274 research outputs found
Early impact of covid-19 outbreak on the availability of cornea donors: Warnings and recommendations
Keratoplasty is one of the irreplaceable treatment options for corneal diseases. Currently, there is no evidence to substantiate that harvested corneal grafts from COVID-19 patients can contain SARS-CoV-2 virus and lead to a systemic infection. Although the risk of transmission through corneal stromal tissue is low, it potentially exists. Lack of clinical data, unclear potential of donor-derived infection and non-established recommendations for transplantation during the COVID-19 pandemic have resulted in a dramatic reduction in the number of keratoplasty and cornea donors at ophthalmology departments and eye banks. To eliminate the risk of infection of recipients and medical personnel, we suggest that the blood samples of all donors should be screened with RT-PCR tests and nasopharyngeal swabs should be taken. In addition, a chest CT scan should be performed if the circulation is maintained. Moreover, the donors’ clinical and epidemiological medical history must be screened for typical symptoms and potential contact with SARS-CoV-2 carriers to reduce the risk of transmission. The Guidelines of the Eye Bank Association of America (EBAA), Global Alliance of Eye Bank Associations (GAEBA) and European Association of Tissue Banks provide useful recommendations to eliminate the risk of transmission according to previous experiences based on similar viruses
Bullous central serous chorioretinopathy: A rare and atypical form of central serous chorioretinopathy. a systematic review
Bullous central serous chorioretinopathy (bCSCR) is a rare variant of the central serous chorioretinopathy, complicated by an exudative retinal detachment with shifting fluid. This systematic review aims to present the epidemiology, the pathogenesis, the clinical presentation, the imaging, the differential diagnosis, and the latest treatments of this disease. A total of 60 studies were identified following a literature search adhering to PRISMA guidelines. After full-text evaluation, 34 studies about bCSCR were included. bCSCR usually affects middle-aged men, and the principal risk factor is corticosteroid medications. Pathogenesis is related to an increased choroidal vessel and choriocapillaris permeability, with subsequent subretinal fluid accumulation, rich in fibrin, which may provoke the exudative retinal detachment. Clinical presentation and imaging are fundamental to distinguish bCSCR from other pathologies, avoiding unappropriated treatment. Corticosteroid withdraws (if assumed) and laser photocoagulation of leakage sites seen at angiography may speed up retinal reattachment. Verteporfin photodynamic therapy, transpupillary thermal therapy, oral eplerenone and scleral thinning surgery are other therapeutic options. An early diagnosis might prevent disease progression due to harmful medications as well as unnecessary surgery
Correlated electron-hole plasma in organometal perovskites
Organic-inorganic perovskites are a class of solution-processed semiconductors holding promise for the realization of low-cost efficient solar cells and on-chip lasers. Despite the recent attention they have attracted, fundamental aspects of the photophysics underlying device operation still remain elusive. Here we use photoluminescence and transmission spectroscopy to show that photoexcitations give rise to a conducting plasma of unbound but Coulomb-correlated electron-hole pairs at all excitations of interest for light-energy conversion and stimulated optical amplification. The conductive nature of the photoexcited plasma has crucial consequences for perovskite-based devices: in solar cells, it ensures efficient charge separation and ambipolar transport while, concerning lasing, it provides a low threshold for light amplification and justifies a favourable outlook for the demonstration of an electrically driven laser. We find a significant trap density, whose cross-section for carrier capture is however low, yielding a minor impact on device performance
Acute myocardial infarction following off label retrobulbar injection of desmopressin for non-arteritic anterior ischemic optic neuropathy (NAION). Causal correlation or coincidence?
A 60-year-old man, apparently healthy with negative history for cardiovascular diseases, was hospitalized because of an unilateral sudden and painless severe visual loss. Diagnosis of NAION was made. Two separate and immediately consecutive injections of betamethasone (2 mg/0.5 mL) and desmopressin (2 mcg/0.5 mL) were performed in the retrobulbar space. Fifteen minutes later, the patient suddenly developed cold sweat, dyspnoea, thoracic pain and severe hypotension. Acute myocardial infarction was diagnosed by ECG. Desmopressin was the probable causative agent. Thrombotic events following intravenous or oral administration of desmopressin have been documented in the medical literature. To the best of our knowledge this is the first case in which a thrombotic event was associated with the retrobulbar route.
Retrobulbar desmopressin administration in patients with NAION can be probably associated with AMI. Considering its invasiveness and the unproven benefit in the treatment of NAION, this therapeutic approach can not be currently recommende
Response to Wirostko et al. Re: "Cross-Linked Hyaluronic Acid as Tear Film Substitute" by Posarelli et al. (J Ocul Pharmacol Ther 2019;35(7):381-387)
Response to Wirostko et al. Re: “Cross-Linked Hyaluronic Acid as Tear Film Substitute” by Posarelli et al. (J Ocul Pharmacol Ther 2019;35(7):381–387)." Journal of Ocular Pharmacology and Therapeutics, 36(4), pp. 206–20
Ophthalmological emergencies and the SARSCoV-2 outbreak
Since the end of 2019, an outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), originating in the Chinese city of Wuhan has spread rapidly worldwide causing thousands of deaths. Coronavirus disease (COVID-19) is supported by SARS-CoV-2 and represents the causative agent of a potentially fatal disease that is of great global public health concern. Italy has been the first European country recording an elevated number of infected forcing the Italian Government to call for total lockdown. The lockdown had the aim to limit the spread of infection through social distancing. The purpose of this study is to analyze how the pandemic has affected the patient’s accesses to the Ophthalmological Emergency Department of a tertiary referral center in central-northern Italy, during the lockdown period. The charts of all patients that came to the Emergency Department during the lockdown period (March 10 –May 4, 2020) have been retrospectively collected and compared with those in the same period of 2019 and the period from 15 January– 9 March 2020. A significant reduction of visits during the lockdown has been observed, compared with those of pre-lockdown period (reduction of 65.4%) and with those of the same period of 2019 (reduction of 74.3%). Particularly, during the lockdown, minor and not urgency visits decreased whereas the undeferrable urgency ones increased. These pieces of evidence could be explained by the fear of patients to be infected; but also revealed patients misuse of emergency services
What is the impact of intraoperative microscope-integrated oct in ophthalmic surgery? Relevant applications and outcomes. a systematic review
Background: Optical coherence tomography (OCT) has recently been introduced in the operating theatre. The aim of this review is to present the actual role of microscope-integrated optical coherence tomography (MI-OCT) in ophthalmology. Method: A total of 314 studies were identified, following a literature search adhering to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. After full-text evaluation, 81 studies discussing MI-OCT applications in ophthalmology were included. Results: At present, three microscope-integrated optical coherence tomography systems are commercially available. MI-OCT can help anterior and posterior segment surgeons in the decision-making process, providing direct visualization of anatomic planes before and after surgical manoeuvres, assisting in complex cases, and detecting or confirming intraoperative complications. Applications range from corneal transplant to macular surgery, including cataract surgery, glaucoma surgery, paediatric examination, proliferative diabetic retinopathy surgery, and retinal detachment surgery. Conclusion: The use of MI-OCT in ophthalmic surgery is becoming increasingly prevalent and has been applied in almost all procedures. However, there are still limitations to be overcome and the technology involved remains difficult to access and use
Safety and efficacy of second ahmed valve implant in refractory glaucoma
Background: Refractory glaucoma still represents a challenge for ophthalmologists to manage intraocular pressure. The present study aimed to evaluate long term efficacy and safety of a second Ahmed valve implantation after the failure of a first implant in patients with refractory glaucoma and elevated intraocular pressure (IOP). Methods: Retrospective, multicenter non-comparative case series. Twenty-eight patients were retrospectively recruited between January 2011 and December 2017. Demographic data, glaucoma type, visual acuity, intraocular pressure, medical therapy, and complications were registered. Three criteria of success were established: Type 1 surgical success: IOP ≤ 15 mmHg and a reduction of IOP ≥ 40% from baseline; Type 2 surgical success: IOP ≤ 18 mmHg and a reduction of IOP ≥ 30% from baseline; and Type 3 surgical success: IOP ≤ 21 mmHg and a reduction of IOP ≥ 20% from baseline. Surgical failure has been established as IOP less than 5 mmHg or over 21 mmHg and less than a 20% reduction of IOP from baseline despite medications in two consecutive visits, light perception loss referable to glaucoma, and the necessity for further glaucoma surgery. Failure was observed in six (21%) patients. (3) Results: Mean IOP and mean glaucoma medication number significantly reduced from baseline after the second implantation, and the surgical success rate at 72 months ranged from 10% to 78% based on the different criteria of success. Failure was observed in six (21%) patients. Conclusions: This study confirmed the safety and efficacy of a second Ahmed valve implantation in patients with refractory glaucoma and elevated IOP at baseline
Twenty-Four-Hour Contact Lens Sensor Monitoring of Aqueous Humor Dynamics in Surgically or Medically Treated Glaucoma Patients
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