Interpretation of the fundus (Proceedings)

Direct Fundic Exam

• Start 1.5-2" away at 0 D setting

• Rotate wheel toward negative (red) until fundus near disk is visible (-2to-4D)

• Examine fundus in quadrants

• Re-focus to evaluate optic disk

• Usually within 1D of fundus focus, more neg. means disk depression, more pos. is elevation

• Advantages: simple, inexpensive instrument, upright image, greater magnification, depth and height can be determined with diopter settings

Review of Indirect Ophthalmoscopy

• Ophthalmoscopes

• Lenses

• Virtual Image

• Arms length & 5 cm

• Organized approach to exam

o Indirect Ophthalmoscopy

• Using a lens and light source to view a projected image of fundus

• Lenses of varying dioptric strength can be used

• Smaller diopter rating=greater magnification

• Light source can be from trans-illuminator held near examiner's eye or from binocular indirect system

• Image is inverted with R-L reversal or "upside down and backwards"

• Organized Approach

• Optic Nerve

• Retinal Vasculature

• 4 Quadrants

• Record Each Eye

o Instrumentation

o Indirect Ophthalmoscopy

o Normal Feline Fundus

o Normal Canine Fundus

o Normal Variation

• Optic Nerve

• Tapetal Color

• Non tapetal color

• Vasculature

Common Fundus Abnormalities

• Blastomycosis

• Toxoplasmosis

• Collie Eye Anomoly (Cea)

• Detachment

• Progressive Retinal Atropy (Pra)

• Glaucoma Cupping

Erg Equipment

• Photostimulator

• Sensors

• Amplifier

• Physiograph

• Printer

o Electroretinogram - Normal

o Electroretinogram - Extinguished

Fundus Abnormality

• Choroidal Hypoplasia

• Collie Eye Anomaly

• CEA

• Coloboma

• Retinal Detachment

• Chorioretinitis

• Granulomatous

• Coccidioidomycosis

• Chorioretinitis

• Serous-multifocal

• Cryptococcosis

• Granulomatous

• Histoplasmosis

• Pre-retinal hemorrhage

• E. canis

• Multifocal hyperreflective

• Old Inflammation

• Pigment Proliferation and hyperreflectivity

• Old chorioretinitis

• Change in vessel color

• Lipemia retinalis

Progressive Retinal Atrophy

• Fundus Abnormal

• ERG Abnormal

• Irreversible

Pra – Non Tapetal Changes

• Fundus Abnormal

• Erg Reduced/Extinquished

• Progressive/Irreversible

Sudden Acquired Retinal Degeneration

• Fundus Normal Or Abnormal

• Erg Extinquisted

• Irreversible

o Retinal Hemorrhage

o Retinal Dysplasia

o Retinal Folds

o Optic Neuritis

• Fundus Inconsistent

• Erg Normal

• Sometimes Reversible

o Retinal Detachment

• Etiologies

o Vitreous degeneration

• Shih tzu, Boston terrier, poodle

o Retinal dysplasia

• Labrador retriever, Springer spaniels

o Post surgical

• Cataract removal, lens luxation

o Intraocular inflammation

• Lens Induced Uveitis (LIU)

o Hypertension

o Trauma

Hypertension: Hemorrhage and detachment

Rhegmatogenous Retinal Detachments

• Giant Peripheral Tears

• Breed Predisposition

• One Eye Probably Proceeds The Other

• Require Prompt Treatment

o Retinal Detachment: Post Op Laser