In the fields of
optometry and
ophthalmology
Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders.
An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medic ...
, the Hirschberg test, also Hirschberg corneal reflex test, is a screening test that can be used to assess whether a person has
strabismus
Strabismus is a vision disorder in which the eyes do not properly align with each other when looking at an object. The eye that is focused on an object can alternate. The condition may be present occasionally or constantly. If present during a ...
(ocular misalignment).
A photographic version of the Hirschberg is used to quantify strabismus.
Technique
It is performed by shining a light in the person's
eyes and observing where the light reflects off the
cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...
s. In a person with normal ocular alignment the light reflex lies slightly nasal from the center of the cornea (approximately 11 prism diopters—or 0.5mm from the pupillary axis), as a result of the cornea acting as a temporally-turned convex mirror to the observer. When doing the test, the light reflexes of both eyes are compared, and will be symmetrical in an individual with normal fixation. For an abnormal result, based on where the light lands on the cornea, the examiner can detect if there is an
exotropia
Exotropia is a form of strabismus where the eyes are deviated outward. It is the opposite of esotropia and usually involves more severe axis deviation than exophoria. People with exotropia often experience crossed diplopia. Intermittent exotrop ...
(abnormal eye is turned out),
esotropia
Esotropia is a form of strabismus in which one or both eyes turns inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of exotropia and usual ...
(abnormal eye is turned in),
hypertropia
Hypertropia is a condition of misalignment of the eyes (strabismus), whereby the visual axis of one eye is higher than the fellow fixating eye.
Hypotropia is the similar condition, focus being on the eye with the visual axis lower than the fell ...
(abnormal eye higher than the normal one) or
hypotropia
Hypertropia is a condition of misalignment of the eyes ( strabismus), whereby the visual axis of one eye is higher than the fellow fixating eye.
Hypotropia is the similar condition, focus being on the eye with the visual axis lower than the fel ...
(abnormal eye is lower than the normal one).
Interpretation
In
exotropia
Exotropia is a form of strabismus where the eyes are deviated outward. It is the opposite of esotropia and usually involves more severe axis deviation than exophoria. People with exotropia often experience crossed diplopia. Intermittent exotrop ...
the light lands on the medial aspect of the cornea. In
esotropia
Esotropia is a form of strabismus in which one or both eyes turns inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of exotropia and usual ...
the light lands on the lateral aspect of the cornea. In
hypertropia
Hypertropia is a condition of misalignment of the eyes (strabismus), whereby the visual axis of one eye is higher than the fellow fixating eye.
Hypotropia is the similar condition, focus being on the eye with the visual axis lower than the fell ...
the light lands on the inferior aspect of the cornea. In hypotropia the light lands on the superior aspect of the cornea. A
cover test A cover test or ''cover-uncover test'' is an objective determination of the presence and amount of ocular deviation. It is typically performed by orthoptists, ophthalmologists and optometrists during eye examinations.
The two primary types of cov ...
can tell you the extent of the eso/exotropia.
Individuals can suffer from several tropias at once. In
Graves ophthalmopathy, it is not uncommon to see an esotropia (due to pathology of the
medial rectus muscle
The medial rectus muscle is a muscle in the orbit near the eye. It is one of the extraocular muscles. It originates from the common tendinous ring, and inserts into the anteromedial surface of the eye. It is supplied by the inferior division o ...
)
co-morbid
In medicine, comorbidity - from Latin morbus ("sickness"), co ("together"), -ity (as if - several sicknesses together) - is the presence of one or more additional conditions often co-occurring (that is, concomitant or concurrent) with a primary ...
with a hypotropia (due to pathology of the
inferior rectus muscle
The inferior rectus muscle is a muscle in the orbit near the eye. It is one of the four recti muscles in the group of extraocular muscles. It originates from the common tendinous ring, and inserts into the anteroinferior surface of the eye. It ...
).
Krimsky Test
The Krimsky test is essentially the Hirschberg test, but with prisms employed to quantitate deviation of ocular misalignment by determining how much prism is required to centre the reflex The Krimsky test is advisably used for patients with tropias, but not with phorias.
History
The technique was developed by German ophthalmologist
Julius Hirschberg
Julius Hirschberg (18 September 1843 – 17 February 1925) was a German ophthalmologist and medical historian. He was of Jewish ancestry.
In 1875, Hirschberg coined the term "campimetry" for the measurement of the visual field on a flat surfa ...
who in 1886 used a
candle
A candle is an ignitable wick embedded in wax, or another flammable solid substance such as tallow, that provides light, and in some cases, a fragrance. A candle can also provide heat or a method of keeping time.
A person who makes candle ...
to observe the light reflex in an eye with strabismus.
[Wheeler, M]
"Objective Strabismometry in Young Children."
''Trans Am Ophthalmol Soc.'' 1942; 40: 547–564.
See also
*
Cover test A cover test or ''cover-uncover test'' is an objective determination of the presence and amount of ocular deviation. It is typically performed by orthoptists, ophthalmologists and optometrists during eye examinations.
The two primary types of cov ...
*
Eye examination
An eye examination is a series of tests performed to assess vision and ability to focus on and discern objects. It also includes other tests and examinations pertaining to the eyes. Eye examinations are primarily performed by an optometrist, ...
*
Terms for anatomical location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
References
{{Eponymous medical signs for eyes and ears
Medical signs
Physical examination
Eye procedures