2017 Group Project 4 - Revision history

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2017-10-26T22:16:26Z

Protected "2017 Group Project 4" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))

← Older revision	Revision as of 08:16, 27 October 2017
(No difference)

Z5117343 at 08:48, 26 October 2017

2017-10-26T08:48:38Z

← Older revision		Revision as of 18:48, 26 October 2017
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	===Extraocular muscles===		===Extraocular muscles===

	[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb\| '''Figure 9''' ~~Extraoccular~~ Muscles]]		[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb\| '''Figure 9''' Extraocular Muscles]]

	The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).		The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).

Z5117343 at 08:05, 26 October 2017

2017-10-26T08:05:59Z

← Older revision		Revision as of 18:05, 26 October 2017
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	To discuss the key anatomical components of the eye, we will break down the eye in parts<ref>Chen, J., 2011. Handbook of Visual Display Technology. Springer Berlin Heidelberg. Chapter 2.1</ref>:		To discuss the key anatomical components of the eye, we will break down the eye in parts<ref>Chen, J., 2011. Handbook of Visual Display Technology. Springer Berlin Heidelberg. Chapter 2.1</ref>:

	'''Supporting Structures (Orbit, ~~Extraoccular~~ Muscles, Lacrimal Gland, Eyelid)'''		'''Supporting Structures (Orbit, Extraocular Muscles, Lacrimal Gland, Eyelid)'''
	[[File:22292144 10208413540209536 722417340 o.jpg\|250px\|thumb\|right\| '''Figure 1.''' Layers of the Eyeball]]		[[File:22292144 10208413540209536 722417340 o.jpg\|250px\|thumb\|right\| '''Figure 1.''' Layers of the Eyeball]]
	The orbit consists of a framework of bones and connective tissue which provide structural support and protection to the sensitive human eye. 7 bones contribute to the orbit of the eye: frontal, lacrimal, sphenoid, zygomatic, ethmoid, maxillary, palatine. Several openings exist in the orbital structure, 2 key fissures are the superior orbital fissure and inferior orbital fissure and the posterior optic canal. These openings allow cranial nerves passageway.		The orbit consists of a framework of bones and connective tissue which provide structural support and protection to the sensitive human eye. 7 bones contribute to the orbit of the eye: frontal, lacrimal, sphenoid, zygomatic, ethmoid, maxillary, palatine. Several openings exist in the orbital structure, 2 key fissures are the superior orbital fissure and inferior orbital fissure and the posterior optic canal. These openings allow cranial nerves passageway.
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	\|-		\|-
	\| Coloboma \|\| A condition where parts of the eye is missing and failed to develop normally.		\| Coloboma \|\| A condition where parts of the eye is missing and failed to develop normally.
	\| Prevalence: ~~Occular~~ coloboma was estimated to be 8.0 per 100 000 cases <ref name="Anophthalmia">Orphanet Report Series – Rare Diseases Collection. (2017). ''Prevalence of rare diseases: Bibliographic data (no. 2). Paris''. France: Author. Retrieved from: [[http://www.orpha.net/consor/cgi-bin/index.php]] </ref>		\| Prevalence: Ocular coloboma was estimated to be 8.0 per 100 000 cases <ref name="Anophthalmia">Orphanet Report Series – Rare Diseases Collection. (2017). ''Prevalence of rare diseases: Bibliographic data (no. 2). Paris''. France: Author. Retrieved from: [[http://www.orpha.net/consor/cgi-bin/index.php]] </ref>
	\|-		\|-
	\| Anopthalmia \|\| The absence of the eyes.		\| Anopthalmia \|\| The absence of the eyes.

Z5117343 at 08:00, 26 October 2017

2017-10-26T08:00:02Z

← Older revision		Revision as of 18:00, 26 October 2017
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	===Lens===		===Lens===
	[[File:Stage_22_image_155.jpg\|thumb\|Human Lens (stage 22)]]		[[File:Stage_22_image_155.jpg\|thumb\|'''Figure 7''' Human Lens (stage 22)]]

	Human lens induction occurs at around 28 days and is completed around day 56. The surface ectoderm will thicken near the optic vesicle and create the lens placode and later form the lens vesicle <ref><pubmed>20171212 </pubmed></ref>. Lens cells come from ectoderm and differentiate into either lens fibres or the lens epithelium. The anterior monolayer of epithelial cells of the lens will create the lens epithelium, which makes the sheet of cuboidal epithelium covering the anterior surface of the lens. The posterior lens vesicle cells will produce the linear primary fibre cells aligned parallel to the optic axis. These fibres will create the lens mass and form the embryonic lens nucleus. The lens epithelial cells will keep proliferating and produce new cells which generate secondary lens fibre cells. These rows of cells will form the outer shells and keep the lens growing throughout life. This makes the eye lens unique - it will have an addition of new cells inside the surrounding capsule all the time <ref><pubmed>25406393</pubmed></ref>.		Human lens induction occurs at around 28 days and is completed around day 56. The surface ectoderm will thicken near the optic vesicle and create the lens placode and later form the lens vesicle <ref><pubmed>20171212 </pubmed></ref>. Lens cells come from ectoderm and differentiate into either lens fibres or the lens epithelium. The anterior monolayer of epithelial cells of the lens will create the lens epithelium, which makes the sheet of cuboidal epithelium covering the anterior surface of the lens. The posterior lens vesicle cells will produce the linear primary fibre cells aligned parallel to the optic axis. These fibres will create the lens mass and form the embryonic lens nucleus. The lens epithelial cells will keep proliferating and produce new cells which generate secondary lens fibre cells. These rows of cells will form the outer shells and keep the lens growing throughout life. This makes the eye lens unique - it will have an addition of new cells inside the surrounding capsule all the time <ref><pubmed>25406393</pubmed></ref>.
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	===Cornea===		===Cornea===
	[[File:Mouse eye neural crest cornea 01.jpg\|\|thumb\|300px\|~~alt=Cornea structure~~]]		[[File:Mouse eye neural crest cornea 01.jpg\|\|thumb\|300px\|'''Figure 8''' Corneal Structure]]
	The cornea is the transparent and avascular component located at the anterior-most section of the eye. It is composed of five layers stemming from the 3 main layers of epithelium, stroma and endothelium:		The cornea is the transparent and avascular component located at the anterior-most section of the eye. It is composed of five layers stemming from the 3 main layers of epithelium, stroma and endothelium:

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	===Extraocular muscles===		===Extraocular muscles===

	[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb]]		[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb\| '''Figure 9''' Extraoccular Muscles]]

	The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).		The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).
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	===Eyelids===		===Eyelids===

	[[File:Stage22_eyelids.jpg\|thumb\|Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]		[[File:Stage22_eyelids.jpg\|thumb\|'''Figure 10''' Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]

	The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.		The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.
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	Through studying zebrafish, it was found that that a mutation in ''chokh/rx3'' gene resulted in the absence of eyes during the earliest stages of development, due to the failure in developing retinal progenitor cells. <ref name="chokh">Loosli, F., Staub, W., Finger-Baier, K. C., Ober, E. A., Verkade, H., Wittbrodt, J. & Baier, H. (2003). Loss of eyes in zebrafish caused by mutation of chokh/rx3. ''EMBO Reports, 4''(9), 894-899. doi: 10.1038/sj.embor.embor919 </ref>. Additionally, the optical vesicle was inverted and the neuronal differentiation was blocked. The study also found that the DNA-binding homeodomain and the entire C-terminal portion led to a nonsense mutation that resulted in complete loss of function in the eye. It was concluded that the gene ''chokh/rx3'' is important for the developing optic primordia. <ref name="Zebrafish"> Glass, A. S. & Dahm, R. (2003). The Zebrafish as a Model Organism for Eye Development. ''Opthalmic Research, 36''(1), 4-24. doi: 10.1159/000076105</ref>		Through studying zebrafish, it was found that that a mutation in ''chokh/rx3'' gene resulted in the absence of eyes during the earliest stages of development, due to the failure in developing retinal progenitor cells. <ref name="chokh">Loosli, F., Staub, W., Finger-Baier, K. C., Ober, E. A., Verkade, H., Wittbrodt, J. & Baier, H. (2003). Loss of eyes in zebrafish caused by mutation of chokh/rx3. ''EMBO Reports, 4''(9), 894-899. doi: 10.1038/sj.embor.embor919 </ref>. Additionally, the optical vesicle was inverted and the neuronal differentiation was blocked. The study also found that the DNA-binding homeodomain and the entire C-terminal portion led to a nonsense mutation that resulted in complete loss of function in the eye. It was concluded that the gene ''chokh/rx3'' is important for the developing optic primordia. <ref name="Zebrafish"> Glass, A. S. & Dahm, R. (2003). The Zebrafish as a Model Organism for Eye Development. ''Opthalmic Research, 36''(1), 4-24. doi: 10.1159/000076105</ref>


	===Mouse===		===Mouse===
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	<gallery>		<gallery>

	Anophthalmia.jpeg\|'''Figure 8.''' Anopthalmia		Anophthalmia.jpeg\|'''Figure 11.''' Anopthalmia
	Microphthalmia-500px.jpg\| '''Figure 9.''' Microphthalmia		Microphthalmia-500px.jpg\| '''Figure 12.''' Microphthalmia
	Opac_figure_7.jpg\| '''Figure 10.''' Iris Coloboma		Opac_figure_7.jpg\| '''Figure 13.''' Iris Coloboma
	Opac figure 10.jpg\| '''Figure 11.''' Partial Aniridia		Opac figure 10.jpg\| '''Figure 14.''' Partial Aniridia
	</gallery>		</gallery>

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	===Will the bionic eye pass clinical trials in the next few years?===		===Will the bionic eye pass clinical trials in the next few years?===
	[[File:BionicEye.jpg\|250px\|thumb\|left\| '''Figure 12.''' Bionic Eye Diagram]]		[[File:BionicEye.jpg\|250px\|thumb\|left\| '''Figure 15.''' Bionic Eye Diagram]]

	The bionic eye is an external visual device that has been in the making for the last several years. It hopes to bring back full vision through the aid of a pair of glasses with a camera attached to it, which then transmits high-frequency radio signals to the microchip implanted in the users' eye. These signals are converted into electrical impulses by the electrodes implanted in the chip, which then stimulates the retinal cells and passes through the optic nerve. Electrical impulses travels to the vision processing centres in the brain and these are then interpreted as an image. At the moment, users must learn to understand light flashes and visual patterns and convert them into images they can interpret. Current prototypes require the users to have a previously working eyes, which means their optic nerves must still be relatively healthy and their visual cortex must be developed. Patients who have suffered from retinitis pigmentosa and age-related macular degeneration would benefit this technology. Bionic Vision Australia<ref>'''Bionic Vision Australia''': http://bionicvision.org.au/about/research_plan</ref> is one of the leading organisations that are aiming to treat blindness and are set to perform clinical trials on two of the devices of the bionic eye implants soon. Their objectives are to develop strategies that can improve the affected visual pathway to the brain by stimulating the remaining working retinal cells and also develop safe surgical procedures.		The bionic eye is an external visual device that has been in the making for the last several years. It hopes to bring back full vision through the aid of a pair of glasses with a camera attached to it, which then transmits high-frequency radio signals to the microchip implanted in the users' eye. These signals are converted into electrical impulses by the electrodes implanted in the chip, which then stimulates the retinal cells and passes through the optic nerve. Electrical impulses travels to the vision processing centres in the brain and these are then interpreted as an image. At the moment, users must learn to understand light flashes and visual patterns and convert them into images they can interpret. Current prototypes require the users to have a previously working eyes, which means their optic nerves must still be relatively healthy and their visual cortex must be developed. Patients who have suffered from retinitis pigmentosa and age-related macular degeneration would benefit this technology. Bionic Vision Australia<ref>'''Bionic Vision Australia''': http://bionicvision.org.au/about/research_plan</ref> is one of the leading organisations that are aiming to treat blindness and are set to perform clinical trials on two of the devices of the bionic eye implants soon. Their objectives are to develop strategies that can improve the affected visual pathway to the brain by stimulating the remaining working retinal cells and also develop safe surgical procedures.

Z5117343 at 06:18, 26 October 2017

2017-10-26T06:18:59Z

← Older revision		Revision as of 16:18, 26 October 2017
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	When the lens is developing the inner layer of the optic cup starts to proliferate and forms a thick neuroepithelium which will later differentiate into the neural retina. The neural retina contains photoreceptors and the cell bodies of neurons and is the light-sensitive region of the retina. The axons of the ganglion cells in the neural retina grow in the wall of the optic stalk and will form the optic nerve <ref name="Larsen'sHumanEmbryology">Schoenwolf, G.C., Bleyl, S.B., Brauer, P.R., Francis-West, P.H. & Philippa H. (2015). Larsen's human embryology (5th ed.). New York; Edinburgh: Churchill Livingstone.</ref>.		When the lens is developing the inner layer of the optic cup starts to proliferate and forms a thick neuroepithelium which will later differentiate into the neural retina. The neural retina contains photoreceptors and the cell bodies of neurons and is the light-sensitive region of the retina. The axons of the ganglion cells in the neural retina grow in the wall of the optic stalk and will form the optic nerve <ref name="Larsen'sHumanEmbryology">Schoenwolf, G.C., Bleyl, S.B., Brauer, P.R., Francis-West, P.H. & Philippa H. (2015). Larsen's human embryology (5th ed.). New York; Edinburgh: Churchill Livingstone.</ref>.

	===Lens=== [[File:Stage_22_image_155.jpg\|thumb\| ~~'''Figure 7'''~~ Human Lens (stage 22)]]		===Lens===
			[[File:Stage_22_image_155.jpg\|thumb\|Human Lens (stage 22)]]

	Human lens induction occurs at around 28 days and is completed around day 56. The surface ectoderm will thicken near the optic vesicle and create the lens placode and later form the lens vesicle <ref><pubmed>20171212 </pubmed></ref>. Lens cells come from ectoderm and differentiate into either lens fibres or the lens epithelium. The anterior monolayer of epithelial cells of the lens will create the lens epithelium, which makes the sheet of cuboidal epithelium covering the anterior surface of the lens. The posterior lens vesicle cells will produce the linear primary fibre cells aligned parallel to the optic axis. These fibres will create the lens mass and form the embryonic lens nucleus. The lens epithelial cells will keep proliferating and produce new cells which generate secondary lens fibre cells. These rows of cells will form the outer shells and keep the lens growing throughout life. This makes the eye lens unique - it will have an addition of new cells inside the surrounding capsule all the time <ref><pubmed>25406393</pubmed></ref>.		Human lens induction occurs at around 28 days and is completed around day 56. The surface ectoderm will thicken near the optic vesicle and create the lens placode and later form the lens vesicle <ref><pubmed>20171212 </pubmed></ref>. Lens cells come from ectoderm and differentiate into either lens fibres or the lens epithelium. The anterior monolayer of epithelial cells of the lens will create the lens epithelium, which makes the sheet of cuboidal epithelium covering the anterior surface of the lens. The posterior lens vesicle cells will produce the linear primary fibre cells aligned parallel to the optic axis. These fibres will create the lens mass and form the embryonic lens nucleus. The lens epithelial cells will keep proliferating and produce new cells which generate secondary lens fibre cells. These rows of cells will form the outer shells and keep the lens growing throughout life. This makes the eye lens unique - it will have an addition of new cells inside the surrounding capsule all the time <ref><pubmed>25406393</pubmed></ref>.
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	The iris develops at the end of the third month of development as a thin layer derived from the anterior rim of the optic cup <ref><pubmed>22219630</pubmed></ref>. It is formed by the pigment-containing internal and external layers of the optic cup and by a layer of vascularised connective tissue which also contains the pupillary muscles. The internal layers of the optic cup form the non-pigmented iris parts whereas the external layers of the optic cup develop into the pigmented epithelial structures. <ref name=’’18168498’’><pubmed>18168498</pubmed></ref>. Iris stroma develops as a result of neural crest cell migration – within this stroma, the dilator and constrictor muscles develop from the neuroectoderm of the optic cup. In the anterior of the eye, the optic epithelium is non-neural and matures as ciliary body and iris epithelia <ref name=’’18168498’’/>.		The iris develops at the end of the third month of development as a thin layer derived from the anterior rim of the optic cup <ref><pubmed>22219630</pubmed></ref>. It is formed by the pigment-containing internal and external layers of the optic cup and by a layer of vascularised connective tissue which also contains the pupillary muscles. The internal layers of the optic cup form the non-pigmented iris parts whereas the external layers of the optic cup develop into the pigmented epithelial structures. <ref name=’’18168498’’><pubmed>18168498</pubmed></ref>. Iris stroma develops as a result of neural crest cell migration – within this stroma, the dilator and constrictor muscles develop from the neuroectoderm of the optic cup. In the anterior of the eye, the optic epithelium is non-neural and matures as ciliary body and iris epithelia <ref name=’’18168498’’/>.

	===Cornea=== [[File:Mouse eye neural crest cornea 01.jpg\|\|thumb\|300px\|alt=Cornea structure~~\|'''Figure 8''' Cornea Layers Histology~~]]		===Cornea===
			[[File:Mouse eye neural crest cornea 01.jpg\|\|thumb\|300px\|alt=Cornea structure]]
	The cornea is the transparent and avascular component located at the anterior-most section of the eye. It is composed of five layers stemming from the 3 main layers of epithelium, stroma and endothelium:		The cornea is the transparent and avascular component located at the anterior-most section of the eye. It is composed of five layers stemming from the 3 main layers of epithelium, stroma and endothelium:

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	===Extraocular muscles===		===Extraocular muscles===

	[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb~~\| '''Figure 9''' Extraocular Muscles Anatomy~~]]		[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb]]

	The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).		The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).
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	===Eyelids===		===Eyelids===

	[[File:Stage22_eyelids.jpg\|thumb\|~~'''Figure 10'''~~ Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]		[[File:Stage22_eyelids.jpg\|thumb\|Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]

	The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.		The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.
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	<gallery>		<gallery>

	Anophthalmia.jpeg\|'''Figure 11.''' Anopthalmia		Anophthalmia.jpeg\|'''Figure 8.''' Anopthalmia
	Microphthalmia-500px.jpg\| '''Figure 12.''' Microphthalmia		Microphthalmia-500px.jpg\| '''Figure 9.''' Microphthalmia
	Opac_figure_7.jpg\| '''Figure 13.''' Iris Coloboma		Opac_figure_7.jpg\| '''Figure 10.''' Iris Coloboma
	Opac figure 10.jpg\| '''Figure 14.''' Partial Aniridia		Opac figure 10.jpg\| '''Figure 11.''' Partial Aniridia
	</gallery>		</gallery>

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	===Will the bionic eye pass clinical trials in the next few years?===		===Will the bionic eye pass clinical trials in the next few years?===
	[[File:BionicEye.jpg\|250px\|thumb\|left\| '''Figure 15.''' Bionic Eye Diagram]]		[[File:BionicEye.jpg\|250px\|thumb\|left\| '''Figure 12.''' Bionic Eye Diagram]]

	The bionic eye is an external visual device that has been in the making for the last several years. It hopes to bring back full vision through the aid of a pair of glasses with a camera attached to it, which then transmits high-frequency radio signals to the microchip implanted in the users' eye. These signals are converted into electrical impulses by the electrodes implanted in the chip, which then stimulates the retinal cells and passes through the optic nerve. Electrical impulses travels to the vision processing centres in the brain and these are then interpreted as an image. At the moment, users must learn to understand light flashes and visual patterns and convert them into images they can interpret. Current prototypes require the users to have a previously working eyes, which means their optic nerves must still be relatively healthy and their visual cortex must be developed. Patients who have suffered from retinitis pigmentosa and age-related macular degeneration would benefit this technology. Bionic Vision Australia<ref>'''Bionic Vision Australia''': http://bionicvision.org.au/about/research_plan</ref> is one of the leading organisations that are aiming to treat blindness and are set to perform clinical trials on two of the devices of the bionic eye implants soon. Their objectives are to develop strategies that can improve the affected visual pathway to the brain by stimulating the remaining working retinal cells and also develop safe surgical procedures.		The bionic eye is an external visual device that has been in the making for the last several years. It hopes to bring back full vision through the aid of a pair of glasses with a camera attached to it, which then transmits high-frequency radio signals to the microchip implanted in the users' eye. These signals are converted into electrical impulses by the electrodes implanted in the chip, which then stimulates the retinal cells and passes through the optic nerve. Electrical impulses travels to the vision processing centres in the brain and these are then interpreted as an image. At the moment, users must learn to understand light flashes and visual patterns and convert them into images they can interpret. Current prototypes require the users to have a previously working eyes, which means their optic nerves must still be relatively healthy and their visual cortex must be developed. Patients who have suffered from retinitis pigmentosa and age-related macular degeneration would benefit this technology. Bionic Vision Australia<ref>'''Bionic Vision Australia''': http://bionicvision.org.au/about/research_plan</ref> is one of the leading organisations that are aiming to treat blindness and are set to perform clinical trials on two of the devices of the bionic eye implants soon. Their objectives are to develop strategies that can improve the affected visual pathway to the brain by stimulating the remaining working retinal cells and also develop safe surgical procedures.

Z5117343 at 06:17, 26 October 2017

2017-10-26T06:17:44Z

← Older revision		Revision as of 16:17, 26 October 2017
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	When the lens is developing the inner layer of the optic cup starts to proliferate and forms a thick neuroepithelium which will later differentiate into the neural retina. The neural retina contains photoreceptors and the cell bodies of neurons and is the light-sensitive region of the retina. The axons of the ganglion cells in the neural retina grow in the wall of the optic stalk and will form the optic nerve <ref name="Larsen'sHumanEmbryology">Schoenwolf, G.C., Bleyl, S.B., Brauer, P.R., Francis-West, P.H. & Philippa H. (2015). Larsen's human embryology (5th ed.). New York; Edinburgh: Churchill Livingstone.</ref>.		When the lens is developing the inner layer of the optic cup starts to proliferate and forms a thick neuroepithelium which will later differentiate into the neural retina. The neural retina contains photoreceptors and the cell bodies of neurons and is the light-sensitive region of the retina. The axons of the ganglion cells in the neural retina grow in the wall of the optic stalk and will form the optic nerve <ref name="Larsen'sHumanEmbryology">Schoenwolf, G.C., Bleyl, S.B., Brauer, P.R., Francis-West, P.H. & Philippa H. (2015). Larsen's human embryology (5th ed.). New York; Edinburgh: Churchill Livingstone.</ref>.

	===Lens===		===Lens=== [[File:Stage_22_image_155.jpg\|thumb\| '''Figure 7''' Human Lens (stage 22)]]
	[[File:Stage_22_image_155.jpg\|thumb\|Human Lens (stage 22)]]

	Human lens induction occurs at around 28 days and is completed around day 56. The surface ectoderm will thicken near the optic vesicle and create the lens placode and later form the lens vesicle <ref><pubmed>20171212 </pubmed></ref>. Lens cells come from ectoderm and differentiate into either lens fibres or the lens epithelium. The anterior monolayer of epithelial cells of the lens will create the lens epithelium, which makes the sheet of cuboidal epithelium covering the anterior surface of the lens. The posterior lens vesicle cells will produce the linear primary fibre cells aligned parallel to the optic axis. These fibres will create the lens mass and form the embryonic lens nucleus. The lens epithelial cells will keep proliferating and produce new cells which generate secondary lens fibre cells. These rows of cells will form the outer shells and keep the lens growing throughout life. This makes the eye lens unique - it will have an addition of new cells inside the surrounding capsule all the time <ref><pubmed>25406393</pubmed></ref>.		Human lens induction occurs at around 28 days and is completed around day 56. The surface ectoderm will thicken near the optic vesicle and create the lens placode and later form the lens vesicle <ref><pubmed>20171212 </pubmed></ref>. Lens cells come from ectoderm and differentiate into either lens fibres or the lens epithelium. The anterior monolayer of epithelial cells of the lens will create the lens epithelium, which makes the sheet of cuboidal epithelium covering the anterior surface of the lens. The posterior lens vesicle cells will produce the linear primary fibre cells aligned parallel to the optic axis. These fibres will create the lens mass and form the embryonic lens nucleus. The lens epithelial cells will keep proliferating and produce new cells which generate secondary lens fibre cells. These rows of cells will form the outer shells and keep the lens growing throughout life. This makes the eye lens unique - it will have an addition of new cells inside the surrounding capsule all the time <ref><pubmed>25406393</pubmed></ref>.
Line 186:		Line 185:
	The iris develops at the end of the third month of development as a thin layer derived from the anterior rim of the optic cup <ref><pubmed>22219630</pubmed></ref>. It is formed by the pigment-containing internal and external layers of the optic cup and by a layer of vascularised connective tissue which also contains the pupillary muscles. The internal layers of the optic cup form the non-pigmented iris parts whereas the external layers of the optic cup develop into the pigmented epithelial structures. <ref name=’’18168498’’><pubmed>18168498</pubmed></ref>. Iris stroma develops as a result of neural crest cell migration – within this stroma, the dilator and constrictor muscles develop from the neuroectoderm of the optic cup. In the anterior of the eye, the optic epithelium is non-neural and matures as ciliary body and iris epithelia <ref name=’’18168498’’/>.		The iris develops at the end of the third month of development as a thin layer derived from the anterior rim of the optic cup <ref><pubmed>22219630</pubmed></ref>. It is formed by the pigment-containing internal and external layers of the optic cup and by a layer of vascularised connective tissue which also contains the pupillary muscles. The internal layers of the optic cup form the non-pigmented iris parts whereas the external layers of the optic cup develop into the pigmented epithelial structures. <ref name=’’18168498’’><pubmed>18168498</pubmed></ref>. Iris stroma develops as a result of neural crest cell migration – within this stroma, the dilator and constrictor muscles develop from the neuroectoderm of the optic cup. In the anterior of the eye, the optic epithelium is non-neural and matures as ciliary body and iris epithelia <ref name=’’18168498’’/>.

	===Cornea===		===Cornea=== [[File:Mouse eye neural crest cornea 01.jpg\|\|thumb\|300px\|alt=Cornea structure\|'''Figure 8''' Cornea Layers Histology]]
	[[File:Mouse eye neural crest cornea 01.jpg\|\|thumb\|300px\|alt=Cornea structure]]
	The cornea is the transparent and avascular component located at the anterior-most section of the eye. It is composed of five layers stemming from the 3 main layers of epithelium, stroma and endothelium:		The cornea is the transparent and avascular component located at the anterior-most section of the eye. It is composed of five layers stemming from the 3 main layers of epithelium, stroma and endothelium:

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	===Extraocular muscles===		===Extraocular muscles===

	[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb]]		[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb\| '''Figure 9''' Extraocular Muscles Anatomy]]

	The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).		The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).
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	===Eyelids===		===Eyelids===

	[[File:Stage22_eyelids.jpg\|thumb\|Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]		[[File:Stage22_eyelids.jpg\|thumb\|'''Figure 10''' Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]

	The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.		The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.
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	<gallery>		<gallery>

	Anophthalmia.jpeg\|'''Figure 8.''' Anopthalmia		Anophthalmia.jpeg\|'''Figure 11.''' Anopthalmia
	Microphthalmia-500px.jpg\| '''Figure 9.''' Microphthalmia		Microphthalmia-500px.jpg\| '''Figure 12.''' Microphthalmia
	Opac_figure_7.jpg\| '''Figure 10.''' Iris Coloboma		Opac_figure_7.jpg\| '''Figure 13.''' Iris Coloboma
	Opac figure 10.jpg\| '''Figure 11.''' Partial Aniridia		Opac figure 10.jpg\| '''Figure 14.''' Partial Aniridia
	</gallery>		</gallery>

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	===Will the bionic eye pass clinical trials in the next few years?===		===Will the bionic eye pass clinical trials in the next few years?===
	[[File:BionicEye.jpg\|250px\|thumb\|left\| '''Figure 12.''' Bionic Eye Diagram]]		[[File:BionicEye.jpg\|250px\|thumb\|left\| '''Figure 15.''' Bionic Eye Diagram]]

	The bionic eye is an external visual device that has been in the making for the last several years. It hopes to bring back full vision through the aid of a pair of glasses with a camera attached to it, which then transmits high-frequency radio signals to the microchip implanted in the users' eye. These signals are converted into electrical impulses by the electrodes implanted in the chip, which then stimulates the retinal cells and passes through the optic nerve. Electrical impulses travels to the vision processing centres in the brain and these are then interpreted as an image. At the moment, users must learn to understand light flashes and visual patterns and convert them into images they can interpret. Current prototypes require the users to have a previously working eyes, which means their optic nerves must still be relatively healthy and their visual cortex must be developed. Patients who have suffered from retinitis pigmentosa and age-related macular degeneration would benefit this technology. Bionic Vision Australia<ref>'''Bionic Vision Australia''': http://bionicvision.org.au/about/research_plan</ref> is one of the leading organisations that are aiming to treat blindness and are set to perform clinical trials on two of the devices of the bionic eye implants soon. Their objectives are to develop strategies that can improve the affected visual pathway to the brain by stimulating the remaining working retinal cells and also develop safe surgical procedures.		The bionic eye is an external visual device that has been in the making for the last several years. It hopes to bring back full vision through the aid of a pair of glasses with a camera attached to it, which then transmits high-frequency radio signals to the microchip implanted in the users' eye. These signals are converted into electrical impulses by the electrodes implanted in the chip, which then stimulates the retinal cells and passes through the optic nerve. Electrical impulses travels to the vision processing centres in the brain and these are then interpreted as an image. At the moment, users must learn to understand light flashes and visual patterns and convert them into images they can interpret. Current prototypes require the users to have a previously working eyes, which means their optic nerves must still be relatively healthy and their visual cortex must be developed. Patients who have suffered from retinitis pigmentosa and age-related macular degeneration would benefit this technology. Bionic Vision Australia<ref>'''Bionic Vision Australia''': http://bionicvision.org.au/about/research_plan</ref> is one of the leading organisations that are aiming to treat blindness and are set to perform clinical trials on two of the devices of the bionic eye implants soon. Their objectives are to develop strategies that can improve the affected visual pathway to the brain by stimulating the remaining working retinal cells and also develop safe surgical procedures.

Z5075778: Undo revision 316996 by Z5075778 (talk)

2017-10-26T05:23:41Z

Undo revision 316996 by Z5075778 (talk)

← Older revision		Revision as of 15:23, 26 October 2017
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	===Eyelids===		===Eyelids===

	[[File:Stage22_eyelids.jpg\|thumb\|Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]		[[File:Stage22_eyelids.jpg\|thumb\|Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]

	The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.		The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.
	No sign of eyelid fold development is evident at week 5 however at this stage the lens pit begins to invaginate from the surface ectoderm <ref name=’’27124372’’><pubmed>27124372</pubmed></ref>. Week 6 initiates the timeline of eyelid development as small depressions emerge in the surface ectoderm both above and below the developing eye – these rapidly deepen to form the folds of the eyelids <ref name=‘’7364662’’><pubmed>7364662</pubmed></ref>. The lower eyelid fold develops first and, by the end of week 6, the lower fold is more distinct than the upper eyelid fold <ref><pubmed>21416630</pubmed></ref>. Week 7 marks the point at which both the upper and lower folds are distinctly developed and during this stage, the upper lid assumes its more dominant role <ref name=’’27124372’’/>. The eyelid is not fully closed - there is a gap between the folds and the cornea is slightly visible – they eventually undergo fusion in week 8 <ref name=’’27124372’’/>.		No sign of eyelid fold development is evident at week 5 however at this stage the lens pit begins to invaginate from the surface ectoderm <ref name=’’27124372’’><pubmed>27124372</pubmed></ref>. Week 6 initiates the timeline of eyelid development as small depressions emerge in the surface ectoderm both above and below the developing eye – these rapidly deepen to form the folds of the eyelids <ref name=‘’7364662’’><pubmed>7364662</pubmed></ref>. The lower eyelid fold develops first and, by the end of week 6, the lower fold is more distinct than the upper eyelid fold <ref><pubmed>21416630</pubmed></ref>. Week 7 marks the point at which both the upper and lower folds are distinctly developed and during this stage, the upper lid assumes its more dominant role <ref name=’’27124372’’/>. The eyelid is not fully closed - there is a gap between the folds and the cornea is slightly visible – they eventually undergo fusion in week 8 <ref name=’’27124372’’/>.


	===Lacrimal Glands===		===Lacrimal Glands===

Z5177670 at 05:22, 26 October 2017

2017-10-26T05:22:50Z

← Older revision		Revision as of 15:22, 26 October 2017
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	===Extraocular muscles===		===Extraocular muscles===

			[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb]]

	The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).		The extraocular muscles are responsible for eye movement within the eye orbit – a critical aspect of sight and communication. 6 main muscles contribute to eye movement. These include: superior rectus(SR), inferior rectus(IR), lateral rectus (LR), medial rectus (MR), superior oblique (SO) and inferior oblique (IO).
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	The development of these muscles is dependent on interactions between the eye, its muscles and the neural crest. <ref name=''21482859''><pubmed>21482859</pubmed></ref>.		The development of these muscles is dependent on interactions between the eye, its muscles and the neural crest. <ref name=''21482859''><pubmed>21482859</pubmed></ref>.
	Somites supplied by cranial nerve III forms 5 of the 6 extraocular muscles which form an interlocking tendinous ring made of fibrous connective tissue. The 5 muscles include the lateral, medial, superior and inferior rectus, and the superior oblique muscle. This common tendinous ring is known as the annulus of Zinn and surrounds the entry of the optic nerve. The remaining sixth muscle is the inferior oblique muscle and is separate from the aforementioned tendinous ring due to its distinct point of origin. <ref name=''21482859''/>.		Somites supplied by cranial nerve III forms 5 of the 6 extraocular muscles which form an interlocking tendinous ring made of fibrous connective tissue. The 5 muscles include the lateral, medial, superior and inferior rectus, and the superior oblique muscle. This common tendinous ring is known as the annulus of Zinn and surrounds the entry of the optic nerve. The remaining sixth muscle is the inferior oblique muscle and is separate from the aforementioned tendinous ring due to its distinct point of origin. <ref name=''21482859''/>.

	~~[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb]]~~

	===Eyelids===		===Eyelids===

Z5075778 at 05:22, 26 October 2017

2017-10-26T05:22:00Z

← Older revision		Revision as of 15:22, 26 October 2017
Line 221:		Line 221:

	===Eyelids===		===Eyelids===

	[[File:Stage22_eyelids.jpg\|thumb\|Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]		[[File:Stage22_eyelids.jpg\|thumb\|Human embryo head showing eyelid development ([[Carnegie stage 22\|Stage 22]], [[Week 8\|Week 8]])]]

	The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.		The eyelids are upper and lower folds of skin functioning as a barrier protecting the anterior surface of the eye from direct local injury. Eyelids also regulate light exposure, distribute precorneal tear film over the corneal surface when blinking and are involved in functions involving tear flow <ref><pubmed>1993591</pubmed></ref>.
	No sign of eyelid fold development is evident at week 5 however at this stage the lens pit begins to invaginate from the surface ectoderm <ref name=’’27124372’’><pubmed>27124372</pubmed></ref>. Week 6 initiates the timeline of eyelid development as small depressions emerge in the surface ectoderm both above and below the developing eye – these rapidly deepen to form the folds of the eyelids <ref name=‘’7364662’’><pubmed>7364662</pubmed></ref>. The lower eyelid fold develops first and, by the end of week 6, the lower fold is more distinct than the upper eyelid fold <ref><pubmed>21416630</pubmed></ref>. Week 7 marks the point at which both the upper and lower folds are distinctly developed and during this stage, the upper lid assumes its more dominant role <ref name=’’27124372’’/>. The eyelid is not fully closed - there is a gap between the folds and the cornea is slightly visible – they eventually undergo fusion in week 8 <ref name=’’27124372’’/>.		No sign of eyelid fold development is evident at week 5 however at this stage the lens pit begins to invaginate from the surface ectoderm <ref name=’’27124372’’><pubmed>27124372</pubmed></ref>. Week 6 initiates the timeline of eyelid development as small depressions emerge in the surface ectoderm both above and below the developing eye – these rapidly deepen to form the folds of the eyelids <ref name=‘’7364662’’><pubmed>7364662</pubmed></ref>. The lower eyelid fold develops first and, by the end of week 6, the lower fold is more distinct than the upper eyelid fold <ref><pubmed>21416630</pubmed></ref>. Week 7 marks the point at which both the upper and lower folds are distinctly developed and during this stage, the upper lid assumes its more dominant role <ref name=’’27124372’’/>. The eyelid is not fully closed - there is a gap between the folds and the cornea is slightly visible – they eventually undergo fusion in week 8 <ref name=’’27124372’’/>.


	===Lacrimal Glands===		===Lacrimal Glands===

Z5177670 at 05:20, 26 October 2017

2017-10-26T05:20:17Z

← Older revision		Revision as of 15:20, 26 October 2017
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	Somites supplied by cranial nerve III forms 5 of the 6 extraocular muscles which form an interlocking tendinous ring made of fibrous connective tissue. The 5 muscles include the lateral, medial, superior and inferior rectus, and the superior oblique muscle. This common tendinous ring is known as the annulus of Zinn and surrounds the entry of the optic nerve. The remaining sixth muscle is the inferior oblique muscle and is separate from the aforementioned tendinous ring due to its distinct point of origin. <ref name=''21482859''/>.		Somites supplied by cranial nerve III forms 5 of the 6 extraocular muscles which form an interlocking tendinous ring made of fibrous connective tissue. The 5 muscles include the lateral, medial, superior and inferior rectus, and the superior oblique muscle. This common tendinous ring is known as the annulus of Zinn and surrounds the entry of the optic nerve. The remaining sixth muscle is the inferior oblique muscle and is separate from the aforementioned tendinous ring due to its distinct point of origin. <ref name=''21482859''/>.

	[[File:Human_extraocular_muscles_01.jpg\|200px]]		[[File:Human_extraocular_muscles_01.jpg\|200px\|thumb]]

	===Eyelids===		===Eyelids===