Metabolic and lifestyle factors in relation to senile cataract: a Mendelian randomization study

We conducted a Mendelian randomization study to determine the associations of body mass index (BMI), type 2 diabetes (T2D), systolic blood pressure (SBP), coffee and alcohol consumption and smoking initiation with senile cataract. Independent single nucleotide polymorphisms associated with the metabolic and lifestyle factors at the p < 5 × 10–8 were selected as instrument variables. Summary-level data for senile cataract were obtained from the FinnGen consortium (20,157 cases and 154,905 non-cases) and UK Biobank study (6332 cases and 354,862 non-cases). Higher genetically predicted BMI and SBP and genetic predisposition to T2D and smoking initiation were associated with an increased risk of senile cataract. The combined odds ratios were 1.19 (95% confidence interval (CI) 1.09–1.29; p < 0.001) per one standard deviation increase in BMI (~ 4.8 kg/m2), 1.13 (95% CI 1.04–1.23; p = 0.004) per 10 mmHg increase in SBP, 1.06 (95% CI 1.03–1.09; p < 0.001) per one unit increase in log-transformed odds ratio of T2D, and 1.19 (95% CI 1.10–1.29; p < 0.001) per one standard deviation increase in prevalence of smoking initiation. Genetically predicted coffee consumption showed a suggestive association with senile cataract (odds ratio per 50% increase, 1.18, 95% CI 1.00–1.40; p = 0.050). This study suggests causal roles of obesity, T2D, SBP and smoking in senile cataract.

Autophagy facilitates age-related cell apoptosis—a new insight from senile cataract

Age-related cell loss underpins many senescence-associated diseases. Apoptosis of lens epithelial cells (LECs) is the important cellular basis of senile cataract resulted from prolonged exposure to oxidative stress, although the specific mechanisms remain elusive. Our data indicated the concomitance of high autophagy activity, low SQSTM1/p62 protein level and apoptosis in the same LEC from senile cataract patients. Meanwhile, in primary cultured LECs model, more durable autophagy activation and more obvious p62 degradation under oxidative stress were observed in LECs from elder healthy donors, compared with that from young healthy donors. Using autophagy-deficiency HLE-B3 cell line, autophagy adaptor p62 was identified as the critical scaffold protein sustaining the pro-survival signaling PKCι-IKK-NF-κB cascades, which antagonized the pro-apoptotic signaling. Moreover, the pharmacological inhibitor of autophagy, 3-MA, significantly inhibited p62 degradation and rescued oxidative stress-induced apoptosis in elder LECs. Collectively, this study demonstrated that durable activation of autophagy promoted age-related cell death in LECs. Our work contributes to better understanding the pathogenesis of senescence-associated diseases.

Risk Factors Which Lead to Development of Senile Cataract: A Review

Maturing processes, including those brought about by various outside factors, have stood out for researchers throughout the last years. Senile cataract is a multifactorial illness. The expense of surgery of cataract medical procedures stays among the highest costing procedures in general public healthcare. Age is an essential element that causes senile cataract morbidity, which double ten every ten years. This article considers some sources which portray research results on impact on cataract development by risk factors like age, sex, race, smoking, alcohol consumption, diabetes (pancreatic), usage of specific drugs, various environmental aspects, including ultraviolet and ionizing radiation; many of which are shown to cause increment or decrease the risk of senile cataract; there is clashing information on specific factors. Depending on etiology, experts spot senile, congenital, traumatic, complicated, and occupational cataracts. Senile cataract (hereafter referred to as “cataract”) is the most prevalent. The layout also contains quantitative data of cataracts and risk, given through odds ratio and advance because of age, alcohol consumption, ionizing radiation, etc. The researchers also express that there is still no finding on whether the dose-effect relationship for cataract evolvement is a non-threshold or threshold. Surgical procedures are the only treatment available. The surgical procedure usually needs less than an hour. The surgeon makes a small incision in the sclera or limbus of the eye, sometimes with a laser. A small tool is put in to break up the cataract and gently suction it out through the opening created. Then they put in the new lens, made of plastic, silicone, or acrylic, and close the incision. Surgical procedures namely phacoemulsification and minor incision cataract surgery (SICS) are widely used for cataract surgeries; the former is the latest development in cataract surgeries and is less time-consuming. If both eyes are affected, two surgeries are done separately.

STUDY OF ROLE OF CIRCULATING ANTIOXIDANTS IN DEVELOPMENT OF SENILE CATARACT

Introduction: Senile cataract is the commonest worldwide cause of treatable blindness, most often due to excess reactive oxygen species [ROS]. Anti-oxidant vitamins namely beta-carotene, ascorbate and tocopherol and enzymes like superoxide dismutase (SOD), constitute rst line defenses against ROS assault, while malondialdehyde (MDA) levels indicate the total burden of lipid peroxidation in-vivo. Objectives: We aimed to compare the levels of above ve analytes in senile cataract patients in contrast to apparently healthy controls and also among smoking and non-smoking sub groups of both cases and controls. Methods: A hospital-based case-control study, was conducted with 102 cases of senile cataract and 102 control subjects, following strict inclusion and exclusion criteria. Recruited individuals were sub-categorized into smokers and non-smokers. After overnight fasting (12 hours), 10 ml blood was drawn aseptically. Serum and plasma were separated and used for biochemical estimations of all ve analytes, following established protocols. Levels were compared between cases and controls as well as between the smoking and non-smoking sub-sections of both groups. Results: Signicantly lower levels of plasma ascorbate and serum tocopherol were seen in cases as compared to controls (P=0.0078 and P<0.0001 respectively). Signicantly lower levels of serum beta carotene (P<0.0001), tocopherol (P<0.0001), plasma ascorbate (P<0.0001), and SOD (P<0.0001). Signicantly higher level of serum MDA (P= 0.0494) was seen in the smokers, as compared to non-smokers Conclusions: Lowered serum tocopherol and plasma ascorbate were signicant factors leading to senile cataract. Furthermore, smoking was found crucial in loss of anti-oxidant defenses and subsequent development of cataract.

Immunohistochemical Expression of Alpha (Α) A Crystallin in Senile Degenerative and Non-Cataract Lenses

Aim: Comparative immunohistochemical study of expression of α A Crystallin in non-cataract lenses and age-related cataract lenses in humans. Methodology: This was an observational cross sectional study. There are two groups in this study. Group A comprised of 121 senile degenerative cataract lenses from diagnosed patients. Group B included of 10 non-cataract lenses from patients who underwent surgeries for enucleation due to trauma and retinoblastoma. Lenses were fixed in 10% Buffered Neutral Formalin and processed to make paraffin blocks. Immunohistochemistry (IHC) staining was performed on sections using primary antibody for α A crystallin. Data was analyzed through SPSS software version 24. Results: Immunohistochemical staining of group A showed 80.2% Strong Positive expression while 19.8% showed Intermediate Positive expression of α A Crystallin. 100% Strong Positive expression of α A Crystallin was seen in group B. Comparison of expression of α A Crystallin in two groups showed significant decrease (p<0.001) in expression. Conclusion: Decreased expression of α A Crystallin in IHC stained senile cataract lens indicates the role of structural alterations of lens fibers in pathogenesis of senile cataract. If mechanism involved in causing these alterations can be identified and targeted so that progression of senile cataract may be delayed. Keywords: Immunohistochemistry, α A crystallin expression, senile cataract, Human eye Lens, Lens Fiber.

Study of peculiarities of intra- and postoperative state of the interface «intraocular lens - posterior capsule» in phacoemulsification of senile cataract

Presence of full contact of interface «intraocular lens (IOL) – posterior capsule (PC)» ensures the transparency of the latter in the early period after phacoemulsification (PE) of senile cataract (SC). The main reasons for absence of full contact of IOL with PC are: the presence of residuals of viscoelastic (VE) in the capsular bag, uneven tension of the capsule by the haptic elements of the IOL, and the incommensurability of the size of the IOL with the capsule. Purpose. To study the features of the intra- and postoperative state of interface «IOL – PC» during PE SC. Material and methods. Dynamic observation of 42 patients (42 eyes), who operated on immature senile cataracts, was carried out. All operations were performed using OPMI LUMERA 700 surgical microscope (Carl Zeiss Meditec AG, Jena, Germany) with integrated intra-operative OCT, state of interface «IOL – PC» was examined. 2 hours after and on the 1st day after the operation state of interface «IOL – PC» was studied in all eyes by OCT on Optovue RTVue-100 (Optovue, Inc., US) with module for anterior segment examining to protocols «Cornea Line» and «Cornea Cross Line». Results. During the operation, the presence of contact between IOL and PC was observed only in 9 eyes (21.4%). 2 hours after surgery, 40 eyes (95.2%) had absence of contact between lens and capsule. On the 1st day after surgery, the optimal interface between IOL and PC was observed in 32 eyes (76.2%). Conclusion. Studies have shown that state of interface «IOL – PC» on the 1st day does not depend on its characteristics revealed intraoperative and 2 hours after the operation. The main reason for absence of contact between IOL and PC is residues of VE, and the using «impulse-irrigation» technique allows completely removing VE from the central zone of the capsule in all cases. Key words: cataract, phacoemulsification, intraocular lens, lens capsule, viscoelastic, interface «IOL – PC».

Study of State of Interface “Intraocular Lens — Posterior Capsule” Depending on Size of Capsulorhexis in Senile Cataract Phacoemulsification

Purpose. To study the state of interface “intraocular lens (IOL) — posterior capsule (PC)” depending on diameter of capsulorhexis in phacoemulsification of senile cataract.Patients and methods. 227 patients (227 eyes) were examined after phacoemulsification of senile cataract at LenSx femtosecond laser (Alcon, USA). The study did not include patients with corneal opacities, signs of axial displacement of lens, with irido- and phacodonesis, glaucoma, axial length less than 22 mm and more than 26 mm. Depending on diameter of performed capsulorhexis, we formed 3 groups: 1st group — 76 eyes with diameter capsulorexis 5.5 mm; 2nd group — 73 eyes with 5.0 mm; 3rd group — 78 eyes with 4.5 mm. We studied type of interface “IOL — PC”, the maximum value of PC diastasis and the maximum depth of its folds using an RTVue-100 Optical Coherence Tomography (Optovue, USA) on the first day after the operation.Results. The maximum number of eyes with absence of contact between IOL and PC was noted in the 3rd group (62.8 %), the largest number of eyes with full contact between IOL and PC (63.2 %) was in the 1st group. The minimum average depth of the PC folds (111.1 ± 32.7 μm) was noted in the 1st group, and the maximum (165 ± 75.4 μm) — in the 2nd group.Conclusion. The analysis showed that type of interface “IOL — PC” in the first day after phacoemulsification of senile cataract depends on diameter of capsulorhexis. The largest number of eyes (64.6 %) with full contact between IOL and PC was observed in the group of patients with capsulorhexis 5.5 mm, and the smallest (6.4 %) — in eyes with diameter capsulorexis 4.5 mm. Presumably, the main reason for the absence or incomplete contact between IOL and PC is the presence of viscous dispersive between them. The deformation of PC in the form of folds does not directly depend on diameter of capsulorhexis and, obviously, is due to the uneven tension of the capsular bag by the IOL haptics.

Comparison of Complications between Manual Small Incision Cataract Surgery and Phacoemulsification

Purpose: To compare per-operative and early post-operative complications between Manual Small Incision cataract surgery and Phacoemulsification in patients with Senile Cataract. Study Design: Quasi experimental study. Place and Duration of Study: Al-Ibrahim Eye Hospital Karachi from December 2018 to October 2019. Methods: Two hundred and seventy patients with senile Cataract were recruited for this study by convenient sampling technique. They were divided equally into two groups. Group I underwent Manual Small Incision Cataract Surgery (MSICS), whereas Group II underwent Phacoemulsification. Per-operative and early post-operative complications were recorded on day 1 in both groups. Data was analyzed using SPSS 24.0. Independent t-test was carried out with P-value of ?0.05 was considered statistically significant. Results: Mean age group – I was 54.95 ± 11.0 and in Group – II was 57.09 ± 10.59 (p = 0.546). There were 72 (53.3%) males in group – I and 74 (54.8%) in group – II with a non-significant difference (p-value > 0.01). There was significant difference for posterior capsule rupture and striate keratitis between the two groups (p = 0.031 and 0.044 respectively). Rest of the study parameters was not statistically different in the both group. None of the groups had a nucleus drop and vitreous prolapse. No significant difference was seen between the two groups concerning iris trauma (p = 0.56), wound leakage (p = 0.15) and hyphema (p = 0.32). Conclusion: There is no significant difference between per-operative and early post-operative complications between MSICS and Phacoemulsification in patients with senile cataract except posterior capsular rupture and striate keratopathy which were more common in phacoemulsification group. Key Words: Cataract, Senile Cataract, Phacoemulsification, Small Incision Cataract Surgery.