1. Assessment and Management of Patients With Eye and Vision Disorders
Chapter 58
Assessment and Management of Patients With Eye and Vision Disorders

2. External Structures of the Eye

3. Cross-Section of the Eye

4. Assessment and Evaluation of Vision
Ocular history
Visual acuity
Snellen chart
Record each eye
20/20 means the patient can read the “20” line at a distance of 20 feet
Finger count or hand motion

5. Diagnostic Evaluation
Ophthalmoscopy
Direct and indirect
Examines the cornea, lens and retina
Tonometry
Measures intraocular pressure

6. Impaired Vision Refractive errors Myopia: nearsighted
Can be corrected by lenses which focus light rays on the retina
Myopia: nearsighted
Hyperopia: farsighted
Astigmatism: distortion due to irregularity of the cornea. Due to refractive error in which light rays are spread over a diffuse area rather than sharply focused on the retina, a condition caused by differences in the curvature of the cornea and lens

7. Glaucoma
A group of ocular conditions in which damage to the optic nerve is related to increased intraocular pressure (IOP) caused by congestion of the aqueous humor
The leading cause of blindness in adults in the U.S.
Incidence increases with age
Risk factors
Family history of glaucoma
Older age
Diabetes mellitus
Cardiovascular disease
Nearsightedness (myopia)
Eye trauma
Prolonged use of topical or systemic corticosteroids

8. Pathophysiology of Glaucoma
In glaucoma, aqueous production and drainage are not in balance.
When aqueous outflow is blocked, pressure builds up in the eye.
Increased IOP causes irreversible mechanical and/or ischemic damage to the optic nerve.
Types of glaucoma:
1. Open-angle
2. Angle-closure (pupillary block) glaucoma
3. Congenital glaucomas
4. glaucoma secondary to other conditions

9. Clinical Manifestations
“Silent thief” of vision; unaware of the condition until there is significant vision loss; peripheral vision loss, blurring, halos, difficulty focusing, difficulty adjusting eyes to low lighting
May also have aching or discomfort around eyes or headache
Diagnosis: Tonometry to assess IOP

10. Treatment Goal is to prevent further optic nerve damage
Maintain IOP within a range unlikely to cause damage
Pharmacologic therapy
Surgery (nursing care)

11. Cataracts An opacity or cloudiness of the lens
Increased incidence with aging; by age 80 more than half of all Americans have cataracts
Risk factors
Aging (Clumping or aggregation of lens protein)
Associated Ocular Conditions (Myopia, retenal surgery)
Toxic Factors (Corticosteroids, smoking)
Nutritional Factors (low antioxidants, poor nutrition)
Physical Factors (dehydration, trauma, ultraviolet ray)
Systemic Diseases and Syndromes (DM, MS Renal)
Aging
Loss of lens transparency
Clumping or aggregation of lens protein (which leads to light scattering)
Accumulation of a yellow-brown pigment due to the breakdown of lens protein
Decreased oxygen uptake
Increase in sodium and calcium
Decrease in levels of vitamin C, protein, and glutathione (an antioxidant)
Associated Ocular Conditions
Retinitis pigmentosa
Myopia
Retinal detachment and retinal surgery
Infection (eg, herpes zoster, uveitis)
Toxic Factors
Corticosteroids, especially at high doses and in long-term use
Alkaline chemical eye burns, poisoning
Cigarette smoking
Calcium, copper, iron, gold, silver, and mercury, which tend to deposit in the pupillary area of the lens
Nutritional Factors
Reduced levels of antioxidants
Poor nutrition
Obesity
Physical Factors
Dehydration associated with chronic diarrhea, use of purgatives in anorexia nervosa, and use of hyperbaric oxygenation
Blunt trauma, perforation of the lens with a sharp object or foreign body, electric shock
Ultraviolet radiation in sunlight and x-ray
Systemic Diseases and Syndromes
Diabetes mellitus
Down syndrome
Disorders related to lipid metabolism
Renal disorders
Musculoskeletal disorders

12. Cataract

13. Clinical Manifestations
Painless, blurry vision
Sensitivity to glare
Reduced visual acuity
Other effects include astigmatism, diplopia (double vision), and color (color value shift to yellow-brown)
Diagnostic findings include decreased visual acuity and opacity of the lens by ophthalmoscope, or inspection

14. Surgical Management
If reduced vision does not interfere with normal activities, surgery is not needed.
Removal of the lens and replacing it with an artificial lens

15. Retinal Detachment
Separation of the sensory retina and the RPE (retinal pigment epithelium)
Manifestations: sensation of a shade or curtain coming across the vision of one eye, bright flashing lights, sudden onset of floaters
Diagnostic findings: assess visual acuity, assessment of retina by indirect ophthalmoscope and fluorescein angiography. Tomography and ultrasound may also be used

16. Retinal Detachment

17. Surgical Treatment
Scleral Buckle

18. Trauma Prevention of injury Patient and public education
Emergency treatment
Flush chemical injuries
Do not remove foreign objects
Protect using metal shield or paper cup

19. Protective Eye Patches