mature cataract

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opacity of the lens of the eye or its capsule. adj., adj catarac´tous.
Causes and Symptoms. Some cataracts result from injuries to the eye, exposure to great heat or radiation, or inherited factors. The great majority, however, are “senile” cataracts, which are apparently a part of the aging process of the human body.

Blurred and dimmed vision are often the first symptoms. The patient may find that a brighter reading light is needed, or objects must be held closer to the eyes for better vision. Continued clouding of the lens may cause double vision; eventually there may be a need for frequent changes of eyeglasses. These symptoms do not necessarily indicate cataract, but if any of them are present, an ophthalmologist should be consulted immediately.
Treatment. The only known effective treatment for cataract is surgical removal of the lens (lens extraction or cataract extraction). The procedure of choice was formerly intracapsular extraction, with total removal of the lens within its capsule. This may be done by forceps or by cryoextraction using a supercooled metal probe that forms a bond with the lens capsule. The inner portion of the lens can be removed by emulsification and aspiration. More recently the removed cataract has been replaced with a plastic intraocular lens. In this procedure the inner portions of the lens (the nucleus and cortex) may be all that is removed; the capsule is retained and the intraocular lens is placed inside it.

The lens of the eye serves only to focus light rays upon the retina. After cataract extraction the loss of the natural lens is compensated for by either special eyeglasses or contact lenses. Implantation of a permanent artificial lens, either during cataract surgery or later, is an alternative to use of cataract spectacles and a removable contact lens.
Patient Care. Eye drops are administered to produce mydriasis and vasoconstriction. Because these patients may have extremely poor eyesight, care should be taken that they do not injure themselves. (See also vision.) Local anesthesia is usually preferred for the surgical procedure and preoperative medications are given to produce drowsiness. Ambulatory care surgery with same-day admission and discharge is becoming increasingly routine. Careful observation of the patient on follow-up visits is important. One needs to be on the alert for a complaint of pain in the eye followed by nausea and vomiting. These could be signs that the patient has increased intraocular pressure within the operative eye and measures need to be taken to reduce the pressure.
after-cataract any membrane of the pupillary area after extraction or absorption of the lens. See also secondary cataract.
atopic cataract cataract occurring, most often in the second to third decade, in those with longstanding atopic dermatitis.
brown cataract (brunescent cataract) senile cataract appearing as a brown opacity.
capsular cataract one consisting of an opacity of the capsule of the lens.
complicated cataract secondary cataract.
cortical cataract an opacity in the cortex of the lens.
hypermature cataract one in which the entire lens capsule is wrinkled and the contents have become solid and shrunken, or soft and liquid.
immature cataract (incipient cataract) an incomplete cataract; the lens is only slightly opaque and the cortex clear.
intumescent cataract a mature cataract that progresses; the lens becomes swollen from the osmotic effect of degenerated lens protein, and this may lead to secondary angle closure (acute) glaucoma.
lenticular cataract opacity of the lens not affecting the capsule.
mature cataract a cataract that produces swelling and opacity of the entire lens; cataracts are removed before maturity.
presenile cataract a subcapsular senile cataract in a person under 40 years of age.
secondary cataract a cataract, usually posterior subcapsular, that arises from either disease (especially iridocyclitis), degeneration (such as chronic glaucoma or retinal detachment), or surgery (such as glaucoma filtering or retinal reattachment).
senile cataract cataract with no obvious cause occurring in persons over 50 years old.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

ma·ture cat·a·ract

a cataract in which both the nucleus and cortex are opaque.
Farlex Partner Medical Dictionary © Farlex 2012

ma·ture cat·a·ract

(mă-chūr' kat'ăr-akt)
A cataract in which both the nucleus and cortex are opaque.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Phacolytic glaucoma was diagnosed clinically based on the presence of the hyper mature cataract with intact capsule, presence of lens protein and flare in AC.
Etology of LIG: In this study 51% cases were mature / hyper mature cataracts. 42% were immature cataracts, 5% were traumatic cataracts, 2% were dislocated cataracts.
RESULTS: In this study 100 eyes with mature cataract with inability to see beyond lens by direct or indirect ophthalmoscope were investigated with B-Scan ultrasound.
Asymmetrical rhexis, especially in mature cataracts and hyper mature cataracts, deformed haptics and zonular weakness causes IOL decentration [21].
However, it may not be feasible to perform phacoemulsification in all cases undergoing a triple procedure due to the lack of resources (especially in developing economies) or expertise (very dense mature cataracts) or both.
He and his colleagues observed L-carnosine levels are "markedly" higher in a transparent lens compared to one with mature cataracts: about 25 [mu]M in transparent lenses and about 5 [mu]M in those with mature cataracts.
The eldest patient treated at the Tanguila camp was a 85-year-old man with mature cataracts, whose vision had been reduced to light perception only; the youngest was a 20-years-old girl with congenital cataracts and severe vision deterioration.
The oldest patient treated at the Tanguila camp in Bangladesh was an 85-year-old man with mature cataracts, whose vision had been reduced to light perception only; the youngest was a 20-years-old girl with congenital cataracts and severe vision deterioration.
She was 23 and completely blind from mature cataracts. She had no prospects in life, no chance to participate in family life, marry, bring up children, contribute to society - all those fundamentals of life which we here in Britain take for granted.
The 31 articles cover nightmares ranging from machine and technique problems with phacoemulsification, difficult cases such as mature cataracts and dyes or floppy iris syndrome, anterior segment problems such as posterior capsular rupture and intraocular lens opacification, posterior segment problems such as malpositioned intraocular implants, and bimanual phacoemulsification problems such as microphakonit.
Ophthalmologists from India and the US cover gas forced infusion, no-anesthesia cataract surgery with the karate chop technique, phacoemulsification in subluxated cataracts, mature cataracts, small pupil phacoemulsification, combined cataract and glaucoma surgery, managing dislocated lens fragments, the malpositioned intraocular implant, infectious endophthalmitis, cystoid macular edema, ophthalmic viscosurgical device surgery, bimanual phacoemulsification/Phakonit/MICS (micro-incision cataract surgery), microphakonit, glued intrascleral haptic fixation of the intraocular lens, glued intraocular lens surgery with add-on procedures, intraocular lens scaffold, and pars plicata anterior vitrectomy.