4F conditions in eent

• Visual field


  Extent of physical space you are able to perceive visual signals; may be tested by perimetry, confrontation test, etc.
• Visual acuity


  Capacity to discriminate the fine details of objects; dependent on sharpness of retina and sensitivity of the brain
• Accommodation


  Ability of the eye to change its focus from distant to near objects (and vice versa); achieved by changing the curvature of the lens
• Refraction


  The turning or bending of light as it passes from one medium into another of different density
• Enucleation


  Removal of the entire eye and part of the optic nerve
• Evisceration


  Surgical removal of the intraocular contents through an incision leaving the scleral shell and muscles intact
• Ceruminous gland


  Specialized sweat glands; secretion binds with sebum and dead epidermal cells to produce Cerumen
• Cerumen


  Yellowish, wax like secretion; "earwax"; purpose is lubrication, waterproofs the canal, protection from foreign agents
• Eye Functions affecting Visual Acuity


  • Pupillary Constriction
  • Refraction
  • Accommodation
  • Convergence
• Refractive Structures of the eye


  • Cornea
  • Aqueous Humor
  • Lens
  • Vitreous Humor
  • Retina

  
• Emmetropia


  Perfect refraction of the eye; light rays from a distant source are focused into a sharp image on the retina

  
• Hyperopia/Farsightedness


  Poor refraction of light; have shallower eyeballs; images fall behind the retina

  
• Myopia/Nearsightedness


  Eye overrefracts or overbends the light; have deeper eyeballs; images are focused in front of the retina

  
• Presbyopia


  Lens loses its elasticity; decreased ability of lens to alter its shape to focus for near vision; common in people aged 30 to 40 yrs

  
• Astigmatism


  Unevenly curved surfaces on or in the eye, especially of the cornea; distortion of vision

  
• Assessment of Refractive Errors

  • Ophthalmic Refraction
• Nonsurgical Management of Refractive Errors


  • Eyeglasses
  • Contact Lenses

  
• Surgical Management of Refractive Errors


  • Keratotomy
  • Laser In-Situ Keratomileusis (LASIK)

  
• Hyphema


  Hemorrhage in the anterior chamber - caused by break in blood vessels; may block the pupil or increase the IOP

  
• Contusion


  Break in small blood vessels caused by contact with blunt objects. Example: Periorbital ecchymosis "black eye".

  
• Intraocular Foreign Bodies


  Foreign objects that enter the eye
• Nonsurgical Management


  • Eyeglasses
  • Contact Lenses
• Eyeglasses


  • Ease of use, durability, availability, low cost
  • Appearance, weight, reduced peripheral vision

  
• Contact Lenses


  • Complications: corneal abrasion and edema, deposits in the lens, lens deterioration
• Surgical Management


  • Keratotomy – reshaping of cornea
  • Laser In-Situ Keratomileusis (LASIK) – laser pulses reshape the deeper corneal layers, outer corneal flap is placed back to original position

  
• Hyphema


  Hemorrhage in the anterior chamber - caused by break in blood vessels
• Hyphema


  • May block the pupil or increase the IOP
• Hyphema Management


  1. Bedrest in semi-Fowler's position

  2. Minimal or no sudden eye movements (3-5 days) - use eye patch/shield

  3. Restrict television and reading

  4. Cycloplegic eye drops

  
• Contusion Management


  1. Apply ice

  2. Eye examination

  
• Intraocular Foreign Bodies


  • Risk factors: working in construction site, MVA, explosion
• Intraocular Foreign Bodies Management


  1. MRI is contraindicated

  2. Tetanus prophylaxis, IV antibiotics

  3. Surgical extraction
• Penetrating Injuries Management


  1. Do not attempt to remove the object

  2. Do not apply pressure, use eye shield - MRI is contraindicated

  3. Tetanus prophylaxis, antibiotics

  4. Surgery
• Lacerations Management


  1. Close eyes and apply ice pack

  2. Surgical suturing

  3. Antibiotics
• Ocular Burns Management


  1. Immediate eye irrigation on-site

  2. Wash over the contact lens if any

  3. Antibiotics

  
• Conjunctivitis


  Inflammation of conjunctiva characterized by a pink appearance due to blood vessel congestion
• Conjunctivitis is the most common ocular disease
• Conjunctivitis Clinical Manifestations


  • Foreign body sensation
  • Scratching or burning sensation - itching
  • Photophobia
• Types of Conjunctivitis


  • Bacterial Conjunctivitis
  • Viral Conjunctivitis
  • Allergic Conjunctivitis
  • Toxic Conjunctivitis
• Bacterial Conjunctivitis


  Mucopurulent discharge may appear white, yellow or green
• Bacterial Conjunctivitis Management


  1. Antibiotics

  2. Hygiene and avoid close contact with others