Turning up your ocular exam techniques for better diagnosis (Proceedings)

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Turning up your ocular exam techniques for better diagnosis (Proceedings)

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Aug 01, 2010

     • Basic Equipment to have on Hand
     • A focal light source (halogen Finoff transilluminator)
     • A direct ophthalmoscope or a indirect ophthalmoscopy lens
     • Loupe for Magnification
     • Serrated Thumb Forcep
     • Schirmer Tear Test Strips
     • Fluorescein strips
     • Rose Bengal strips
     • A Kimura spatula or a #10 blade
     • Glass Slides
     • Sterile cotton tipped swabs
     • Culture Swabs and transport media
     • Proparicaine
     • Tropicamide 1%
     • 23g IV catheter
     • Digital camera

Historical Data

A good ocular examination begins with a complete medical history. The saying goes that the eyes are the window to the soul – to the ophthalmologist they are often a window to illness elsewhere in the body. The general medical history should be scrutinized starting with signalment and work/play/housing environments. Travel history can be important when considering some infectious diseases that have different geographic occurrences. Many Arizona snowbirds have returned to the Midwest bringing with them pets with Valley Fever (coccidiomycosis) which is endemic in the Southwestern US. A vaccine and deworming history can also be integral in finding answers to the problems at hand. Other clinical signs not thought to be directly related to the ocular condition may be very important to an accurate diagnosis. Ie, skin lesions or GI signs with can accompany ocular histoplasmosis. When assessing the primary ocular complaint, onset of signs, duration of and response or lack of response treatments as well as current medications should be considered.

Restraint

The best restraint for an ocular exam is normally the least amount necessary. Sedation will often make the examination more difficult by causing protrusion of the third eyelid (TEL), enophthalmos, and rolling down of the globe in the orbit. The TEL is often a formidable obstacle to getting a good exam done even without sedation. Dogs will utilize the retractor bulbi muscles to pull the globe caudally causing TEL elevation, while cats have a direct mechanism to raise the TEL. Keeping the animal alert, positioning them over the edge of a table or making noises to attract their attention will often help to keep the TEL in its normal position. There are times that proparicaine and a serrated thumb forceps or a cotton swab will be required to move the lid out of the field of view. A systematic exam and short periods of exposure to the bright light of the exam will allow for the most affective and complete exam.