Health assessment is a critical part of proper treatment. This is just as true for the human eye as it is for other body organs. So how is the health of the eye assessed?
Health assessment of the eye consists of a series of systematic steps, these are external examination, visual acuity, pupil function, ocular motility, visual field confrontation testing, intraocular pressure, opthalmoscopy and slit lamp. Palpation of the orbital rim may also be done depending on the presenting signs and symptoms.
A health assessment plan for the human eye would consist of mainly the following steps;
1. External Examination:
External examination of the eyes consists of inspecting the eyelids, surrounding tissues and palpebral fissure. Palpation of the orbital rim may also be desirable, depending on the presenting signs and symptoms. The conjunctiva and sclera can be inspected by having the individual look up, and shining a light while retracting the upper or lower eyelid. The same method works for the cornea and the iris.
2. Visual Acuity:
Visual acuity is the ability of the eye to detect fine details. It is a quantitative measure of the eye’s ability to see an in-focus image at a certain distance. The standard definition of normal visual acuity (20/20 or 6/6 vision) is the ability to resolve a spatial pattern separated by a visual angle of one minute of arc. This is often measured with a Snellen chart.
3. Pupil Function:
The assessment of the pupil function’s health includes inspecting the pupils for equal size (1mm or less of difference may be normal), regular shape, reactivity to light, and direct and consensual accommodation. The swinging flashlight test is the most commonly used clinical procedure used by physicians, mainly due to its simplicity and accurate results.
4. Ocular Motility:
Ocular motility refers to the movement of the eye to form a sharp image on the retina. This should always be tested for, especially in patients who complain of double vision or if the physician suspects a neurological disease. To begin with, the doctor should visually assess the eyes for deviations that could result from strabismus, extra-ocular muscle dysfunction, or oculomotor nerve dysfunction.
Saccades are assessed by having the patient move his or her eye quickly to a target at the far right, left, top and bottom. Slow tracking is assessed by the ‘follow my finger’ test, in which the examiner’s finger traces an imaginary “H” in the air in front of the patient, which touches upon the six cardinal fields of gaze. These test the inferior, superior, lateral and medial rectus muscles of the eye, as well as the superior and inferior oblique muscles.
Intraocular pressure can be measured by any of a series of devices designed to measure the outflow (and resistance to the outflow) of the aqueous humor from the eye.
A red reflex can be seen when looking at a patient’s pupil through a direct ophthalmoscope. This part of the examination is done from a distance of about 50 cm. The actual color varies with the patient’s complexion, but should be symmetrical between the two eyes. Opacity may indicate a cataract. This is best done after the pupil has been dilated with eye drops.
7. Slit lamp:
A closer inspection with a slit lamp is performed by ophthalmologists to detect eye diseases. A small vertical beam of light is run over the eye horizontally. It allows inspection of all the media, from cornea to vitreous, and ophthalmoscopy can also be performed through the slit lamp.
The purpose of this part of the assessment is to check for any abrasions on the cornea or herpes simplex.
To have a full eye health assessment, please call 05-255 9185 for appointment.