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Topic Review
Corneal Transplantation in the Past Decade
The cornea is a transparent avascular structure located in the front of the eye that refracts light entering the eyes and also serves as a barrier between the outside world and the internal contents of the eye. Like every other body part, the cornea may suffer insult from trauma, infection, and inflammation. In the case of trauma, a prior infection that left a scar, or conditions such as keratoconus that warrant the removal of all or part of the cornea (keratoplasty), it is important to use healthy donor corneal tissues and cells that can replace the damaged cornea. The types of cornea transplant techniques employed currently include penetrating keratoplasty, endothelial keratoplasty (EK), and artificial cornea transplant. Postoperative failure acutely or after years can result after a cornea transplant and may require a repeat transplant. This research briefly examines the various types of corneal transplant methodologies, indications, contraindications, presurgical protocols, sources of cornea transplant material, wound healing after surgery complications, co-morbidities, and the effect of COVID-19 in corneal transplant surgery.
  • 841
  • 18 Apr 2023
Topic Review
Incidence and Risk Factors of Bilateral Herpetic Keratitis
Herpetic keratitis is the result of a corneal infection with Herpes Simplex Virus (HSV) and it is recognized as a leading cause of corneal blindness worldwide. Bilateral HSV keratitis is a rare clinical manifestation and consists of simultaneously occurring infection in both eyes.
  • 839
  • 21 Jun 2022
Topic Review
Prevention of AMD Onset
Age-related macular degeneration (AMD) represents the leading cause of irreversible blindness in elderly people, mostly after the age of 65. The progressive deterioration of visual function in patients affected by AMD has a significant impact on quality of life and has also high social costs. Many studies showed that a higher dietary intake of nutrients, such as lutein, zeaxanthin, beta carotene, omega-3 fatty acids and zinc, reduced the risk of early AMD. Regarding lifestyle habits, the association between smoking and AMD is currently accepted. Finally, retinal damage caused by ultraviolet rays and blue light is also worthy of attention. 
  • 837
  • 12 Aug 2021
Topic Review
Mouse Models of Retinitis Pigmentosa-59
Retinitis pigmentosa-59 (RP59) is a rare, recessive form of RP, caused by mutations in the gene encoding DHDDS (dehydrodolichyl diphosphate synthase). DHDDS forms a heterotetrameric complex with Nogo-B receptor (NgBR; gene NUS1) to form a cis-prenyltransferase (CPT) enzyme complex, which is required for the synthesis of dolichol, which in turn is required for protein N-glycosylation as well as other glycosylation reactions in eukaryotic cells. The mouse is the most commonly used vertebrate animal model in experimental biology, there have been efforts to generate murine models of RP59.
  • 832
  • 30 Nov 2022
Topic Review
Oxidative Stress for Optic Nerve Diseases
Glaucoma is the most prevalent optic nerve disease worldwide. Oxidative stress plays a pivotal role in the pathophysiology of optic nerve diseases such as glaucoma, Leber’s hereditary optic neuropathy (LHON), and anterior ischemic optic neuropathy (AION). Imbalances between reactive oxygen species (ROS) as well as reactive nitrogen species (RNS) generation and antioxidant systems lead to reactive species overproduction, adenosine triphosphate (ATP) insufficiency, irreversible cellular injuries, and ultimately retinal ganglion cell (RGC) loss.
  • 831
  • 29 Aug 2023
Topic Review
Cell Therapy for Retinal and Optic Nerve Diseases
Retinal Degenerative diseases and Optic Nerve diseases have been largely characterized and are considered leading causes of blindness worldwide.  One of the hopes for possible treatments lies in cell therapy. This entry updates those that are the subject of clinical trials and therefore have a better chance of reaching clinical use. The aim of this review was to provide an update on the potential of cell therapies to restore or replace damaged and/or lost cells in retinal degenerative and optic nerve diseases, describing the available cell sources and the challenges involved in such treatments when these techniques are applied in real clinical practice.
  • 830
  • 07 Dec 2021
Topic Review
In Vivo Confocal Microscopy in Dry Eye Diagnosis
There are many common ocular surface disorders (OSD), such as Dry Eye Disease (DED), blepharitis, and meibomian gland dysfunction (MGD), whose management requires visualization of certain ocular surface structures via slit-lamp biomicroscopy. In vivo confocal microscopy (IVCM), a more recent imaging technique has been evaluated in clinics for similar visualization.
  • 829
  • 04 Aug 2022
Topic Review
3D Printing in Ophthalmology
Three-dimensional (3D) printing is a process in which materials are added together in a layer-by-layer manner to construct customized products. Many different techniques of 3D printing exist, which vary in materials used, cost, advantages, and drawbacks. Medicine is increasingly benefiting from this transformative technology, and the field of ophthalmology is no exception. The possible 3D printing applications in eyecare are vast and have been explored in the literature, such as 3D-printed ocular prosthetics, orbital implants, educational and anatomical models, as well as surgical planning and training. 
  • 827
  • 01 Feb 2024
Topic Review
Models of Diabetic Retinopathy
Diabetic retinopathy (DR) is an ocular complication of diabetes mellitus (DM), a metabolic disorder characterized by elevation in blood glucose level. The pathogenesis of DR includes vascular, neuronal, and inflammatory components leading to activation of complex cellular molecular signaling. If untreated, the disease can culminate in vision loss that eventually leads to blindness. Animal models mimicking different aspects of DM complications have been developed to study the development and progression of DR. Despite the significant contribution of the developed DR models to discovering the mechanisms of DR and the recent achievements in the research field, the sequence of cellular events in diabetic retinas is still under investigation. Partially, this is due to the complexity of molecular mechanisms, although the lack of availability of models that adequately mimic all the neurovascular pathobiological features observed in patients has also contributed to the delay in determining a precise molecular trigger.
  • 825
  • 16 Feb 2022
Topic Review
AMD and the Complement System
Wet age-related macular degeneration (wAMD) is characterized by choroidal neovascularization (CNV), and it is the leading cause of blindness affecting elderly in the Western world. AMD is a complex disease that has strong associations with the complement system. All three initiating complement pathways may be relevant in CNV formation, but most evidence indicates a major role for the alternative pathway (AP) and for the terminal complement complex, as well as certain complement peptides generated upon complement activation. Since the complement system is associated with AMD and CNV, a complement inhibitor may be a therapeutic option for patients with wAMD. The aim of the review is to (i) reflect on the possible complement targets in the context of wAMD pathology, (ii) investigate the results of prior clinical trials with complement inhibitors for wAMD patients, and (iii) outline important considerations when developing a future strategy for the treatment of wAMD.
  • 822
  • 22 Feb 2021
Topic Review
Omics-Based Biomarker Discovery in Retinal Vascular Diseases
Retinal vascular disease is a highly prevalent vision-threatening ocular disease in the global population; however, its exact mechanism remains unclear. The expansion of omics technologies has revolutionized a new medical research methodology that combines multiple omics data derived from the same patients to generate multi-dimensional and multi-evidence-supported holistic inferences, providing unprecedented opportunities to elucidate the information flow of complex multi-factorial diseases. Omics data from eye biopsies can identify the molecular mechanisms of retinal vascular diseases in addition to the associated diagnostic prognostic and predictive biomarkers.
  • 821
  • 13 Jan 2023
Topic Review
Nano-Based DDS for Glaucoma
The eye is a complex and delicate organ that is protected by robust anatomical barriers. These barriers limit the penetration, bioavailability, and residence time of topically administered drugs. To address this challenge, researchers have developed polymeric nano-based drug delivery systems (DDS) that offer a promising solution. These DDS can penetrate ocular barriers, improving the bioavailability of administered drugs to targeted tissues and leading to better therapeutic outcomes. Biodegradable polymers are often used in these DDS to minimize adverse effects that can result from drugs that are not naturally decomposable, such as the risk of infection, tissue damage, or toxic byproducts.
  • 821
  • 12 May 2023
Topic Review
Optical Coherence Tomography in Neurological and Vessel Diseases
For glaucoma evaluation, several studies have suggested that in the early stages, ganglion cell complex (GCC) analysis, especially the thickness of the infero and that of the inferotemporal GCC layers, is a more sensitive examination than circumpapillary retinal nerve fiber layer (pRNFL). In the moderate stages of glaucoma, inferior pRNFL thinning is better correlated with the disease than in advanced cases. Another strategy for glaucoma detection is to find any asymmetry of the ganglion cell–inner plexiform layers (GCIPL) between the two macular hemifields, because this finding is a valuable indicator for preperimetric glaucoma, better than the retinal nerve fiber layer (RNFL) thickness or the absolute thickness parameters of GCIPL. In preperimetric and suspected glaucoma, GCC and pRNFL have better specificity and are superior to the visual field. In advanced stages, pRNFL and later, GCC reach the floor effect. 
  • 817
  • 08 Feb 2023
Topic Review
Myopia Control in Children
The growing incidence of myopia worldwide justifies the search for efficient methods of myopia prevention. Numerous pharmacological, optical, and lifestyle measures have already been utilized, but there remains a need to explore more practical and predictable methods for myopia control.
  • 814
  • 26 Oct 2023
Topic Review
Oxidative Stress Implications for Retinal Diseases
Oxidative stress plays a significant role in the pathogenesis of various retinal diseases, including diabetic retinopathy (DR), age-related macular degeneration (AMD), glaucoma, and retinopathy of prematurity (ROP).
  • 813
  • 29 Feb 2024
Topic Review
Corneal Biomechanics following Laser Refractive Surgery in Eyes
The role of corneal biomechanics in laser vision correction (LVC) is being raised in the assessment of postoperative corneal ectasia risk. Research reveal the highest corneal biomechanics reduction after laser in situ keratomileusis (LASIK) followed by small incision lenticule extraction (SMILE) and surface procedures, such as photorefractive keratectomy (PRK) or laser-assisted sub-epithelial keratectomy (LASEK). In SMILE procedure treatment planning, the use of thicker caps preserves the corneal biomechanics. Similarly, reduction of flap thickness in LASIK surgery maintains the corneal biomechanical strength.
  • 811
  • 04 Jan 2023
Topic Review
Nanofibers as an Ocular System
Nanofibers are frequently encountered in daily life as a modern material with a wide range of applications. The important advantages of production techniques, such as being easy, cost effective, and industrially applicable are important factors in the preference for nanofibers. Nanofibers, which have a broad scope of use in the field of health, are preferred both in drug delivery systems and tissue engineering. Due to the biocompatible materials used in their construction, they are also frequently preferred in ocular applications. The fact that they have a long drug release time as a drug delivery system and have been used in corneal tissue studies, which have been successfully developed in tissue engineering, stand out as important advantages of nanofibers. 
  • 808
  • 05 May 2023
Topic Review
Diabetic Macular Oedema
Diabetic macular oedema (DMO) is one of the leading causes of vision loss associated with diabetic retinopathy (DR). New insights in managing this condition have changed the paradigm in its treatment, with intravitreal injections of antivascular endothelial growth factor (anti-VEGF) having become the standard therapy for DMO worldwide. However, there is no single standard therapy for all patients DMO refractory to anti-VEGF treatment; thus, further investigation is still needed.
  • 805
  • 24 Aug 2021
Topic Review
The Ophthalmic Manifestations of Down Syndrome
Down Syndrome is one of the most common chromosomal conditions in the world, affecting an estimated 1 in 400–1500 live births. It is a multisystem genetic disorder, resulting from an extra copy of chromosome 21, either as a complete separate chromosome (most common), as a partial or full translocation, or existing in some but not all cells (mosaic form). This excess genetic material disrupts normal development, leading to characteristic physical features and developmental differences. Down Syndrome manifests with a wide range of ophthalmic findings. These include strabismus, amblyopia, accommodation defects, refractive error, eyelid abnormalities, nasolacrimal duct obstruction, nystagmus, keratoconus, cataracts, retinal abnormalities, optic nerve abnormalities, and glaucoma. These ophthalmic conditions are more prevalent in children with Down Syndrome than the general pediatric population, and without exception, early identification with thoughtful screening in this patient population can drastically improve prognosis and/or quality of life. 
  • 805
  • 23 Feb 2023
Topic Review
Retinal Pigment Epithelial Cells in Age-Related Macular Degeneration
Age-related macular degeneration (AMD) causes vision loss in the elderly population. Dry AMD leads to the formation of Drusen, while wet AMD is characterized by cell proliferation and choroidal angiogenesis. The retinal pigment epithelium (RPE) plays a key role in AMD pathogenesis. In particular, helioreceptor renewal depends on outer segment phagocytosis of RPE cells, while RPE autophagy can protect cells from oxidative stress damage.
  • 803
  • 21 Aug 2023
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