Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite. The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison.
Polyvinylpyrrolidone (PVP), also commonly called polyvidone or povidone, is a water-soluble polymer compound made from the monomer N-vinylpyrrolidone. PVP is available in a range of molecular weights and related viscosities, and can be selected according to the desired application properties.
A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or double vision, halos around light, trouble with bright lights, and difficulty seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts cause 51% of all cases of blindness and 33% of visual impairment worldwide.
In anatomy, a crystallin is a water-soluble structural protein found in the lens and the cornea of the eye accounting for the transparency of the structure. It has also been identified in other places such as the heart, and in aggressive breast cancer tumors. Since it has been shown that lens injury may promote nerve regeneration, crystallin has been an area of neural research. So far, it has been demonstrated that crystallin β b2 (crybb2) may be a neurite-promoting factor.
Phacoemulsification is a cataract surgery method in which the internal lens of the eye which has developed a cataract is emulsified with the tip of an ultrasonic handpiece and aspirated from the eye. Aspirated fluids are replaced with irrigation of balanced salt solution to maintain the volume of the anterior chamber during the procedure. This procedure minimises the incision size and reduces the recovery time and risk of surgery induced astigmatism.
Cataract surgery, also called lens replacement surgery, is the removal of the natural lens of the eye that has developed a cataract, an opaque or cloudy area. The eye's natural lens is usually replaced with an artificial intraocular lens (IOL) implant.
The selenate ion is SeO2−
4.
Iron(II) hydroxide or ferrous hydroxide is an inorganic compound with the formula Fe(OH)2. It is produced when iron(II) salts, from a compound such as iron(II) sulfate, are treated with hydroxide ions. Iron(II) hydroxide is a white solid, but even traces of oxygen impart a greenish tinge. The air-oxidised solid is sometimes known as "green rust".
Corneal abrasion is a scratch to the surface of the cornea of the eye. Symptoms include pain, redness, light sensitivity, and a feeling like a foreign body is in the eye. Most people recover completely within three days.
Selenite refers to the anion with the chemical formula SeO2−3. It is the oxyanion of selenium. It is the selenium analog of the sulfite ion, SO2−3. Thus selenite is pyramidal and selenium is assigned oxidation state +4. Selenite also refers to compounds that contains this ion, for example sodium selenite Na2SeO3 which is a common source of selenite. Selenite also refers to the esters of selenous acid, for example dimethyl selenite (CH3)2SeO3.
Calcium hypochlorite is an inorganic compound with formula Ca(ClO)2. It is a white solid, although commercial samples appear yellow. It strongly smells of chlorine, owing to its slow decomposition in moist air. This compound is relatively stable as a solid and solution and has greater available chlorine than sodium hypochlorite. "Pure" samples have 99.2% active chlorine. Given common industrial purity, an active chlorine content of 65-70% is typical. It is the main active ingredient of commercial products called bleaching powder, used for water treatment and as a bleaching agent.
Lanosterol is a tetracyclic triterpenoid and is the compound from which all animal and fungal steroids are derived. By contrast, plant steroids are produced via cycloartenol.
Endophthalmitis, or endophthalmia, is inflammation of the interior cavity of the eye, usually caused by an infection. It is a possible complication of all intraocular surgeries, particularly cataract surgery, and can result in loss of vision or loss of the eye itself. Infection can be caused by bacteria or fungi, and is classified as exogenous, or endogenous. Other non-infectious causes include toxins, allergic reactions, and retained intraocular foreign bodies. Intravitreal injections are a rare cause, with an incidence rate usually less than 0.05%.
Johnson & Johnson Vision (JJV) is a subsidiary of Johnson & Johnson and is composed of two divisions, Johnson & Johnson Surgical Vision and Johnson & Johnson Vision Care. Services include Intraocular lenses, laser vision correction systems, phacoemulsification systems, viscoelastic, Microkeratomes and related products used in cataract and refractive surgery.
Capsulorhexis or capsulorrhexis, and the commonly used technique known as continuous curvilinear capsulorhexis (CCC), is a surgical technique used to remove the central anterior part of the capsule of the lens from the eye during cataract surgery by shear and tensile forces. It generally refers to removal of the central part of the anterior lens capsule, but in situations like a developmental cataract a part of the posterior capsule is also removed by a similar technique.
Bromfenac is a nonsteroidal anti-inflammatory drug (NSAID) marketed in the US as an ophthalmic solution by ISTA Pharmaceuticals for short-term, local use. Prolensa and Bromday are the once-daily formulation of bromfenac, while Xibrom was approved for twice-daily administration. In the European Union, the brand name is Yellox. Bromfenac is indicated for the treatment of ocular inflammation and pain after cataract surgery.
Visual perception in animals plays an important role in the animal kingdom, most importantly for the identification of food sources and avoidance of predators. For this reason, blindness in animals is a unique topic of study.
Congenital cataracts are a lens opacity that is present at birth. Congenital cataracts occur in a broad range of severity. Some lens opacities do not progress and are visually insignificant, others can produce profound visual impairment.
Calcium perchlorate is classified as a metal perchlorate salt with the molecular formula Ca(ClO4)2. It is an inorganic compound that is a yellow-white crystalline solid in appearance. As a strong oxidizing agent, it reacts with reducing agents when heated to generate heat and products that may be gaseous. Calcium perchlorate has been categorized as having explosive reactivity. Ca(ClO4)2 is a common chemical on the soil of planet Mars, counting for almost 1% of the Martian dust, by weight.
Phacolytic glaucoma (PG) is a form of glaucoma which is caused due to a leaking mature or immature cataract. Inflammatory glaucoma which occurs in phacolysis is a condition which is a result of the leakage of protein within the lens into the capsule of a mature or hyper mature cataract and involves a simple procedure to be cured that is referred to as cataract extraction.
