The loss of retinal pigment epithelium (RPE) with aging is related to age-related macular degeneration (AMD). This study was conducted to investigate the mechanism of hydrogen peroxide (H2O2) induced cell death in a human retinal pigment epithelial cell line, ARPE-19. Hydrogen peroxide was added at different concentrations to ARPE-19 cells and cultured. The cytotoxicity was assayed by mitochondrial function using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) testing. The patterns of cell damage were assessed using an acridine orange-ethidium bromide differential staining method, in situ end labeling (ISEL) assay and transmission electron microscopy (TEM). Catalase, a major antioxidant, was used to prevent cell death. The cleavage of procaspase 3 and poly (ADP-ribose) polymerase (PARP) was determined by western blot analysis. Hydrogen peroxide significantly induced cell death in ARPE-19 cells, whereas pretreatment of the cells with catalase prevented cell death. Application of the ISEL assay and acridine orange/ethidium bromide staining demonstrated that the H2O2-induced cell death occurred by an apoptotic mechanism at lower concentrations of H2O2 (400, 500, 600 microM), whereas higher concentrations of H2O2 induced necrosis rather than apoptosis. Caspase 3 was associated with the apoptotic pathway in human RPE cell death. Western blot analysis confirmed caspase 3 activation and cleavage of substrate proteins in ARPE-19 cells treated with an H2O2 concentration of 600 microM. These results indicate that treatment with H2O2 induces apoptotic and necrotic cell death in ARPE-19, and that caspase 3 is associated with apoptotic cell death. Therefore, H2O2 may induce the destruction of RPE cells in AMD by the combined effects of apoptosis and necrosis.
PurposeTo evaluate changes over time of the anterior capsule opening size after phacoemulsification, based on haptic number and composition of three acrylic intraocular lenses (IOLs).MethodsFifty-five patients (70 eyes) were included. All underwent phacoemulsification followed by implantation of either an acrylic IOL with two-haptic (one-piece, 26 eyes; three-piece, 22 eyes), or four-haptic (one-piece, 22 eyes). The area of the anterior capsule opening size was measured one week postoperatively (baseline) and at three months.ResultsThere was a significant reduction in the area of the anterior capsule opening from one week as compared to three months postoperatively in all groups (p < 0.001). However, there was no significant difference in the reduction in the anterior capsule opening between the IOLs (p = 0.36).ConclusionsThe number and material of the haptic of the three acrylic IOLs did not influence the degree of anterior capsule opening shrinkage.
PurposeTo determine the relationship between the differences in the ocular component values with the degree of anisomyopia.MethodsRefraction, corneal power (CP), and biometry were examined in 50 myopic adults with refractive differences (RD) over 1.50 diopters (D). Ocular components were measured by ultrasound biometry and keratometry. The correlation between the differences in the ocular component values with the degree of anisomyopia was analyzed by linear regression analysis.ResultsAmong 50 adults with anisomyopia, 5 had RD from 1.50 to 2.99 D, 11 had RD from 3.00 to 3.99 D, 9 had RD from 4.00 to 5.99 D, 12 had RD from 6.00 to 7.99 D, 7 had RD from 8.00 to 11.99 D, and 6 had ≥12.00 D. There was no significant correlation between the ocular components (CP, crystalline lens thickness [LT], and anterior chamber depth [ACD], and the length from the cornea to the posterior surface of the lens [ACD + LT]) and the RD (p > 0.05). The RD showed a significantly positive correlation with vitreous chamber depth (VCD), and axial length (r = 0.963, p < 0.0001).ConclusionsThe severity of anisomyopia was not correlated with the between-eye differences in the anterior chamber values of the eye (CP, ACD, LT, ACD + LT). The severity of anisomyopia was significantly correlated with the between-eye differences in VCD.
Purpose: To report a case of retinal detachment surgery in a patient with oculocutaneous albinism. Case summary: A 44-year-old man visited our clinic complaining of decreased visual acuity in his left eye.His best corrected visual acuity was hand movement in his left eye, and rhegmatogenous retinal detachment involving the macula at the superior temporal site was found. We performed pars plana vitrectomy and attempted to reattach the retina using endolaser photocoagulation; however, the laser burn was not made, and we failed to reattach the retina. At that point, we carried out cryopexy around the retinal tear, and injected silicone oil into the vitreous cavity. Ten months after surgery, his best corrected visual acuity was 0.06, and there was no recurrent retinal detachment or proliferative vitreoretinopathy. Conclusions:In patients with albinism with melanin deficiency, cryopexy is more useful than laser photocoagulation for retinal detachment surgery.
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