1. Assisting with Eye and Ear Care Lesson 1: The Study of the Eye39
Assisting with Eye and Ear Care
Lesson 1:
The Study of the Eye

2. Lesson Objectives
Upon completion of this lesson, students should be able to …
Define the terms to learn in this chapter.
Explain procedures to evaluate distance vision, color vision, near vision, and contrast sensitivity.
Explain procedures to irrigate the eye and instill eye medications.
Name three causes of blindness.

3. Lesson Objectives
Explain the procedure for assisting visually-impaired patients to prepare for physical examinations.
List and explain five age-related changes in the eye.

4. Structures of the Eye 4

5. Anatomy and Physiology of the Eye5

6. Critical Thinking Question
If you were having vision problems would you go to an ophthalmologist, an optometrist, or an optician? Explain.

7. Ophthalmologist Medical doctor
Performs eye examinations and eye surgery
Prescribes medications, eyeglasses, and contact lenses

8. Doctor of Optometry (OD)
Also referred to as an optometrist
Performs eye examinations, prescribes medications, and writes prescriptions for eyeglasses and contact lenses

9. Optician Grinds lenses and prepares eyeglasses and contact lenses
Completes a 2- to 4-year apprenticeship
Licensure required by some states 9

10. Otoscope
Used to examine the tympanum or myringa for signs of infection and inflammation
Tympanum or myringa are medical terms for the eardrum

11. Ophthalmoscope Used to view inner parts of the eye
Physician positions the ophthalmoscope so light penetrates the pupil of the patient’s eye and screens for retinal damage and vascular problems

12. Evaluating the Status of the Patient’s Pupils
PERRLA is an acronym that stands for Pupils Equal, Round, React to Light and Accommodation and focus on objects at different distances
Normally the pupils of the eyes are the same size and change or accommodate when a beam of light is focused on the eye and is then removed
Injuries to the brain may result in the patient having pupils of unequal size

13. Visual Acuity
Normal visual acuity, or clearness of vision, is referred to as 20/20 vision, which means the eye should see an object 20 feet away clearly.
Errors of refraction occur when the eyeball is:
Too long
Too short
The lens loses its elasticity
The lens or cornea has an irregular curvature

14. Refractive Errors

15. Myopia Also known as nearsightedness
When the eye sees near objects well but distant objects appear blurry
Occurs either because the eyeball is too long or because the lens is too thick, and the light rays do not reach the retina
Myopic eye requires a concave lens to correct vision

16. Myopia

17. Hyperopia Also known as farsightedness
When the eyes see distant objects well, but near objects are blurry
In this case, the eyeball is too short or the lens too thin
The hyperopic eye requires a convex lens to correct the visual defect

18. Hyperopia

19. Refractive Errors Presbyopia Astigmatism
Term associated with farsightedness that occurs with aging
The lens loses its elasticity and glasses are needed for reading
Astigmatism
The lenses or cornea are uneven and light is not bent or refracted evenly
Images may be clear in the center and blurry at the outer edges of the visual field

20. Strabismus
Caused by weakness in the external eye muscles resulting in the eyes looking in different directions
Normally the eyes focus on a subject in coordination; otherwise double vision occurs
Children with strabismus appear “cross-eyed” and may need to wear a patch over the “good” eye to strengthen the weaker eye

21. Strabismus
It is important that treatment begin at an early age to prevent permanent damage to the eye
If the patch and exercise plan are ineffective, surgery on the eye muscle may be necessary

22. Snellen Chart
Largest symbols are on the top line and each line after is of decreasing size
Person with normal vision can read the top line at 200 feet
To the right of each line is a ratio indicating that a person with normal vision could read at decreasing distances of 100, 70, 50, 40, 30, and 20 feet

23. Snellen Chart
A result of 20/20 vision means that a person with normal distance acuity could read that line at a distance of 20 feet
For preschool children or patients who are illiterate or have a language barrier, the Snellen E, the Landolt C, or pictorial charts are used

24. Snellen Chart
With the Snellen E chart, have the patient demonstrate by pointing his or her finger in the direction the E is pointing prior to testing so as to determine whether or not the patient can follow directions
When dealing with young children, it may be helpful to make a game of it, showing them how to hold their hands to illustrate which direction the E is facing

25. Eye Abbreviations Abbreviation for the right eye is OD (oculus dexter)
Abbreviation for the left eye it is OS (oculus sinister)
Abbreviation for both eyes is OU (oculus uterque)
Although these abbreviations are used, the Institute for Safe Medication Practices (ISMP) recommends that the complete words must be used to avoid misinterpretation and error.

26. The Snellen Eye Chart

27. Steps for Using the Snellen Chart
Assemble equipment
Review physician’s order
Perform hand hygiene and identify the patient
Explain the procedure
Determine the patient’s ability to recognize letters – If the patient is unable to read letters, use the necessary chart to accommodate the patient’s abilities

28. Steps for Using the Snellen Chart
Place the patient 20 feet from the chart, either seated or standing, as long as the Snellen eye chart is at eye level
Following office policies (regarding which eye to test first) have the patient cover the other eye with a cup or occluder
The occluder should be held in such a way as not to interfere with the normal position of a patient’s glasses

29. Steps for Using the Snellen Chart
Instruct the patient to keep both eyes open even though one eye is covered
Have patient read the lines with both eyes first at a distance of 20 feet
Use pointer and point to letters or appropriate symbols in random order
Starting with the 20/70 line ask the patient to identify each line and proceed down the chart to the last line the patient can read without error

30. Steps for Using the Snellen Chart
Observe for signs of squinting or tilting the head which indicate difficulty identifying letters
Record the ratio numbers adjacent to the line the patient can read without error
If there is an error, note it (e.g., Right eye 20/40 –1 or Right eye 20/40 –1 with correction; meaning glasses were worn during testing)

31. Steps for Using the Snellen Chart
ISMP recommends using words instead of abbreviations of eye designations to avoid misinterpretation
Follow office protocol regarding charting
Repeat the procedure with the other eye and record the result, noting any unusual symptoms such as squinting, or blinking excessively

32. Steps for Using the Snellen Chart
Clean the occluder with gauze and alcohol
Remove gloves and perform hand hygiene
Document the results accurately

33. Steps to Test for Near Vision Acuity Using the Jaeger Card
Patient reads a card held at normal reading distance (14 to 16 inches)
Card has a series of paragraphs decreasing in size of print with a number above each
Number one (J1) is next to the paragraph with the smallest text and as the text becomes larger the number increases
Paragraph J2 represents 20/20 vision

34. Steps to Test for Near Vision Acuity Using the Jaeger Card
Patient’s result is the number above the last paragraph he or she can read easily
This test should always be performed in a well-lit room

35. Color Vision Impairment
The inability to distinguish colors of the spectrum distinctly
Defects in color vision are either congenital or inherited, or acquired through disease or injury
Congenital means the individual was born with the condition – more prevalent in males

36. Color Vision Impairment
It is important to test for color vision defects because changes in color vision may indicate diseases of the retina, optic nerve, or thyroid
The most common type of color vision defect, which is inherited, is the inability to distinguish red and green

37. The Ishihara Test Screening for color vision acuity
Printed card or booklet with a single color-dot illustration containing a number, or curved lines and shapes
Patient is shown 14 color plates or pages and must correctly identify 10 to be considered to have color vision within normal limits
Ishihara Booklet or cards should be stored out of direct light to prevent fading of the color plates

38. The Ishihara Test

39. Contrast Sensitivity
Measures the patient’s ability to distinguish faint differences in shades of grey
Several new testing procedures are used to test for contrast sensitivity – Vistech Consultant system and the Pelli-Robson chart

40. Contrast Sensitivity
To perform a procedure for contrast sensitivity, adhere to manufacturer’s directions and observe the usual procedural steps for appropriate patient care
Contrast sensitivity is affected by most major eye conditions such as macular degeneration, cataracts, glaucoma, and diabetic retinopathy

41. Procedures and Diagnostic Tests Related to the Eye
Corneal transplant:
The surgical process of transferring the cornea from a donor to a patient
Electroretinogram:
A record of the electrical response of the retina to light stimulation

42. Fluorescein Angiography
Process of injecting fluorescein (a dye) followed by a series of photographs of the retina through dilated pupils
Provides diagnostic information about the blood flow in the retina
Detects vascular changes in diabetic and hypertensive retinopathy
Identifies lesions in the macular area of the retina, determining if there is detachment of the retina

43. Procedures and Diagnostic Tests Related to the Eye
Gonioscopy:
Use of gonioscope to examine the anterior chamber of the eye to determine ocular motility and rotation
Keratometry:
Measurement of the cornea using an instrument called a keratometer
Keratoplasty:
Surgical repair of the cornea (corneal transplant)

44. Procedures and Diagnostic Tests Related to the Eye
Laser surgery:
Surgical procedure performed with a laser handpiece that transfers light into intense, small beams capable of destroying or fixing tissue in place
Optomyometer:
An instrument used to measure the strength of the muscles of the eye

45. Procedures and Diagnostic Tests Related to the Eye
Phacoemulsification:
The process of using ultrasonic vibrations to disintegrate a cataract
A needle is inserted through a small incision and the disintegrated cataract is aspirated
The ophthalmic surgeon uses a small, self-sealing scleral-tunnel incision

46. Radial Keratotomy
A surgical procedure that may be performed to correct nearsightedness (myopia)
Delicate spoke-like incisions are made in the cornea to flatten it, thereby shortening the eyeball so that light reaches the retina
Not all patients have their vision improved, and complications could lead to blindness

47. Slit-Lamp Microscopy
The instrument used in ophthalmology for examining the posterior surface of the cornea

48. Tonometry
Measurement of intraocular pressure (IOP) of the eye using a tonometer to check for glaucoma
An air puff tonometer records the cornea’s resistance to pressure

49. Procedures and Diagnostic Tests Related to the Eye
Visual acuity:
Measurements of the sharpness of a patient’s vision
Usually a Snellen eye chart is used and the patient identifies letters from a distance of 20 feet
Vitrectomy:
A surgical procedure for replacing the contents of the vitreous chamber of the eye

50. Procedures and Diagnostic Tests Related to the Eye
Near-Vision Acuity Chart

51. Contrast Sensitivity Chart

52. Eye Irrigation
Irrigation or lavage (rinsing) of the eye is necessary to remove foreign substances or chemicals
Requires the use of sterile technique and equipment
Never try to remove a foreign object from the eye using an applicator stick, as this may cause corneal abrasions

53. Eye Irrigation

54. Steps to Irrigating the Eye
Identify the patient and explain the procedure
Review the physician’s order
Assemble the equipment
Check the label of the irrigating solution three times to make sure it is the correct solution and the concentration ordered by the physician

55. Steps to Irrigating the Eye
Check the expiration date on the label to make sure the solution has not expired
The solution should be brought to room temperature by wrapping the bottle in a dry heating pad or standing the bottle in a warm water bath
Perform hand hygiene and apply gloves
Ask the patient which position he or she would prefer, sitting or lying down

56. Steps to Irrigating the Eye
Place a towel over the patient’s shoulder
If both eyes are to be irrigated, then two separate sets of equipment must be used to prevent cross-infection
Open the irrigating solution and fill the syringe
Ask the patient to tilt the head to the affected side if seated, and hold the basin

57. Steps to Irrigating the Eye
Open the patient’s eye using the index finger and thumb of the nondominant hand
Hold a tissue on the patient’s cheekbone below the lower lid and pull down and expose the conjunctiva
Hold the syringe ½ inch from the eye
Gently irrigate from inner to outer canthus, or the corner of eye, aiming at the lower conjunctiva

58. Steps to Irrigating the Eye
Continue irrigating until the solution is used up
Dry the area around the eye with sterile gauze
Dispose of the equipment properly
Perform hand hygiene
Document information in the patient’s chart in the appropriate manner

59. Instillation of Eye Medications
Only ophthalmic or optic medications can be used in the eye, and they must be sterile
Important to reinforce the need for sterile medications with patients
Encourage patients to discard eye medications when the prescribed treatment time has been completed
Eye medications should never be shared with others or even used in their other eye if treatment is needed

60. Steps for the Instillation of Eye Medication
Perform hand hygiene
Check the physician’s orders
Identify the patient, introduce yourself, and explain the procedure
Check the name of the medication, expiration date, and concentration three times
Ask the patient if he or she has any known allergies to the medication

61. Steps for the Instillation of Eye Medication
Give the patient a tissue to blot cheeks
Put on gloves
Position the patient with head tilted back and looking up
Pull down the lower eyelid exposing the conjunctiva
Place the dropper about ½ inch above the eyeball with the dominant hand

62. Steps for the Instillation of Eye Medication
Insert the proper amount of drops to the center of the conjunctiva, or if ointment is used, apply as a thin strip from inner to outer canthus
Do not touch the dropper or ointment tube to the eye
Ask the patient to gently close the eye and rotate the eyeball

63. Steps for the Instillation of Eye Medication
Using sterile gauze, dry the excess medication from the inner canthus to the outer canthus
Explain to the patient that vision may be blurry
Clean the area and dispose of unused medication
Remove gloves and perform hand hygiene
Document the procedure appropriately

64. Steps for the Instillation of Eye Medication

65. Questions? 65