Cataract classification: Difference between revisions
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* Hereditary | * Hereditary | ||
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* Congenital cataract - Result of heredity (often autosomal dominant), prenatal infections such as rubella or metabolic disorders. | * '''Congenital cataract''' - Result of heredity (often autosomal dominant), prenatal infections such as rubella or metabolic disorders. | ||
*# Intrauterine infections e.g. [[Congenital rubella syndrome|Rubella]] and [[Toxoplasmosis congenital|Toxoplasmosis]]. | *# Intrauterine infections e.g. [[Congenital rubella syndrome|Rubella]] and [[Toxoplasmosis congenital|Toxoplasmosis]]. | ||
*# Maternal drug ingestion e.g. [[Thalidomide]] and corticosteroids. | *# Maternal drug ingestion e.g. [[Thalidomide]] and corticosteroids. | ||
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*# Ocular conditions with associated anomalies e.g. [[Retinopathy of Prematurity]] and some types of retinitis pigmentosa. | *# Ocular conditions with associated anomalies e.g. [[Retinopathy of Prematurity]] and some types of retinitis pigmentosa. | ||
*# Secondary to metabolic disorders e.g. [[Galactosemia]] and [[Wilson's disease|Wilson’s disease]] | *# Secondary to metabolic disorders e.g. [[Galactosemia]] and [[Wilson's disease|Wilson’s disease]] | ||
* Degenerative or "Age-Related" (senile)- Most adults have some degree of opacification of the lens and therefore technically exhibit cataract. | * '''Degenerative or "Age-Related" (senile)'''- Most adults have some degree of opacification of the lens and therefore technically exhibit cataract. | ||
*# Subcapsular Anterior subcapsular cataract (directly under the capsule) is associated with fibrous metaplasia of anterior lens epithelium. Posterior subcapsular cataract (cupuliform) lies just in front of the posterior capsule and is associated with posterior migration of epithelial cells. | *# Subcapsular Anterior subcapsular cataract (directly under the capsule) is associated with fibrous metaplasia of anterior lens epithelium. Posterior subcapsular cataract (cupuliform) lies just in front of the posterior capsule and is associated with posterior migration of epithelial cells. | ||
*# Cortical cataract commonly develops as radial or spoke-shaped “water-clefts” (cuneiform) together with vacuoles. Cuneiform changes affect anterior, posterior and equatorial cortex affected. | *# Cortical cataract commonly develops as radial or spoke-shaped “water-clefts” (cuneiform) together with vacuoles. Cuneiform changes affect anterior, posterior and equatorial cortex affected. | ||
*# Nuclear sclerosis Nuclear cataract is an exacerbation of the normal aging of lens nucleus and appears as a yellowing of the nucleus. | *# Nuclear sclerosis Nuclear cataract is an exacerbation of the normal aging of lens nucleus and appears as a yellowing of the nucleus. | ||
*''' | *'''Traumatic''' - Trauma is the commonest cause of unilateral cataract in young individuals. Opacities can be the result of various injuries including penetrating injury. Concussion to the eye may cause the iris to be flattened against the lens leaving a Vossius’ ring. | ||
*''' | *'''Secondary''' - Cataract can occur secondary to systemic disease or syndromes including metabolic disorders and due to local disease (ocular). | ||
**Secondary to systemic diseases/metabolic disorders | **Secondary to systemic diseases/metabolic disorders | ||
**#Diabetes - Diabetes mellitus can cause an exacerbation of the progression of age-related degenerative changes. So-called (classical) diabetic cataract occurs during an acute and untreated hyperglycaemic episode and takes the form of cortical “snowflakes”. These occur due to osmotic over-hydration of the lens and can be anterior and/or posterior in position. | **#Diabetes - Diabetes mellitus can cause an exacerbation of the progression of age-related degenerative changes. So-called (classical) diabetic cataract occurs during an acute and untreated hyperglycaemic episode and takes the form of cortical “snowflakes”. These occur due to osmotic over-hydration of the lens and can be anterior and/or posterior in position. | ||
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**#High myopia - Hight myopia can be associated with secondary posterior lens opacities as well as the earlier development of nuclear sclerosis. | **#High myopia - Hight myopia can be associated with secondary posterior lens opacities as well as the earlier development of nuclear sclerosis. | ||
**#Glaukomflecken - These are grey-white anterior capsular or subcapsular opacities in pupillary zone pathognomonic with previous attacks of acute angle-closure glaucoma. | **#Glaukomflecken - These are grey-white anterior capsular or subcapsular opacities in pupillary zone pathognomonic with previous attacks of acute angle-closure glaucoma. | ||
*'''Toxic ''' | |||
*#Corticosteroids - Steroids used for prolonged therapy produce a posterior subcapsular cataract. | |||
*#Amiodarone - Amiodarone can cause anterior capsular changes in up to 50% of patients. The opacities tend to be visually insignificant. | |||
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Revision as of 18:05, 22 February 2018
Cataract Microchapters |
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Cataract classification On the Web |
American Roentgen Ray Society Images of Cataract classification |
Risk calculators and risk factors for Cataract classification |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Rohan Bir Singh, M.B.B.S.[2]
Overview
Classification
The classification of cataracts is based on four different criteria.
- Morphology,
- Age of Onset
- Maturity
- Etiology
- Location of opacity
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Morphology |
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Maturity |
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Location of opacity |
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Etiological |
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- Congenital cataract
- Sutural cataract
- Lamellar cataract
- Zonular cataract
- Total cataract
- Secondary cataract
- Drug-induced cataract (e.g. Corticosteroids)
- Traumatic cataract
- Blunt trauma (capsule usually intact)
- Penetrating trauma (capsular rupture & leakage of lens material - calls for an emergency surgery for extraction of lens and leaked material to minimize further damage)
- Nuclear cataract - Grading correlates with hardness & difficulty of surgical removal
- 1 - Grey
- 2 - Yellow
- 3 - Amber
- 4 - Brown/Black (Note: "Black cataract" translated in some languages (like Hindi) refers to Glaucoma, not the color of the lens nucleus)
- After-cataract - posterior capsular opacification subsequent to a successful extracapsular cataract surgery (usually within 3 months - 2 years) with or without IOL implantation. Requires a quick & painless office procedure with Nd:YAG laser capsulotomy to restore optical clarity.