Simplified slides for better understanding. Share and like if you love it. Thank you!!

1. ANATOMY OF RETINA
BY – ROBIN SINGH

2. What is Retina?
2
“The retina is the innermost tunic of
the eyeball which is a thin, delicate
and transparent membrane and is
the most highly developed tissue of
the eyeball.”

3. 3

4. 4
Gross anatomy of Retina
 Extent : From the optic disc to the ora serrata
 Thickness : At posterior pole about 0.56mm
At the equator about 0.2mm
At the ora serrata approx 0.1mm
 Colour : Purplish red
 Regions : 3 distinct regions
- Optic disc
- Macula Lutea
- Peripheral retina (General fundus)

5. 1.
REGIONS OF RETINA

6. 6

7. “
7
Optic Disc
 Pale-pink, well defined circular area of about
1.5mm diameter.
 Colour may vary.
 All the retinal layers terminate here except the
nerve fibres, which pass through the Lamina
cribrosa into the optic nerve.
• Appears pale to due lamina cribrosa and
absence of vascular choroid.

8. “
8
 Physiological cup is a depression seen in the
centre of it from where the central retinal
vessels emerge.
 Cup varies in size, shape, position and depth in
the two eyes.
 Increase in the size of cup or difference in the
size of cup of the two eyes should be properly
examined to exclude glaucoma.

9. Macula Lutea
9
 A.k.a macular area or area centralis.
 Yellow spot, comparatively dark area of
5.5mm
in diameter.
 Situated at the posterior pole of the eyeball,
temporal to the optic disc.
 It is situated at 4.0mm temporal and 0.8mm
inferior to the centre of optic disc.

10. 10
 It corresponds to approximately 15° of the
visual field.
 The photopic vision and colour vision are
primarily the functions of this area.
 It comprises of three main areas : Fovea
Parafovea,
and
Perifovea

11.  Fovea/Fovea Centralis : Central depressed part of the macula
viz. about 1.50mm in diameter and 1.55mm in thickness.
It corresponds to 5° of visual field and is the most sensitive
part of the retina.
Foveola : 0.35mm in diameter and 0.15mm in thickness, forms
the central part of fovea.
Umbo : Tiny depression seen in the centre of foveola viz
referred
to as the central bouquet of cones due to greatest
concentration
of cones.
Foveal avascular zone : Is located inside the fovea but outside
the foveola.
11

12.  Parafovea : Refers to a belt that measures 0.5mm
in width which surrounds the margin of fovea.
This include 4-6 layers of ganglion cell and 7-1o
layers of bipolar cells.
 Perifovea : Refers to a belt which measures 1.5mm
in width and surrounds the parafoveal area.
This include several layers of ganglion cells and
six
layers of bipolar cells.
12

13. Peripheral Retina
Near periphery
Circumscribed
region of about
1.5mm width around
the macula lutea.
Mid periphery
It occupies a 3mm
wide zone around
the near periphery.
Far periphery
Extends from the
equator to the ora
serrata. The width of
this belt depend upon
the eye size and
refractive error.
13
Extreme periphery
Refers to the area of
ora serrata and pars
plana.
Ora serrata – The
retina is firmly
attached to the
vitreous and RPE.

14. Microscopic structure of Retina
14
1. Retinal pigmented epithelium
2. Layers of rods and cones
3. External limiting membrane
4. Outer nuclear layer
5. Outer plexiform layer
6. Inner nuclear layer
7. Inner plexiform layer
8. Ganglion cell layer
9. Nerve fibre layer
10. Internal limiting membrane

15. 15

16. 16

17. 1. Retinal pigmented epithelium
17
 Outermost layer of the retina.
 Consists of single layer of hexagonal shaped cells containing
pigment.
 It is firmly adherent to the underlying bruch’s membrane and loosely
to
the layer of rods and cones of the retina.
 The space between RPE and the sensory retina is called subretinal
space.
 Separation of the RPE from sensory retina is called retinal detachment
and the fluid between the two layers is called Sub retinal fluid (SRF).
 RPE cells are connected to each other by tight junctions i.e. zonulae
occludents and zonulae adherents.

18. 18
Functions of RPE :
 Photoreceptor renewal and recycling of viatmin A.
 Maintains the integrity of sub retinal space.
 Transport of nutrients and metabolites.
 Phagocytosis or digestion of photoreceptors.
 Manufactures pigment.
 Regeneration and repairing after injury.

19. 19

20. 2. Layer of Rods and Cones
20
 Rods and cones cell transform light energy into nerve impulses.
 Rods contain photosensitive substance Rhodopsin whereas cones
contain photosensitive substance Idopsin.
 Cone cells - Photopic vision
 Rod cells – Scotopic vision
 Cones = 6.5M
 Rods = 120M
 At fovea maximum cones are present and rods are absent.
 Density of cones = 100000-324000/mm sq
 Density of rods = 160000/mm sq

21. 21
Structure of rod cell
 Length = 40-60µm
 Outer segment is cylindrical &
composed of numerous protein
lamellar disc.
 Disc = 600-1000/rod
 Thickness of disc = 22.5-24.5 nm
 Disc contain 90% of visual purple.
 Outer segment is attached to inner
segment via cilium.

22. 22
Structure of cone cell
 Length = 40-80µm
 At periphery = 40µm (shortest)
 At fovea = 80µm (longest)
 Outer segment is conical viz shorter
than rod.
 Contains idopsin pigment packed in
lamellar disc.
 Disc = 1000-1200 disc/cone
 Inner segment & cilium are similar to
rods.

23. External limiting membrane
23
Last
 Fenestrated membrane extending from the ora serrata
upto the edge of optic disc.
 Processes of rods and cones pass through it.
 This layer is formed by the junction between the cell
membrane of photoreceptors & muller cells.
Outer nuclear layer
 Made up of the nuclei of rods & cones.
 Cones nuclei – 6-7µm
 Rod nuclei – 5.5µm
 These nuclei lie in a single layer next to the external
limiting membrane.
 Rod nuclei form the bulk of this layer except at the cone
dominated foveal region.

24. Outer plexiform layer
24
 This layer is made up of synapses between the rod
spherules and cone pedicles with the dendrites of
bipolar cells.
Inner nuclear layer
 It is a very thin layer, similar to outer nuclear layer,
which dissappears at fovea.
 It consists of : Bipolar cells
Horizontal cells
Amacrine cells
Muller cells
Central retinal vessels
Other glial cells

25. Inner plexiform layer
25
 Consists of synapses between bipolar cell and
dendrites of ganglion cell.
 Absent at fovea.
Ganglion cell layer
 Consist of cell body and nuclei of ganglion cell ( 2nd
order neurons )
 Absent at fovea
 Various type of ganglion cell :
- W,X,Y ganglion cell
- P & M ganglion cell
- Off centre & on centre cell
- Monosynaptic & polysynaptic cell

26. 26
Nerve fibre layer
 Consists of unmyelinated axons of ganglion cells
which converge at optic nerve head.
 Thickness – 0.5 to 2µm
 Thickness decrease from optic disc to lateral side.
 Fibres show definite pattern of arrangement.
Internal limiting membrane
 Consists of following elements :
- Collagen fibrils
- Proteoglycans of vitreous
- Basement membrane
- Plasma membrane of muller cells
- Other glial cells

27. 27
Blood supply of Retina
 RPE, Layer of rods and cones, External limiting membrane and
outer nuclear layer gets blood supply from choriocappilaries.
 The rest six layers gets blood supply from central retinal artery.
 Fovea is avascular but partially gets blood suppy from
choriocappilaries.
 Macular area gets blood supply from central retinal artery and
cilioretinal artery.

28. This slide is
available on
slideshare.net
28
Place your screenshot here

29. THANKS!
Any questions?
You can find this slide at
https://www.slideshare.net/robynshekhawat
29