HIF-1α-dependent upregulation of angiogenic factors by mechanical stimulation in retinal pigment epithelial cells.

Mechanical stimulation as a mimic of drusen formation in the eye increases the expression of angiogenic factors in retinal pigment epithelial (RPE) cells, but the underlying molecular mechanisms remain unclear. We investigated and characterized the effects of mechanical stimulation on the expression of angiogenic factors in RPE cells both in vitro and in a mouse model. Mechanical stimulation increased the expression of vascular endothelial growth factor (VEGF, encoded by VEGFA) and other angiogenesis-related genes in cultured RPE1 cells. The presence of hypoxia-inducible factor 1α (HIF-1α, encoded by HIF1A) was also increased, and both knockdown of HIF-1α and treatment with the HIF-1α inhibitor CAY10585 attenuated the effect of mechanical stimulation on angiogenesis factor gene expression. Signaling by the tyrosine kinase SRC and p38 mitogen-activated protein kinase was involved in HIF-1α activation and consequent angiogenesis-related gene expression induced by mechanical stimulation. Our results suggest that SRC-p38 and HIF-1α signaling are involved in the upregulation of angiogenic factors in RPE cells by mechanical stimulation. Such in vivo suppression of upregulated expression of angiogenesis-related genes by pharmacological inhibitors of HIF-1α suggests a new potential approach to the treatment of age-related macular degeneration.

Treatment of Failure of Macular Hole Closure due to Post-Vitrectomy Macular Edema Using Sub-Tenon Triamcinolone Acetonide Injection: A Case Report.

Introduction: Post-vitrectomy cystoid macular edema (CME) can lead to failure of macular hole (MH) closure. We report 2 cases of failure of MH closure due to post-vitrectomy CME, which were successfully treated using sub-Tenon triamcinolone acetonide (STTA) injection. Case Presentations: Case 1 involved a 72-year-old male patient with a Gass Stage 3 MH in the right eye. He underwent pars plana vitrectomy (PPV), internal limiting membrane translocation, and sulfur hexafluoride (SF6) gas injection with cataract surgery in his right eye. The MH did not close postoperatively; further, CME developed at the edge of the MH. Accordingly, the patient underwent an STTA injection. Approximately 2 weeks after the STTA injection, the CME disappeared and the MH closed, which has remained closed 1 year after PPV. Case 2 involved a 78-year-old female patient with Gass Stage 3 MH in the left eye. The patient underwent the same surgical procedure as that performed in case 1. Further, she presented with failure of MH closure caused by CME; therefore, an STTA injection was performed. Approximately 6 weeks after STTA injection, the CME disappeared and the MH closed; further, there was maintained improvement of best-corrected visual acuity for 6 months. Conclusions: STTA injection could be considered before reoperation in cases involving failure of MH closure due to postoperative CME.

Exacerbation of Diabetic Retinopathy following Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitor Administration: A Case Report.

Introduction: Hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors, used in the treatment of renal anemia, hold the potential to increase the production of vascular endothelial growth factors. Therefore, HIF-PH inhibitors may exacerbate retinal hemorrhage in diseases such as diabetic retinopathy. Here, we present a case involving the administration of an HIF-PH inhibitor, resulting in the exacerbation of retinal hemorrhage in a patient with diabetic retinopathy. Case Presentation: A 32-year-old man with diabetes mellitus and renal anemia caused by diabetic nephropathy was referred to our department for ophthalmic examination, revealing diabetic retinopathy with scattered retinal hemorrhages, exudates, and diabetic maculopathy in both eyes. Darbepoetin alfa was initially administered and switched to the HIF-PH inhibitor roxadustat on day 74. By day 88, fresh retinal hemorrhage was observed in the right eye. On day 132, the retinal hemorrhage had further worsened, with new preretinal hemorrhage in both eyes. Roxadustat was discontinued, replaced with darbepoetin alfa, resulting in retinal hemorrhage improvement by day 181 (49 days post-roxadustat cessation). On day 201, fundus hemorrhage further improved, optical coherence tomography showed no macular edema or subretinal fluid, and the retina was thinning. Fluorescein angiography showed neovascular vessels, active fluorescein leakage, and extensive avascular areas in both eyes, prompting pan-retinal photocoagulation. Visual acuity remained stable throughout treatment. Conclusion: Patients with advanced diabetic retinopathy taking HIF-PH inhibitors should be aware of retinal hemorrhage exacerbations. If observed, the treatment plan, including discontinuation of the HIF-PH inhibitor or switching to another agent, should be discussed with a diabetologist, nephrologist, and ophthalmologist.

Risk Factors for Legal Blindness in 237 Japanese Patients with Exogenous Endophthalmitis: A Multicenter Cohort Study from J-CREST.

PURPOSE: We investigated potential risk factors for visual prognosis in Japanese patients with exogenous endophthalmitis. METHODS: In this retrospective observational multicenter cohort study, risk factors for legal blindness at 12 weeks after treatment initiation were evaluated based on patient characteristics, initial BCVA, causative events, pathogens, ocular symptoms, duration from symptom onset to initial treatment, and selected treatments. RESULTS: Overall, 23.1% of eyes developed legal blindness. The six risk factors for legal blindness were presence of eye pain, pathogen identification, poor BCVA at the initial visit, longer duration from symptom onset to initial treatment, type of causative event, and type of causative pathogen. Regarding the type of causative pathogen, coagulase-negative staphylococci was associated with a better visual impairment outcome. CONCLUSION: Exogenous endophthalmitis remains a severe ocular infection; however, it can be managed with rapid treatment, as well as other advances in medical knowledge and technology.

Risk Factors for Legal Blindness in 77 Japanese Patients with Endogenous Endophthalmitis: A Multicenter Cohort Study from J-CREST.

PURPOSE: We investigated potential predictive factors for visual prognosis in Japanese patients with endogenous endophthalmitis. DESIGN: Retrospective observational multicenter cohort study. METHODS: We examined the characteristics of 77 Japanese patients with endogenous endophthalmitis and performed statistical analyses of these real-world data. The primary endpoint was the identification of factors associated with visual prognosis. We examined differences between patients in the better vision and legal blindness groups at 12 weeks after treatment initiation. RESULTS: The five risk factors for visual impairment at 12 weeks after treatment initiation were presence of pressure injuries, severe clinical symptoms (presence of eye pain and ciliary injection), pathogen identification, and poor best-corrected visual acuity at baseline. Staphylococcus aureus and fungus were associated with a better visual impairment outcome. CONCLUSIONS: Endogenous endophthalmitis remains a severe ocular infection; however, it can be managed with rapid treatments, as well as other advances in medical knowledge and technology.

Evaluation of microaneurysms as predictors of therapeutic response to anti-VEGF therapy in patients with DME.

Administration of intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy is the first-line therapy for diabetic macular oedema (DME). However, some patients show no or insufficient response to repeated anti-VEGF injections. Therefore, it is necessary to identify factors that can predict this resistance against anti-VEGF treatment. Presence of microaneurysms (MAs) is a predictor of the development and progression of DME, but its relationship with the treatment response to the anti-VEGF agents is not well known. Therefore, we aimed to elucidate the relationship between the distribution of MAs and the response to anti-VEGF therapy in patients with DME. The number of MAs was measured before anti-VEGF therapy in each region using fluorescein angiography, indocyanine green angiography (IA), and optical coherence tomography angiography. Patients with DME were divided into the responder and non-responder groups after three loading phases. Differences in the distribution of MAs between the groups were investigated. Pre-treatment IA revealed more MAs in the nasal area in the non-responder group than in the responder group (10.7 ± 10.7 and 5.7 ± 5.7, respectively, in the nasal macula) (1.4 ± 2.1 and 0.4 ± 0.7, respectively, in the nasal fovea). Whereas, pre-treatment FA and OCTA could not reveal significantly difference between the groups. Detection of MAs in the nasal macula using pre-treatment IA may indicate resistance to anti-VEGF therapy. We recommend the clinicians confirm the presence of MAs in the nasal macula, as shown by IA, as a predictor of therapeutic response to anti-VEGF therapy in patients with treatment naive DME.

Evaluation of corneal hysteresis after pars plana vitrectomy combined phacoemulsification and intraocular lens implantation.

We evaluated the early effects of pars plana vitrectomy (PPV) on corneal biomechanics by comparing corneal hysteresis (CH) after cataract surgery (phacoemulsification and aspiration with intraocular lens implantation; PEA + IOL) alone and PPV combined with cataract surgery. This study included 20 eyes (18 patients), who underwent cataract surgery alone (PEA + IOL group), and 28 eyes (27 patients) who underwent PPV combined with cataract surgery (PPV triple group). The CH was 11.1 ± 1.1, 10.4 ± 1.1, and 11.0 ± 1.0 mmHg in the PEA + IOL group and 11.0 ± 1.4, 9.8 ± 1.4, and 10.6 ± 1.6 mmHg in the PPV triple group, preoperatively, at 2 weeks, and 3 months after surgery, respectively. The CH was not significantly different after surgery in the PEA + IOL group, but decreased significantly in the PPV triple group 2 weeks following surgery (p < 0.01). Intraocular pressure (IOP) and central corneal thickness (CCT) did not change significantly after surgery in either group. Preoperatively, there was a positive correlation between CH and CCT in the PPV triple group, but the correlation disappeared postoperatively. In PPV combined with cataract surgery, CH temporarily decreased postoperatively, independent of IOP and CCT. Removal of the vitreous may reduce the elasticity and rigidity of the entire eye.

Simultaneous Vitreoretinal Surgery and Sclerokeratoplasty for Keratoglobus with Intraocular Hemorrhage and Extensive Corneal Rupture.

We reported a case of simultaneous vitrectomy and sclerokeratoplasty (SKP) performed for keratoglobus with extensive corneal rupture and intraocular hemorrhage caused by trauma. A 73-year-old woman was treated for keratoglobus and glaucoma. She was punched in both eyes, her right eye showed corneal rupture and the left eye showed prolapse of the ocular contents due to eyeball rupture. She immediately underwent corneal sutures in the right eye and resection of the prolapsed ocular contents in the left eye at a nearby ophthalmological clinic. Three days after the injury, the patient was referred to our clinic for vision recovery. The best corrected visual acuity of the right eye was measured by counting fingers. Her right eye presented severe corneal edema with a sutured corneal wound in the upper periphery, which was positive in the Seidel test. B-mode ultrasound revealed choroidal detachment and subchoroidal hemorrhage. Fourteen days after injury, simultaneous corneal suture and posterior sclerotomy were performed in the right eye, but corneal fragility and corneal opacity were prominent, and B-mode examination revealed prolonged vitreous hemorrhage and retinal detachment. Twenty-one days after injury, we performed simultaneous SKP and 25-G pars plana vitrectomy (PPV). In this procedure, we initially performed SKP followed by 25-G PPV without a keratoprosthesis or endoscope. The visibility of the fundus through the corneoscleral graft was good during vitrectomy. Three months after surgery, her corrected visual acuity improved to 10/1,000. Although there was mild corneal stromal edema and khodadoust line, there were no obvious fundus complications. Simultaneous SKP and PPV for keratoglobus with extensive corneal rupture and vitreous diseases may be a good option.

Retinal Pigment Epithelial Detachment Associated with Immunoglobulin A Nephropathy: A Case Report.

Uveitis and scleritis are eye diseases associated with immunoglobulin A (IgA) nephropathy, but reports on retinal pigment epithelial detachment (PED) in relation to IgA nephropathy are scarce. We have experienced a case of PED associated with IgA nephropathy that was improved by pulse steroid treatment. A 68-year-old woman underwent examination for visual loss in the right eye. Her corrected visual acuity was 20/20 on both sides, and serous PED was observed in both eyes. One month later, the PED improved in both eyes but recurred 3 months later. Results of blood examination raised suspicion of IgA nephropathy, and she was referred to a nephrologist. Two weeks later, the PED in both eyes worsened, and a retinal pigment epithelium (RPE) tear appeared in the right eye. A sub-Tenon's injection of triamcinolone acetonide was performed to address the PED, but it was not effective; thus, pulse steroid therapy was performed twice. The PED disappeared from both eyes, and the visual acuity in her left eye was maintained at 20/20, but it decreased to 20/200 in her right eye due to macular atrophy after the RPE tear. The PED had not recurred despite having no improvement in renal function. In conclusion, in IgA nephropathy, deposition of immune complexes on the RPE causes its inflammation, which may lead to PED. In cases of unexplained PED, the possibility of a systemic disease as the cause should be considered.

Intravitreal Tissue Plasminogen Activator Injection for Treatment-Resistant Diabetic Macular Edema of the Vitrectomized Eye.

Diabetic macular edema (DME) is the main cause of visual loss in patients with diabetic retinopathy. DME has been treated using intravitreal anti-vascular endothelial growth factor (VEGF) drugs, steroids, laser photocoagulation, vitreoretinal surgery, and their combinations. These modalities are generally effective in preserving vision, but they sometimes produce only limited responses in patients with persistent or refractory DME. The levels of various inflammatory factors, including cytokines, chemokines, and extracellular matrices, as well as VEGF in the vitreous fluid, are increased in patients with DME. Excessive fibrinogen/fibrin levels in the vitreous fluid or fibrin deposition in the retina also contribute to DME pathogenesis. Tissue plasminogen activator (t-PA) promotes the degradation of fibrinogen or fibrin. Intravitreal t-PA injection is a commonly used treatment for subretinal hemorrhage secondary to age-related macular degeneration. Intravitreal t-PA injections have previously been used to restore vision by inducing posterior vitreous detachment in patients with DME. Herein, we describe the visual outcomes of intravitreal t-PA injection in a 78-year-old woman with treatment-resistant DME in her vitrectomized eye after several previous treatments. Before the injection, her best-corrected visual acuity (BCVA) was 0.7 logMAR and central foveal retinal thickness (CRT) was 735 µm. At 1 month after the injection, her BCVA was 0.8 logMAR and CRT was 558 µm, and 3 months later, her BCVA was 0.8 logMAR and CRT was 207 µm. Her BCVA was sustained, and CRT showed gradual improvements. These findings suggested the effectiveness of intravitreal t-PA injections for DME in the vitrectomized eye.

Early manifestations and differential gene expression associated with photoreceptor degeneration in Prom1-deficient retina.

Retinitis pigmentosa (RP) and macular dystrophy (MD) are characterized by gradual photoreceptor death in the retina and are often associated with genetic mutations, including those in the prominin-1 (Prom1) gene. Prom1-knockout (KO) mice recapitulate key features of these diseases including light-dependent retinal degeneration and constriction of retinal blood vessels. The mechanisms underlying such degeneration have remained unclear, however. We here analysed early events associated with retinal degeneration in Prom1-KO mice. We found that photoreceptor cell death and glial cell activation occur between 2 and 3 weeks after birth. Whereas gene expression was not affected at 2 weeks, the expression of several genes was altered at 3 weeks in the Prom1-KO retina, with the expression of that for endothelin-2 (Edn2) being markedly upregulated. Expression of Edn2 was also induced by light stimulation in Prom1-KO mice reared in the dark. Treatment with endothelin receptor antagonists attenuated photoreceptor cell death, gliosis and retinal vessel stenosis in Prom1-KO mice. Our findings thus reveal early manifestations of retinal degeneration in a model of RP/MD and suggest potential therapeutic agents for these diseases. This article has an associated First Person interview with the first author of the paper.

Benzalkonium chloride-induced myofibroblastic transdifferentiation of Tenon's capsule fibroblasts is inhibited by coculture with corneal epithelial cells or by interleukin-10.

Benzalkonium chloride (BAC) is used as a preservative in eyedrops but induces subconjunctival fibrosis that can result in failure of glaucoma surgery. Tenon's capsule fibroblasts in subconjunctival tissue interact with the corneal epithelium through tear fluid. With the use of a coculture system, we have now investigated the effect of human corneal epithelial (HCE) cells on myofibroblastic transdifferentiation of human Tenon fibroblasts (HTFs) induced by BAC (5 × 10-6%). Immunofluorescence and immunoblot analyses revealed that the BAC-induced expression of α smooth muscle actin (αSMA) in HTFs was suppressed by coculture of these cells with HCE cells (p < 0.01). The concentration of interleukin-10 (IL-10) in culture supernatants of BAC-treated HTFs was increased by coculture with HCE cells (17.26-fold, vs. coculure, p < 0.001). Immunofluorescence and immunoblot analyses also showed that exogenous IL-10 (300 pg/ml) suppressed the BAC-induced expression of αSMA by 43.65% (p < 0.05) as well as the nuclear translocation of myocardin-related transcription factor-A (MRTF-A) by 39.32% (p < 0.01) in HTFs cultured alone. Our findings suggest that corneal epithelial cells may protect against subconjunctival fibrosis by maintaining IL-10 levels and preventing the MRTF-A-dependent transdifferentiation of HTFs into myofibroblasts.

Inhibition of epithelial-mesenchymal transition in retinal pigment epithelial cells by a retinoic acid receptor-α agonist.

Epithelial-mesenchymal transition (EMT) in retinal pigment epithelial (RPE) cells plays a key role in proliferative retinal diseases such as age-related macular degeneration by contributing to subretinal fibrosis. To investigate the potential role of retinoic acid receptor-α (RAR-α) signaling in this process, we have now examined the effects of the RAR-α agonist Am580 on EMT induced by transforming growth factor-ß2 (TGF-ß2) in primary mouse RPE cells cultured in a three-dimensional type I collagen gel as well as on subretinal fibrosis in a mouse model. We found that Am580 inhibited TGF-ß2-induced collagen gel contraction mediated by RPE cells. It also attenuated the TGF-ß2-induced expression of the mesenchymal markers α-smooth muscle actin, fibronectin, and collagen type I; production of pro-matrix metalloproteinase 2 and interleukin-6; expression of the focal adhesion protein paxillin; and phosphorylation of SMAD2 in the cultured RPE cells. Finally, immunofluorescence analysis showed that Am580 suppressed both the TGF-ß2-induced translocation of myocardin-related transcription factor-A (MRTF-A) from the cytoplasm to the nucleus of cultured RPE cells as well as subretinal fibrosis triggered by laser-induced photocoagulation in a mouse model. Our observations thus suggest that RAR-α signaling inhibits EMT in RPE cells and might attenuate the development of fibrosis associated with proliferative retinal diseases.

Clinical Characteristics and Outcomes in 314 Japanese Patients with Bacterial Endophthalmitis: A Multicenter Cohort Study from J-CREST.

Bacterial endophthalmitis is an intraocular infection that causes rapid vison loss. Pathogens can infect the intraocular space directly (exogenous endophthalmitis (ExE)) or indirectly (endogenous endophthalmitis (EnE)). To identify predictive factors for the visual prognosis of Japanese patients with bacterial endophthalmitis, we retrospectively examined the bacterial endophthalmitis characteristics of 314 Japanese patients and performed statistics using these clinical data. Older patients, with significantly more severe clinical symptoms, were prevalent in the ExE group compared with the EnE group. However, the final best-corrected visual acuity (BCVA) was not significantly different between the ExE and EnE groups. Bacteria isolated from patients were not associated with age, sex, or presence of eye symptoms. Genus Streptococcus, Streptococcus pneumoniae, and Enterococcus were more prevalent in ExE patients than EnE patients and contributed to poor final BCVA. The presence of eye pain, bacterial identification, and poor BCVA at baseline were risk factors for final visual impairment.

A Trinity regimen with aflibercept for treatment-naïve neovascular age-related macular degeneration: 2-year outcomes.

PURPOSE: To evaluate the advantages of the Trinity regimen for treatment-naïve neovascular age-related macular degeneration (nAMD). METHODS: Thirty-one treatment-naïve nAMD eyes were treated using the Trinity regimen with an intravitreal aflibercept injection (IVA) and evaluated after 24 months. Three treatment methods, pro re nata (PRN), treat and extend (TAE), and fixed regimen were changed depending on recurrence frequency. After the initial treatment, PRN or TAE (started for 4 or 8 weeks) was selected as per the recurrence interval. Subsequently, the recurrence interval became constant, transitioning from a TAE to fixed regimen. When the recurrence frequency became irregular, the treatment regimen was changed to TAE. RESULTS: After the initial treatment, 15 eyes (48.4%) were allocated to the PRN group, 12 (38.7%) to the TAE 8-week group, and 4 (12.9%) to the TAE 4-week group. Mean logMAR significantly improved in all cases, 0.53 ± 0.40 at baseline to 0.36 ± 0.34 at 24 months (p < 0.01), in the PRN group (0.63 ± 0.46 to 0.42 ± 0.43, p < 0.01), and the TAE 8-week group (0.44 ± 0.29 to 0.27 ± 0.19, p < 0.05). LogMAR in the TAE 4-week group was maintained. The mean number of injections for all and in the PRN, TAE 8-week, and TAE 4-week groups were 9.7, 5.3, 13.1, and 15.8, respectively, with the PRN group being significantly less (p < 0.01). CONCLUSION: The Trinity regimen delivered the benefits of the PRN, TAE, and FIXED regimens while minimizing injections during the early treatment phase without visual loss. TRIAL REGISTRATION: This trial was registered with the University Hospital Medical Information Network (UMIN ID: 000038335).