CHLAMYDIAL CONJUNCTIVITIS

Chlamydia lie midway between bacteria and viruses,
sharing some of the properties of both. Like viruses,
they are obligate intracellular and filterable, whereas
like bacteria they contain both
DNA and RNA, divide
by binary fission and are sensitive to antibiotics.
The chlamydia combinedly form the PLT group
(Psittacosis, Lymphogranuloma venereum and
Trachomatis group).

Life cycle of the chlamydia. The infective particle
invades the cytoplasm of epithelial cells, where it
swells up and forms the 'initial body'. The initial
bodies rapidly divide into 'elementary bodies'
embedded in glycogen matrix which are liberated when
the cells burst. Then the 'elementary bodies' infect
other cells where the whole cycle is repeated.

Ocular infections produced by chlamydia in human
beings are summarised in Table 1.

Jones' classification. Jones' has classified chlamydial
infections of the eye into following three classes :

Class 1 : Blinding trachoma. Blinding trachoma refers
to hyperendemic trachoma caused by serotypes A,
B, Ba and C of Chlamydia trachomatis associated with
secondary bacterial infection. It is transmitted from
eye to eye by transfer of ocular discharge through
various modes.

Class 2 : Non-blinding trachoma. It is also caused
by Chlamydia trachomatis serotypes A, B, Ba, and C;
but is usually not associated with secondary bacterial
infections. It occurs in mesoendemic or hypoendemic
areas with better socioeconomic conditions. It is a
mild form of disease with limited transmission owing
to improved hygiene.

Class 3: Paratrachoma. It refers to oculogenital
chlamydial disease caused by serotypes D to K of
chlamydia trachomatis. It spreads from genitals to
eye and mostly seen in urban population. It manifests
as either adult inclusion conjunctivitis or chlamydial
ophthalmia neonatorum.

ocular infections caused by chlamydia