MEDICAL AND SURGICAL NURSING
OPHTHALMOLOGY
ASSESSMENT OF THE VISUAL SYSTEM
A complete visual examination includes the following,
- Patient interview (history collection).
- Physical examination.
- Other diagnostic tests uniquely for the eye.
a.) History collection:-
The nurse can assess the patient by concentrating on the following issues,
- Patient’s recent changes in visual acuity.
- Usage of glasses or lenses by the patient.
- Questions on the signs and symptoms like blurring of vision, floaters, pain, headaches, redness, discharges etc.
- Whether the patient uses any eye protective equipments like goggles, coolers.
- Any recent history of head injury, loss of conscious, direct trauma, or infections.
- Any family history of eye disorders like cataract, glaucoma, hypertension, STD etc.
b.) Physical examination:-
Physical examination of the eye includes the inspection of the visual system and its external structures.
- Facial and ocular expression – eye prominence, and the eye expression.
- Eyelids and conjunction – symmetricity, any oedema, itching and irritation, redness, ptosis, entropion or ectropion, hordeolum, chalazion etc.
- Sclera – colour whether white or yellow.
- Cornea – clarity, dryness, vascularity.
- Lacrimal duct – tears, swelling, growths.
- Iris and pupils – irregularities in colour, shape, size and reaction to light.PERRLA- pupils equal, regular reacting to light and accommodation.
- Anterior chamber – depth , presence of blood or pus.
- Lens – transparency, opacity etc.
- Visual acuity with and without glasses.
- Intra ocular pressure measurement.
- Range of motion of the extra ocular muscles.
- Optic nerve activity.
The physical assessment of the normal visual system includes,
- Vision 20/20 with no double vision.
- External eye structures devoid of any deformities or lesions.
- Lacrimal apparatus without any drainage.
- Clear conjunctiva and lens.
- White sclera.
- PERRLA
- EMOI
- Sharp disc margins.
- No spots or hemorrhage in the retinal vessels.
C.) Other diagnostic tests:-
- Visual acuity testing:
It helps to determine the near and distant visual acuity of the patient by using the snellan’s chart for distance vision test and Jaoeger’s test for near vision testing.
- Extraocular mjuscle testing:
This test is performed to know whether the patient’s ocular muscles are functioning in a normal manner without hypoactivity or hyperactivity.
- Confrontation visual test:
This test helps to interpret the patient has full field of vision without the scotomas.
- Pupil function test:
It helps to find the pupillary response of the patient.
- Tonometry:
It helps to measure the intra ocular pressure of the patient.
- Slit- lamp microscopy:
It provides a magnified view of the conjunctiva, sclera, cornea and the anterior chamber, iris, lens etc.
- Ophthalmoscopy:
It gives the magnified view of the retina and the optic nerve head.
- Colour vision testing:
It helps to find out the ability of the patient to distinguish colours.
- Stereopsis testing:
It helps to determine the patient’s ability to see objects in all the three dimensions and the perceptual powers.
- Keratometry:
It helps to measure the curvature of the cornea.
- Retinoscopy:
It helps to measure the refractive errors of the eye.
- Refractometry:
It also helps to determine the refractive errors of the eye.
- Visual field perimetry:
This test gives us a detailed mapping of the visual field.
- Ultrasonography:
It helps to diagnose ocular tumours, retinal detachments or foreign bodies in the eye.
- Fluorescein angiography:
It provides information about the blood flow through RPE and retinal vessels and to find out areas of diabetic retinopathy.
- Amsler grid:
It is used to identify any macular disorders.
- Schirmer tear test:
This test is used to measure the volume of tear produced in a specified time.
- Tests used to assess the function of visual pathway are,
- Electroretinogram (ERG).
- Electrooculogram (EOG).
- Dark adaptometry.
- Visual evoked potential.
These tests are used to diagnose occlusions, toxic drug exposure, retinal diseases and foreign body in the eye.