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Author(s):  
Sławomir Liberski ◽  
Bartlomiej J. Kaluzny ◽  
Jarosław Kocięcki

AbstractMethanol-induced optic neuropathy (Me-ION) is a serious condition that may result in long-term or irreversible visual impairment or even blindness secondary to damage and loss of function of the optic nerve and retina. Me-ION shows a tendency to occur as mass poisonings around the world with a clear predilection for poor societies in developing countries. The main mechanism underlying the molecular basis of Me-ION is the inhibition of the mitochondrial oxidative phosphorylation process through the binding of the toxic metabolite of methanol—formic acid—with the key enzyme of this process—cytochrome c oxidase. However, other mechanisms, including damage to the eye tissues by oxidative stress causing the intensification of the oxidative peroxidation process with the formation of cytotoxic compounds, as well as an increase in the synthesis of pro-inflammatory cytokines and influence on the expression of key proteins responsible for maintaining cell homeostasis, also play an important role in the pathogenesis of Me-ION. Histopathological changes in the eye tissues are mainly manifested as the degeneration of axons and glial cells of the optic nerve, often with accompanying damage of the retina that may involve all its layers. Despite the development of therapeutic approaches, persistent visual sequelae are seen in 30–40% of survivors. Thus, Me-ION continues to be an important problem for healthcare systems worldwide.


2021 ◽  
pp. 108896
Author(s):  
Wenhan Lu ◽  
Zhenle Pei ◽  
Wei Hu ◽  
Chen Tan ◽  
Xiaoyu Tong ◽  
...  

Author(s):  
A.V. Tereshchenko ◽  

Purpose. To prevent intraoperative complications during fixation of the IOL-intracapsular ring-capsule bag complex during femto-assisted phacoemulsification of cataract complicated by congenital lens ectopia (Marfan syndrome) using intraoperative OCT. Material and methods. 3 men (6 eyes), with a diagnosis of cataract complicated by congenital ectopia of the lens (Marfan syndrome). The age of patients ranged from 19 to 25 years. Cataract phacoemulsification (CFE) with femto support and hydrophobic IOL implantation was performed by all patients. Fixation of complex "IOL-intracapsular ring-capsule bag" in sulcus ciliaris was performed with the control of intraoperative OCT. Results. BCVA was 0.6-0.8 at the first day after the operation. According to ultrasound biomicroscopy (UBM), the IOL was in the capsule bag in a horizontal position in all cases. Any damage of the iris and ciliary body was not found. After 6 months, according to UBM, a stable horizontal position of the IOL and the consistency of suture fixation of the «intracapsular ring-capsule bag-IOL» complex was recorded in all patients. Conclusion. The use of intraoperative OCT allows to accurately determine the individual anatomical location of the sulcus ciliaris and provide visual control of the IOL suturing and the «intracapsular ring-capsule bag» complex in congenital lens tectopia, avoiding excessive trauma of the surrounding eye tissues, and also to ensure a stable horizontal position of the IOL in the postoperative period. Key words: intraoperative optical coherence tomography, femtoassisted cataract phacoemulsification, congenital lens ectopia.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1685
Author(s):  
Ayah Mohammad Burhan ◽  
Butsabarat Klahan ◽  
Wayne Cummins ◽  
Vanessa Andrés-Guerrero ◽  
Mark E. Byrne ◽  
...  

Posterior segment eye diseases (PSEDs) including age macular degeneration (AMD) and diabetic retinopathy (DR) are amongst the major causes of irreversible blindness worldwide. Due to the numerous barriers encountered, highly invasive intravitreal (IVT) injections represent the primary route to deliver drugs to the posterior eye tissues. Thus, the potential of a more patient friendly topical route has been widely investigated. Mucoadhesive formulations can decrease precorneal clearance while prolonging precorneal residence. Thus, they are expected to enhance the chances of adherence to corneal and conjunctival surfaces and as such, enable increased delivery to the posterior eye segment. Among the mucoadhesive polymers available, chitosan is the most widely explored due to its outstanding mucoadhesive characteristics. In this review, the major PSEDs, their treatments, barriers to topical delivery, and routes of topical drug absorption to the posterior eye are presented. To enable the successful design of mucoadhesive ophthalmic drug delivery systems (DDSs), an overview of mucoadhesion, its theory, characterization, and considerations for ocular mucoadhesion is given. Furthermore, chitosan-based DDs that have been explored to promote topical drug delivery to the posterior eye segment are reviewed. Finally, challenges of successful preclinical to clinical translation of these DDSs for posterior eye drug delivery are discussed.


2021 ◽  
pp. 108796
Author(s):  
Wenhan Lu ◽  
Zhenle Pei ◽  
Wei Hu ◽  
Chen Tan ◽  
Xiaoyu Tong ◽  
...  

2021 ◽  
Vol 21 ◽  
Author(s):  
Hui Zhang ◽  
Xiaomin Zhang ◽  
Xiaorong Li

: Exosomes, nanosized extracellular vesicles with a size of 30–150nm, contain many biological materials, such as messenger RNA (mRNA), microRNA (miRNA), proteins, and transcription factors. It has been identified in all biological fluids and recognized as an important part of intercellular communication. While the role of exosomes in cancer has been studied in-depth, our understanding of their relevance for ocular tissues has just begun to evolve. Intraocular fluids, including aqueous humor and vitreous humor, play a role in nourishing eye tissues and in expelling metabolites. In the pathological state, intraocular exosomes can mediate pathological processes such as ECM remodeling, retinal inflammation, and blood-retinal barrier dysfunction. Herein, we reviewed the latest advances of intraocular exosomes in the research of several eye diseases, including glaucoma, age-related macular degeneration, myopia, and ocular tumors, and discuss how intraocular exosomes contribute to the pathogenesis and progression of multiple eye diseases.


2021 ◽  
Vol 10 (16) ◽  
pp. 3611
Author(s):  
Hiroyuki Shimada ◽  
Hiroyuki Nakashizuka

Postoperative endophthalmitis after cataract surgery is typically caused by the patient’s own conjunctival normal bacterial flora. A three-step approach is recommended to prevent endophthalmitis: (1) “border control” to prevent microorganisms from entering the eye by disinfecting the ocular surface is the most important measure; (2) bacteria that have gained access into the anterior chamber are reduced by irrigation; (3) bacteria remaining in the anterior chamber and vitreous at the end of surgery are controlled by antibacterial drugs. We have devised a method, “the Shimada technique”, for irrigating the ocular surface with povidone-iodine, a disinfectant with potent microbicidal effect and established effective and safe concentrations for eye tissues. Povidone-iodine exhibits a bactericidal effect for a wide concentration range of 0.005–10%, but 0.1% povidone-iodine has the highest activity and requires the shortest time of only 15 s to achieve microbicidal effect. When used to irrigate the ocular surface every 20–30 s during cataract surgery, 0.25% povidone-iodine is conceivably diluted to around 0.1%. Irrigation with 0.25% povidone-iodine during cataract surgery significantly reduced bacteria contamination rate in the anterior chamber compared with saline (p = 0.0017) without causing corneal endothelial damage.


2021 ◽  
pp. 29-37
Author(s):  
Irina Aleksandrovna Rakitina ◽  
Alfiya Gumyarovna Iskhakova ◽  
Evgeny Andreevich Zamytsky ◽  
Marina Vladimirovna Makolina ◽  
Farida Sagitovna Goleeva ◽  
...  

Optical Coherence Tomography (OCT) is a modern, highly accurate, non-invasive study of various eye structures. OCT is a non-contact method that allows a specialist to visualize eye tissue with a very high resolution (1–15 microns), the accuracy of which is comparable to microscopic examination. The theoretical foundations of the OCT method were developed in 1995 by the American ophthalmologist K. Pulafito, and already in 1996–1997 Carl Zeiss Meditec introduced the first device for optical coherence tomography into clinical practice. Today, OCT devices are used to diagnose various diseases of the fundus and anterior segment of the eye. Due to the maximum accuracy, the method of light scanning greatly simplifies the diagnosis of pathologies of the organs of vision, regardless of the cause of their occurrence and the stage of the course. In terms of information content, the technique is not inferior to histology, but the advantage of OCT is the absence of the risk of injury to the eye tissues [1, 2].


2021 ◽  
Author(s):  
Dattatreya Mukherjee

Uveitis is a general term describing a group of inflammatory diseases that produces swelling anddestroys eye tissues. These diseases can slightly reduce vision or lead to severe vision loss.The uvea is the middle layer of the eye. It lies beneath the white part of the eye (the sclera). It ismade of the iris, ciliary body, and choroid. These structures control many eye functions,including adjusting to different levels of light or distances of objects. The term “uveitis” is used because the diseases often affect a part of the eye called the uvea.Nevertheless, uveitis is not limited to the uvea. These diseases also affect the lens, retina, opticnerve, and vitreous, producing reduced vision or blindness.It is characterized as seen in young adults with both eyes affected to it, mostly recurrent and cancause blindness.Uveitis may be caused by problems or diseases occurring in the eye or it can be part of aninflammatory disease affecting other parts of the body.It can happen at all ages and primarily affects people between 20-60 years old.Uveitis can last for a short (acute) or a long (chronic) time. The severest forms of uveitis reoccurmany times.


2021 ◽  
pp. 108693
Author(s):  
Jody A. Summers ◽  
Frank Schaeffel ◽  
Susana Marcos ◽  
Hao Wu ◽  
Andrei V. Tkatchenko

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