation, excessive coproporphyrin is accumulated in the BALB.NCT-Cpoxnct lens. In this study, we analyzed the changes in transcriptome and proteins in the lenses of 4- and 12-week-old BALB.NCT-Cpoxnct to further elucidate the molecular etiology of cataracts in this mouse strain. Transcriptome analysis revealed that endoplasmic reticulum (ER) stress was increased in the BALB.NCT-Cpoxnct lens that induced persistent activation of the PERK signaling pathway of the ER stress response. Also, levels of crystallin transcripts and proteins were reduced in the BALB.NCT-Cpoxnct lens. Analysis of proteins disclosed aggregation of crystallins and keratins prior to the manifestation of cataracts in 4-week-old BALB.NCT-Cpoxnct mice. At 12 weeks of age, insoluble crystallins were accumulated in the cataractous BALB.NCT-Cpoxnct lens. Overall, our data suggest the following sequence of events in the BALB.NCT-Cpoxnct lens: accumulated coproporphyrin induces the aggregation of proteins including crystallins. Aggregated proteins increase ER stress that, in turn, leads to the repression of global translation of proteins including crystallins. The decline in the molecular chaperone crystallin aggravates aggregation and insolubilization of proteins. This vicious cycle would eventually lead to cataracts in BALB.NCT-Cpoxnct.

Correlation of aqueous humor electrolytes with serum electrolytes in cataract patients.

Purpose:To correlate the aqueous humor electrolytes with serum electrolytes in patients with cataract.Methods:In this study, 348 eyes of patients undergoing cataract surgery, who had presented between 1st January 2019 and 30th June 2020, were included. Serum electrolytes were obtained and 0.15 ml of aqueous humor was obtained during surgery using an insulin syringe via the side port incision. Mean and standard deviation was used to analyze all the categorical and continuous data including all the electrolytes levels. Pearson’s correlation of coefficient was used to analyze the comparison between serum and aqueous humor electrolytes. Student T-test was used to compare electrolyte values between the serum and aqueous humor.Results:We observed a significant correlation of the aqueous humor electrolytes with their serum counterparts. The coefficient of correlation is 0.155, 0.44, and 0.405 for Na+, K+, and Cl−, respectively. There is also a significant increase in the aqueous humor electrolytes as compared to the serum levels.Conclusion:A significant increase in electrolytes levels in the aqueous humor of cataract patients possibly could have a role in the etiology of cataract.

Management of Cataracts in Pediatric Patients with Developmental Delay at a Tertiary Care Pediatric Hospital

Background: Childhood cataract causing visual impairment can compound developmental delay (DD) if left untreated. Current literature in children with DD is limited; thus, we evaluated cataract etiology, challenges, and treatment compliance in this group. Purpose: To report the presentation and challenges associated with cataract management in children with developmental delay (DD) at a tertiary care pediatric hospital. Methods: Retrospective review of 100 patients (173 eyes) presenting with cataracts and DD from February 2014 to December 2017. Results: 100 patients (173 eyes) were included. 27 patients had unilateral cataracts and 73 bilateral. The average age was 120.55 months (SD 63.77, range 5.87 - 243.16); the average follow-up period was 57.7 months (SD 139.14, range 1.03 - 1412.30). 61% of patients (55% eyes) underwent medical management for cataracts due to: cataract was not visually significant (66% eyes), parent deferred surgery (11% eyes), self-abusive behavior (14% eyes), and medical conditions that limited visual recovery (9% eyes). 32% of patients were unable to perform objective visual acuity by age 5. Patients with self-abusive behavior were more likely to present with or develop retinal detachment (RD) (35%) compared to those without self-abusive behavior (6%) (p = 0.0028). A statistically significant difference in the difficulty of examination (p < 0.0001) and poor compliance of glasses wear (p < 0.0001) was found in nonverbal patients. Surgical complications occurred in 39% of eyes. Those with intraocular lens placement after cataract extraction were more likely to develop visual axis opacification (27% eyes) than those who remained aphakic (9% eyes) (p = 0.0313). Conclusion: Cataract extraction in pediatric patients with DD can be associated with success, however, providers should prepare for limitations in managing these patients.

Vitamin C and the Lens: New Insights into Delaying the Onset of Cataract.

Cataracts or clouding of the lens is the leading cause of blindness in the world. Age and diabetes are major risk factors, and with an increasing aging and diabetic population, the burden of cataracts will grow. Cataract surgery is an effective way to restore vision; however, alternatives to cataract surgery are required to reduce the looming cataract epidemic. Since it is well established that oxidative damage plays a major role in the etiology of cataracts, antioxidants have been promoted as therapies to delay and/or prevent cataracts. However, many antioxidant interventions including vitamin C have produced mixed results as anti-cataract therapies. Progress has been made towards our understanding of lens physiology and the mechanisms involved in the delivery and uptake of antioxidants to the lens which may guide future studies aimed at addressing some of the inconsistencies seen in previous animal and human studies. Of interest is the potential for vitamin C based supplements in delaying the onset of cataracts post vitrectomy which occurs in up to 80% of patients within two years. These targeted approaches are required to reduce the burden of cataract on hospitals and improve the quality of life of our aging and diabetic population.

Advanced ophthalmic nurse practitioners: the potential to improve outcomes for older people with cataracts.

An ageing population has led to a substantial increase in the prevalence of visual impairments, which can compromise lifestyle, health and general physical and psychological well-being. Age-related cataracts can have a negative effect on older people's quality of life but can be corrected by surgery. It is imperative that older people have access to cataract surgery and, given government objectives of NHS efficiency gains, advanced level nurse practitioners have the potential to increase capacity for and access to cataract surgery. This article outlines the aetiology of cataracts, developments in ophthalmic nursing and the broadened scope of practice of advanced ophthalmic nurse practitioners (AONPs). It explores how the AONP is well-placed to provide high quality care to the older person who requires cataract surgery. Professional drivers for role development are explored in relation to older people.

Structural stability and solubility of glycated camel lens ζ-crystallin

The camel has several biochemical, physiological, and anatomical features to withstand the harsh desert climate. Camel eye lens contains a novel protein (ζ-crystallin) in bulk quantity. Previous reports suggest that non-enzymatic glycation of eye lens proteins plays an important role in the etiology of cataract. In this study, we have characterized the role of glucose, fructose, and methylglyoxal (MGO) in the glycation of camel lens ζ-crystallin. From the results obtained, it was found that MGO reacted rapidly, fructose reacted moderately, and glucose was the least reactive even after prolonged incubation (>100 days). Glycation with MGO and fructose led to changes in the structure of ζ-crystallin, while glucose had no remarkable effect. The surface hydrophobicity did not change and no aggregates or amyloid fibrils were observed in the glycated ζ-crystallin. Moreover, the secondary structure of glycated ζ-crystallin remained similar after glycation. Our results suggested that due to natural adaptation, the camel lens protein ζ-crystallin retained its structure and solubility even after glycation to perform the single known function of the lens proteins: to focus unscattered light on the retina.

Molecular Processes Implicated in Human Age-Related Nuclear Cataract.

Human age-related nuclear cataract is commonly characterized by four biochemical features that involve modifications to the structural proteins that constitute the bulk of the lens: coloration, oxidation, insolubility, and covalent cross-linking. Each of these is progressive and increases as the cataract worsens. Significant progress has been made in understanding the origin of the factors that underpin the loss of lens transparency. Of these four hallmarks of cataract, it is protein-protein cross-linking that has been the most intransigent, and it is only recently, with the advent of proteomic methodology, that mechanisms are being elucidated. A diverse range of cross-linking processes involving several amino acids have been uncovered. Although other hypotheses for the etiology of cataract have been advanced, it is likely that spontaneous decomposition of the structural proteins of the lens, which do not turn over, is responsible for the age-related changes to the properties of the lens and, ultimately, for cataract. Cataract may represent the first and best characterized of a number of human age-related diseases where spontaneous protein modification leads to ongoing deterioration and, ultimately, a loss of tissue function.

Cataracts Risk Factors and Comparison of Blood Glucose Levels in Diabetic and Non-Diabetic Patients towards the Occurrence of Cataracts.

BACKGROUND:Cataracts are a multifactorial systemic disease that causes opacity of the optical lens. One aetiology of cataracts is chronic hyperglycemia, usually caused by uncontrolled diabetes mellitus.AIM:The objective of this study is to identify risk factors of cataracts and to analyse if there is a significant difference in blood glucose values between diabetic patients with cataracts and non-diabetic patients with cataracts.METHODS:This was an analytical case-control study with a sample size of 140 patients that were obtained via consecutive sampling of medical records.RESULTS:This study found that age, high body mass index and hypertension were the dominant risk factors of cataracts. The mean value of blood glucose levels in diabetic patients with cataracts is 195.58 ± 63.9 and 109.7 ± 26.4 in non-diabetic patients with cataracts. There was a significant difference between the blood glucose values of diabetic patients with cataracts and non-diabetic patients with cataracts (p < 0.001). The dominant risk factors of cataracts were old age, high body mass index and hypertension. The majority of hyperglycemic patients belong in the group of diabetic patients with cataracts.CONCLUSION:Chronic hyperglycemia can increase a patient’s risk of cataracts.

Protective Effects of Lanosterol Synthase Up-Regulation in UV-B-Induced Oxidative Stress.

UV-B radiation may be an important risk factor in cataract etiology. After exposure to UV-B radiation, cells show imbalances in the repair of DNA damage, which induce changes in the levels of certain proteins, including alpha-crystallin, which is the most abundant protein in the lens and crucial for the maintenance of lens transparency. Lanosterol synthase (LSS), an essential rate-limiting enzyme in cholesterol biosynthesis, might play significant roles in oxidative stress and in the maintenance of lens transparency. However, the roles of LSS in UV-B-induced apoptosis are not well understood. Therefore, we irradiated female Sprague-Dawley rats with ultraviolet radiation to establish an animal model for exploring the variations in LSS expression during the early stages of UV-B exposure. In addition, we cultured human lens epithelial (HLE) cells that overexpress LSS and exposed them to UV-B radiation to explore the function of increased LSS expression in UV-B-induced apoptosis. The data demonstrated that UV-B exposure induced oxidative stress and apoptosis in rat lens epithelial cells and that irradiance exposure increased the level of lenticular damage. Additionally, UV-B exposure decreased the alpha-crystallin content and increased the expressions of Bax and cleaved caspase-3 compared with the control levels. After exposure to UV-B, the apoptosis-related index of HLE cells overexpressing LSS was lower than that of the control cells. Furthermore, ROS overproduction might activate the sirtuin 1 (Sirt1) pathway, which induced protein expressions of sterol regulatory element-binding transcription factor 2 (SREBF2), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), and LSS. However, the specific mechanism of the Sirt1 pathway needed to be further studied. In summary, UV-B exposure induced oxidative injury and resulted in crystallin denaturation and apoptosis in lens epithelial cells, and LSS might play a protective role during the early stages of this process and could be an important target in the cataract prevention.

Nutritional Strategies to Prevent Lens Cataract: Current Status and Future Strategies.

Oxidative stress and the subsequent oxidative damage to lens proteins is a known causative factor in the initiation and progression of cataract formation, the leading cause of blindness in the world today. Due to the role of oxidative damage in the etiology of cataract, antioxidants have been prompted as therapeutic options to delay and/or prevent disease progression. However, many exogenous antioxidant interventions have to date produced mixed results as anti-cataract therapies. The aim of this review is to critically evaluate the efficacy of a sample of dietary and topical antioxidant interventions in the light of our current understanding of lens structure and function. Situated in the eye behind the blood-eye barrier, the lens receives it nutrients and antioxidants from the aqueous and vitreous humors. Furthermore, being a relatively large avascular tissue the lens cannot rely of passive diffusion alone to deliver nutrients and antioxidants to the distinctly different metabolic regions of the lens. We instead propose that the lens utilizes a unique internal microcirculation system to actively deliver antioxidants to these different regions, and that selecting antioxidants that can utilize this system is the key to developing novel nutritional therapies to delay the onset and progression of lens cataract.

Biochemical analysis of aqueous humor in diabetic and non-diabetic patients with cataracts

Background: Although there are many factors stated in the etiology of cataract, the mechanisms which are formed during the formation of cataract are still not illuminated. The purpose of this study is to evaluate the biochemical analysis of aqueous humor in diabetic and non-diabetic patients with cataract in terms of the existence of pseudoexfoliation (PSX). Material and methods: Seventy-six patients who presented to our ophthalmology clinic with the complaint of cataract and who were planned to undergo phacoemulsification and IOL implementation were included in the study. The patients were classified into 4 groups as Group I: Cataracts with diabetes and without PSX, Group II: Cataracts without diabetes and PSX, Group III: Cataracts with diabetes and PSX, Group IV: Cataracts without diabetes and with PSX. The groups were compared statistically in terms of biochemical analysis of aqueous humor. Results: The mean age of the patients was 68.0 ± 8.5, and 51.3% of the patients were male. In Group II, Na value was significantly higher than in Group I and Group III. In Group IV, Na value was significantly higher than in Group I and Group III. Cl value in Group IV was significantly higher than in Group I-III-III. In Group IV, Ca value was significantly higher than in Group I-III-III. In Group I, P value was significantly higher than in Group II and Group III. Glucose levels in Group I were significantly higher than in Group II-III-IV. Glucose levels in Group III were significantly higher than in Group II-IV. Na value in the PSX (+) group was significantly lower than in the PSX (–) group. In the PSX (+) group, glucose value was significantly higher than in the PSX (–) group. Conclusion: High glucose and low Na levels in the anterior chamber may play a role in the development of PSX and PSCC. High P level in the anterior chamber may be contributed to the development of cataract in diabetic non-PSX eyes. In non-diabetic PSX (+) group, high Ca and Cl levels may be contributed to developing cataracts.

Cataract etiology and prevention in traditional Persian medicine texts

Context: According to the World Health Organization, cataract is the most common retrievable blind cause in the world. Nowadays, surgery is the only treatment to restore vision in patient with cataract. In regard to the high costs of surgery, prevention has a particular importance. In modern medicine, cataract risk factors are hardly preventable. Aims: Determination of the etiology and preventive solutions of cataract in traditional Persian medicine (TPM). Settings and Design: This is a summative qualitative content analysis that focused on Persian medicine texts in from 4th to 13th AH centuries. Materials and Methods: TPM literature were searched during centuries 4th to 13th AH, by using this key words: “Nuzūl-ul-mā”, “Ā’b murwārīd” and “āb āvardan chishm” or just “Mā,” and Databases (PubMed, PMC, Google Scholar, and Scopus) were searched by: Cataract; risk factor, etiology, prevention and treatment of cataract; This research has been done in seven phases. Statistical Analysis Used: All data about the treatment of cataract were collected and categorized into modern style. Results: According to TPM, to prevent cataract, first, it must be reduced or eliminated the causes of cataract; Those causes are classified to four themes such as physical factors, habits and inappropriate lifestyle, diseases, and age. Persian Physicians (Ḥakīm) proposed and used some prevention and medications to change some of these etiological factors to decrease the incidence of cataract. Conclusions: In this research, a wide range of preventive measures for cataract is observed which cannot be found in modern medicine. Changes in some etiological factors such as lifestyle can prevent this disease. Affirming this claim depends on clinical researches.

Anatomical-spatial dissection of single-cell retinal transcriptomics yields new insights in complement regulation

Human γd-crystallin (Hγd-crystallin), a major protein component of the human eye lens, is associated with the development of juvenile- and mature-onset cataracts. Evidence suggests that nonenzymatic protein glycation plays an important role in the aetiology of cataract and diabetic sequelae. This research compared the effects of various glycation modifiers on Hγd-crystallin aggregation, by treating samples of Hγd-crystallin with ribose, galactose, or methylglyoxal using several biophysical techniques. To measure advanced glycation end products, an Nε-(carboxyethyl)lysine enzyme-linked immunosorbent assay was performed on the glycating agent-treated Hγd-crystallin samples. Fructosamine production detection was performed for both ribose-treated and galactose-treated samples. Methylglyoxal-treated samples had the highest level of aggregation and the greatest extent of unfolding, and upon incubation for a minimum of 12 days, exhibited a marked enhancement in the amount of Nε-(carboxyethyl)lysine. The molecular profiles and morphological features of the glycated samples were highly correlated to the type of glycation agent used. These findings highlight a close connection between the type of glycation modifier and the various aggregation species that form. Thus, these results may facilitate deciphering of the molecular mechanism of diabetic cataractogenesis.

Effects of glycation on human γd-crystallin proteins by different glycation-inducing agents

Human γd-crystallin (Hγd-crystallin), a major protein component of the human eye lens, is associated with the development of juvenile- and mature-onset cataracts. Evidence suggests that nonenzymatic protein glycation plays an important role in the aetiology of cataract and diabetic sequelae. This research compared the effects of various glycation modifiers on Hγd-crystallin aggregation, by treating samples of Hγd-crystallin with ribose, galactose, or methylglyoxal using several biophysical techniques. To measure advanced glycation end products, an Nε-(carboxyethyl)lysine enzyme-linked immunosorbent assay was performed on the glycating agent-treated Hγd-crystallin samples. Fructosamine production detection was performed for both ribose-treated and galactose-treated samples. Methylglyoxal-treated samples had the highest level of aggregation and the greatest extent of unfolding, and upon incubation for a minimum of 12 days, exhibited a marked enhancement in the amount of Nε-(carboxyethyl)lysine. The molecular profiles and morphological features of the glycated samples were highly correlated to the type of glycation agent used. These findings highlight a close connection between the type of glycation modifier and the various aggregation species that form. Thus, these results may facilitate deciphering of the molecular mechanism of diabetic cataractogenesis.

Epidemiology and clinical presentation of feline cataracts in france: A retrospective study of 268 cases.

To describe the epidemiology and the clinical presentation of cataracts in a population of cats in France. A review of medical records of cats presented to the Ophthalmology Unit of the National Veterinary School of Alfort between January 2010 and June 2017 was carried out to identify cats affected by cataracts. The signalment of affected cats, medical history, etiology of cataract, age of onset, stage of development, location of opacities, and concurrent ocular lesions were evaluated. Of 2054 cats which were presented to the Ophthalmology Unit of the National Veterinary School of Alfort during the study period, 268 (383 eyes) were diagnosed with a cataract (13%; CI [11.3-14.7]). The median age of all cats affected by cataract was 9.5years (range: 0.1-18.6years). Eighteen breeds were represented. The recorded causes of cataract were uveitis (35.8%), congenital (15.7%), aging (10.8%), presumed hereditary (8.2%), trauma (7.8%), lens luxation (3.3%), glaucoma (1.5%) and diabetes mellitus (0.4%). In 16.4% of the cases, the etiology could not be determined. The domestic short-hair was significantly overrepresented in cats with uveitis-related cataract (P<.001). The most common ocular lesions associated with cataracts were lens subluxation or luxation (17.8%), glaucoma (14.9%), and retinal detachment (4.4%). Lens subluxation/luxation and glaucoma were also significantly associated with uveitis-related cataract (P<.001). In a French population of referred cats, 13% were affected by cataract. The main causes identified were anterior uveitis, congenital, and aging. Lens subluxation/luxation and glaucoma were associated with uveitis-related cataract.

Nutrient patterns and risk of cataract: a case-control study.

To assess the relation between nutrient patterns and cataract risk. This is a hospital-based case-control study with 97 cataract patients and 198 matched controls. Dietary consumption was collected through a valid food frequency questionnaire (FFQ). Nutrient patterns were detected by applying factor analysis. Unconditional logistic regression models were used to estimate odds ratio (ORs) and 95%CIs. We extracted 5 main nutrient patterns. Factor 1 included niacin, thiamin, carbohydrates, protein, zinc, vitamin B6 and sodium (sodium pattern). Factor 2 was characterized by oleic acid, monounsaturated fats, polyunsaturated fats, linoleic acid, trans fatty acid, linolenic acid, vitamin E and saturated fats (fatty acid pattern). The third factor represented high intake of vitamin B12, vitamin D, cholesterol and calcium (mixed pattern). The 4th pattern was high in intake of beta and alpha carotene, vitamin A and vitamin C (antioxidant pattern). Finally, the 5th pattern loaded heavily on docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) (omega-3 pattern). In crude and multivariate analysis, the sodium pattern was associated with increased risk of cataract (OR=1.97, 95%CI: 1.09-3.96). The fatty acid pattern elevated the risk of cataract (OR=1.94, 95%CI: 1.1-3.86). Antioxidant pattern was associated with a significant 79% reduced risk (2nd category compared with the 1st). Omega-3 pattern was significantly negatively associated with risk of cataract (P=0.04). These findings imply that nutrient patterns reflecting a combined consumption of nutrients might be important in the etiology of cataract. Additional studies with more efficient designs are warranted to confirm our findings.

Validation of Guidelines for Undercorrection of Intraocular Lens Power in Children

Initial undercorrection of intraocular lens (IOL power) is a common practice in children undergoing pediatric cataract surgery. However, the long-term refractive status of these children is largely unknown. The purpose of this study is to analyze the long-term refractive status of these children. Retrospective observational study. We analyzed records of children (<7 years of age) who underwent cataract surgery with a primary IOL implantation and had completed follow-up to ≥7 years of age. Data were collected regarding demographics, etiology of cataract, method of undercorrection, and serial follow-up refractions. Prediction error was defined as refractive error minus emmetropia. The main outcome measure was prediction error at 7 years of age. Eighty-four eyes of 56 children (28 unilateral and 28 bilateral cases) met the study criteria. The median age at surgery was 3.3 years (interquartile range 2.7-5 years), and the median follow-up period was 3.75 years. At 7 years of age, the median absolute prediction was 1.5 diopters (interquartile range 0.75-2 diopters). Seven of 84 (8.3%) children achieved emmetropia while an equal proportion were myopic (45%) or hypermetropic (46%). Prediction error (adjusted for using both eyes) at 7 years of age was not significantly different in any group (P > .05). Maximum myopic shift was observed in children <2 years of age. Age at surgery was the only significant factor that influenced prediction error (â=-0.32; P= .001). This study suggests that children undercorrected using guidelines suggested by Enyedi and associates may achieve an acceptable refractive error at 7 years of age. However, in children <2 years of age, more hypermetropia may be observed. More studies are needed to validate various methods of undercorrection and compare with other guidelines.

Visual outcomes of patients presenting with bilateral infantile cataracts and nystagmus

ObjectiveTo evaluate the outcomes of cataract surgery in pediatric patients presenting with bilateral infantile cataracts and nystagmus. DesignRetrospective case study. ParticipantsThirteen pediatric patients who presented between September 2002 and February 2014 at a single tertiary care institution. MethodsPatients were included if they presented with bilateral visually significant cataracts and preoperative manifest nystagmus and had no other systemic or ocular condition that could explain the presence of the nystagmus. Data collected included best-corrected visual acuity (BCVA), etiology of cataracts, associated systemic/ocular conditions, status of strabismus, surgical complications, and presence of nystagmus. ResultsMean age at diagnosis of the cataracts was 8.1 ± 10.6 months. Mean age at surgery was 8.4 ± 10.5 months. Average length of follow-up was 54.3 ± 32.6 months. Twelve patients were left aphakic bilaterally; 1 patient received primary intraocular lenses bilaterally. Ten patients were able to perform visual acuity at the most recent visit, with 5 out of 10 having BCVA ≥20/40 in the better-seeing eye. Two patients had no visible nystagmus and 3 patients had latent nystagmus only at the most recent visit. ConclusionsThe presence of preoperative nystagmus does not preclude good visual outcomes in pediatric patients with cataracts.