Paracentral acute middle maculopathy-review of the literature.

Paracentral acute middle maculopathy (PAMM) is a recently identified spectral-domain optical coherence tomography (SD-OCT) finding characterized by a hyper-reflective band spanning the inner nuclear layer (INL), which typically evolves to INL atrophy in later stages. Typical clinical features include the sudden onset of one or multiple paracentral scotomas, normal or mild reduction in visual acuity, and a normal fundus appearance or a fundus with a deep grayish lesion. Although its pathophysiology is not yet fully understood, ischemia at the level of the intermediate and deep capillary plexa has been demonstrated to play a major role. Since its first description, an increasing number of publications on PAMM have been published in ophthalmology scientific journals. The purpose of this study is to provide a review of the current literature on PAMM.

Methylenetetrahydrofolate reductase polymorphisms as risk factors for retinal venous occlusive disease: A literature review.

The role of polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene in retinal vein occlusion (RVO) is a theme of discussion since the first reports of RVO in patients with MTHFR C677T mutation and without classic acquired risk factors for retinal vascular disease. The association between MTHFR polymorphisms and RVO has been studied over the last 20 years producing conflicting results. This review aims to summarize the literature concerning the role MTHFR polymorphisms as risk factors for RVO.

Dril Influences Short-term Visual Outcome after Intravitreal Corticosteroid Injection for Refractory Diabetic Macular Edema.

Purpose: Intravitreal injections (IVI) of anti-vascular endothelial growth factor (anti-VEGF) are considered the gold standard for diabetic macular edema (DME). Despite adequate anti-VEGF treatments, many patients present persistent DME. The aim of this study is to identify systemic, ocular and anatomical characteristics influencing functional and anatomical outcomes in refractory DME patients treated with IVI of corticosteroid.Materials and Methods: Retrospective multicenter hospital-based cohort study including type 2 diabetic adult patients with refractory DME that switched from intravitreal anti-VEGF to intravitreal corticosteroid between January 2017 and September 2018. Sociodemographic, clinical data, DME and treatment characteristics were collected at baseline (visit before switch), as well as spectral domain OCT features.Results: A total of 101 eyes were included. The median number of anti-VEGF injections before switch was 5.0 (min-max: 4.0-9.0) and the median anti-VEGF treatment duration before switch was 33.2 (min-max: 19.5-50.3) months. More than half of the patients (56; 54.9%) were diagnosed with diffuse DME. At baseline, 80 (88%) patients had cystoid DME, 55 (62.5%) patients had disorganization of retinal inner layers (DRIL) and 16 (17.6%) had subretinal fluid. Dexamethasone was the corticosteroid more commonly used (71.4%), followed by triamcinolone (24.4%) and fluocinolone (4.2%). Regarding best corrected visual acuity (BCVA), post-switch results showed no statistically significant improvement at three-month follow-up (p = .048/0.096), but the mean central macular thickness (CMT) decreased significantly from 486.3 (SD = 159) µm to 369.3 (SD = 129) µm at three-month follow-up (p < .001). DRIL was the tomographic characteristic able to influence significantly both CMT and BCVA final results (p = .02 and 0.012, respectively).Conclusions: Subfoveal DRIL on structural OCT was the DME factor influencing significantly clinical and imaging outcomes in refractory DME patients treated with intravitreal corticosteroid. Portuguese care trend towards DME shows preference for the use of dexamethasone implant after therapeutic failure with ranibizumab or bevacizumab injection.

The Neurotropic Varicella Zoster Virus: a Case of Isolated Abducens Nerve Palsy without Skin Rash in a Young Healthy Woman.

INTRODUCTION: Varicella Zoster Virus (VZV) is a neurotropic virus whose reactivation can affect the central nervous system (CNS) and manifest as different neurological syndromes usually with dermatological involvement. Extraocular muscle palsies are not commonly described associated with VZV and their presence in the absence of a typical zoster rash is even rarer. METHODS: Case report of a young immunocompetent patient with unilateral abducens nerve palsy, as an isolated manifestation of VZV infection. RESULTS: A 25-year-old healthy female presented to the emergency department with a subacute onset of painless horizontal binocular diploplia, over a month. Ophthalmological and neurological examination revealed an isolated right abducens nerve palsy, and polymerase chain reaction of the cerebrospinal fluid identified a VZV infection. There was no skin rash involvement. Other infectious, inflammatory, and autoimmune diseases were excluded. Treatment with intravenous acyclovir and dexamethasone improved but not completely resolved the diplopia and strabismus. The patient was submitted to a medial rectus recession surgery. DISCUSSION: VZV manifestations in the CNS can occur in healthy young individuals and can manifest in the absence of the typical skin rash. Isolated sixth nerve palsy is a very rare manifestation of VZV infection. Young patients with isolated ocular motor mononeuropathies, even with cardiovascular risk factors, benefit from a CNS-based approach and MRI and lumbar puncture should be considered. Reports show that extraocular muscle palsy associated with VZV is a transient condition and resolve partially or completely after few weeks.

Corneal Subbasal Nerve Plexus Evaluation by in Vivo Confocal Microscopy in Multiple Sclerosis: A Potential New Biomarker.

Purpose/Aim: Our study aims to evaluate corneal subbasal nerve plexus morphology by in vivo corneal confocal microscopy (CCM) in Multiple Sclerosis (MS) patients and to explore its potential ability to distinguish between MS patients and healthy subjects.Materials and methods: Cross-sectional study, including 60 MS patients and 22 healthy subjects. Expanded Disability Status Scale (EDSS) was used to assess neurological disability. All participants underwent full ophthalmology evaluation, CCM and optical coherence tomography (OCT). Corneal nerve fibre density (CNFD), branch density (CNBD), fibre length (CNFL) and fibre tortuosity (CNFT) were analysed. Generalized additive regression models were used to analyse the data.Results: Compared to controls, MS patients had lower CNFD, CNBD and CNFL (p < .001) and higher CNFT (p = .002). The area under the ROC curve to distinguish MS patients from healthy controls with CNFD and CNBD was 0.84 (95%CI: 0.75 to 0.93; 95%CI: 0.75 to 0.92, respectively). A nonlinear association between EDSS and CNFD was found, with an initial density increase followed by a significant decrease until more severe disability status. EDSS was associated with CNFL and CNBD, with values being significantly lower for patients with an EDSS > 2.5 (-2.06 mm/mm2; 95%CI: -3.84 to -0.28; p = .027 and -8.70 branches/mm2; 95%CI: -14.69 to -2.71; p = .006, respectively). An optic neuritis (ON) history did not influence CCM parameters.Conclusions: Our results confirm CCM parameters' potential to differentiate MS patients from healthy subjects, not being influenced by a previous ON history. A significant relationship between patient's disability and corneal nerve morphology was also found.

Nanotechnology-Ocular Devices for Glaucoma Treatment: A Literature Review.

Nanotechnology enabled the development of materials and devices with great utility in different fields of medicine. By using engineered-based nano-devices and structures, human biological systems may be controlled and repaired at a molecular scale, ultimately leading to a biological benefit. In particular, in the field of glaucoma treatment, nanotechnology may, for example, enhance drug residence time on the ocular surface and ocular bioavailability, as well as improve surgical success by both optimizing postoperative scarring and providing a wider safety window. Further studies are still needed to entirely explain the pharmacodynamics of nanotechnology-based therapeutic approaches and prove their biological consequences in human eyes. This review aims to summarize the literature concerning the advances in nanotechnology, specifically regarding ocular devices applied to the treatment of glaucoma.