Transcript Раптова втрата зору. Гострий приступ гла

Lecture 3
CATARACTS
Classification of cataracts:
By age: congenital, juvenile, age-related (senile)
By location opacities in the lens as seen with slit
beam: cortical, nuclear, anterior subcapsular,
posterior subcapsular
By maturity: early, immature, mature,
hypermature (Morgagnian cataract)
By pattern: cuneiform (typical senile type),
zonular, polar, pyramidal (congenital types)
DIFFERENTIAL DIAGNOSIS
The same sign is progressive (not acute) painless visual loss
CATARACT
Sign
Visual acuity
Field
vision
GLAUCOMA
MACULAR
DEGENERATION
is decreased
of is not damaged
constriction of nasal may
be
visual field, Bjerrum’s scotoma
scotoma
Intraocular
pressure
normal,
increased
normal
Lens
opaque
transparent,
transparent,
Fundus
If
is
seen,
damaged.
if increased-secondary
phakogenic glaucoma
central
if opaque– complicated if opaque– complicated
cataract
cataract
not optic disc changes - degenerative patches
dislocation of vessels, in central area
If
damaged
- pale colour, increased
complicated cataract
cupping
Artificial lens
Artiphakia is a condition of eye with artificial lens (IOL).
Aphakia is a condition of eye without lens. The visual acuity
without correction is very poor – 0,02-0,04. Iridodenesis (iris
vibration) is typical.
Thick plus glasses are needed for vision:
for far distance – sph convex 10,0-12,0 D
for near distance – sph convex 13,0-15,0 D.
Secondary cataract occurs eventually in about 20 % cases after
cataract surgery. It is opacity of natural posterior capsule. It
can be treated by YAG laser capsulotomy.
Attention! The term «complicated cataract» is used to describe
a lens opacity which occurs as a result of some other disease of
the eye. Longstanding uveitits, an untreated retinal detachment
or an intraocular tumour are all examples of an associated
disease.
CONGENITAL CATARACTS :
I degree – visual acuity is 0,3 and more; the size
of opacity is less then 1,5 mm; the surgery may
be done at the age of 14-16 years.
II degree– visual acuity is 0,05-0,2; the surgery
is usually done at the age of 3-4 years.
III degree– visual acuity is less then 0,05; the
surgery must be done during first year of life.
Ectopia lentis (displacement of the lens) may be
partial (subluxation) or complete (luxation).
Aethiology: trauma, familial ectopia lentis (may be
associated with ectopic pupil), associated with
other ocular disorders (aniridia and buphtalmos),
Marfan’s and Weill-Marchesani syndromes,
metabolic (homocystinuria and hyperlysinaemia).
Clinical features: iridodenesis (vibration of iris)
and not proportional depth of anterior chamber.
Marfan’s syndrome: tall person with partial
displacement of the lens (subluxation), fragile
bones and arachnodactyly.
THANK YOU FOR ATTENTION !