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Abbreviation for:
Pediatric Symptom Checklist
peptide-sensitive channel
peripheral stem cell
Pharmaceutical Services Committee 
posterior semicircular canal
posterior subcapsular cataract
Postmarket Strategies Committee
Primary Service Co-ordinator
primary sclerosing cholangitis
primary synovial chondromatosis
primitive stem cells
prospective studies collaboration
public sector comparator
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


(kat'a-rakt?) [L. catar(r)acta, fr Gr. katarraktes, waterfall]
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CATARACT: (Courtesy of Christine Chung, MD)
An opacity of the lens of the eye, usually occurring as a result of aging, trauma, endocrine or metabolic disease, intraocular disease, or as a side effect of the use of tobacco or certain medications, e.g., steroids. Cataracts are the most common cause of blindness in adults. See: illustration; visual field for illus.


At first, vision is distorted, particularly during night driving or in very bright light, causing light sensitivity (photophobia). As the cataract progresses, severe visual impairment develops.


Ninety percent of adults over 65 have cataracts.


Removal of the lens is the only effective treatment. In the U.S. about a million cataract surgeries are performed annually, usually as an outpatient, same-day procedure. Typically, the lens and its anterior capsule are removed by extracapsular extraction or by phacoemulsification, leaving the posterior capsule of the lens in place, and a posterior chamber intraocular lens is inserted where the patient’s own lens used to be. See: extracapsular extraction; intraocular lens; phacoemulsification

Patient care

Preoperative: The procedure is explained to the patient. An antiseptic facial scrub is performed. Mydriatic and cycloplegic eye drops are instilled to dilate the pupil, followed by lidocaine jelly and betadine drops prior to surgery; osmotic diuretics may be given to reduce intraocular pressure. An intravenous access is initiated, and antibiotics, a sedative, short-acting general anesthetic, and a local anesthetic are provided.

Postoperative: The patient is instructed to wear a clear eyeshield if prescribed, and to call if experiencing pain, or loss of vision. Blurred vision the day of surgery is to be expected. Eye drops are to be placed as directed and the patient should not swim or strain himself. A postoperative checkup visit is scheduled for the day following surgery. Both patient and family are taught how to inspect the eye for redness or watering and to report these conditions as well as any photophobia or sudden visual changes; wash hands well and then to instill eye drops (antibiotic to prevent inflammation and steroids to reduce infection) as prescribed; and to maintain the eye patch and shield as prescribed by the surgeon. The patient should be taught to protect the eye from bright sunlight or glare by wearing dark glasses. The patient should not swim or strain himself or herself.

capsular cataract

A cataract occurring in the capsule of the ocular lens.

cortical cataract

A cataract that develops in the cortex of the lens. It has a spiky or spoked appearance on physical examination of the eye.

hypermature cataract

A cataract in which the lens solidifies and shrinks. This stage follows the mature stage.

immature cataract

An early cataract, too poorly developed to require therapy.

lenticular cataract

A cataract occurring in the lens.

mature cataract

Sufficiently dense changes in the anterior cortex of the lens to prevent the examiner from viewing the posterior portion of the lens and the posterior portion of the eye; that is, the entire lens is opaque and ophthalmoscopic examination of the eye past the lens is not possible.

morgagnian cataract

See: Morgagni cataract

nuclear cataract

, nuclear sclerotic c.
A cataract in which the central portion of the lens is opacified.

posterior cortical cataract

Posterior subcapsular cataract.

posterior subcortical cataract

Posterior subcapsular cataract.

posterior subcapsular cataract

Abbreviation: PSC
A cataract between the posterior capsule and cortex. It is more common in younger patients, diabetics, and patients who use steroids. It tends to diminish near vision before it affects distance vision.
Synonym: posterior subcortical cataract; posterior cortical cataract

radiation cataract

A cataract caused by exposure to radiation, esp. from sunlight.

senile cataract

A cataract occurring in an older person.

zonular cataract

A cataract with opacity limited to certain layers of the lens.

posterior subcapsular cataract

Abbreviation: PSC
A cataract between the posterior capsule and cortex. It is more common in younger patients, diabetics, and patients who use steroids. It tends to diminish near vision before it affects distance vision.
Synonym: posterior subcortical cataract; posterior cortical cataract
See also: cataract
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
'Submit to PSC and POC the required financial reports and make available all records and documents, including disbursement vouchers, relative to the utilization of the funds,' the agreement read.
Effective July 1 last year, airport operator Malaysia Airports Holdings Bhd (MAHB) imposed a higher PSC of RM73 per person.
Kim Raissa Uy, Assistant Secretary Joseph Encabo of the Presidential Management Staff and PSC Executive Director Merlita Ibay.
'I have already explained that the PSC must work within the existing auditing and accounting rules in the transaction,'' added Ramirez.
Cojuangco had made the remark after another dispute between the POC and PSC.
PSC Shove-It - This is a is fiberglass pole designed to push against flat surfaces, corners or rounded edges of suspended loads, move pipe and tubular with the "V" shaped end and manoeuvre and grab slings and taglines with the opposing hooks.
'It gives me immense pleasure to note that the restructured institution of PSC has succeeded in effectively clearing backlog of unfilled posts in government departments,' he said.
The president assured that both the Presidency and the government will extend full cooperation to the PSC in its endeavours to make civil servants induction process more transparent and merit based.
PSC is a chronic, progressive liver disease characterised by inflammation and fibrosis of the bile ducts, leading to the formation of multifocal bile duct strictures.
The compere, director events of PSC and prominent poet, Qamar Riaz, highly admired Aslam's outstanding efforts as an ex-director of PSM's BoDs and PSC's BoDs, towards promoting education, literature and social work for his countrymen in North Batinah region and Muscat governorate.
The tournament is limited to 32 teams and entries will be accepted on first-come-first-serve basis," PSC vice-chairman Shabbir Ahmed Nadeem said.