uvea

1. UVEA

2.  Uveal tissue constitutes the middle
vascular coat of the eyeball. From
anterior to posterior it can be divided
into three parts, namely, iris, ciliary
body and choroid.

3. CONGENITAL ANOMALIES OF
UVEAL TRACT
 HETEROCHROMIA OF IRIS
 It refers to variations in the iris color
and is a common congenital anomaly.
In heterochromia iridium colour of
one iris differs from the other.
 Sometimes, one sector of the iris may
differ from the remainder of iris; such a
condition is called heterochromia
iridis.

4.  CORECTOPIA
 It refers to abnormally eccentric
placed pupil.
 Normally pupil is placed slightly nasal
to the centre.
 POLYCORIA
 In this condition, there are more than
one pupil

5. CONGENITAL ANIRIDIA
(IRIDREMIA)
 It refers to congenital absence of iris.
 True aniridia, i.e., complete absence
of the iris is extremely rare.
 Usually, a peripheral rim of iris is
present and this condition is called
‘Clinical aniridia'.
 Zonules of the lens and ciliary
processes are often visible.

6. PERSISTENT PUPILLARY
MEMBRANE
 It represents the remnants of the
vascular sheath of the lens. It is
characterized by thread like-shaped
shreds of the pigmented tissue coming
from anterior surface of the iris
(attached at collarets).
 These float freely in the anterior
chamber or may be attached to the
anterior surface of the lens

8. CONGENITAL COLOBOMA
OF THE UVEAL TRACT
 Congenital coloboma (absence of
tissue) of iris, ciliary body and choroid
may be seen in association or
independently.
 Coloboma may be typical or atypical.
 Typical coloboma is seen in the
inferonasal quadrant and occurs due to
defective closure of the embryonic
fissure.
 Atypical coloboma is occasionally

10. UVEITIS
 The term uveitis strictly means
inflammation of the uveal tissue only.
 However, practically there is always
some associated inflammation of the
adjacent structures such as retina,
vitreous, sclera and cornea.

11. CLASSIFICATION
 I. ANATOMICAL CLASSIFICATION
 1. Anterior uveitis. It is inflammation of the
uveal tissue from iris up to pars plicata of
ciliary body.
 It may be subdivided into :
 Iritis, in which inflammation predominantly
affects the iris.
 Iridocyctitis in which iris and pars plicata
part of ciliary body are equally involved,
and
 Cyclitis, in which pars plicata part of ciliary

12.  2. Intermediate uveitis.
 It includes inflammation of the pars
plana and peripheral part of the retina
and underlying ‘choroid’. It is also called
‘pars planitis'.
 3. Posterior uveitis. It refers to
inflammation of the choroid (choroiditis).
Always there is associated inflammation
of retina and hence the term
‘chorioretinitis’ is used.
 4. Panuveitis. It is inflammation of the
whole uvea

13. II. CLINICAL
CLASSIFICATION
 1. Acute uveitis. It has got a sudden
symptomatic onset and the disease lasts
for about six weeks to 3 months.
 2. Chronic uveitis. It frequently has an
insidious and asymptomatic onset. It
persists longer than 3 months to even
years and is usually diagnosed when it
causes defective vision.

14. III. PATHOLOGICAL
CLASSIFICATION
 1. Supportive or purulent uveitis.
 2. Non-suppurative uveitis. It has been
further

15. IV. ETIOLOGICAL (DUKE ELDER'S)
CLASSIFICATION
 1. Infective uveitis
 2. Allergic uveitis
 3. Toxic uveitis
 4. Traumatic uveitis
 5. Uveitis associated with non-infective
systemic
 diseases
 6. Idiopathic uveitis

16. ETIOLOGY OF UVEITIS
 1. Infective uveitis.
 In this, inflammation of the uveal
tissue is induced by invasion of the
organisms. Uveal infections may be
exogenous, secondary or
endogenous.

17.  Exogenous infection wherein the
infecting organisms directly gain
entrance into the eye from outside.
 It can occur following penetrating
injuries, perforation of corneal ulcer and
postoperatively (after intraocular
operations).
 Secondary infection of the uvea
occurs by spread of infection from
neighboring structures,

18.  e.g., acute purulent conjunctivitis.
(pneumococcal and gonococcie),
kératites, scleraitis etc..
 Endogenous infections are caused
by the entrance of organisms from
some source situated elsewhere in the
body, by way of the bloodstream.

19. 2. Allergic (hypersensitivity linked)
uveitis
 i. Microbial allergy. In this, primary
source of infection is somewhere else
in the body and the escape of the
organisms or their products into the
bloodstream causes sensitization of
the uveal tissue with formation of
antibodies.

20.  ii. Anaphylactic uveitis.
 It is said to accompany the systemic
anaphylactic reactions like serum
sickness and angioneurotic edema.
 iii. Atopic uveitis.
 It occurs due to airborne allergens and
inhalants, e.g., seasonal iritis due to
pollens. A similar reaction to such
materials as dander's of cats, chicken
feather, house dust.

21.  iv. Autoimmune uveitis.
 It is found in association with
autoimmune disorders

22. 3. Toxic uveitis
 Toxins responsible for uveitis
 can be endotoxins, endocular toxins or
exogenous toxins
 i. Endotoxins
 These may be autotoxins or microbial
toxins (produced by organisms involving
the body tissues).
 Toxic uveitis seen in patients with acute
pneumococcal or gonococcal
conjunctivitis and in patients with fungal
corneal ulcer is thought to be due to
microbial toxins.

23.  ii. Endocular toxins
 - are produced from the ocular
tissues.
 Uveitis seen in patients with blind
eyes, long-standing retinal
detachment and intraocular
hemorrhages is said to be due to
endocular toxins.

24.  iii. Exogenous toxins
 - causing uveitis are irritant chemical
substances of inorganic, animal or
vegetative origin.

25. 4. Traumatic uveitis.
 Direct mechanical effects of trauma.
 Microbial invasion.
 Chemical effects of retained
intraocular foreign bodies; and
 Sympathetic ophthalmia in the other
eye.