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Hydrodelineation
Hydrodelineation is a method of separating an outer shell (or multiple shells) of the lens of the eye from the central compact mass of inner nuclear cataract (also called endonucleus) during a cataract surgery by the forceful irrigation of a fluid into the mass of the nucleus. While hydrodissection disconnects the lens from the lens capsule, hydrodelineation splits it into endonuclear and epinuclear sections thus reducing the size of the hard nucleus, making its extraction possible through a smaller incision. This also facilitates phacoemulsification. An injection of fluid into the body of the lens through the cortex against the nucleus of a cataract separates the hardened nuclear cataract from the softer lens cortex shell by flowing along the interface between them. The smaller hard nucleus can then be expeditiously phacoemulsified, while the posterior cortecx serves as a buffer protecting the posterior capsule membrane. The smaller size of the separated nucleus requires less d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens (anatomy)
The lens, or crystalline lens, is a transparent biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. By changing shape, it functions to change the focal length of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. This adjustment of the lens is known as '' accommodation'' (see also below). Accommodation is similar to the focusing of a photographic camera via movement of its lenses. The lens is flatter on its anterior side than on its posterior side. In humans, the refractive power of the lens in its natural environment is approximately 18 dioptres, roughly one-third of the eye's total power. Structure The lens is part of the anterior segment of the human eye. In front of the lens is the iris, which regulates the amount of light entering into the eye. The lens is suspended in place by the suspensory ligament of the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Sclerosis
Nuclear sclerosis is an age-related change in the density of the crystalline lens nucleus that occurs in all older animals. It is caused by compression of older lens fibers in the nucleus by new fiber formation. The denser construction of the nucleus causes it to scatter light. Although nuclear sclerosis may describe a type of early cataract in human medicine,Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company, 1990. in veterinary medicine the term is also known as lenticular sclerosis and describes a bluish-grey haziness at the nucleus that usually does ''not'' affect vision, except for unusually dense cases. Immature senile cataract has to be differentiated with nuclear sclerosis while making its diagnosis. Veterinary Medicine In veterinary practice, nuclear sclerosis is a consistent finding in dogs greater than six years old. Nuclear sclerosis appears as a bilateral bluish-grey haziness at the nucleus, or center of the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrodissection
Hydrodissection is the process of injecting small amounts of a special fluid into the capsule of the lens in the eye in order to make dissection easier. It makes the surgeon more capable of performing maneuvers during extracapsular or phacoemulsification surgeries. Hydrodissection in general surgery means injection of small amounts of fluid to release a trapped nerve or to reduce intraoperative blood losses. See also * Cataract surgery Cataract surgery, also called lens replacement surgery, is the removal of the natural lens of the eye (also called "crystalline lens") that has developed an opacification, which is referred to as a cataract, and its replacement with an intraocul ... References Eye surgery Human eye anatomy Lenses {{surgery-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacoemulsification
Phacoemulsification is a modern cataract surgery method in which the eye's internal lens is emulsified with an ultrasonic handpiece and aspirated from the eye. Aspirated fluids are replaced with irrigation of balanced salt solution to maintain the anterior chamber. Etymology The term originated from phaco- (Greek ''phako-'', comb. form of ''phakós'', lentil; see lens) + emulsification. Preparation and precautions Proper anesthesia is essential for ocular surgery. Topical anesthesia is most commonly employed, typically by the instillation of a local anesthetic such as tetracaine or lidocaine. Alternatively, lidocaine and/or longer-acting bupivacaine anesthetic may be injected into the area surrounding (peribulbar block) or behind ( retrobulbar block) the eye muscle cone to more fully immobilize the extraocular muscles and minimize pain sensation. A facial nerve block using lidocaine and bupivacaine may occasionally be performed to reduce lid squeezing. General anest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
