Nuclear sclerosis
3995475
155192920
2007-09-02T11:18:39Z
GregorB
179697
[[Category:Dog diseases]]
[[Image:Nuclear sclerosis 1.JPG|thumb|Nuclear sclerosis]]
'''Nuclear sclerosis''' is an age-related change in the [[density]] of the [[lens (anatomy)|crystalline lens]] nucleus that occurs in all older animals.<ref>[http://www.vetmed.iastate.edu/services/vth/clinical/ophth/faq-vet.asp#sclerosis "Cataract Surgery – FAQs: What is nuclear sclerosis?"] Iowa State University, College of Veterinary Medicine, Veterinary Teaching Hospital, Ophthalmology Department. Accessed November 18, 2006.</ref> It is caused by compression of older lens fibers in the nucleus by new fiber formation. The more dense construction of the nucleus causes it to [[scattering|scatter]] light. Although nuclear sclerosis may describe a type of early [[cataract]] in [[medicine|human medicine]]<ref name="Cassin">Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainsville, Florida: Triad Publishing Company, 1990.</ref>, 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.<ref>{{cite web | last = Sapienza | first = John S. | title = Cataracts | work = Proceedings of the 27th World Congress of the World Small Animal Veterinary Association | date = 2002 | url = http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2002&PID=2648 | accessdate = 2007-03-13 }}</ref>
==Veterinary medicine==
In veterinary practice, nuclear sclerosis is a consistent finding in [[dogs]] greater than seven years old.<ref name=Gelatt_1999>{{cite book|author=Gelatt, Kirk N. (ed.)|title=Veterinary Ophthalmology|edition=3rd ed.|publisher=Lippincott, Williams & Wilkins|year=1999|id=ISBN 0-683-30076-8}}</ref> Nuclear sclerosis appears as a bilateral bluish-grey haziness at the nucleus, or center of the lens, caused by an increase in the [[refractive index]] of that part of the lens due to its increased density. It is often confused with cataracts. The condition is differentiated from a cataract by its appearance and by shining a penlight into the eye. With nuclear sclerosis, a reflection from the [[tapetum lucidum|tapetum]] will be seen, while a cataract will block reflection.<ref>{{cite web | last = Petersen-Jones | first = Simon M. | title = Conditions of the Lens | work = Proceedings of the 28th World Congress of the World Small Animal Veterinary Association | date = 2003 | url = http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2003&PID=6686&O=Generic | accessdate = 2007-03-13 }}</ref>
==References==
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==External links==
*[http://www.opt.indiana.edu/riley/HomePage/Age_related_Cats/2Text_age_related_cats.html Images]
[[Category:Dog diseases]]
[[Category:Ophthalmology]]
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