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Indian Journal of Ophthalmology Dec 2019Tumors of the conjunctiva and cornea comprise a large and varied spectrum of conditions. These tumors are grouped into two major categories of congenital and acquired... (Review)
Review
Tumors of the conjunctiva and cornea comprise a large and varied spectrum of conditions. These tumors are grouped into two major categories of congenital and acquired lesions. The acquired lesions are further subdivided based on origin of the mass into surface epithelial, melanocytic, vascular, fibrous, neural, histiocytic, myxoid, myogenic, lipomatous, lymphoid, leukemic, metastatic and secondary tumors. Melanocytic lesions include nevus, racial melanosis, primary acquired melanosis, melanoma, and other ocular surface conditions like ocular melanocytosis and secondary pigmentary deposition. The most frequent nonmelanocytic neoplastic lesions include squamous cell carcinoma and lymphoma, both of which have typical features appreciated on clinical examination. The caruncle displays a slightly different array of tumors compared to those elsewhere on the conjunctiva, as nevus and papilloma are most common, but oncocytoma and sebaceous gland hyperplasia, adenoma, and carcinoma can be found. In this report, we provide clinical description and illustration of the many conjunctival and corneal tumors and we discuss tumor management.
Topics: Conjunctival Neoplasms; Corneal Diseases; Eye Neoplasms; Humans
PubMed: 31755426
DOI: 10.4103/ijo.IJO_2040_19 -
Indian Journal of Ophthalmology Jul 2022Mucopolysaccharidosis (MPS) is a group of genetic disorders with seven types and 13 subgroups which are characterized by an inherent deficiency of the enzymes... (Review)
Review
Mucopolysaccharidosis (MPS) is a group of genetic disorders with seven types and 13 subgroups which are characterized by an inherent deficiency of the enzymes responsible for the degradation of glycosaminoglycans (GAGs). Defective breakdown of GAG products leads to their widespread accumulation within the lysosomes of various organs involving the eye, central nervous system, skeletal, ocular, nervous, respiratory, cardiac, and the gastrointestinal systems. Clinical spectrum varies from mild systemic and ocular abnormalities with a normal life span to severe phenotype, fatal in the first few months of life. Visual disability due to corneal clouding, retinopathy, and optic nerve involvement causes additional impairment of physical and cognitive functions. Treatment modalities such as bone marrow transplantation and enzyme replacement therapies help in increasing the life span as well as the quality of life of the affected patients. For patients with significant corneal clouding, keratoplasty is the answer. The decision to proceed with keratoplasty is governed by various factors such as the motivation of the patient and his family, other systemic affections and anesthesia concerns. A detailed preoperative counseling should be done regarding the expected visual outcomes in the presence of other ocular comorbidities and the postoperative complication such as graft re-opacification, rejection and glaucoma. Future treatment options such as targeted gene therapy and substrate reduction therapy hold promise to reverse corneal clouding, thereby obviating the need for corneal transplantation. These treatment therapies are still in the experimental stages and human trials are needed to validate their outcomes.
Topics: Corneal Diseases; Corneal Opacity; Corneal Transplantation; Humans; Mucopolysaccharidoses; Quality of Life
PubMed: 35791104
DOI: 10.4103/ijo.IJO_425_22 -
Indian Journal of Ophthalmology Jul 2021Laser-assisted in situ keratomileusis (LASIK) is one of the most commonly performed kerato-refractive surgery globally. Since its introduction in 1990, there has been a... (Review)
Review
Laser-assisted in situ keratomileusis (LASIK) is one of the most commonly performed kerato-refractive surgery globally. Since its introduction in 1990, there has been a constant evolution in its technology to improve the visual outcome. The safety, efficacy, and predictability of LASIK are well known, but complications with this procedure, although rare, are not unknown. Literature review suggests that intraoperative complications include suction loss, free cap, flap tear, buttonhole flap, decentered ablation, central island, interface debris, femtosecond laser-related complications, and others. The postoperative complications include flap striae, flap dislocation, residual refractive error, diffuse lamellar keratitis, microbial keratitis, epithelial ingrowth, refractive regression, corneal ectasia, and others. This review aims to provide a comprehensive knowledge of risk factors, clinical features, and management protocol of all the reported complications of LASIK. This knowledge will help in prevention as well as early identification and timely intervention with the appropriate strategy for achieving optimal visual outcome even in the face of complications.
Topics: Corneal Diseases; Humans; Intraoperative Complications; Keratitis; Keratomileusis, Laser In Situ; Postoperative Complications; Surgical Flaps
PubMed: 34146007
DOI: 10.4103/ijo.IJO_1872_20 -
Digital Journal of Ophthalmology : DJO Apr 2019Spheroidal degeneration, involving the cornea and/or the conjunctiva, is characterized by amber-colored homogeneous, translucent spherules in the corneal stroma,...
Spheroidal degeneration, involving the cornea and/or the conjunctiva, is characterized by amber-colored homogeneous, translucent spherules in the corneal stroma, Bowman's membrane, and subepithelium. The condition has a higher prevalence in areas with extreme temperatures, low humidity, high wind, and presence of sand. We report the case of a 46-year-old man with a 10-year history of gradual progressive diminution of vision, severe blepharospasm, and photophobia. Examination revealed bilateral plaques of amber-colored nodules covering about half of the cornea. Superficial keratectomy was performed for the lesions in both eyes, leaving an epithelial defect overlying a plane of opaque cornea. Histopathology showed amorphous protein in the anterior stroma, confirming the clinical diagnosis of advanced grade 4 spheroidal degeneration. Visual acuity and other symptoms dramatically improved, and the patient was scheduled for keratoplasty.
Topics: Cornea; Corneal Diseases; Disease Progression; Humans; Keratoplasty, Penetrating; Male; Middle Aged; Visual Acuity
PubMed: 32076391
DOI: 10.5693/djo.02.2019.11.001 -
Survey of Ophthalmology 2023Congenital aniridia is a panocular disorder that is typically characterized by iris hypoplasia and aniridia-associated keratopathy (AAK). AAK results in the progressive... (Review)
Review
Congenital aniridia is a panocular disorder that is typically characterized by iris hypoplasia and aniridia-associated keratopathy (AAK). AAK results in the progressive loss of corneal transparency and thereby loss of vision. Currently, there is no approved therapy to delay or prevent its progression, and clinical management is challenging because of phenotypic variability and high risk of complications after interventions; however, new insights into the molecular pathogenesis of AAK may help improve its management. Here, we review the current understanding about the pathogenesis and management of AAK. We highlight the biological mechanisms involved in AAK development with the aim to develop future treatment options, including surgical, pharmacological, cell therapies, and gene therapies.
Topics: Humans; Corneal Diseases; Aniridia; Cornea; Vision Disorders; Forecasting
PubMed: 37146692
DOI: 10.1016/j.survophthal.2023.04.003 -
Experimental Eye Research Dec 2018There has been a drive to develop new cell based therapies to treat corneal blindness, one of the most common causes of blindness worldwide. Mechanical and physical cues... (Review)
Review
There has been a drive to develop new cell based therapies to treat corneal blindness, one of the most common causes of blindness worldwide. Mechanical and physical cues are known to regulate the behavior of many cell types, however studies examining these effects on corneal epithelial cells have been limited in number and their findings have not previously been amalgamated and contrasted. Here, we provide an overview of the different types of mechanical stimuli to which the corneal epithelium is exposed and the influence that these have on the cells. Shear stress from the tear film motion and blinking, extracellular matrix stiffness and external physical forces such as eye rubbing and contact lens wear are among some of the forms of mechanical stimuli that the epithelium experiences. In vivo and in vitro studies examining the mechanobiology on corneal epithelial cells under differing mechanical environments are explored. A greater understanding of the mechanobiology of the corneal epithelium has the potential to lead to improved tissue engineering and cell based therapies to repair and regenerate damaged cornea.
Topics: Corneal Diseases; Epithelium, Corneal; Extracellular Matrix; Eyelids; Humans; Regenerative Medicine; Stress, Mechanical; Tears
PubMed: 30086260
DOI: 10.1016/j.exer.2018.08.001 -
Ugeskrift For Laeger Nov 2023Corneal grafting is performed approximately 650 times a year in Denmark. A summary of these procedures is given in this review. Fuchs' endothelial dystrophy and... (Review)
Review
Corneal grafting is performed approximately 650 times a year in Denmark. A summary of these procedures is given in this review. Fuchs' endothelial dystrophy and pseudophakic bullous keratopathy are frequent indications for transplantation. Previously, penetrating keratoplasty was the technique of choice but is nowadays mainly used for combined stromal and endothelial pathology. Instead, techniques specifically replacing diseased layers are more common. The Danish Cornea Bank is the only center in Denmark which undertakes preparation and distribution of tissue. The operative procedures are performed at Aarhus University Hospital or Rigshospitalet Glostrup.
Topics: Humans; Corneal Diseases; Corneal Transplantation; Cornea; Fuchs' Endothelial Dystrophy; Keratoplasty, Penetrating
PubMed: 38018729
DOI: No ID Found -
Cells Apr 2023One of the most remarkable advancements in medical treatments of corneal diseases in recent decades has been corneal transplantation. However, corneal transplants,... (Review)
Review
One of the most remarkable advancements in medical treatments of corneal diseases in recent decades has been corneal transplantation. However, corneal transplants, including lamellar strategies, have their own set of challenges, such as graft rejection, delayed graft failure, shortage of donor corneas, repeated treatments, and post-surgical complications. Corneal defects and diseases are one of the leading causes of blindness globally; therefore, there is a need for gene-based interventions that may mitigate some of these challenges and help reduce the burden of blindness. Corneas being immune-advantaged, uniquely avascular, and transparent is ideal for gene therapy approaches. Well-established corneal surgical techniques as well as their ease of accessibility for examination and manipulation makes corneas suitable for in vivo and ex vivo gene therapy. In this review, we focus on the most recent advances in the area of corneal regeneration using gene therapy and on the strategies involved in the development of such therapies. We also discuss the challenges and potential of gene therapy for the treatment of corneal diseases. Additionally, we discuss the translational aspects of gene therapy, including different types of vectors, particularly focusing on recombinant AAV that may help advance targeted therapeutics for corneal defects and diseases.
Topics: Humans; Cornea; Genetic Therapy; Corneal Transplantation; Corneal Diseases; Blindness
PubMed: 37174680
DOI: 10.3390/cells12091280 -
International Journal of Molecular... May 2022Communication between cells and the microenvironment is a complex, yet crucial, element in the development and progression of varied physiological and pathological... (Review)
Review
Communication between cells and the microenvironment is a complex, yet crucial, element in the development and progression of varied physiological and pathological processes. Accumulating evidence in different disease models highlights roles of extracellular vesicles (EVs), either in modulating cell signaling paracrine mechanism(s) or harnessing their therapeutic moiety. Of interest, the human cornea functions as a refractive and transparent barrier that protects the intraocular elements from the external environment. Corneal trauma at the ocular surface may lead to diminished corneal clarity and detrimental effects on visual acuity. The aberrant activation of corneal stromal cells, which leads to myofibroblast differentiation and a disorganized extracellular matrix is a central biological process that may result in corneal fibrosis/scarring. In recent years, understanding the pathological and therapeutic EV mechanism(s) of action in the context of corneal biology has been a topic of increasing interest. In this review, we describe the clinical relevance of corneal fibrosis/scarring and how corneal stromal cells contribute to wound repair and their generation of the stromal haze. Furthermore, we will delve into EV characterization, their subtypes, and the pathological and therapeutic roles they play in corneal scarring/fibrosis.
Topics: Cicatrix; Cornea; Corneal Diseases; Corneal Injuries; Extracellular Vesicles; Fibrosis; Humans; Wound Healing
PubMed: 35682600
DOI: 10.3390/ijms23115921 -
Survey of Ophthalmology 2020Ocular complications from diabetes mellitus are common. Diabetic keratopathy, the most frequent clinical condition affecting the human cornea, is a potentially... (Review)
Review
Ocular complications from diabetes mellitus are common. Diabetic keratopathy, the most frequent clinical condition affecting the human cornea, is a potentially sight-threatening condition caused mostly by epithelial disturbances that are of clinical and research attention because of their severity. Diabetic keratopathy exhibits several clinical manifestations, including persistent corneal epithelial erosion, superficial punctate keratopathy, delayed epithelial regeneration, and decreased corneal sensitivity, that may lead to compromised visual acuity or permanent vision loss. The limited amount of clinical studies makes it difficult to fully understand the pathobiology of diabetic keratopathy. Effective therapeutic approaches are elusive. We summarize the clinical manifestations of diabetic keratopathy and discuss available treatments and up-to-date research studies in an attempt to provide a thorough overview of the disorder.
Topics: Cornea; Corneal Diseases; Diabetes Mellitus; Humans
PubMed: 32092364
DOI: 10.1016/j.survophthal.2020.02.005