Cataractous Lenses Research Articles

Scleral Tunnel Fixated Intraocular Lens in Complicated Cataract: A Case Series

When capsular support is inadequate in complicated cataract, scleral fixated IOL (SFIOL) has its advantage whereby it is nearer to physiological nodal point when compared to other types of IOL implantation. Scleral tunnel fixated intraocular lens (STFIOL) technique is gaining popularity due to its simplicity and ease of placement compared to sutured IOL. We report our experience with eight cases of STFIOL implantation from September 2016 to May 2018 in Universiti Kebangsaan Malaysia Medical Centre (UKMMC). All patients had improvement of vision except one case who had unchanged vision. Mean post-operative BCVA was logMAR 0.57±1.13 (which is almost equivalent to 6/21) and improved to logMAR 0.37±0.43 (which is almost equivalent to 6/12) excluding one patient with chronic RRD with band keratopathy. Post-op complications include raised intraocular pressure, cystoid macular oedema, hyphaema, and wound leak. However, all complications were not severe and responded to topical eyedrops. In conclusion, STFIOL insertion technique is safe and works well to restore vision in majority of patients operated with this technique.

Anterior Chamber Configuration Changes after Phacoemulsification and Intraocular Lens Implantation Measured by Anterior Segment Optical Coherence Tomography

Background: Phacoemulsification can cause changes in the measurements of the anterior segment. Anterior segment optical coherence tomography [AS-OCT] is a disconnected probe device that can detect variations in the anterior segment parameters. The aim of the work: The current study aimed to investigate changes in anterior chamber angle [ACA] morphology and intraocular pressure [IOP] after phacoemulsification of cataract and intraocular lens implantation by comparing two groups of patients using two brands of IOL [Sensar 1 hydrophobic one-piece IOL] and [Eyecryl hydrophilic one-piece IOL] in patients with senile cataract using [AS-OCT]. Patients and Methods: Our study was a prospective randomized study including 30 eyes with impaired vision due to cataract, as the only cause of visual regression selected from the patients who attended Al-Azhar University Hospital [Damietta branch] Ophthalmic outpatient Clinic and were randomized into two groups. Group A [15 eyes] was implanted with [Sensar 1 hydrophobic IOL] and Group B [15 eyes] was implanted with [Eyecryl hydrophilic IOL]. Results: the results revealed that there was a significant increase in the AC angle in both groups, except for the AC depth in group A, but the difference between groups was statistically non-significant. Conclusion: Phacoemulsification with IOL implantation led to an increase in the ACA, a marked increase in BCVA and a reduction in IOP, if using [Sensar 1 hydrophobic one-piece IOL] or [Eyecryl hydrophilic one-piece IOL]. However, we cannot generalize the results because of the small sample size.

Comparison of trifocal or hybrid multifocal-extended depth of focus intraocular lenses: a systematic review and meta-analysis

This meta-analysis aimed to evaluate the clinical outcomes following implantation of trifocal intraocular lenses (IOLs) or a hybrid multifocal-extended depth of focus (EDOF) IOL in cataract or refractive lens exchange surgeries. We examined 13 comparative studies with bilateral implantation of trifocal (898 eyes) or hybrid multifocal-EDOF (624 eyes) IOLs published through 1 March 2020. Better uncorrected and corrected near visual acuity (VA) were observed in the trifocal group (MD: − 0.143, 95% CI: − 0.192 to − 0.010, P < 0.001 and MD: − 0.149, 95% CI: − 0.217 to − 0.082, P < 0.001, respectively), while the hybrid multifocal-EDOF group presented better uncorrected intermediate VA (MD: 0.055, 95% CI: 0.016 to 0.093, P = 0.005). Trifocal IOLs were more likely to achieve spectacle independence at near distance (RR: 1.103, 95% CI: 1.036 to 1.152, P = 0.002). The halo photic effect was generated more frequently by the trifocal IOLs (RR: 1.318, 95% CI: 1.025 to 1.696, P = 0.031). Contrast sensitivity and subjective visual quality yielded comparable results between groups. Trifocal IOLs demonstrated better performance at near distance but apparently led to more photic disturbances. Our findings provided the most up-to-date and comprehensive evidence by comparing the benefits of advanced IOLs in clinical practice.

Aging lens epithelium is susceptible to ferroptosis

Age-related cataracts (ARC) are the primary cause of blindness worldwide, and oxidative stress is considered the central pathogenesis of age-related cataractogenesis. Interestingly, ample evidence suggests that there is no remarkable apoptosis present in aged and cataractous human lenses despite the profound disruption of redox homeostasis, raising an essential question regarding the existence of other cell death mechanisms. Here we sought to explore the lens epithelial cell's (LEC) susceptibility to ferroptosis after documentation has concluded that aged and cataractous human lenses manifest with increased reactive oxygen species (ROS) formation, elevated lipid peroxidation, and accumulative intracellular redox-active iron, constituting the three hallmarks of ferroptosis during aging and cataractogenesis. Here we show that very low concentrations of system Xc- inhibitor Erastin (0.5 μM) and glutathione peroxidase 4 (GPX4) inhibitor RSL3 (0.1 μM) can drastically induce human LEC (FHL124) ferroptosis in vitro and mouse lens epithelium ferroptosis ex vivo. Depletion of intracellular glutathione (GSH) in human LECs and mouse lens epithelium significantly sensitizes ferroptosis, particularly under RSL3 challenge. Intriguingly, both human LECs and the mouse lens epithelium demonstrate an age-related sensitization of ferroptosis. Transcriptome analysis indicates that clusters of genes are up-or down-regulated in aged LECs, impacting cellular redox and iron homeostases, such as downregulation of both cystine/glutamate antiporter subunits SLC7A11 and SLC3A2 and iron exporter ferroportin (SLC40A1). Here, for the first time, we are suggesting that LECs are highly susceptible to ferroptosis. Moreover, aged and cataractous human lenses may possess more pro-ferroptotic criteria than any other organ in the human body.

Resident immune cells of the avascular lens: Mediators of the injury and fibrotic response of the lens.

Tissues typically harbor subpopulations of resident immune cells that function as rapid responders to injury and whose activation leads to induction of an adaptive immune response, playing important roles in repair and protection. Since the lens is an avascular tissue, it was presumed that it was absent of resident immune cells. Our studies now show that resident immune cells are a shared feature of the human, mouse, and chicken lens epithelium. These resident immune cells function as immediate responders to injury and rapidly populate the wound edge following mock cataract surgery to function as leader cells. Many of these resident immune cells also express MHCII providing them with antigen presenting ability to engage an adaptive immune response. We provide evidence that during development immune cells migrate on the ciliary zonules and localize among the equatorial epithelial cells of the lens adjacent to where the ciliary zonules associate with the lens capsule. These findings suggest that the vasculature‐rich ciliary body is a source of lens resident immune cells. We identified a major role for these cells as rapid responders to wounding, quickly populating each wound were they can function as leaders of lens tissue repair. Our findings also show that lens resident immune cells are progenitors of myofibroblasts, which characteristically appear in response to lens cataract surgery injury, and therefore, are likely agents of lens pathologies to impair vision like fibrosis.

Postoperative Complications after Phacoemulsification and Implantation of Foldable Acrylic Intraocular Lenses in Dogs

Background: Despite significant advances in canine cataract surgery over the years, many post-operative complications persist and reduces the success rate of phacoemulsification procedure. The aim of current study was to evaluate post-operative complications encountered till 90 days after bimanual phacoemulsification with implantation of different acrylic Intraocular Lenses.Methods: The study was conducted on 24 canine eyes. All the clinical cases were subjected to detailed ocular, ultrasonography and neuro-ophthalmic tests for ascertaining cataract and associated neuro-ophthalmic pathology. Dogs were divided in four groups with 6 eyes in each group and subjected to phacoemulsification procedure for removal of cataractous lens and implanted with square edge or round edge hydrophilic or hydrophobicintra ocular lenses.Result: Statistically non-significant (p£0.05) variations were found for all the post- operative complications among the groups. Within the groups initially higher values were recorded and on subsequent days a declining trend of varying degrees were observed. The corneal opacity was a major postoperative complication leading to failure to achieve vision with other coinciding neuro-ophthalmic conditions.

MiR-23a-3p regulates the proliferation and apoptosis of human lens epithelial cells by targeting Bcl-2 in an in vitro model of cataracts.

Cataracts account for ~50% of the cases of blindness in individuals worldwide. The apoptosis of lens epithelial cells (LECs) occurs during the formation of cataracts, which is a non-congenital condition. Numerous microRNAs (miRs) have been reported to regulate apoptosis in LECs. For instance, miR-23a expression levels were shown to be upregulated in cataractous lenses; however, the function of miR-23a in cataracts remains undetermined. To establish an in vitro model of cataracts, human LECs, HLE-B3 cells, were induced with 200 µmol/l H2O2 for 24 h. HLE-B3 cells were transfected with the miR-negative control (NC) mimic, miR-23a-3p mimic, miR-NC inhibitor, miR-23a-3p inhibitor, small interfering RNA (siRNA) targeting BCL2 (siRNA-BCL2) and siRNA-NC. The expression levels of miR-23a-3p were detected using reverse transcription-quantitative PCR. The interaction between miR-23a-3p and the 3'-untranslated region (UTR) of the target mRNA BCL2 was predicted by TargetScan 7.1, and further validated using a dual luciferase reporter assay. The BCL2 protein expression levels were analyzed using western blotting, cell proliferation was determined using a CCK-8 assay and the levels of cell apoptosis were analyzed using flow cytometric analysis. The results of the present study revealed that the expression levels of miR-23a-3p were significantly upregulated, while the expression levels of BCL2 were significantly downregulated in H2O2-induced HLE-B3 cells compared to untreated control cells. BCL2 was shown to be a target of miR-23a-3p. The miR-23a-3p inhibitor subsequently attenuated H2O2-induced apoptosis and increased the proliferation of HLE-B3 cells, which was partially reversed by siRNA-BCL2. In conclusion, the findings of the current study suggested that the inhibition of miR-23a-3p may attenuate H2O2-induced cataract formation by targeting BCL2, thus providing a novel therapeutic target for the treatment of patients with cataracts in the clinic.

Optical Iridectomy as An Alternative Clear Visual Axis for Peters Anomaly

Introduction and objective: Peters anomaly is a rare congenital disease presented with central leukoma, iridocorneal adhesion, and with or without a cataractous lens. The presence of central leukoma will block the visual axis and lead to a disruption in normal visual development. Therefore, optical iridectomy, which can overcome the high incidence of graft failure in penetrating keratoplasty (PK), has been proposed as the alternative treatment to clear the visual axis. This study aims to show the outcome of optical iridectomy in patients with Peters’ anomaly. Method: Systematic literature searched in Pubmed, Google Scholar, and Cochrane from their inception to August 2020 was conducted using keywords “iridectomy” and “Peters’ anomaly”. Full- text articles in English that report the outcome of iridectomy in Peters’ anomaly were included, and a manual review of article bibliographies was done. Outcome measures were analyzed using the following clinical questions: indication, age, visual acuity (VA), and intraocular pressure (IOP). Result: One case series and two case reports demonstrating the use of optical iridectomy in Peters anomaly were identified. In total, 26 patients aged one week to 7.7 years received optical iridectomy to establish a clear visual axis. All studies showed an improvement in visual acuity through clinical findings, and one of the studies showed a better postoperative VA in bilateral cases. Studies showed good control of IOP. Conclusion: Optical iridectomy can be used as a safe procedure to improve visual acuity in Peters anomaly patient.

Device-Dependent Medical Intervention is Not a Panacea: Analysis of Cataract Surgery Outcomes in China from 2009 to 2018 Based on Data From the National Cataract Recovery Surgery Information Registration and Reporting System

Background: During the last decade, support to public welfare programs, development of device-dependent techniques and increased awareness of public health have all caused rapid growth in the number of cataract surgeries performed in China. However, cataract surgery outcomes and the applicability of device-dependent interventions for cataract patients nationwide are still unknown. This study aimed to evaluate the outcomes of cataract surgeries, from a health administration perspective. The data analysed were based on the National Cataract Recovery Surgery Information Registration and Reporting System. The final objective was to provide a roadmap for future health service policies for cataract surgeries. Methods: The data source of this study is the National Cataract Recovery Surgery Information Registration and Reporting System. All cataract cases receiving any surgical treatment, both in medical services and institutes nationwide, should be registered and reported online within four days of the surgery. The variables included: medical institute settings, clinical characteristics of patients, pre-surgical examinations of the cataract-operated eyes, surgical information, and post-surgical visual status. A case-control design was adopted for this study based on the data collected from the electronic registered report system. A descriptive analysis was conducted to analyse the tendency of cataract surgery in the past decade. With LogMAR transferred, the pre-surgical best-corrected visual acuity (BCVA) level was stratified to compare the BCVA improvement level before and after the surgery. The multinomial logistic regression model was used to explore the influencing factors of 3-day post-surgical BCVA improvement, and Normogram visualisation was used to predict the prognosis of cataract surgery. Findings: A total of 1,4157,463 original records were reported from July 1st 2009 to the 31st of December 2018. The mean age of the reported data was 69.7 years, with 69% of the cases in the 61-80 years group. Female accounted for 58.0%. The median of pre-surgical LogMAR transferred BCVA was 0.2, while those of the post-surgery 3-day and 3-month were 0.5 and 0.6, respectively. Cataract surgery had a very good effect on improving post-surgical BCVA. From binary logistic regression analysis, history of hypertension (OR = 0.916) or diabetes (OR = 0.912), pre-surgical pupil abnormality (OR = 0.571), high intraocular pressure (OR = 0.578) did not affect post-surgical BCVA improvement (BCVA ≥ 6/18), while male sex (OR = 1.113), better pre-surgical BCVA level (OR = 5.996 for 0.5-0.7 and OR = 2.610 for 0.2-0.4 taken ≤ 0.1 as reference), age-related cataract (OR = 1.825), and intraocular lens implantation (OR = 1.886) were statistically beneficial for post-surgical BCVA improvement. Considering the surgery types, compared with the ECCE with large incision, the ECCE with small incision (OR value = 1.810) and the phacoemulsification (OR = 1.420) significantly improved the benefit probability. Among the hospital administration affiliation, compared with the provincial medical institutions, the benefit probability of county medical institutions was doubled, with an OR value of 2.084 (95% CI 2.029-2.140). Interpretation: ECCE with small incision has comparable effects on post-surgical BCVA improvement of phacoemulsification. Therefore, it could be an alternative cataract surgical treatment in economically underdeveloped areas in China. Funding Statement: None. Declaration of Interests: All authors claimed no conflict of interest. Ethics Approval Statement: Due to the application of the electronic data from the system, we deemed and were granted ethical approval for the study plan, data management plan and an exemption of informed consent. The approval was provided by the Ethics Committee of the National Institute of Hospital Administration in China (Ethics NO. 1015).

On the Nature of Murine Radiation-Induced Subcapsular Cataracts: Optical Coherence Tomography-Based Fine Classification, In Vivo Dynamics and Impact on Visual Acuity.

Ionizing radiation is widely known to induce various kinds of lens cataracts, of which posterior subcapsular cataracts (PSCs) have the highest prevalence. Despite some studies regarding the epidemiology and biology of radiation-induced PSCs, the mechanism underscoring the formation of this type of lesions and their dose dependency remain uncertain. Within the current study, our team investigated the in vivo characteristics of PSCs in B6C3F1 mice (F1-hybrids of BL6 × C3H) that received 0.5-2 Gy γ-ray irradiation after postnatal day 70. For purposes of assessing lenticular damages, spectral domain optical coherence tomography was utilized, and the visual acuity of the mice was measured to analyze their levels of visual impairment, and histological sections were then prepared in to characterize in vivo phenotypes. Three varying in vivo phenotype anterior and posterior lesions were thus revealed and correlated with the applied doses to understand their marginal influence on the visual acuity of the studied mice. Histological data indicated no significantly increased odds ratios for PSCs below a dose of 1 Gy at the end of the observation time. Furthermore, our team demonstrated that when the frequencies of the posterior and anterior lesions were calculated at early time points, their responses were in accordance with a deterministic model, whereas at later time points, their responses were better described via a stochastic model. The current study will aid in honing the current understanding of radiation-induced cataract formation and contributes greatly to addressing the fundamental questions of lens dose response within the field of radiation biology.

English

Phthisis bulbi is an ocular condition caused by wound healing secondary to severe trauma, inflammation, or necrotising tumours of the eye. It represents an ocular endstage disease characterised by atrophy, shrinkage, disorganisation of the eyeball, and intraocular contents. Disfigurement associated with the eye can cause significant physical and emotional disturbance. Prosthetic rehabilitation over the residual eyeball is the preferred treatment of choice over surgical intervention such as enucleation or evisceration. Treatment of such patients is challenging and a multidisciplinary approach is required to provide a satisfactory ocular prosthesis. This case report describes the prosthetic management of a patient with phthisis bulbi by a novel impression-less technique. The initial unsaid communication that takes place between two individuals is through their “eyes”. A confident person will always maintain eye contact while conversing. They are the organs of the visual system which are sensitive to various stimuli.1 Any anomaly involving the eyes causes psychological, emotional, and aesthetic trauma to the patient. Phthisis bulbi is an ocular condition due to multifactorial conditions such as delayed wound healing secondary to severe trauma, infections such as keratitis, uveitis and endophthalmitis. Also, some failed surgical procedures including cataract, glaucoma, retinal surgery and intraocular malignancies like choroidal melanoma, retinoblastoma as well as systemic diseases like diabetes or hypertension may result in phthisis bulbi.2,3 The name “Phthisis bulbi” comes from a Greek word which means “to waste away” or “shrinkage. It is a histopathological diagnosis of end-stage non-functional ocular disease showing atrophy, shrinkage, and disorganisation of the eye and intraocular contents. Clinically, the eyes have no perception of light due to intraocular calcium deposition within band keratopathy, cataractous lens, sclera, gliotic neural retina, or within an optic nerve in the phthisical eye.4 Surgical procedures are not desired in a patient of phthisis bulbi unless it becomes painful. Hence, prosthetic rehabilitation is the only preferred treatment of choice in the patient with phthisis bulbi.5 A properly fabricated custom-made prosthesis enhances the patient's comfort, confidence, and aesthetics by increased adaptiveness, natural appearance, and functional stimulation.6 Hence, we devised an innovative approach to fabricate an ocular prosthesis for a patient suffering from phthisis bulbi by using an impression less technique which has been described in this case report.

Leukocyte chemotactic receptor Fpr1 protects against aging-related posterior subcapsular cataract formation.

Cataracts are a common consequence of aging; however, pathogenesis remains poorly understood. Here, we observed that after 3months of age mice lacking the G protein-coupled leukocyte chemotactic receptor Fpr1 (N-formyl peptide receptor 1) began to develop bilateral posterior subcapsular cataracts that progressed to lens rupture and severe degeneration, without evidence of either systemic or local ocular infection or inflammation. Consistent with this, Fpr1 was detected in both mouse and human lens in primary lens epithelial cells (LECs), the only cell type present in the lens; however, expression was confined to subcapsular LECs located along the anterior hemispheric surface. To maximize translucency, LECs at the equator proliferate and migrate posteriorly, then differentiate into lens fiber cells by nonclassical apoptotic signaling, which results in loss of nuclei and other organelles, including mitochondria which are a rich source of endogenous N-formyl peptides. In this regard, denucleation and posterior migration of LECs were abnormal in lenses from Fpr1-/- mice, and direct stimulation of LECs with the prototypic N-formyl peptide agonist fMLF promoted apoptosis. Thus, Fpr1 is repurposed beyond its immunoregulatory role in leukocytes to protect against cataract formation and lens degeneration during aging.

Molecular Simulations of Ocular Lens Membranes at Various Stages of Age and Cataract

The human ocular lens consists primarily of elongated, static fibers characterized by high stability and low turnover, which differ dramatically in their composition and properties from other biological membranes. Cholesterol (Chol) and sphingolipids (SL) are present at high concentrations, including saturated SLs, such as dihyrosphingomyelin. Past molecular dynamics (MD) simulations demonstrated that the presence of DHSM and high Chol concentration contributes to higher order in lipid membranes. Using the CHARMM36 all-atom force field, this study simulated more complex models of human lens membranes with the inclusion of lysolipids and plasmanyl lipids. Models were developed representing physiological compositions in cataractous lenses aged 74±6 years and in healthy lenses aged 22±4, 41±6, and 69±3 years. With older age, Chol and ceramide concentrations increase and glycerophospholipid concentration decreases. With cataract, ceramide concentration increases and Chol and glycerophospholipid concentrations decrease. Surface area per lipid, deuterium order parameters (SCD), sterol tilt angle, electron density profiles (EDP), bilayer thickness, chain interdigitation, two-dimensional radial distribution functions (2D-RDF), mean-square displacement, lipid clustering, and hydrogen bonding were calculated for all simulations. All systems exhibited low surface area per lipid and high bilayer thickness, indicative of strong vertical packing. SCD parameters suggest similarly, with saturated tails in the hydrophobic core of the membrane having order parameter exceeding 0.4. Vertical packing and acyl tail order increased with both age and cataract. Lateral diffusion decreased with age and cataracts, with the older and cataractous models demonstrating increased long-range structure by the 2D-RDF analysis. Experimental results have found crystallization of Chol in older lenses, which similarly indicates increased order. In future work examining the membrane proteins of the lens, these models can serve as physiologically accurate representations of the lens lipidome.

Mutation of the TRPM3 cation channel underlies progressive cataract development and lens calcification associated with pro-fibrotic and immune cell responses.

Transient-receptor-potential cation channel, subfamily M, member 3 (TRPM3) serves as a polymodal calcium sensor in diverse mammalian cell-types. Mutation of the human TRPM3 gene (TRPM3) has been linked with inherited forms of early-onset cataract with or without other eye abnormalities. Here, we have characterized the ocular phenotypes of germline "knock-in" mice that harbor a human cataract-associated isoleucine-to-methionine mutation (p.I65M) in TRPM3 (Trpm3-mutant) compared with germline "knock-out" mice that functionally lack TRPM3 (Trpm3-null). Despite strong expression of Trpm3 in lens epithelial cells, neither heterozygous (Trpm3+/- ) nor homozygous (Trpm3-/- ) Trpm3-null mice developed cataract; however, the latter exhibited a mild impairment of lens growth. In contrast, homozygous Trpm3-M/M mutants developed severe, progressive, anterior pyramid-like cataract with microphthalmia, whereas heterozygous Trpm3-I/M and hemizygous Trpm3-M/- mutants developed anterior pyramidal cataract with delayed onset and progression-consistent with a semi-dominant lens phenotype. Histochemical staining revealed abnormal accumulation of calcium phosphate-like deposits and collagen fibrils in Trpm3-mutant lenses and immunoblotting detected increased αII-spectrin cleavage products consistent with calpain hyper-activation. Immunofluorescent confocal microscopy of Trpm3-M/M mutant lenses revealed fiber cell membrane degeneration that was accompanied by accumulation of alpha-smooth muscle actin positive (α-SMA+ve) myofibroblast-like cells and macrosialin positive (CD68+ve) macrophage-like cells. Collectively, our mouse model data support an ocular disease association for TRPM3 in humans and suggest that (1) Trpm3 deficiency impaired lens growth but not lens transparency and (2) Trpm3 dysfunction resulted in progressive lens degeneration and calcification coupled with pro-fibrotic (α-SMA+ve) and immune (CD68+ve) cell responses.

Cataract-causing mutations L45P and Y46D impair the thermal stability of γC-crystallin

Crystallin gene mutations are responsible for about half of the congenital cataract caused by genetic disorders. L45P and Y46D mutations of γC-crystallin have been reported in patients with nuclear congenital cataract. In this study, we explored the thermal stability of wild type (WT), L45P, and Y46D mutants of γC-crystallin at low and high concentrations, as well as the effect of αA-crystallin on the thermal stability of mutants. Spectroscopic experiments were used to monitor the structural changes on temperature-gradient and time-course heating process. Intermediate morphologies were determined through cryo-electron microscopy. The thermal stability of WT and mutants at concentrations ranging up to hundreds of milligrams were assessed via the UNcle multifunctional protein stability analysis system. The results showed that L45P and Y46D mutations impaired the thermal stability of γC-crystallin at low (0.2 mg/mL) and high concentrations (up to 200 mg/mL). Notably, with increase in protein concentration, the thermal stability of L45P and Y46D mutants of γC-crystallin simultaneously decreased. Thermal stability of L45P and Y46D mutants could be rescued by αA-crystallin in a concentration-dependent manner. The dramatic decrease in thermal stability of γC-crystallin caused by L45P and Y46D mutations contributed to congenital cataract in the mature human lens.

Accuracy of ARFI elastography in the differentiation of cataract stages in dogs

ABSTRACT: Objective was to evaluate the accuracy of elastography in the differentiation between normal and cataract lenses One hundred forty-five eyes of 98 dogs were divided into groups according to cataract stage. Forty-twoeyes were submitted to phacoemulsification. Biometric parameters, echogenicity and echotexture patterns of the anterior, posterior and vitreous chambers, lens and retina-choroid-sclera complexes were evaluated by ocular ultrasound in modes A and B. Deformability, and color (blue color = indicated less rigid structures, color red = more rigid structures) of the lenses were evaluated by the elastogram. The shear wave velocity (SWV; m/s) was calculated in three regions of the lens, both in the cortex and in the nucleus. The SWV of nucleus was statistically different between the normal lenses and with cataracts, and between the stages of cataract (P&lt;0.001). Healthy lenses and incipient cataracts had a more rigid nucleus. Mature cataracts presented lowest nuclear rigidity (P&lt;0.001). On cortical region the SWV was significantly higher (P&lt;0.01) in intumescent and incipient cataracts. SWV less than 2.67m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. SWV greater than 2.66 m/s are associated with normal lenses or incipient cataract, presenting sensitivity of 94% and specificity of 84%. Qualitative method allowed differentiation between healthy and affected lenses and the classification of evolutionary stages. There was a correlation between the degree of stiffness of lens in cortical and nuclear regions (p=00165, r=0.37) and between the balanced saline solution quantitative and surgical time (P&lt;0.01, r=0.73). Degree of stiffness of lens did not correlate with parameters of phacoemulsification. Elastographic proved feasible for evaluating the lens of dogs, characterizing the types of cataracts, and demonstrating increased stiffness of the diseased lenses.

Patient preference and pain-reported outcomes for topical versus subtenon anesthetic for cataract surgery.

PURPOSE:Cataract extraction and lens implantation is the most common surgical procedure performed worldwide, with surgeons opting for either a topical or a subtenon anesthetic in majority of cases. While complication rates and pain scores have been previously examined in a bid to determine which modality was better, patients who have had both eyes operated upon under different techniques have never previously been asked which method they prefer. We undertook this study to fill in this crucial gap in our knowledge.METHODS:This is a retrospective study of patients who have undergone bilateral cataract surgery with one eye operated on with topical anesthesia and the other eye with subtenon anesthesia. Patients were identified who had had surgery undertaken in the previous 6 months at Singleton Hospital, Swansea, where both eyes had been operated upon using different anesthetic techniques. Telephone interviews with these patients were performed and their pain scores recorded on a scale from 0 (no pain) to 10 (severe pain) for both eyes, with the patients then being asked which the method of anesthetic they preferred. Statistical analysis of pain scores was compared using Wilcoxon rank-sum testing.RESULTS:One hundred and fifty-two patients in total were identified. One hundred and forty-one of the applicable patients participated in the study. Of these, 78 patients received topical anesthesia for their first operation and 63 had subtenon block for their first operation. The mean pain scores reported for surgery with topical anesthesia and subtenon block were 2.30 and 1.38, respectively. The pain data were analyzed using a Wilcoxon signed-rank test, returning a z-score of 4.038. This result therefore suggests that patients experience statistically significantly less pain from cataract surgery when given a subtenon block. Patients expressed a preference for subtenon anesthesia, with 70% preferring subtenon block, 23% preferring topical anesthesia, and 7% having no preference.CONCLUSIONS:Patients report less pain with subtenon anesthesia compared with topical anesthesia in cataract surgery, where both eyes were operated upon with different anesthetic techniques. This is the first study in which patients who have had both anesthetic techniques performed independently for cataract surgery have had their pain scores reported and statistically analyzed.

Crystalline Lens Vitamin C Levels in Cataract Surgical Patients

To determine the amount of Vitamin C in the lenses of Diabetic and Non-Diabetic Patients with Operable Cataract and ascertain association between Vitamin C levels and Blood Glucose, Glycated Haemoglobin and Intraocular pressure. Thirty Diabetic and Thirty Non-Diabetic Patients cataract surgical patients were matched for age and sex and selected for the study. Plasma fasting blood glucose and whole blood glycated Haemoglobin levels were determined by glucose oxidase enzymatic assay and immunodetection methods respectively. Cataractous lens samples obtained during surgery were weighed and homogenized in 10 volumes of phosphate buffer pH 7 and the resulting homogenate centrifuged at 18,000 g for 5 minutes at 4˚C, separated and supernatant stored at -80˚C. Vitamin C assay was carried out using commercial assay kits. Data was analyzed using SPSS version 23. Age range of participants was 55 - 83 years, with a mean of 66.7 ± 1.8 years. Mean Vitamin C levels in the Diabetic and Non-Diabetic groups were 49.5 μg/g ± 6.47 and 57.02 μg/g ± 8.0 respectively. Although the Non-diabetic group had higher levels of Vitamin C, the difference was not significant. Levels of Vitamin C found in both groups are much lower than what has previously been reported in Literature for clear lenses. There was negative association between Vitamin C and Glucose, Glycated Haemoglobin and Intraocular Pressure. Vitamin C supplementation may be useful in prolonging incidence of cataract in both aging and diabetic Nigerian populations. Larger study involving estimation of Vitamin C in both lens and Plasma samples is desirable.

Goat eye integrated with soap pellet as cataractous lens for phaco emulsification training: A thread to catch up the learning curve during pandemic

Goat eye integrated with soap pellet as cataractous lens for phaco emulsification training: A thread to catch up the learning curve during pandemic

Disaggregation of amyloid-like protein aggregates isolated from human cataract lens

Crystallins, which represents the major lens protein, play a significant role in ensuring the lens transparency and maintenance of appropriate refractive index of the lens that help in accurate focusing of incident visible light precisely on retina to create clear image perception. Aggregation of lens proteins is known to form the basis of cataract formation. The present study is an attempt to examine the stability of the lens protein aggregates, isolated from human cataract eye lens, against an anionic detergent Sodium dodecyl sulphate (SDS), which is known to disrupt the hydrophobic interaction of protein aggregates. Data that emerged from Congo red (CR), thioflavin T (ThT) and 8-anilino-1-naphthalene sulfonic acid (ANS) binding assaysindicated their amyloidogenic nature. A significant reduction in the bathochromic shift of CR λmax and ThT fluorescence emission intensity were observed after treatment of the aggregated proteins with SDS. In the presence of SDS, a significant change in the number and size of the protein aggregates were observed during their morphological analyses under transmission electron microscopy (TEM). Based on the above data it became evident that the hydrophobic interaction plays a crucial role in formation and stabilizing the protein aggregates during cataract formation.