Dr samarth mishra

Briggs coined papilla for optic disc Buzz,Sommering,Reil described macula Helmoltz invented eye mirror Ruete introduced indirect

ophthalmoscopy

Fundus is the portion of the inner eye that can be seen during an eye examination while looking through the pupil.

FUNDUS OCCULI

OPTIC DISC/PAPILLA MACULA LUTEA PERIPHERAL RETINA

Insensitive area in retina where ganglion cell axons exit eye to form optic nerve

Diameter-1.5mm Shape-round/vertically oval Colour-pale red/yellowsh red tint due to

lamina cribrosamedullated nerve fibres and

capillary plexus

Fibres continuous with sclera & choroid bridge the sclerochoroidal aperture forming a sieve like structure

LC is partly collagenous & partly neuroglial and derived from

Sclera (major part),pia mater &perivascular sheaths of central retinal

artery

Funnel shaped depression from which retinal vessels appear to emerge

15% cases do not show cup Nasal border steeper than temporal border Cup disc ratio- is<0.4 Depth of cup depends on –size, shape, obliquity ,vascularity of optic disc degree of development & regressionof hyaloid artery and glial tissue.

Diameter-5.5mm Situation-2DD temporal to OD Colour-yellow Function-photopic vision & colour vision Consists of- fovea centralis (1.5mm) foveola (0.35mm) parafovea(0.5mm),

perifovea(1.5mm),

Fully developed after 4yrs Diam - 1.5mm,0.25mm thick Situation - 4mm temp to OD 5 degree of visual field Foveola - no rods ,highest visual acquity Umbo - tiny depression in centre of

foveola Foveal avascular zone(0.4-0.6mm)

densely packed red & green cones central fovea has no rods

FOVEA 3MM AWAY FROM FOVEA

10MM AWAY FROM FOVEA

1,00,000- 3,24,000 cones/mm2Avg- 1,99,000 cones/mm2

6000 cones/mm2 4000 cones/mm2

Central retina:direct one-to-one relationship

In extra macular region

At least 1/3rd of all the nerve fibres which enter the ON originates in macular region.

Single cone cell Single bipolar cell

Single ganglion cell

20-100 cones 3-15 bipolar cells

Single ganglion cell

Nasal fibres-superior and inferior fibres

Macular fibres-papillomacular bundle

Temporal fibres-arcuate fibres

Nerves are nonmedullated

Near periphery – 1.5mm around ML

Mid periphery – 3mm around near periphery

far periphery – extend from OD 9mm on temporal side & 16mm on nasal side

Ora serrata - region where retina ends - 2.1mm wide temporally & 0.7mm

nasally

colour - orange to vermilion. Factors - amount of pigment in the

choroid, - hexagonal epithelium of retina & - Choroidal vasculature

At birth Choroid

unpigmented-most brilliant.

In old age Choroid fully pigmented

Greyish brown tint

Walls of choroidal BVs lost trasparency

finely granular or stippled texture. due to variation or unequal

pigmentation of hexagonal cells of pigmented epithelium of retina.

Watersilk reflex: Mainly patchy type. May be round, oval or irregular in

shape. They are highly mobile & elusive.

Tapeto-retinal reflex: seen near macular area

specular ill-defined patch of light against which a striking picture of the circumfoveal vessels can be seen

Gunn’s Dot: minute + highly glistening + colourless specs usually in the posterior part of the fundus

seen best in the course of the retinal nerve fibres above & below the disc

Weiss’s Reflex: annular reflex concentric with the border of the disc & is mobile

formed by the elevation of the internal limiting membrane where the nerve fibre layer is thickened

present at the nasal border of the disc

Many a times tunics of eye at the margin of OD don’t make contact with ON.

narrow zone of border tissue produces a narrow pale border to the disc, known as SR

mostly seen at the temporal

border of disc

Retinal vessels are end arteries.

anastomosis b/w the retinal vessels & cilliary system of vessels exist near the LC.

Retinal vessels form 4 groups to supply 4 quadrants of fundus

Only vessels in body not controlled by ANS

Blood flow 35-45ul/min 4% of total blood to eye Wall to lumen ratio-artery-1:5,vein-1:10 AV ratio-2:3 Mean retinal circulation-4-5sec 20% shows cilioretinal artery and vein

More on temporal than nasal Arteries never cross arteries and veins never

cross veins When 2 vessels cross they share a common

adventitia

Direct ophthalmoscopy Indirect ophthalmoscopy Biomicroscopic methods- negative lens positive lensHruby lens, El biyardi lens,

+78Goldmann3 mirror +90D,Mainster

lens panfunduscopic

lens

Done on a printed form with 12clock hours area

3 circles- inner corressponds to equator - outer to ora serrata, - outermost to anterior border of

pars plana ciliaris

Mydriasis Media OD-Size,shape,colour,margin,cup disc

ratio Macula-foveal reflex Peripheral retina Blood vessels

FUNDUS of eye is the only part of human body where microcirculation can be observed directly

THANK YOU