Browsing by Author "Arevalo, J. Fernando"
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- ItemEnhanced oxidative stress and other potential biomarkers for retinopathy in type 2 diabetics : beneficial effects of the nutraceutic supplements(Hindawi, 2015) Roig-Revert, Maria J.; Lleo-Perez, Antonio; Zanon-Moreno, Vicente; Vivar-Llopis, Barbara; Marin-Montiel, Juan; Dolz-Marco, Rosa; Alonso-Munoz, Luis; Albert-Fort, Mara; Lopez-Galvez, Maria I.; Galarreta-Mira, David; Garcia-Esparza, Maria F.; Galbis-Estrada, Carmen; Marco-Ramirez, Carla; Shoaie-Nia, Kian; Sanz-Gonzalez, Silvia M.; Vila-Bou, Vicente; Bendala-Tufanisco, Elena; Garcia-Medina, Jose J.; Nucci, Carlo; Gallego-Pinazo, Roberto; Arevalo, J. Fernando; Pinazo-Duran, Maria D.; Valencia Study on Diabetic Retinopathy (VSDR)We have studied the global risk of retinopathy in a Mediterranean population of type 2 diabetes mellitus (T2DM) patients, according to clinical, biochemical, and lifestyle biomarkers. The effects of the oral supplementation containing antioxidants/omega 3 fatty acids (A/ω3) were also evaluated. Suitable participants were distributed into two main groups: (1) T2DMG (with retinopathy (+DR) or without retinopathy (−DR)) and (2) controls (CG). Participants were randomly assigned (+A/ω3) or not (−A/ω3) to the oral supplementation with a daily pill of Nutrof Omega (R) for 18 months. Data collected including demographics, anthropometrics, characteristics/lifestyle, ophthalmic examination (best corrected visual acuity, ocular fundus photographs, and retinal thickness as assessed by optical coherence tomography), and blood parameters (glucose, glycosylated hemoglobin, triglycerides, malondialdehyde, and total antioxidant capacity) were registered, integrated, and statistically processed by the SPSS 15.0 program. Finally, 208 participants (130 diabetics (68 +DR/62 −DR) and 78 controls) completed the follow-up. Blood analyses confirmed that the T2DMG+DR patients had significantly higher oxidative stress , inflammatory , and vascular risk markers than the T2DMG−DR and the CG. Furthermore, the A/ω3 oral supplementation positively changed the baseline parameters, presumptively by inducing metabolic activation and ameliorating the ocular health after 18 months of supplementation.
- ItemIntravitreal Bevacizumab as anti-vascular endothelial growth factor in the management of complications of diabetic retinopathy(Stellenbosch : Stellenbosch University, 2018-12) Arevalo, J. Fernando; Meyer, David; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medicine: Clinical Pharmacology.ENGLISH ABSTRACT: Bevacizumab is a complete full-length humanized antibody that binds to all subtypes of vascular endothelial growth factor (VEGF) and is used successfully in tumor therapy as a systemic drug. Recent studies have demonstrated the usefulness of an intravitreal injection of bevacizumab (IVB) in the reduction of macular edema secondary to central retinal vein occlusion, and choroidal neovascularization secondary to age-related macular degeneration (AMD). The drug is extremely cost-effective compared to similar anti-VEGF drugs on the market, hence the need to examine its effect in diabetic eye disease (the ever-growing global health epidemic challenge) for application in middle to low income countries. The purpose of the current research is to determine if intravitreal bevacizumab (IVB) as anti-VEGF is helpful in the management of complications of diabetic retinopathy. We conducted several multicenter retrospective studies of eyes with complications from diabetic retinopathy treated with off-label IVB. Ten previously published studies (one prospective), and one unpublished prospective study are included here on the management of diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). We progressively reported over the years our experienced as we followed patients with DME treated with IVB at 6 months, 12 months, and 24 months of follow up. In addition, 5 year follow up data was added later on. We found that primary IVB at doses of 1.25 to 2.5 mg seem to provide stability or improvement in best correct visual acuity (BCVA), optical coherence tomography (OCT), and fluorescein angiography (FA) in diffuse DME at 24 months. The results show no evident difference between IVB at doses of 1.25 or 2.5 mg. However, the early visual gains due to IVB were not maintained 5 years after treatment. Later, we provide evidence to support the use of primary IVB with or without grid laser photocoagulation (GLP) as treatment of diffuse DME. Primary IVB without GLP seems to be superior to GLP alone to provide stability or improvement in best-corrected visual acuity in patients with diffuse diabetic macular edema at 24 months. We showed first that IVB resulted in marked regression of retinal neovascularization (RN) in patients with PDR and previous pan retinal photocoagulation (PRP), and rapid resolution of vitreous hemorrhage in three naive eyes. Six-months results of intravitreal bevacizumab at doses of 1.25 or 2.5 mg in patients with PDR did not reveal any safety concerns. Later, we published that IVB resulted in marked regression of RN in patients with PDR and previous pan-retinal photocoagulation at 2 years. Intravitreal bevacizumab in naive eyes resulted in control or regression of 42.1% of eyes without adjunctive laser or vitrectomy during 24 months of follow-up. Meaning that a large number of patients (almost 58%) needed PRP or vitrectomy. Another one of our studies demonstrated the usefulness of using preoperative IVB during small-gauge vitreoretinal surgery in eyes with tractional retinal detachment (TRD) in PDR. This was a prospective non-comparative study and patients had significant anatomic and functional success. In addition, we reported for the first time ever that TRD may occur or progress shortly following administration of IVB in patients with severe PDR (5.2% and 3.2% in two studies). Based on our data, we now believe that extreme care must be taken in using a dose of 2.5 mg or more of bevacizumab in patients with PDR. In addition, to have more than 15 years with a diagnosis of diabetes can increase the risk of TRD. Physicians must be prepared to perform the vitrectomy preferably before 13 days after the application of IVB and to perform a vitrectomy immediately on those patients in whom a TRD occurs. We recommend less than 5 days after injection as more than 80% of the retinal detachments developed after that period of time. Finally, in our prospective randomized clinical trial, pre-operative intravitreal bevacizumab therapy as adjuvant to PPV may be helpful and beneficial for patients with TRD secondary to severe PDR. Pre-operative IVB seems to reduce intraoperative bleeding, improving surgical visual field visualization, and reducing intraoperative and postoperative complications including iatrogenic retinal breaks and postoperative hemorrhage. In summary, IVB as anti-VEGF agent is helpful in the management of complications of diabetic retinopathy to prevent blindness with a more accessible drug worldwide.
- ItemSmall-gauge pars plana vitrectomy for the management of symptomatic posterior vitreous detachment after phacoemulsification and multifocal intraocular lens implantation : a pilot study from the Pan-American Collaborative Retina Study Group(Hindawi, 2015-08) Navarro, Rodrigo M.; Machado, Leonardo M.; Maia Jr., Ossires; Wu, Lihteh; Farah, Michel E.; Magalhaes Jr., Octaviano; Arevalo, J. Fernando; Maia, MauricioPurpose. To determine the efficacy of 23-gauge pars plana vitrectomy (PPV) for symptomatic posterior vitreous detachment (PVD) on visual acuity (VA) and quality after multifocal intraocular lenses (IOLs). Methods. In this prospective case series, patients who developed symptomatic PVD and were not satisfied with visual quality due to floaters and halos after multifocal IOL implantation underwent PPV. Examinations included LogMAR uncorrected visual acuity (UCVA), intraocular pressure, biomicroscopy, and indirect ophthalmoscopy at baseline and 1, 7, 30, and 180 days postoperatively. Ultrasonography and aberrometry were performed. The Visual Functioning Questionnaire 25 (VFQ-25) was administered preoperatively and at 30 days postoperatively. Both the postoperative UCVA and questionnaire results were compared to preoperative findings using the Wilcoxon test. Results. Sixteen eyes of 8 patients were included. VA significantly improved from 0.17 to 0.09 postoperatively (𝑃 = 0.017). All patients reported improvement of halos, glare, and floaters. VFQ-25 scores significantly improved in general vision (𝑃 = 0.023), near activities (𝑃 = 0.043), distance activities (𝑃 = 0.041), mental health (𝑃 = 0.011), role difficulties (𝑃 = 0.042), and driving (𝑃 = 0.016). Conclusion. PPV may increase UCVA and quality of vision in patients with bilateralmultifocal IOLs and symptomatic PVD. Larger studies are advised