D

dacryocystitis INFLAMMATION of the lacrimal
(tear) ducts, typically the nasolacrimal ducts in the
corners of the EYEnear the NOSE. Dacryocystitis
develops when there is a blockage of the lacrimal
duct, which may result from DACRYOSTENOSIS(nar-
rowing of the lacrimal duct), INFECTION, or chronic
irritation such as might occur with ALLERGIC RHINI-
TISor ALLERGIC CONJUNCTIVITIS. Dacryocystitis can be
acute (of sudden onset) or chronic (recurrent or
long-standing). It also can be congenital (the
result of defects of the lacrimal gland and duct
structures) or acquired. Most people who have
acquired dacryocystitis are over age 65.
Common symptoms include

• redness and swelling between the eye and the
  bridge of the nose


• rhinitis (runny nose)


• PAIN


• overflowing tears


• FEVERwhen an infection is present

The doctor can typically diagnose dacryocystitis
based on its presentation. Dye tests, in which
the doctor places a special dye in the eye and
watches to see whether the dye discolors nasal
discharge, help identify the extent of blockage
causing the inflammation. Treatment includes
ANTIBIOTIC MEDICATIONSwhen there is an infection,
or procedures to dilate the lacrimal duct when
there is no infection. Sometimes surgery is neces-
sary to correct dacryostenosis or other structural
defects. Appropriate treatment resolves the dacry-
ocystitis.
See also BLEPHARITIS; EYE PAIN; OPERATION; ORBITAL
CELLULITIS.

dacryostenosis Narrowing of the lacrimal (tear)

duct, usually congenital, that blocks the flow of

tears. An infant does not produce a great volume

of tears during the first few weeks to months after

birth, so the doctor may not suspect or diagnose

dacryostenosis until the infant is three to four

months of age. The most common symptom is

tears that overflow the eye and run down the face

(epiphora). Most infants outgrow dacryostenosis

by age six months, so doctors tend to take an

approach of watchful waiting. When dacryosteno-

sis persists, the doctor may dilate the lacrimal duct

(under anesthetic) to gently stretch and enlarge

the opening for tears to pass unimpeded.

Untreated dacryostenosis can result in frequent

episodes of DACRYOCYSTITIS(infected lacrimal ducts)

in adulthood. Appropriate treatment can com-

pletely resolve dacryostenosis.

See also INFECTION; ORBITAL CELLULITIS.

dark adaptation test A test that assesses the

ability to see in a dimly lighted environment.

There are several ways to perform a dark adapta-

tion test. One of the most common is to have the

person sit in a dimly lit room. The examiner

shines a light into the EYE, gradually increasing the

light’s intensity until the person reports seeing the

light. The examiner notes the light’s intensity and

the length of time it takes for the light to become

noticeable. Depending on the reason for the test,

the examiner may direct the light to different

parts of the RETINAto test the responsiveness of the

rods (the cells responsible for low-light vision). A

decrease in dark adaptation response is normal

with aging as the photochemical reactions in the

eye slow.

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