Concentrations of glucose metabolites in the aqueous humour of diabetic cataract eyes.

PURPOSE: Glucose metabolism underpins diabetic cataracts (DCs), but the relationship between the two remains unclear. Here, we tested the aqueous humour (AH) of patients with DCs to elucidate glucose metabolite levels. METHODS: In this study, aqueous humour (AH) samples were collected preoperatively from DC eyes (n = 37) and age-related cataract eyes (n = 37) from 74 patients (74 eyes) undergoing uncomplicated cataract surgery. The content of glucose, pyruvate, L-lactate were detected by biochemical methods and advanced glycation end-products (AGEs) was detemined using enzyme-linked immunosorbent assay (ELISA) technique. Furthermore, the ratios of glucose/pyruvate and L-lactate/pyruvate in the AH were calculated. In addition, we calculated the correlation between glucose levels and AGEs in the AH. RESULTS: The concentrations of glucose, pyruvate and AGEs in the DC group were higher than those in the control group. Significantly lower levels of L-lactate in the AH were found in the DC group. We calculated the glucose/pyruvate ratio and the L-lactate/pyruvate ratio in the AH, which showed that glucose metabolism was changed in the AH from DC patients. Interestingly, we observed that AGEs in the AH were significantly correlated with increased anterior chamber glucose permeability. A stronger correlation was found in the subgroups of male patients, younger patients, and patients with poor glycaemic control status. CONCLUSIONS: Comparison of the levels of glucose metabolism-related products in the AH in the DC group highlight a potential pathological mechanism for DC from a glucose metabolism perspective. The findings indicated an alteration in the metabolic pathways of energy metabolism and amino acids in the AH of DC patients.

Prolidase activity in aqueous and serum samples of cataract cases with Pseudoexfoliation syndrome.

Pseudoexfoliation syndrome (PEX) represents an age-related systemic disease that is characterized by the accumulation of extracellular matrix material in ocular tissues and visceral organs. Abnormal matrix remodeling is thought to be one of the important factors in the etiopathogenesis of the disease. Prolidase represents an enzyme, which takes a significant part in collagen biosynthesis and remodeling of the extracellular matrix. The purpose of the current research was to assess the prolidase enzyme activity in the aqueous and serum samples of subjects with PEX. The study population consisted of 66 subjects, involving 33 subjects with age-related cataract among patients with PEX and 33 subjects with age-related cataract without PEX. The prolidase activity measurement was performed using the modified Chinard's method. Significantly increased aqueous prolidase activity was detected in the group with PEX (p < 0.01). Despite about a three times higher increase in the serum prolidase activity of the group with PEX in comparison with the control group, the two groups did not differ statistically significantly (p > 0.05). The high prolidase enzyme activity in the aqueous samples of subjects with PEX suggests that the collagen cycle and the remodeling of the extracellular matrix are accelerated. These results can be a guide for understanding the formation mechanisms of PEX.

Serum Aß Levels are Associated with Age-related Cataract.

To investigate the levels and clinical relevance of serum ß-amyloid (Aß) in age-related cataract (ARC) patients. In the present study, an overall of 402 ARC patients and 450 normal controls were recruited between June 2018 and December 2019. Serum Aß1-40 and Aß1-42 concentrations were assessed by Elisa. The ARC patients were further grouped into several subgroups according to gender, age, types of ARC, and degree of lens opacity. The association of Aß levels with ARC was determined using logistic regression models. ARC patients had significantly higher serum Aß1-40 and Aß1-42 levels than normal control. A similar finding was observed in subjects aged over 60 years. Serum Aß concentrations were significant correlated with the degrees of lens opacity in C-ARC and N-ARC subjects. Logistic regression analyses revealed that serum Aß1-40 (ORs = 1.202, 95% CI 1.077 to 1.341) and Aß1-42 (ORs = 1.686, 95% CI 1.351 to 2.103) levels were potential risk factors for ARC. ARC patients have higher serum Aß1-40, as well as Aß1-42 levels, which may reflect an association between Aß and ARC pathogenesis. Serum Aß1-42 and Aß1-40 levels are potential risk factors for ARC.

Vitamin D Levels in Young Adult Cataract Patients: A Case-Control Study.

OBJECTIVE: We aimed to investigate whether a relationship is present between early cataract formation and vitamin D in young adults. METHODS: A total of 37 cataract patients (18 males and 19 females) and 53 healthy participants (27 males and 26 females) under the age of 60 years were included in this study. The 25-OH vitamin D values were measured in all subjects and the mean vitamin D levels compared between the 2 groups. Additionally, the differences between the vitamin D levels of the genders in both groups were investigated. RESULTS: The mean age of the study group was 48.1 ± 8.5 (range 33-59) years, and the mean age of the control group was 49.3 ± 7.8 (range 31-59) years (p = 0.48 and p = 0.83). The mean vitamin D level was 15.6 ± 8.4 ng/mL in the study group and 20.8 ± 7.1 ng/mL in the healthy subjects (p = 0.002). Among the females, the vitamin D level was 10.6 ± 4.7 ng/mL in the study group and 18.1 ± 6.4 ng/mL in the control group (p = 0.0001). No significant difference was found between the groups among the males (p = 0.24). CONCLUSION: We found vitamin D deficiency to be associated with early age-related cataract in a statistically significant manner. We believe it is worth investigating the reason for this concurrence with large longitudinal studies.

Identification of tRNA-derived fragments and their potential roles in diabetic cataract rats.

Aim: To illustrate the expression profile of transfer RNA-derived fragments and reveal their putative role in the pathogenesis of diabetic cataract (DC) rats. Materials & methods: Small RNA sequencing was conducted in the lens epithelium of rats lens. The data were validated by quantitative real-time PCR, and bioinformatic analysis was performed to explore the roles of the fragments in DC pathogenesis. Results: A total of 213 differentially expressed tRNA-related fragments were identified, in which 111 were upregulated and 102 were downregulated in DC rats. Bioinformatics analysis revealed that several associated pathways might participate in the development of DC rats. Conclusion: tRNA-derived fragments may be involved in the pathogenesis of DC rats.

[Determination of cytokines in the blood serum and in the aqueous humor of the anterior camera during pseudoexfoliative syndrome and cataract.]

There have been studied changes of proinflammatory cytokines, IL-1ß and TNF-α, in anterior chamber aqueous humor and in blood serum before cataract surgery in 81 patients with cataract. Of these, 46 patients had verified diagnosis of pseudoexfoliative syndrome (PEÐ¥) of varying degree of manifestation of dystrophic changes and deposits of pseudoexfoliative material (main group). In 35 patients, PES (comparison group) has not been detected. 2-stage biomicroscopy (with a narrow pupil, after tonometry with mydriasis) and ultrasound biomicroscopy (UBM) have been conducted. According to the results of biomicroscopy and UBM structures of the eye, 3 stages of development of PEX have been identified: I - 11 (23,91%), II - 20 (43,48%), III - 15 (32,61%). Inflammatory complications after cataract surgery have been in 17,39% of eyes with PEÐ¥, of which PEX Stage II in 13,04% and PEÐ¥ Stage III in 4,35%. There have been no complications in the eyes with PEX Stage I and without PEX. In comparison with patients without PEX, significant differences in the indicators of IL-1ß and TNF-α both in the blood serum and in the aqueous humor of the anterior chamber of patients with PEX have been found. In particular, there have been confirmed significant differences of indicators depending on the stage of development of changes during PEX. At the same time, higher concentrations of IL-1ß and TNF-α during PEX, as well as somatic pathologies in patients with PES occurring 2 times more often, confirm the opinion that PEX should be considered as pathology of the organ of vision. Thus, decrease in the compensatory abilities of the body with age and a set of chronic age-related pathology form the pathogenetic mechanisms of PEX, including age-related changes in structures and surgery background in older patients, to a certain extent predetermining the nature and features of the postoperative period and possible complications.

Impaired nitric oxide production in patients with primary open-angle glaucoma.

BACKGROUND: Glaucoma is an optic neuropathy induced by many factors. Vascular dysfunction is involved in the mechanism underlying glaucoma. AIM: To determine the involvement of nitric oxide (NO), which is implicated in the regulation of ocular blood flow, in primary open angle glaucoma (POAG). Furthermore, lactate and uric acid (UA) levels were investigated. METHODS: Concentrations of NO, UA and lactate in plasma and aqueous humor (AH) were measured in 214 Tunisian patients (100 patients with POAG and 114 subjects with cataract as control group). NO metabolites, nitrate and nitrite (NOx) production were determined using the Griess reaction. UA and lactate concentrations were measured using enzymatic- colorimetric methods. RESULTS: NOx concentrations in patients with POAG were significantly lower compared to cataract group in plasma (5.23±1.55 µmol/L vs 18.35±6.87 µmol/L, p=0.01) and AH (20.54±7.41 µmol/L vs 45.25±10.92 µmol/L, p=0.02). Plasma and AH levels of lactate and UA were significantly higher in glaucoma patients than in control subjects. CONCLUSIONS: In the present study, decreased NO and increased UA and lactate levels were found in the AH and plasma of POAG patients compared to control subjects. These data suggest a possible involvement of these factors in glaucoma.

Klotho ameliorates the onset and progression of cataract via suppressing oxidative stress and inflammation in the lens in streptozotocin-induced diabetic rats.

Increased oxidative stress and inflammation play an important role in the pathogenesis of diabetic cataract. Klotho, known as an anti-ageing protein, has antioxidative and anti-inflammatory properties. Klotho is expressed in limited tissues including the lens. Here we examined whether klotho expression is decreased in diabetic lens and, if so, whether klotho treatment can prevent diabetic cataract formation. Streptozotocin (STZ)-induced diabetic rats and age-matched control rats were treated with vehicle or klotho protein, starting at 1 week after STZ injection. Twelve weeks after treatment, cataract formation was observed in diabetic rats but not control rats. Cataract formation and scores were significantly less in klotho-treated diabetic rats than vehicle-treated diabetic rats. Levels of klotho in plasma, aqueous humor and lens were significantly decreased in vehicle-treated diabetic rats, compared with control rats, but were restored in klotho-treated diabetic rats. Additionally, vehicle-treated diabetic rats had increased oxidative stress and inflammation in the lens, which were associated with decreased antioxidant transcriptional master regulator Nrf2 activity and increased transcription factor NF-κB activity. All of these findings were ameliorated in klotho-treated diabetic rats. Notably, klotho treatment did not alter blood glucose in diabetic rats. These results indicate that klotho reduction may increase susceptibility of the lens to oxidative and inflammatory insults, promoting cataract formation under diabetic conditions. Klotho treatment can ameliorate the onset and progression of diabetic cataract via enhancing Nrf2-mediated antioxidant defense and suppressing NF-κB-mediated inflammatory responses. Klotho in the lens may be a novel therapeutic target for prevention of cataract formation in diabetes.

Mutations in FYCO1 identified in families with congenital cataracts.

Purpose: This study was designed to identify the pathogenic variants in three consanguineous families with congenital cataracts segregating as a recessive trait. Methods: Consanguineous families with multiple individuals manifesting congenital cataracts were ascertained. All participating members underwent an ophthalmic examination. A small aliquot of the blood sample was collected from all participating individuals, and genomic DNAs were extracted. Homozygosity-based linkage analysis was performed using short tandem repeat (STR) markers. The haplotypes were constructed with alleles of the STR markers, and the two-point logarithm of odds (LOD) scores were calculated. The candidate gene was sequenced bidirectionally to identify the disease-causing mutations. Results: Linkage analysis localized the disease interval to chromosome 3p in three families. Subsequently, bidirectional Sanger sequencing identified two novel mutations-a single base deletion resulting in a frameshift (c.3196delC; p.His1066IlefsTer10) mutation and a single base substitution resulting in a nonsense (c.4270C>T; p.Arg1424Ter) mutation-and a known missense (c.4127T>C, p.Leu1376Pro) mutation in FYCO1. All three mutations showed complete segregation with the disease phenotype and were absent in 96 ethnically matched control individuals. Conclusions: We report two novel mutations and a previously reported mutation in FYCO1 in three large consanguineous families. Taken together, mutations in FYCO1 contribute nearly 15% to the total genetic load of autosomal recessive congenital cataracts in this cohort.

ALTERED BLOOD AND AQUEOUS HUMOR LEVELS OF ASPROSIN, 4-HYDROXYNONENAL, AND 8-HYDROXY-DEOXYGUANOSINE IN PATIENTS WITH DIABETES MELLITUS AND CATARACT WITH AND WITHOUT DIABETIC RETINOPATHY.

PURPOSE: Diabetic retinopathy (DRP) is the formation of edema and small vessels in the retina due to high blood glucose levels. Asprosin is a hormone that stimulates the release of glucose from the liver into the circulation. Considering the relationship between oxidative stress and DRP, our study aimed to determine the levels of the oxidative stress markers 4-hydroxynonenal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), as well as asprosin, in the blood and aqueous humor (Aq) of patients with and without DRP. METHODS: Thirty patients with single-eye DRP and cataract (DRP + C), 30 patients with diabetes mellitus and cataract without DRP (DM + C), and 30 healthy control (CON) participants were enrolled into this retrospective study. Except for healthy controls, Aq and blood samples were taken from these patients during their cataract operation. Asprosin, 4-HNE, and 8-OHdG concentrations were analyzed using enzyme-linked immunosorbent assays. RESULTS: In patients with DRP, the levels of asprosin, 4-HNE, and 8-OHdG were significantly higher in both Aq and blood samples compared with the group of patients without DRP. CONCLUSION: These findings suggest that the measurement of asprosin, 4-HNE, and 8-OHdG levels may support clinicians in determining the risk of DRP development.

Effect of astaxanthin on metabolic cataract in rats with type 1 diabetes mellitus.

OBJECTIVE: The purpose of this study was to investigate the effect of astaxanthin on metabolic cataract in rats with type 1 diabetes and its antioxidant capacity to lens. METHODS: Rats were randomly divided into four groups (n = 8): control group, diabetes mellitus (DM) group, low-dose astaxanthin (DM + AL) and low-dose astaxanthin (DM + AH) group. A rat model of type I diabetes mellitus was established by intraperitoneal injection of 60 mg/kg streptozotocin (STZ). After successful modeling, rats in the administration group were given different doses of astaxanthin (AST) for 12 weeks. The lens opacity of rats was observed by slit-lamp camera system. The double antibody sandwich method was used to detect the levels of advanced glycation end product (AGE), lipid peroxide/malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) in the lens. Hematoxylin-eosin (HE) staining was used to examine the morphologic changes in the lens. RESULTS: The severity of cataract in the lens was obviously increased after induced by STZ, whereas it was significantly decreased after treatment with AST (p < .05, respectively). In addition, in the AST groups, the levels of AGE and MDA in the lens tissue were notably decreased when compared with those in the DM group (p < .05, respectively). However, the levels of GSH, SOD, and CAT were increased in the AST group in comparison with those in the DM group (p < .05, respectively). CONCLUSIONS: Astaxanthin may play an antioxidant role in the lens. Additionally, it exerts a protective function in the lens by delaying the development and progression of metabolic cataract and inhibiting the oxidative stress of lens in diabetic rats.

Mechanism of atopic cataract caused by eosinophil granule major basic protein.

Atopic cataracts develop under the ages of 40 years, after which visual acuity rapidly declines. However, the mechanism underlying the development of atopic cataracts is not yet clear. We focused on the eosinophil granule major basic protein (MBP), which was detected in the aqueous humor of atopic cataracts previously, and which was cytotoxic. Specifically, we investigated its origin in this fluid and its effects on lens epithelial cells (LECs). MBP immunostaining was positive in atopic cataract-derived LECs, but negative in age-related cataract-derived LECs. MBP mRNA was not detected in either type of cataract, but protein was detected in the aqueous humor. Furthermore, the flare values associated with atopic cataracts were higher than those with age-related cataracts. When MBP was purified from eosinophils or recombinant MBP was added to LEC culture medium, cell viability decreased in a concentration-dependent manner, but an MBP antibody neutralized the cytotoxic effect of this protein towards these cells. These results were consistent with the flow of MBP into the aqueous humor from the blood due to a compromised blood-aqueous barrier. Thus, MBP could further penetrate the lens capsule and adhere to LECs, resulting in decreased cell viability and the development of atopic cataracts.

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.

Prevention of α-crystallin glycation and aggregation using l-lysine results in the inhibition of in vitro catalase heat-induced-aggregation and suppression of cataract formation in the diabetic rat.

The principle role of α-crystallin is chaperoning activity that protect s other proteins against different stresses. High glucose concentration induces the osmotic stress and results in biomacromolecules glycation, which is subsequently cause their conformational and functional changes. Here, the roles of l-lysine (Lys) on the prevention of α-crystallin glycation in both in vitro and in vivo conditions are investigated. The catalase (CAT) activity was considered as a marker of α-crystallin functionality in both conditions. Streptozotocin-induced diabetic rats were treated with 0.1% of the Lys in drinking water. The purified α-crystallin was also incubated with glucose, in the presence or absence of the Lys and its structure-function was compared. The results showed that the visual cataract score was significantly lower in the diabetic rats treated with Lys. After Lys treatment, CAT, superoxide dismutase, aldose reductase and other biochemical parameters in the lens and serum of the diabetic rats returned to the normal value. Formation of the advanced glycation endproducts (AGEs), protein cross-linking, and the hydrophobicity of α-crystallin were changed due to glycation, but they were reversed by Lys treatment. The glycated α-crystallin lost its chaperone activity against heat denatured-CAT, but in the presence of Lys, it preserved its activity and prevented CAT aggregation. In conclusion, Lys treatment significantly inhibited the progression of diabetic cataract in rats. These effects were due to the Lys antiglycating and antioxidant effects, in addition to its protective effect against α-crystallin chaperoning activity.

[Corneal endothelial evaluation of diabetic patients after phacoemulsification]. / Évaluation endothéliale cornéenne des patients diabétiques après une phacoémulsification.

PURPOSE: To determine whether phacoemulsification with intraocular lens implantation has a greater impact on the corneal endothelium of type 2 diabetic patients compared to non-diabetic patients. MATERIALS AND METHODS: This study compared the endothelial status in 32 diabetics with good glycemic control and 32 non-diabetic patients before and after uneventful phacoemulsification. Central corneal thickness (CCT), central corneal endothelial cell density (CD), hexagonal cell percentage (HEX), and percent coefficient of variation (% CV) were measured using a specular microscope. RESULTS: Data were matched by age and sex. Diabetics showed a significantly higher loss of endothelial cells compared to non-diabetics. After 3 months, there was a decline of 165 endothelial cells (SD 97) in the diabetic group and 114 (SD 45) in the control group. This was statistically significant (P=0.0065). In addition, diabetics showed a slower recovery trend of endothelial healing as evidenced by a lower CV variation. The CV change was 4.7 in the control group and 3.2 in the diabetic group, which was statistically significant (P=0.023). A significant correlation was found between the energy used and the change in endothelial count as well as the CV in both groups. CONCLUSION: Despite good glycemic control, diabetics have significantly more endothelial damage compared to non-diabetics with a similar nuclear classification and phacoemulsification energy used. This justifies a more careful use of phacoemulsification energy in diabetics.

Probucol Slows the Progression of Cataracts in Streptozotocin-Induced Hyperglycemic Rats.

We examined the effect of probucol, an antihyperlipidemic drug with potent antioxidant properties, on cataract formation in streptozotocin (STZ)-induced hyperglycemic rats that were given 5% D-glucose as drinking water. Probucol treatment was initiated immediately after the induction of hyperglycemia was confirmed. Using full horizontal-plane lens images captured with an original digital camera system, the opacity of central region of lens was assessed by measuring the opaque area in the region. Central opacities were detected after 3 weeks of hyperglycemia, and progressed in a time-dependent manner. The majority of STZ-induced hyperglycemic rats developed severe cataracts after 9 weeks of hyperglycemia. Probucol slowed the progression of cataracts in a dose-dependent manner. Levels of sorbitol and protein carbonyls in lenses of STZ-induced hyperglycemic rats were higher than those of control rats. Probucol suppressed the increase in protein carbonyls, but not of sorbitol, in lenses of STZ-induced hyperglycemic rats. Probucol had no significant effect on increases in plasma concentrations of glucose, total cholesterol, and triglyceride observed in STZ-induced hyperglycemic rats. These results suggest that probucol slows the progression of sugar cataracts, independent of its lipid-lowering effects. The beneficial effect of probucol on cataracts is partially attributable to the attenuation of oxidative damage to lens proteins.

Efficacy of Femtosecond Laser-Assisted Phacoemulsification for Cataract Patients and its Influence on Serum Levels of Inflammatory Factors.

OBJECTIVE: To investigate effect of femtosecond laser-assisted phacoemulsification in treating cataract patients, and to analyse its influence on serum inflammatory factors IL-6, IL-1ß, TNF-α . STUDY DESIGN: An analytical, descriptive study. PLACE AND DURATION OF STUDY: The Ophthalmologic Center, Rehabilitation Center Hospital of Gansu, China, from January 2016 to September 2017. METHODOLOGY: A total of 94 eyes were randomly divided into control group (47 cases) and observation group (47 cases). Control group was treated with traditional phacoemulsification. The observation group was added with femtosecond laser based on the treatment of the control group. Clinical efficacy of two groups was compared. RESULTS: Surgery time of the observation group was longer than that of the control group (p<0.001). Effective phacoemulsification time, cumulative dissipated energy, and liquid flow of the observation group were all less than those of the control group (all p<0.001). One day after surgery, aqueous flare and rate of corneal endothelium loss in the observation group were less than those of the control group (both p<0.001). Seven days after surgery, serum levels of IL-6, IL-1 and TNF- in the observation group were lower than those of the control group (all p<0.001). CONCLUSION: Femtosecond laser-assisted phacoemulsification has better clinical effect in treating cataract, and can reduce the energy and time cost in the phacoemulsification, decrease the serum levels of inflammatory factors and cause less postoperative complications. But it takes longer operation time and relatively higher treatment cost.

Correlations of insulin resistance and HbA1c with cytokines IGF-1, bFGF and IL-6 in the aqueous humor of patients with diabetic cataract.

OBJECTIVE: The study aimed to investigate the correlations of insulin resistance and hemoglobin A1c (HbA1c) with cytokines [insulin-like growth factor 1 (IGF-1), basic fibroblast growth factor (bFGF) and interleukin-6 (IL-6)] in the aqueous humor of patients with diabetic cataract. PATIENTS AND METHODS: 59 patients with diabetic cataract and 58 patients with simple cataract treated in Jining No. 1 People´s Hospital (Jining, China) from January 2017 to February 2018, were selected randomly. The levels of homeostasis model assessment of insulin resistance (HOMA-IR) and HbAlc, as well as IGF-1, bFGF and IL-6 in the aqueous humor were compared between the two groups. The correlations of HOMA-IR and HbAlc with IGF-1, bFGF and IL-6 were analyzed. In control group, the levels of HOMA-IR and HbAlc, as well as IGF-1, bFGF and IL-6 in the aqueous humor were significantly lower than those in observation group (p<0.05). RESULTS: Compared with the group with HbAlc ≤ 7%, the groups with HbAlc ≥ 9% and 7%

YKL-40 is a local marker for inflammation in patients with pseudoexfoliation syndrome.

PURPOSE: To investigate the YKL-40, as a marker of inflammation, in aqueous humor and serum of cataract patients with and without pseudoexfoliation syndrome (PEX). METHODS: Aqueous humor and serum samples were obtained from 44 patients who underwent phacoemulsification surgery. All patients were divided into two groups: PEX (n = 24) and control (n = 20). YKL-40 levels were measured with enzyme-linked immunosorbent assay (ELISA). The differences between the groups were assessed by using Chi-square and independent sample t-tests. The Pearson correlation coefficient was used to evaluate the correlation between variables. RESULTS: There was a significant difference between the mean YKL-40 levels in the aqueous humor of PEX group (112.0 ± 35.8 ng/mL) and control subjects (88.2 ± 30.6 ng/mL) (P = 0.025). However, the difference between the mean YKL-40 levels in the serum of PEX group (53.5 ± 29.1 ng/mL) and control subjects (44.6 ± 30.2 ng/mL) was non-significant (P = 0.326). The correlation between aqueous humor and serum YKL-40 concentrations was significant in both the groups (r = 0.833, P < 0.001; r = 0.840, P < 0.001, respectively). CONCLUSIONS: Increased aqueous humor levels of YKL-40 demonstrate that it is local, but not a systemic marker for inflammation in patients with PEX.

A systematic review of risk factors for cataract in type 2 diabetes.

Type 2 diabetes (T2D) is a risk factor for cataract development. With T2D prevalence increasing, the burden of cataract-associated vision loss will also increase. We aimed to characterise cataract diabetes-specific risk factors to assist prevention and management strategies. As part of a systematic review, two investigators independently searched online electronic databases according to a predetermined protocol for relevant published data to end-March 2018. Studies were included if they were longitudinal with ≥100 participants, diabetes was defined, a description of cataract assessment was provided, data were from humans, and the reports were in English. Study quality was assessed using the Newcastle Ottawa Scale and GRADE. Of 5255 publications identified, 19 from 13 study populations were included. The overall risk of bias was low. There was between-study variability. Age and glycaemic control were consistently associated with cataract development in T2D, but blood pressure, diabetes duration, sex, and aspirin use were not. Serum lipids and smoking remain possible risk factors, but available data are inconclusive. Glycaemia is the only consistent modifiable risk factor amongst a range of candidate variables. Due to the lack of consistency of the available evidence, and since mortality associated with T2D is declining with the likelihood of increased cataract-associated vision loss, additional well-conducted longitudinal studies are needed to identify modifiable risk factors that could prevent or delay cataract formation.