Lens Capsule, Crystalline
Anterior Capsule of the Lens
Capsulorhexis
The making of a continuous circular tear in the anterior capsule during cataract surgery in order to allow expression or phacoemulsification of the nucleus of the lens. (Dorland, 28th ed)
Lens Diseases
'Lens diseases' is a broad term referring to various pathological conditions affecting the lens of the eye, including cataracts, subluxation, and dislocation, which can lead to visual impairment or blindness if not managed promptly.
Lenses, Intraocular
Artificial implanted lenses.
Joint Capsule
Cataract
Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)
Cataract Extraction
The removal of a cataractous CRYSTALLINE LENS from the eye.
Lens Implantation, Intraocular
Insertion of an artificial lens to replace the natural CRYSTALLINE LENS after CATARACT EXTRACTION or to supplement the natural lens which is left in place.
Acrylic Resins
Acrylic resins, also known as polymethyl methacrylate (PMMA), are a type of synthetic resin formed from polymerized methyl methacrylate monomers, used in various medical applications such as dental restorations, orthopedic implants, and ophthalmic lenses due to their biocompatibility, durability, and transparency.
Lens, Crystalline
A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.
Phacoemulsification
A procedure for removal of the crystalline lens in cataract surgery in which an anterior capsulectomy is performed by means of a needle inserted through a small incision at the temporal limbus, allowing the lens contents to fall through the dilated pupil into the anterior chamber where they are broken up by the use of ultrasound and aspirated out of the eye through the incision. (Cline, et al., Dictionary of Visual Science, 4th ed & In Focus 1993;1(1):1)
Polymethyl Methacrylate
Polymerized methyl methacrylate monomers which are used as sheets, moulding, extrusion powders, surface coating resins, emulsion polymers, fibers, inks, and films (From International Labor Organization, 1983). This material is also used in tooth implants, bone cements, and hard corneal contact lenses.
Laser Therapy
Lenses
Bacterial Capsules
An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.
Capsule Endoscopy
Non-invasive, endoscopic imaging by use of VIDEO CAPSULE ENDOSCOPES to perform examination of the gastrointestinal tract, especially the small bowel.
Contact Lenses, Hydrophilic
Soft, supple contact lenses made of plastic polymers which interact readily with water molecules. Many types are available, including continuous and extended-wear versions, which are gas-permeable and easily sterilized.
Lens Cortex, Crystalline
Capsule Endoscopes
Crystallins
A heterogeneous family of water-soluble structural proteins found in cells of the vertebrate lens. The presence of these proteins accounts for the transparency of the lens. The family is composed of four major groups, alpha, beta, gamma, and delta, and several minor groups, which are classed on the basis of size, charge, immunological properties, and vertebrate source. Alpha, beta, and delta crystallins occur in avian and reptilian lenses, while alpha, beta, and gamma crystallins occur in all other lenses.
Internal Capsule
Contact Lenses, Extended-Wear
Hydrophilic contact lenses worn for an extended period or permanently.
Lens Subluxation
Contact Lens Solutions
Sterile solutions used to clean and disinfect contact lenses.
Posterior Capsule of the Lens
Presbyopia
Fungal Capsules
Bowman Capsule
Accommodation, Ocular
The dioptric adjustment of the EYE (to attain maximal sharpness of retinal imagery for an object of regard) referring to the ability, to the mechanism, or to the process. Ocular accommodation is the effecting of refractive changes by changes in the shape of the CRYSTALLINE LENS. Loosely, it refers to ocular adjustments for VISION, OCULAR at various distances. (Cline et al., Dictionary of Visual Science, 4th ed)
Subrenal Capsule Assay
Capsule Opacification
Clouding or loss of transparency of the posterior lens capsule, usually following CATARACT extraction.
Refraction, Ocular
Refraction of LIGHT effected by the media of the EYE.
Eye Proteins
'Eye proteins' are structural or functional proteins, such as crystallins, opsins, and collagens, located in various parts of the eye, including the cornea, lens, retina, and aqueous humor, that contribute to maintaining transparency, refractive power, phototransduction, and overall integrity of the visual system.
Silicones
Eye
beta-Crystallins
A class of crystallins that provides refractive power and translucency to the lens (LENS, CRYSTALLINE) in VERTEBRATES. Beta-crystallins are similar in structure to GAMMA-CRYSTALLINS in that they both contain Greek key motifs. Beta-crystallins exist as oligomers formed from acidic (BETA-CRYSTALLIN A CHAIN) and basic (BETA-CRYSTALLIN B CHAIN) subunits.
Polysaccharides, Bacterial
Polysaccharides found in bacteria and in capsules thereof.
Aphakia
Absence of crystalline lens totally or partially from field of vision, from any cause except after cataract extraction. Aphakia is mainly congenital or as result of LENS DISLOCATION AND SUBLUXATION.
Eyeglasses
alpha-Crystallins
A subclass of crystallins that provides the majority of refractive power and translucency to the lens (LENS, CRYSTALLINE) in VERTEBRATES. Alpha-crystallins also act as molecular chaperones that bind to denatured proteins, keep them in solution and thereby maintain the translucency of the lens. The proteins exist as large oligomers that are formed from ALPHA-CRYSTALLIN A CHAIN and ALPHA-CRYSTALLIN B CHAIN subunits.
Epithelial Cells
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.