Contrast is the differential luminance between one object and another. Contrast sensitivity (CS) quantifies the ability to detect this difference: estimating contrast threshold provides information about the quality of vision and helps diagnose and monitor eye diseases. High contrast visual acuity assessment is traditionally performed in the eye care practice, whereas the estimate of the discrimination of low contrast targets, an important complementary task for the perception of details, is far less employed. An example is driving when the contrast between vehicles, obstacles, pedestrians, and the background is reduced by fog. Many conditions can selectively degrade CS, while visual acuity remains intact. In addition to spatial CS, “temporal” CS is defined as the ability to discriminate luminance differences in the temporal domain, i.e., to discriminate information that reaches the visual cortex as a function of time. Likewise, temporal sensitivity of the visual system can be investigated in terms of critical fusion frequency (CFF), an indicator of the integrity of the magnocellular system that is responsible for the perception of transient stimulations. As a matter of fact, temporal resolution can be abnormal in neuro-ophthalmological clinical conditions. This paper aims at considering CS and its application to the clinical practice.
Abstract: We reviewed randomized controlled trials associated with the intravitreal use of aflibercept for this article. These studies proved that aflibercept is an effective anti-vascular endothelial growth factor agent for the treatment of neovascular age-related macular degeneration (nAMD), myopic choroidal neovascularization (mCNV), diabetic macular edema (DME), and macular edema associated with retinal vein occlusion. The incidence of severe ocular or systemic complications after intravitreal administration of aflibercept was low.
Abstract: High speed and small gauge vitrectomy systems have made surgical intervention in complications of diabetic retinopathy (DR) safer. The availability of anti-vascular endothelial growth factor (anti-VEGF) compounds for use in DR has significantly improved intraoperative and postoperative outcomes. This review discusses the indications for surgical intervention in DR. The role of anti-VEGF compounds is discussed as surgical adjuvants with an emphasis on timing of treatment before surgery.
Abstract: Diabetic retinopathy (DR) is a complex multifactorial disease and one of the leading causes of visual impairment worldwide. DR pathogenesis is still not completely understood and, even if studies performed in the past focused on microvascular dysfunction as the main event, growing body of scientific evidence has demonstrated an important role of inflammation and neurodegeneration in the onset and progression of DR. This review summarizes current literature on the role of inflammation in the pathogenesis and progression of DR. In particular, it focuses on clinical inflammatory biomarkers detectable with non-invasive retinal imaging, suggestive of a local inflammatory condition. Current available treatments are applicable only at advanced stages of disease, therefore, there is the need to detect biomarkers of subclinical or early DR that can help in DR management before irreversible damage occurs. A better understanding of inflammatory pathways involved in DR may permit to implement more specific and personalized therapeutic strategies and clinical biomarkers may be a helpful tool in the everyday clinical practice to direct the patient to the most appropriate treatment option.
Background: To measure the anterior and posterior segment structural features of acute primary angle-closure (APAC) eyes.
Methods: A total of 36 subjects with unilateral APAC were recruited in this study. The ocular biometric characteristics were measured by anterior segment optical coherence tomography (AS-OCT) and swept source optical coherence tomography (SS-OCT), respectively at baseline, 2 weeks, and 1 month after surgical intervention.
Results: At baseline, when compared with the fellow eyes, APAC-affected eyes showed significantly greater corneal thickness (P=0.004), shallower anterior chamber depth (ACD) (P<0.001), smaller anterior chamber area (ACA) (P=0.013), angle opening distance at 750 μm from the scleral spur (AOD750) (P=0.002), trabecular–iris space area at 750 μm from the scleral spur (TISA750) (P=0.033), angle recess area (ARA) (P=0.014), and iris area (IARE) (P=0.003), less iris curvature (ICURVE) (P=0.003), and larger lens vault (LV) (P=0.030). After intervention, the corneal thickness was significantly decreased at 1 month (P<0.001), while ACD, ACA, and AOD750 were significantly increased at 2 weeks and 1 month (all P<0.017). Changes in ACD were correlated with decreasing LV (P<0.05). The posterior segment parameters did not change over the 4-week period.
Conclusions: When compared with the fellow eyes, APAC-affected eyes had greater corneal thickness, shallower anterior chamber, narrower angle, less ICURVE, and larger LV. After intervention, the corneal thickness was decreased, while the shallower anterior chamber was relieved to some extent.
Abstract: Macular neovascularization (MNV) is the hallmark of neovascular age-related macular degeneration (nAMD), one of the leading causes of vision loss in the developed world. The current MNV standard of care including frequent intravitreal anti-vascular endothelial growth factor (VEGF) injections, although has revolutionized favorably the treatment, places a substantial burden on patients, caregivers, and physicians. Brolucizumab is a newly developed single-chain antibody fragment that inhibits activation of VEGF receptor 2 with in vitro affinity and potency comparable to commercially-available anti-VEGF agents. Its small molecular weight and its design allow for high solubility and retinal tissue penetration, and improve bynding affinity to the target. Also a high clearance rate leading to minimal systemic exposure was observed. Brolucizumab has shown similar gains in visual acuity compared with other anti-VEGF molecules but a higher and earlier resolution of nAMD related fluid, achieving sustained macular dryness with longer mantainance injection interval ranging from 8 to 12 weeks after monthly loading doses. Rare cases of ocular inflammation also including retinal vasculitis and retinal vascular occlusions referred to an immune-mediated reaction posed safety concerns on selected patients and mantainance treatment interval shorter than 8 weeks.The present review summarizes several key points including the molecular structure and pharmacokinetics, the preclinical and clinical evidence of brolucizumab administration evaluating its efficacy, tolerability, and safety, extended dosing regimens and other indications still under clinical investigation.
