This study will measure the normal range of the human electro-oculogram (EOG) in people of
various age groups. EOGs are recordings of electrical signals generated by the retina (the
light-sensitive tissue in the back of the eye) when going from a dark to a bright
environment. They provide valuable information about the function of the eye in health and
disease. A knowledge of what results are to be expected in tests of normal, healthy eyes
will be valuable in assessing EOG results in patients with known or suspected retinal
Normal volunteers from ages 6 to 65 who have healthy eyes and normal eyesight will
participate in this study. Candidates will undergo tests to check vision and the health of
the eye. Study participants will then have an electro-oculogram. In this test, eye drops
are placed in the eye to enlarge the pupils. Two electrodes (small disks that picks up
electrical signals) are attached to the left and right of each eye and one to the forehead.
(These are similar to electrodes placed on the body during an electrocardiogram (ECG), which
measures electrical signals from the heart.) During the EOG recording, the volunteer looks
at the inside of a hollow sphere, following with their eyes small red lights that turn on
and off. The background light is also turned on or off during the test. Some volunteers
may be asked to repeat the EOG at another time.
Study participants may also be asked to provide a blood sample for tests to study how the
immune cells in the blood respond to proteins found in the retina. The response from normal
volunteers will be compared with that of patients with eye diseases like retinitis
Electro-oculograms (EOGs) will be recorded in volunteers of different age groups with normal
visual function. The fast and slow oscillations of the EOG will be studied. For the
analysis of fast EOG oscillations, peak-to-peak amplitude (micro V), peak-to-trough ratio,
and phase (degrees) will be measured. The analysis of slow EOG oscillations will include
measurements of the ratio of light peak to dark trough (Arden ratio), implicit time
(latency) of the light peak (ms), and amplitude of the dark trough (micro V).
Subjects must have best corrected visual acuity equal or better than 20/20.
Subjects must have normal visual fields.
Subjects must have normal color vision.
Subjects must have a normal ophthalmological exam.
Subjects should not be subjective to or objective evidence of visual loss.
Subjects cannot have subjective evidence of abnormal night vision or subjective evidence
of abnormal light sensitivity.
Subjects cannot have a personal history of non-trivial ocular disease.
Subjects cannot have a family history of hereditary ocular disease.
Subjects cannot have current systemic disease.
Subjects cannot currently take neuropharmacological medication.
Subjects will not be admitted with an abnormal ophthalmological examination.
Subjects will need the ability to cooperate with EOG recording.