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Veterinary ophthalmology for the technician (Proceedings)

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Nov 01, 2010

• Anatomy
• Medical and Ophthalmic History
      o Signalment
      o Primary complaint
      o Concurrent disease
      o General heath questions (travel, indoor/outdoor, changes in weight, eating, drinking, urination)
      o Vision (night vs. day, vision in unfamiliar environment)
      o Duration of problem
      o Trauma
      o Redness and characteristic of discharge
      o Swelling
      o Color change
      o Pain (rubbing, tearing, squinting, painful to touch, reluctance to open mouth or eat, photophobia, general malaise, or depression)

• What to look for as a Technician
      o Red eye, Cloudy cornea, Mucoid discharge (grey or green), Blepharospasms , Swelling on or around eyelids, Color change to eye, Normal pupil shape and size

• What to do and what not to do?
      o Don't clean discharge,
      o Measure tears prior to putting stain or proparacaine in the eye
      o If cornea has a deep ulcer- Handle eye very gently , Forgo diagnostics (eye tests as well as rectal temperature)
      o Gentle restraint (excessive neck pressure and struggling can cause a fragile eye to worsen)
      o Dogs and cats can become very aggressive if their eye hurts, so be cautious when touching their face

• Diagnostic Tests
      o Tonometry
      o Schirmer Tear Test
          ■ To measure tears for dry eye
          ■ Normal test is 15-20 mm/minute
      o What falsely alters a normal tear test?
          ■ Any drops placed in eye prior to tear test
          ■ Atropine usage, topically or injectable will "dry" up tears
          ■ Benadryl and other anti-histamines will decrease tear production
          ■ Sedation/Anesthesia will lower tear production
      o Fluorescein Stain
          ■ Identify corneal ulceration
          ■ Patency of nasal-lacrimal duct
      o Tonometry
          ■ Tonometry is measuring of the intraocular pressure
          ■ Glaucoma is a high pressure in the eye and is best detected by measuring IOP
          ■ Normal dogs and cats- 13-21mmHg
          ■ Proper restraint for accurate IOP measurement
               • Neck or jugular pressure will cause a false elevation
               • Pulling back on the eyelids will place pressure on the globe

• Basic Exam Tools
      o Transilluminator and direct ophthalmascope
      o Head Loupes (3X-7X magnification)

• Most common ocular diseases
      o Corneal Ulcers
          ■ Superficial/simple
          ■ Infected/malacic
          ■ Desmetocoele
          ■ Rupture
          ■ Puncture/laceration
          ■ Indolent- age related