Nystagmus
Nystagmus is a syndrome
manifested by spontaneous oscillatory movements of eyeballs. Two
basic forms of pathological nystagmus are distinguished — ocular or
fixation, and neurogenic or central.
Nystagmus usually arises in
congenital or early acquired weakness of vision due to various
diseases of the eye, congenital pathology of the oculomotor
apparatus, and it is also an inherited pathology.
The reduction of visual acuity
in nystagmus is caused by organic changes in the apparatus of
the central vision and dysfunctions due to insufficient activity
of the visual analyzer (relative amblyopia). Potential possibilities
of vision improvement in nystagmus basically depend on a degree
of dysfunctions.
There are
distinguished congenital
and
acquired
nystagmus
caused by blindness or sharp reduction of vision as a result of
various diseases of the eye. There is congenital nystagmus
without evident changes of the eye and nystagmus with
accompanying visible changes (congenital cataract, albinism,
atrophy of the visual nerves, degeneration of the retina, coloboma,
aniridia etc.).
According to the character of
oscillatory movements the following forms of nystagmus are
distinguished:
oscillating
nystagmus
with equal in magnitude phases of fluctuations;
jerky
nystagmus
with different phases of fluctuations — slow in one side and fast
in another;
mixed
nystagmus
when pendular or jerky nystagmus is observed. There is also
distinguished horizontal,
vertical, rotatory and
diagonal
nystagmus.
Horizontal nystagmus is observed more often.
Treatment
of
nystagmus includes selection of optic correction, influence on the
apparatus of accommodation, pleoptic treatment and operations on the
oculomotor muscles.
