Search

Age-related macular degeneration (AMD) is the leading cause of irreversible vision damage among elderly individuals. There is still no efficient treatment for dry AMD. Retinal pigment epithelial (RPE) degeneration has been confirmed to play an important role in dry AMD. Recent studies have reported that ferroptosis caused by iron overload and lipid peroxidation may be the primary causes of RPE degeneration. However, the upstream regulatory molecules of RPE ferroptosis remain largely unknown. Pigment epithelium-derived factor (PEDF) is an important endogenic protective factor for the RPE. Our results showed that in the murine dry AMD model induced by sodium iodate (SI), PEDF expression was downregulated. Moreover, dry AMD-like pathology was observed in PEDF-knockout mice. Therefore, the aim of this study was to reveal the effects and mechanism of PEDF on RPE ferroptosis and investigate potential therapeutic targets for dry AMD. The results of lipid peroxidation and transmission electron microscope showed that retinal ferroptosis was significantly activated in SI-treated mice and PEDF-knockout mice. Restoration of PEDF expression ameliorated SI-induced retinal dysfunction in mice, as assessed by electroretinography and optical coherence tomography. Mechanistically, western blotting and immunofluorescence analysis demonstrated that the overexpression of PEDF could upregulate the expression of glutathione peroxidase 4 (GPX4) and ferritin heavy chain-1 (FTH1), which proved to inhibit lipid peroxidation and RPE ferroptosis induced by SI. This study revealed the novel role of PEDF in ferroptosis inhibition and indicated that PEDF might be a potential therapeutic target for dry AMD. [ABSTRACT FROM AUTHOR]

Introduction: It remains unclear whether systemic factors are associated with an increased risk of vitreous hemorrhage (VH) secondary to polypoidal choroidal vasculopathy (PCV), and there is no method to predict the possibility of VH occurrence in patients with PCV. This study aimed to investigate and visualize systemic risk factors for VH in patients with PCV. Methods: Data on the sex, age, history of systematic diseases, best-corrected visual acuity, intraocular pressure, and laboratory data of patients with PCV were collected from the medical record system. Univariate and multivariate binary logistic regression analyses were applied to investigate independent risk factors for VH in patients with PCV. Receiver operating characteristic analysis and nomograms were used to visualize the independent risk factors. Results: The patient population comprised 115 patients with VH secondary to PCV and 181 patients with PCV without VH. Binary logistic regression analyses showed that higher white blood cell count [WBC; odds ratios (OR) 1.247], higher aspartate aminotransferase/alanine aminotransferase ratio (AST/ALT; OR 2.339), and longer activated partial thromboplastin time (APTT; OR 1.196) were independent risk factors of VH in patients with PCV. Integrated application of APTT, AST/ALT, and WBC as markers showed the best performance for distinguishing patients with VH, with an area under the curve of 0.723. The nomogram was created for doctors to calculate the possibility of VH in a patient with PCV. Conclusions: Higher WBC, higher AST/ALT, and longer APTT are independent serum risk factors of VH secondary to PCV, which may shed light on VH prevention in patients with PCV. [ABSTRACT FROM AUTHOR]

Purpose: To find a new approach of pan-retinal photocoagulation (PRP) with less damage to the retina in the treatment of severe non-proliferative diabetic retinopathy (NPDR), this study compared functional changes in the retina after subthreshold and threshold PRP treatment in severe NPDR eyes.Methods: Post hoc analysis of a randomized clinical trial was conducted in this study. Seventy eyes of 35 patients with bilateral, symmetric, severe NPDR were enrolled. Two eyes from the same patient were randomized into two groups, one eye received subthreshold PRP (S-PRP) and the other eye received threshold PRP (T-PRP). Comprehensive ophthalmological evaluations were performed on the baseline and every 3 months for 1 year. Visual field (VF) and full-field electroretinography (ERG) were performed on the baseline and repeated at month 12.Results: During the 12-month follow-up, 4 eyes (11.4%) in the S-PRP group and 3 eyes (8.6%) in the T-PRP group progressed to proliferative diabetic retinopathy (PDR) stage, and there was no statistical difference in PDR progression rate between the two groups (P = 0.69). In addition, the changes in best-corrected visual acuity (BCVA) from baseline to month 12 between the two groups had no statistical difference (P = 0.30). From baseline to month 12, changes in central VF between the two groups had no statistical difference (P = 0.25), but changes in total score points of peripheral VF in the S-PRP group (- 242.1 ± 210.8 dB) and the T-PRP group (- 308.9 ± 209.7 dB) were statistically significant (P = 0.03). At month 12, ERG records showed that the amplitude of dark-adapted 0.01 ERG, dark-adapted 3.0 ERG, oscillatory potentials, light-adapted 3.0 ERG, and 30 Hz flicker ERG of both groups were significantly decreased from the baseline (P < 0.05). In addition, the amplitude of each ERG record in the S-PRP group decreased significantly less than those in the T-PRP group (P < 0.05).Conclusions: Subthreshold PRP is as effective as threshold PRP for preventing severe NPDR progress to PDR within 1 year with less damage to periphery VF and retinal function.Trial Registration: Clinicaltrials: gov Identifier: NCT01759121. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the dynamic changes and possible affecting variables of outer retinal microstructure in macular area of central serous chorioretinopathy (CSC) patients. Methods: This was a retrospective study. The data of optical coherence tomography (OCT) and autofluoroscopy (AF) of 36 CSC patients admitted to our hospital from February 2012 to February 2013 were included. Dynamic variations and possible correlated variables of central retinal thickness (CRT), subretinal fluid diameter (SRFD), ellipsoid zone (EZ), interdigitation zone (IZ) and/or hyperautofluorescent spot (HAS) were analyzed. Results: The outer retinal microstructure was gradually restored along with the subretinal fluid absorption during the follow-up. EZ in 94.4% (34/36) and the IZ in 100% (36/36) eyes were completely disappeared at baseline and restored (completed or incomplete) in 88.9% (8/9) and 44.4% (4/9) eyes, respectively, after 6-month follow-up. HAS was evident in 25% eyes (8/32 eyes) at baseline, and the density was initially increased and then declined during follow-up. Correlation analysis demonstrated that the restoration of EZ and IZ was correlated with the restoration period and subretinal fluid absorption. Conclusion: The outer retinal microstructure was restored during the subretinal fluid absorption in CSC patients, with EZ restored earlier than IZ. The restoration period and the absorption of subretinal fluid were two closely correlated variables of macular microstructure restoration. [ABSTRACT FROM AUTHOR]

To compare the efficacy of 50% threshold power with 25% threshold power of 577-nm subthreshold micropulse laser (SMPL) for acute central serous chorioretinopathy (CSC). Prospective, interventional, non-randomized, comparative case series. A total of 54 patients (54 eyes) with acute CSC were enrolled. Twenty-four eyes received 25% threshold power and 30 eyes received 50% threshold power of 577-nm SMPL. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and complete absorption of subretinal fluid (SRF) were evaluated at 1 month and 3 months. The complete absorption rate of SRF in the 50% power group was significantly greater than that in the 25% power group at 1 month (70.0% vs 25.0%, p < 0.001) and at 3 months (83.3% vs 54.2%, p < 0.001). Mean BCVA improved from 0.34 ± 0.20 LogMAR to 0.02 ± 0.13 LogMAR in the 50% power group and from 0.27 ± 0.15 LogMAR to 0.14 ± 0.21 LogMAR in the 25% power group with a significant difference between the two groups after 3 months (p = 0.027). In the 50% power group, the CMT decreased from 491.6 ± 154.8 μm at baseline to 231.3 ± 92.3 μm at 1 month and 228.2 ± 88.1 μm at 3 months, and in the 25% power group, the CMT decreased from 444.9 ± 164.1 to 306.8 ± 102.6 μm at 1 month and 254.5 ± 101.7 μm at 3 months. There was statistical difference of CMT at 1 month (p = 0.009) but no significant difference at 3 months between the two groups (p = 0.232). SMPL with 50% threshold power may be more effective than 25% threshold power for acute CSC. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the safety and efficacy of intravitreal injection of Tc-MDP, a decay product of Tc-MDP, on the development of laser-induced choroidal neovascularization (CNV) in rhesus monkeys. Methods: Experimental CNV was induced by argon laser with a small high-energy laser spot. Monkeys were given 50 μL of Tc-MDP at a concentration of 0.005 μg/mL ( n = 6) or 0.01 μg/mL ( n = 6) by intravitreal injection once a week immediately after laser injury for a period of 56 days. Control animals were treated with the same volume of PBS ( n = 6) in the same way. Eyes were monitored by ophthalmic examination, color fundus photography, fluorescence fundus angiography (FFA), optical coherence tomography (OCT) and histology. Incidences of grade 4 CNV lesions as well as the leakage areas of grade 4 CNVs on the late-phase of fluorescein angiograms were measured in a standardized, randomized and masked fashion fortnightly. The maximum widths and heights of grade 4 CNVs were also calculated by histology at the end of the experiment. Toxicity of Tc-MDP on the retina was evaluated by electroretinogram (ERG) and histologic analysis. Results: Tc-MDP reduced the incidences of grade 4 CNVs by 33.33 % and 39.40 % in the 0.005 μg/mL and 0.01 μg/mL groups, respectively, compared with the PBS group on day 28 ( P < 0.05; n = 6). The leakage areas of grade 4 CNVs were smaller in the 0.005 μg/mL (0.7136 ± 0.0283 mm, p <0.01; n = 6) and 0.01 μg/mL (0.4351 ± 0.0349 mm, p < 0.01; n = 6) groups than those in the PBS control group (0.9373 ± 0.0455 mm; n = 6) in a dose-dependent manner on day 28. OCT and histology also showed that the sizes of CNVs were smaller in the Tc-MDP treated groups than those in the PBS group. Although intravitreal injection of Tc-MDP led to mild inflammatory reaction in the anterior chamber, histology and ERG findings demonstrated that Tc-MDP did not cause any change in histological structure or function of the retina ( p>0.05). Conclusions: Intravitreal injection of Tc-MDP can inhibit the development of laser-induced CNV without toxic effect on retina, suggesting that Tc-MDP has therapeutic potential for CNV related diseases. [ABSTRACT FROM AUTHOR]