RETINA APPLIED ANATOMY

1. RETINA VIRAL KERATITIS
DR M SAQUIB
MBBS,MS , FSCEH DELHI,FHVDESAI PUNE,
EX REGISTRARA JNMCH,AMU
CONSULTANT OPHTHALMOLOGIST
HOD D/O OPHTHALMOLOGY
G.S .MEDICAL COLLEGE
Founder sec: MEDICS India , www.medicsngo.org
Mail-dms2k5@gmail.com , 9634123800

2. CONTENTS
1.ANATOMY
2.CONGENITAL & DEVELOPMENTAL DISORDER S
3.INFLAMMATORY DISORDER –Retinitis, Vasculitis
4.VASCULAR DISORDER OF RETINA –
Vascular Occlusions Diabetic ,Hypertension ,sickle cell ,Prematurity
Retinopathy , Retinopathy in Pregnancy ,Blood Disorders ,Retinal
Telangiectasia, Ocular Ischemic Syndrome
5. RETINAL DYSTROPHIES & DEGENERATION
6.MACULAR DISORDER
7. RETINAL DETACHMENT – Rhegmetogenous ,Exudative,
Tractional .
8.TUMOURS OF RETINA

3. Retina Developed from 2 walls of optic cup
Nervous Retina –From Inner wall
Pigment Epithelium from Outer wall

4. A. ANATOMY
• Retina is a thin delicate transparent membrane forming the
innermost covering of the eyeball and extending from the optic
disc to the ora serrata.
• Appears Purplish Red ( Rods& choroid)
• Surface Area -266 mm2
• Thickness-
Ora serrata -0.1mm
Equator – 0.18 mm
Peripapillary-0.56mm

5. MACULA LUTEA
• 5.5 mm circular area deeper red than rest of the fundus at the
posterior pole of retina,.
• lying inside the temporal vascular arcades, 2 disc diameters
temporal to the optic disc
• Macula lutea (5.5mm)
– Fovea centralis (1.5mm)- Most sensitive part of Retina ,Cones only
– Foveola (0.35mm)- 2DD ( 3-4mm) from temporal margin og
Disc and 1 mm below horizontal meridean
– Umbo- Tiny depression . Shining foveal Reflex on examination.
– Parafoveal region(o.5mm)-
– Perifoveal region(1.5mm)
– -Foveal Avascular Zone (FAZ)-0.8 mm Not contain any
capillaries

6. Macula Lutea
Fovea Centralis
1.5mm
Foveola
Diameter:0.35mm
Umbo:
Tiny Depression in the Very
Centre of Foveola
Parafovea
0.5mm wide
Perifovea
1.5mm wide

7. Optic disc
• Pale pink
• Well defined circular area
• 1.5 mm
• Cup It varies in size,
shape, position and
depth in different eyes.
• All the retinal layers
terminate at the optic
disc except the nerve
fibres ,which pass
through the lamina
cribrosa to run into
the optic nerve.

8. OPTIC DISC ( Optic Nerve Head )
• Oval area vertical-1.88 mm
• Horizontal- 1.76 mm
• Begining of Optic Nerve / Optic Nerve Head
• Depression in Optic Disc – Physiological Cup
• No Photoreceptors at Optic Disc –
ABSOLUTE SCOTOMA
PHYSIOLOGICAL BLINDSPOT
• Nasal border is steeper & temporal border has a more
gradual slope

9. Peripheral Retina
• Area of Retina Ant –ora Serrata & Posteriorly by Equator .
• Examined – I.O or Goldman Three Mirror contact Lens

10. Ora Serrata
• Serrated Peripheral Margin
• Anterior End of Retina
• Retina Firm attachement with
Vitreous & Choroid
• Pars Plana Extends Anteriorly

11. MICROSCOPIC STRUCTURE
• 10 Layers
• Pigment Epithelium
• Neurosensory Retina –
3 types of cells Muller
Amacarine
Bipolar
synapses

14. Retinal pigment epithelium(RPE)
• Outermost Layer Of Retina
• Provide metabolic support & Antireflective layer
• Consisting Of A Single Layer Of Hexagonal Cells
• Containing Pigment
• Firmly Adherent To The Underlying Bruch’s Membrane of
choroid
• And Loosely Arranged To The Layer Of Rods And Cones
• The Potential Space Between RPE And The Sensory Retina Is
Called Subretinal Space
• INTERPHOTORECEPTOR MATRIX (IPM) Present in the
potential space binding support .

15. RPE Electron microscopy shows that adjacent RPE cells are
connected with each other by tight junctions(zonulae occludens
anzonulae adherens) and constitutes the outer blood-retinal
barrier

16. PHOTORECEPTORS -Rods & Cones
Electromagnetic wave of light to Electro chemical
• 120 million rods
• 6.5 million cones
• Outer segment of photoreceptor cells
Rods – 40-60 um, Scotopic Vision
Visual Purple (Rhodopsin)
Vision of low illumination
Peripheral Vision
Cones- Photopic Vision
Colour Vision
40-80um long,
longest at the fovea and shortest at the periphery.

17. External limiting membrane:
• In low magnification, it appears as a fenestrated
membrane extending from the ora serrata to the
edge of the optic disc.
• Electron microscopy studies show that ELM is
formed by the junctions between the cell
membranes of photoreceptors and mullers cell.
• Process of Rods and Cons pass throgh

19. INNER NUCLEAR LAYER
• This layer resembles the outer nuclear layer
except it is very thin. It disappears at fovea and in
rest of the retina consists of the following;
– Bipolar cells,( First Order Neuron )
– Horizontal cells,
– Amacrine cells,
– soma of the Mullers cells,
– Capillaries of central retinal vessels

21. BIPOLAR CELLS
• These are the neurons of first order of vision.The
body of the bipolar cells consists entirely of the
nucleus which lies in the inner nuclear layer.
Their dendrites arborize with the rod spherules
and cone pedicles in the outer plexiform layer and
their axons arborize with the dendrites of ganglion
cells in the inner molecular layer.

22. MULLER CELLS
• The nucleus and cell bodies of the mullers cells
are located with in the inner nuclear layer.The
mullers cell provide structural support and
contribute to the metabolism of the sensory retina.

23. Inner Plexiform Layer
This layer essentially consists of synapses
between the axons of bipolar cells(first order
neurons),dendrites of ganglion cells(second order
neurons) and the processes of integrative
amacrine cells.
• This layer is absent at the foveola.

24. Ganglion cell layer
• The cell bodies and the nuclei of the ganglion
cells ( Second Order Neuron of visual pathway )
lie in this layer.
• Monosynaptic Ganglion cells –
• In macular region
• Dendrites of each cell synapse with single Axon of Bipolar cells
• Polysynaptic Ganglion Cells –
• One dendrites may synapse with hundred of Axon cells .
• Peripheral Retina

25. Nerve fibre layer
• This layer consists of the unmyelinated axons of
the ganglion cells which converge at the optic
nerve head, pass through lamina cribrosa and
become ensheathed by myelin posterior to lamina.
• This layer also contains the follwing;
• Centrifugal nerve fibres,
• Processes of mullers cells,
• The neuroglial cells present in the nerve fibre
layer,
• Retinal vessels lie in the nerve fibre layer.

26. Internal Limiting Membrane
• It mainly consists of a PASpositive true basement
membrane that forms the interface between retina
and vitreous. It consists of four elements,
Collagen fibrils,
Proteoglycans(mostly hyaluronic acid)of the
vitreous,
• The basement membrane,
• The plasma membrane of the mullers cells and
possibly other glial cells of the retina.

27. Fovea Centralis
• In this area, there are no rods, cones are larger,in
abundance and tightly packed, and other layers of
retina are very thin.
• Its central part (foveola) largely consists of cones
and their nuclei covered by a thin internal limiting
membrane.
• All other retinal layers are absent in foveolar
region.

28. Henle’s layer – In the
foveal region surrounding
the foveola cone axons are
arranged obliquely .

29. Functional Division of Retina

30. VASCULAR SUPPLY OF RETINA
• Outer four layers of the retina get their nutrition
from the choriodal vessels.
• The six inner layers get their blood supply from
the central retinal artery.
• The fovea is an avascular area mainly supplied by
the choriocapillaries.
• The macular region gets its blood supply by small
twigs from the superior and inferior temporal
branches of central retinal artery.
• The branches of central retinal artery are end
arteries i.e they dont anastomose with each other.

31. Central Retinal Artery
• Branch of ophthalmic Artery
• Emerge from center of physiological
• cup of disc
• 4 brances – Sup –nasal,Su-Inf
• Inf –Nasal-Inf Temp
• End Artery

32. Retinal Veins
• Follow pattern of Retinal Artery
• Drains into cavernous sinus directly or through
superior ophthalmic vein