Optometrist group

26/08/2024

Quiz on Human eye 28 august
All ophthalmic assistant student ready??

26/08/2024

???

25/01/2023

13/11/2022

The Lacrimal apparatus

The Lacrimal apparatus consists

1. Lacrimal gland
2. Lacrimal lake and
3. Lacrimal passages.

Main Lacrimal gland - Superior or orbital gland. It is about the size of the almond situated in Lacrimal fossa of the frontal bone 10 -12 ducts from it open at the outer part of the upper fornix.


Inferior or palpebral gland - Small consists only one or two lobules.

Accessory Lacrimal gland -
1. Gland of krause - Microscopic lying between fornix.
2. Gland of Walfring.

13/11/2022

Nerve supply
All the muscle are supplyed by 3rd cranial nerve, except IR or SO.
Nerve supply of LR and SO -
LR6 SO4
6th nerve - abducent 4th n- trochlea.
Action

Muscle primary action 2nd a 3 rd
MR adduction ...... .......

LR Abduction ....... .........


SR Elevation intorsion ........


IR Depression Extortion abduction


SO Intorsion Depression Abduction


IO Extorsion Elevation abduction

13/11/2022

Extraocular muscles

Muscle of the eyeball which organ the eye.
1. Sinary muscle
2. Iris
There are 6 extra ocular muscles. 4 re**us and2 oblique. Re**us muscle are superior (SR) , inferior (IR) , medial ( MR) and lateral (LR) , the oblique muscle are superior (SO),
Inferior (iO) .
Origin and insertion - The re**us muscle originate from a common Tendinous ting (the annual of zinn) , which attached to the apex of orbit encircling optic nerve.

There are inserted into the sclera at different distance from the limbus sa under.
MR - 5.5 mm
IR - 6.5 mm
LR - 6.9 mm
SR- 7.5 mm

Superior oblique muscle - arises from Bone above and medial to the optic Foraminate.
It runs forward and turn around a Pillery.
The trochlea and inserted in the uppon and outer part of sclera behind the equator.

The inferior oblique muscle - arises for orbital plate of maxilla lateral to the arifice of the NLD. It instead into the lower and outer part of sclera behind the.

13/11/2022

Vitreous Humour
Vitreous humour is an inter transparent HYDROPHILICGEL that fills the post 4/5 th of the cavity of the eyeball.
Amount - approx 4.5 mm in volume.

Function
1. It provides a clear transparent medium.
2. It mechanically stabilize the structural integrity of the globe.
3. It gives pathway for the nutrients.

Composition - approx 99℅
Hyaluronic acid
Nuco poly saccharoid and Hyalochyst.


Type

1 . Coloured vitreous .
2. Main vitreous body or nucleus.

13/11/2022

The Retina
The retina is the Membranous light sensitive layer of the eye . All the layer of the retina are transparent life except RPE.
1. Optic dise - pink coloured 15 mm in diameter.
- All the layer of the retina termind except nerve fibers layer.
- Central depression in the dise is called physiological cup.

2. Macula lutea ( yellow spot) - Which surround fovea centralized.
- Fovea central.
- 1.5 mm in diameter.
- 3 mm optic dise margin.

Fovea- central depression in the fovea is Foveola.
Measuring approx 0.5 mm in diameter Photorecepters are exclusively cones most sensitive past of retina.

3 . Peripheral retina - the Photorecepter are mainly rods
Ora serrata - where retina is anterior termination of the retina.
Located about 8 mm retina.

Structure of retina
Retina consist of 10 layers. Form out side inward the.

RP 1. Retina pigment epithelium - outermost layer signal layered pigmented cell's.
2. Layer of rods and cones ( Photorecepter ) - end organ of vision.

E -3 . External limiting membrane- Fenestrated membrane.

O2 . 4. Outer nuclear layer- consists nucleus of rods and cones.

5. Outer Plexiform layer- consists connective rods and cones .


I2. 6. Inner nuclear layer- consists cell bodies bipolar cells.
7. Inner Plexiform layer- Consists connective between bipolar cells and ganglion cells.
8 . Ganglion cell layer- consists bodies of ganglion cells.

9. Nerve fiber layer- consists axon of ganglion cells.

10. Internal limiting membranes- The inner most layer. Which separate retina from vitreous.