Engineered Sumoylation-Deficient Prdx6 Mutant Protein-Loaded Nanoparticles Provide Increased Cellular Defense and Prevent Lens Opacity

Aberrant Sumoylation-mediated protein dysfunction is involved in a variety of oxidative and aging pathologies. We previously reported that Sumoylation-deficient Prdx6K(lysine)122/142R(Arginine) linked to the TAT-transduction domain gained stability and protective efficacy. In the present study, we formulated wild-type TAT-HA-Prdx6WT and Sumoylation-deficient Prdx6-loaded poly-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) to further enhance stability, protective activities, and sustained delivery. We found that in vitro and subconjuctival delivery of Sumoylation-deficient Prdx6-NPs provided a greater protection of lens epithelial cells (LECs) derived from human and Prdx6−/−-deficient mouse lenses against oxidative stress, and it also delayed the lens opacity in Shumiya cataract rats (SCRs) than TAT-HA-Prdx6WT-NPs. The encapsulation efficiencies of TAT-HA-Prdx6-NPs were ≈56%–62%. Dynamic light scattering (DLS) and atomic force microscopy (AFM) analyses showed that the NPs were spherical, with a size of 50–250 nm and a negative zeta potential (≈23 mV). TAT-HA-Prdx6 analog-NPs released bioactive TAT-HA-Prdx6 (6%–7%) within 24 h. Sumoylation-deficient TAT-HA-Prdx6-NPs provided 35% more protection by reducing the oxidative load of LECs exposed to H2O2 compared to TAT-HA-Prdx6WT-NPs. A subconjuctival delivery of TAT-HA-Prdx6 analog-NPs demonstrated that released TAT-HA-Prdx6K122/142R could reduce lens opacity by ≈60% in SCRs. Collectively, our results demonstrate for the first time that the subconjuctival delivery of Sumoylation-deficient Prdx6-NPs is efficiently cytoprotective and provide a proof of concept for potential use to delay cataract and oxidative-related pathobiology in general.

Comparison of cumulative dispersed energy between conventional phacoemulsification and femtosecond laser-assisted cataract surgery with two different lens fragmentation patterns

The purpose of the study is to compare the total ultrasound power used between eyes undergoing different lens fragmentation patterns of femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS). A total of 506 patient eyes underwent preoperative grading of lens opacity using the Lens Opacity Classification System III (LOCSIII). The eyes were divided into two subgroups: subgroup 1 had a LOCSIII grade of 1–3, and subgroup 2 had a LOCSIII grade of 4–6. The eyes underwent FLACS (LenSx) for clear corneal wound, capsulotomy, and lens fragmentation. Either a grid pattern or radial pattern was used for lens fragmentation. The eyes received one of the following three treatments: (1) CPS without femtosecond laser assistant, (2) FLACS with a grid pattern (FGP) lens fragment, or (3) FLACS with a quadrant pattern (FQP) lens fragment. The mean cumulative dispersed energy (CDE) for each subgroup and treatment was evaluated. The mean CDE was lower in the two FLACS groups (1.21±1.91 in FGP and 1.22±1.92 in FQP) than that in the CPG group (2.67±2.84). In subgroup 1, CDE was higher in the CPG group (1.54±1.18) as compared with the FLACS groups (0.16±0.31 in FGP and 0.74±1.17 in FQP; P<0.001). In subgroup 2, CDE was higher in the CPG (6.47±3.46) as compared with the FLACS groups (2.74±2.21 in FGP and 5.34±2.17 in FQP; P<0.001). CDE was lower in the two FLACS groups than that in the CPS group, and CDE was the lowest with FGP in both subgroups 1 and 2.

Development of Scale Invariant lens Opacity Estimation System using Hough Circle Detection Transform, Normalization and Entropy

Clear eye lens is responsible for correct vision. Ageing effect acquires opacity at lens structure causing foggy or blurred vision. It is termed as cataract. This may become cause of permanent blindness if remain unidentified and untreated. Due to hazards change in environment and adoption of sluggish lifestyle many diseases like cataract are becoming universal challenge for health organization over the world. Lack of medication and diagnosis facility in developing countries makes cataract as savior vision problem. Proposed methodology suggests image processing based, low cost solution for lens opacity or cataract detection. In this system eye lens image from input image is acquired using Iterative Hough circle detection transform. It is normalized using Daugman’s rubber sheet normalization algorithm which makes system scale invariant. Structural variation in normalized lens image is estimated in terms of entropy or mean value. Comparison of right and left half entropies of normalized image is basis for estimation of lens opacity. It is used to detect and categorize lens opacity or cataract. This system easily categorize lens opacity based on structural features of opacity in one of three grades such as “No cataract”, “Cortical cataract” or “Nuclear cataract”.

Clinical Characteristics of Presenile Cataract: Change over 10 Years in Southern Taiwan

Purpose. The purpose of this study is to investigate the clinical characteristics of presenile cataract and compare that to ten years ago in southern Taiwan. Methods. The subjects who received cataract surgeries aged 30 to 54 years were recruited in Kaohsiung Chang Gung Memorial Hospital during September 2015 and August 2016. Patients with uveitis or those who received combined cataract surgeries were excluded. Retrospective chart review was performed in this study. Results. A total number of 2439 cataract surgeries were performed, and 302 (12.38%) eyes were having presenile cataract. Mean age was 47.55 ± 5.64 years old, and mean axial length was 26.00 ± 2.89 mm. Among 302 presenile cataract eyes, the leading cause was high myopia (defined as mean axial length ≥ 26 mm, 47.02%), followed by diabetes mellitus (26.82%). In types of lens opacity analysis, 67.55% of the patients were nuclear sclerosis dominant. Compared to the previous study 10 years ago, the leading cause of presenile cataract changed from idiopathy to high myopia, whereas the lens opacity types changed from posterior subcapsular opacity dominant to nuclear sclerosis dominant. Conclusions. High myopia has become the most important clinical characteristic associated with presenile cataract in a myopia epidemic area, and the most common type of lens opacity was nuclear sclerosis. With the increasing prevalence of high myopia, we should pay more attention to the management of presenile cataracts in high myopes to avoid complications.

Phakochronology - The Forgotten Science

A 30 year old male, had history of bomb blast injury to the face 24 months ago with multiple foreign bodies perforating the eye (operated for vitrectomy and foreign body explant). The iris entry wound and the cataract caused by one such foreign body is shown in (Figure 1a). The opacity in the lens substance (Figure 1b) is 156 microns behind the anterior lens capsule (Figure 1c) (meaning growth of these much lens fresh clear lens fibres over the time has pushed the lens opacity backwards which earlier would have been on the surface). Calculating by phakochronology [1], we would like to report the in-vivo lens growth in this patient to be 6.5 microns/month.