Basics of Optic fundus Exam

Norwin A. Detalla, MD

Objectives

Describe Patient preparation Demonstrate correct procedure using

the ophthalmoscope Describe the normal fundus Describe abnormal findings, and

recognize disease process

Direct Ophthalmoscope

Viewing aperture

Beam Selector

Rheostat

Handle

Brow Rest

Peephole

Lens wheel

Lens power

Optic disc

Optic cup

Vein

Arterioles

Fovea

Normal Ocular Fundus

Normal fundus

Disc: Clear outline; optic cup is pale and centrally located.

Normal fundus

Disc: Clear outline; optic cup is pale and centrally located.

Retina: Normal red/orange colour, macula is dark. The macula is approximately 2 disc diameters away from disc and 1.5 degrees below horizon.

Normal fundus

Disc: Clear outline; optic cup is pale and centrally located.

Retina: Normal red/orange colour, macula is dark. The macula is approximately 2 disc diameters away from disc and 1.5 degrees below horizon.

Vessels: Arterial/venous ratio 2 to 3; the arteries appear a bright red, the veins a slightly purplish colour.

Optic nerve

Consists of 1 million axons that arise from the retina.

Leaves the eye through the sclera – optic canal – into the cranium.

What to observe

Optic disc- colour/size/edges Cup – size Blood vessels –

number/width/tortuosity Macular / fovea Other findings –hemorrhages, soft

and hard exudates, edema

Procedure

Ask patient to fix stare at far object Turn on scope and set dial to 0 Remember right eye right hand Rest hand on patients forehead Begin at arms length away, should see red

reflex. Move closer until optic disc visible ( approx. 3-

5cms) Turn dial until disc in focus. Hyperopic – turn disc for plus numbers (green) Myopic – minus numbers (red)

Micro Spot Aperture: Allows quick visual entry in very small, undilated pupil

Small Aperture: Provides easier view of fundus through undilated pupil

Large Aperture: Standard aperture for dilated pupil and general examination of the eye

Fixation Aperture: Features graduated cross-hairs for measuring eccentric fixation or for locating lesions and other abnormalities

Slit: Used to determine various levels of lesions and tumors

Cobalt Filter: Blue filter used with Fluorescein dye permits easy viewing of small lesions, abrasions and foreign objects on the corneal surface

Red Free Filter: Green filter used to study blood vessels and retinal nerve fiber layer (RNFL)

Microaneurysm / dot blot hemorrhage

Flame-shaped hemorrhage

Exudates

Macular edema

Cotton-wool spot

Vitreous hemorrhage

Neovascularization

Hypertensive Retinopathy

Modified Scheie Classification Grade 0: No changes Grade 1: Minimal arteriolar narrowing Grade 2: Obvious arteriolar narrowing

with focal irregularities Grade 3: Grade 2 + retinal hemorrhages

and/or exudate Grade 4: Grade 3 + swollen optic nerve

(Malignant hypertension)

Hypertensive RetinopathyGrade 2

Arteriovenous nicking in association with hypertension Grade 2

(black arrows)

Hypertensive RetinopathyGrade 3 Flame-shaped

hemorrhage in association with severe hypertension Grade 3 (red arrow)

Hypertensive RetinopathyGrade 4 Papilledema from

malignant hypertension. There is blurring of the borders of the optic disk with hemorrhages (red arrows) and exudates (white arrow)