Bony orbits are Quadrangular truncated pyramids with Anterior cranial fossa above and the maxillary sinuses below.
in this presentation we study the detailed anatomy of the arbit, the bones, relations of each wall, the contents, the apertures, orbital fissures and structures passing, fascia, septa and the surgical spaces of the orbit
Bony orbits are Quadrangular truncated pyramids with Anterior cranial fossa above and the maxillary sinuses below.
in this presentation we study the detailed anatomy of the arbit, the bones, relations of each wall, the contents, the apertures, orbital fissures and structures passing, fascia, septa and the surgical spaces of the orbit
EMBRYOLOGY
ANATOMY
BONY ORBIT
WALLS OF ORBIT
MUSCLES OF THE ORBIT
NERVE SUPPLY OF THE ORBIT
VASCULAR SUPPLY
LACRIMAL SYSTEM
ORBITAL FAT
ORBITAL INJURIES AND INFECTION
DENTAL SIGNIFICANCE
The orbit is a four-sided pyramidal socket in the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents.
The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and nasolacrimal duct, the eyelids, medial and lateral palpebral ligaments, check ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves.
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EMBRYOLOGY
ANATOMY
BONY ORBIT
WALLS OF ORBIT
MUSCLES OF THE ORBIT
NERVE SUPPLY OF THE ORBIT
VASCULAR SUPPLY
LACRIMAL SYSTEM
ORBITAL FAT
ORBITAL INJURIES AND INFECTION
DENTAL SIGNIFICANCE
The orbit is a four-sided pyramidal socket in the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents.
The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and nasolacrimal duct, the eyelids, medial and lateral palpebral ligaments, check ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves.
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A case of intermittent exotropia by Krishna BanjadeKrishna Banjade
Intermittent exotropia is the most common type of strabismus in India, also known as "Intermittent divergent squint."
This PPT gives us the clear idea about different types of intermittent exotropia and the importance of patch test to differentiate basic X(T) from pseudodivergence X(T)
Base of orbit is closed partly by globe , extraocular muscles
& their fascial expansions.
- These fascial expansions & sup and inferior oblique muscles
bound 5 orifices between them & orbital margins .
-These are the communications between orbital cavity & deep
portion of eyelid.
- Through them blood & pus passes out of orbit . Further
spread in lid is prevented by orbital septum.
Clinical significance:
* A sharp object injury through upper lid penetrates the roof &
may damage frontal lobe.
* Orbital roof anamolies or fractures can lead to pulsatile
exophthalmos.
* Since roof is neither perforated by major nerves nor vessels , it
can be easily nibbed away in transfrontal orbitotomy
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Anatomy of Orbit and its clinical importanceAshish Gupta
It's a presentation of Anatomy of Bony Orbit and its applied aspects. It's been made by compiling images from many sources and includes almost all the information needed for a postgraduate .
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CHAPTER 1 SEMESTER V PREVENTIVE-PEDIATRICS.pdfSachin Sharma
This content provides an overview of preventive pediatrics. It defines preventive pediatrics as preventing disease and promoting children's physical, mental, and social well-being to achieve positive health. It discusses antenatal, postnatal, and social preventive pediatrics. It also covers various child health programs like immunization, breastfeeding, ICDS, and the roles of organizations like WHO, UNICEF, and nurses in preventive pediatrics.
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From navigating policy options to staying informed about industry trends, this comprehensive guide explores everything you need to know about the health insurance market.
Defecation
Normal defecation begins with movement in the left colon, moving stool toward the anus. When stool reaches the rectum, the distention causes relaxation of the internal sphincter and an awareness of the need to defecate. At the time of defecation, the external sphincter relaxes, and abdominal muscles contract, increasing intrarectal pressure and forcing the stool out
The Valsalva maneuver exerts pressure to expel faeces through a voluntary contraction of the abdominal muscles while maintaining forced expiration against a closed airway. Patients with cardiovascular disease, glaucoma, increased intracranial pressure, or a new surgical wound are at greater risk for cardiac dysrhythmias and elevated blood pressure with the Valsalva maneuver and need to avoid straining to pass the stool.
Normal defecation is painless, resulting in passage of soft, formed stool
CONSTIPATION
Constipation is a symptom, not a disease. Improper diet, reduced fluid intake, lack of exercise, and certain medications can cause constipation. For example, patients receiving opiates for pain after surgery often require a stool softener or laxative to prevent constipation. The signs of constipation include infrequent bowel movements (less than every 3 days), difficulty passing stools, excessive straining, inability to defecate at will, and hard feaces
IMPACTION
Fecal impaction results from unrelieved constipation. It is a collection of hardened feces wedged in the rectum that a person cannot expel. In cases of severe impaction the mass extends up into the sigmoid colon.
DIARRHEA
Diarrhea is an increase in the number of stools and the passage of liquid, unformed feces. It is associated with disorders affecting digestion, absorption, and secretion in the GI tract. Intestinal contents pass through the small and large intestine too quickly to allow for the usual absorption of fluid and nutrients. Irritation within the colon results in increased mucus secretion. As a result, feces become watery, and the patient is unable to control the urge to defecate. Normally an anal bag is safe and effective in long-term treatment of patients with fecal incontinence at home, in hospice, or in the hospital. Fecal incontinence is expensive and a potentially dangerous condition in terms of contamination and risk of skin ulceration
HEMORRHOIDS
Hemorrhoids are dilated, engorged veins in the lining of the rectum. They are either external or internal.
FLATULENCE
As gas accumulates in the lumen of the intestines, the bowel wall stretches and distends (flatulence). It is a common cause of abdominal fullness, pain, and cramping. Normally intestinal gas escapes through the mouth (belching) or the anus (passing of flatus)
FECAL INCONTINENCE
Fecal incontinence is the inability to control passage of feces and gas from the anus. Incontinence harms a patient’s body image
PREPARATION AND GIVING OF LAXATIVESACCORDING TO POTTER AND PERRY,
An enema is the instillation of a solution into the rectum and sig
Antibiotic Stewardship by Anushri Srivastava.pptxAnushriSrivastav
Stewardship is the act of taking good care of something.
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
WHO launched the Global Antimicrobial Resistance and Use Surveillance System (GLASS) in 2015 to fill knowledge gaps and inform strategies at all levels.
ACCORDING TO apic.org,
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
ACCORDING TO pewtrusts.org,
Antibiotic stewardship refers to efforts in doctors’ offices, hospitals, long term care facilities, and other health care settings to ensure that antibiotics are used only when necessary and appropriate
According to WHO,
Antimicrobial stewardship is a systematic approach to educate and support health care professionals to follow evidence-based guidelines for prescribing and administering antimicrobials
In 1996, John McGowan and Dale Gerding first applied the term antimicrobial stewardship, where they suggested a causal association between antimicrobial agent use and resistance. They also focused on the urgency of large-scale controlled trials of antimicrobial-use regulation employing sophisticated epidemiologic methods, molecular typing, and precise resistance mechanism analysis.
Antimicrobial Stewardship(AMS) refers to the optimal selection, dosing, and duration of antimicrobial treatment resulting in the best clinical outcome with minimal side effects to the patients and minimal impact on subsequent resistance.
According to the 2019 report, in the US, more than 2.8 million antibiotic-resistant infections occur each year, and more than 35000 people die. In addition to this, it also mentioned that 223,900 cases of Clostridoides difficile occurred in 2017, of which 12800 people died. The report did not include viruses or parasites
VISION
Being proactive
Supporting optimal animal and human health
Exploring ways to reduce overall use of antimicrobials
Using the drugs that prevent and treat disease by killing microscopic organisms in a responsible way
GOAL
to prevent the generation and spread of antimicrobial resistance (AMR). Doing so will preserve the effectiveness of these drugs in animals and humans for years to come.
being to preserve human and animal health and the effectiveness of antimicrobial medications.
to implement a multidisciplinary approach in assembling a stewardship team to include an infectious disease physician, a clinical pharmacist with infectious diseases training, infection preventionist, and a close collaboration with the staff in the clinical microbiology laboratory
to prevent antimicrobial overuse, misuse and abuse.
to minimize the developme
One of the most developed cities of India, the city of Chennai is the capital of Tamilnadu and many people from different parts of India come here to earn their bread and butter. Being a metropolitan, the city is filled with towering building and beaches but the sad part as with almost every Indian city
CHAPTER 1 SEMESTER V - ROLE OF PEADIATRIC NURSE.pdfSachin Sharma
Pediatric nurses play a vital role in the health and well-being of children. Their responsibilities are wide-ranging, and their objectives can be categorized into several key areas:
1. Direct Patient Care:
Objective: Provide comprehensive and compassionate care to infants, children, and adolescents in various healthcare settings (hospitals, clinics, etc.).
This includes tasks like:
Monitoring vital signs and physical condition.
Administering medications and treatments.
Performing procedures as directed by doctors.
Assisting with daily living activities (bathing, feeding).
Providing emotional support and pain management.
2. Health Promotion and Education:
Objective: Promote healthy behaviors and educate children, families, and communities about preventive healthcare.
This includes tasks like:
Administering vaccinations.
Providing education on nutrition, hygiene, and development.
Offering breastfeeding and childbirth support.
Counseling families on safety and injury prevention.
3. Collaboration and Advocacy:
Objective: Collaborate effectively with doctors, social workers, therapists, and other healthcare professionals to ensure coordinated care for children.
Objective: Advocate for the rights and best interests of their patients, especially when children cannot speak for themselves.
This includes tasks like:
Communicating effectively with healthcare teams.
Identifying and addressing potential risks to child welfare.
Educating families about their child's condition and treatment options.
4. Professional Development and Research:
Objective: Stay up-to-date on the latest advancements in pediatric healthcare through continuing education and research.
Objective: Contribute to improving the quality of care for children by participating in research initiatives.
This includes tasks like:
Attending workshops and conferences on pediatric nursing.
Participating in clinical trials related to child health.
Implementing evidence-based practices into their daily routines.
By fulfilling these objectives, pediatric nurses play a crucial role in ensuring the optimal health and well-being of children throughout all stages of their development.
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QA Paediatric dentistry department, Hospital Melaka 2020Azreen Aj
QA study - To improve the 6th monthly recall rate post-comprehensive dental treatment under general anaesthesia in paediatric dentistry department, Hospital Melaka
2. INTRODUCTION
Orbit is the anatomical space bounded:
Superiorly – Anterior cranial fossa
Medially - Nasal cavity & Ethmoidal air sinuses
Inferiorly - Maxillary sinus
Laterally - Middle cranial fossa & Temporal fossa
3.
4. EMBRYOLOGY
Orbital walls- derived from cranial neural crest
cells which expand to form:
Frontonasal process
Maxillary process
Lateral nasal process + Maxillary process =
medial, inferior and lateral orbital walls
Capsule of forebrain forms orbital roof
5. Early in the human
development eyes point
almost in the opposite
direction.
As the facial growth occurs,
the angle between the optic
stalks decreases and is ~68˚
in an adult.
EMBRYOLOG
Y
7. Frontal, Zygomatic, Maxillary and Palatine bones-
Intramembranous origin
First bone- Maxillary (at 6 wks of intrauterine life)
- develops from elements in the region of the canine tooth
- secondary ossification centres in the orbitonasal and
premaxillary regions
Other bones develop at around 7 wks of intrauterine
life
EMBRYOLOG
8. Sphenoid bone- both enchondral and
intramembranous origins
Lesser wing of the sphenoid- 7 wks (Enchondral)
Greater wing of the sphenoid- 10 wks
(Intramembranous)
Both wings join- 16 wks
Ossification is complete at birth (except orbital apex)
EMBRYOLOG
9. CLINICAL SIGNIFICANCE
DERMOID CYSTS:
Most common orbital
cystic lesions
Origin:
◦ Pouches of ectoderm
trapped into bony
sutures
◦ Most common site
frontozygomatic suture
10. CEPHALOCOELES:
Reflect orbital
entrapment of
neuroectoderm
Most commonly-
◦ At the junction of frontal
& ethmoid
Pathology:
◦ Herniation of brain
parenchyma into the
orbit
EMBRYOLOG
11. FIBROUS DYSPLASIA:
Benign, developmental
fibro-osseous lesion
Origin:
◦ Arrest in maturation at
woven bone stage
Pathology:
◦ Bone replaced by
fibrous tissue
EMBRYOLOG
18. ROOF
Underlies Frontal sinus and
Anterior cranial fossa
Formed by-
◦ 1. Frontal bone (Orbital
plate)
◦ 2. Lesser wing of Sphenoid
Triangular
Faces downwards, and
slightly forwards
Left orbit
19. Concave anteriorly, almost flat posteriorly
The anterior concavity is greatest about 1.5 cm from
the orbital margin & corresponds to the equator of
the globe.
Thin, transluscent and fragile (except the lesser
wing of the sphenoid)
ROOF
20. LANDMARKS
• 1. FOSSA FOR THE LACRIMAL GLAND-
LOCATION:
behind the zygomatic process of the frontal bone
CONTENTS:
lacrimal gland
some orbital fat
ROOF
21. 2. TROCHLEAR FOSSA (FOVEA)
LOCATION:
4 mm from the orbital margin
CONTENTS:
insertion of tendinous pulley of Superior Oblique
o sometimes (≈10%) surmounted by a spicule of bone
(Spina trochlearis)
o Extremely rarely trochlea completely ossified
cracks easily
SURFACE ANATOMY:
Palpable just within the supero-medial angle
ROOF
22. 3. SUPRAORBITAL
NOTCH:
LOCATION:
≈15 mm lateral to the
superomedial angle
TRANSMITS:
- Supraorbital nerve
- Supraorbital vessels
SURFACE ANATOMY:
- At the junction of lateral
2/3rd and medial 1/3rd
- About two finger breadth
ROOF
Right orbit
23. 4. OPTIC FORAMEN:
LOCATION:
- Lies medial to superior
orbital fissure
- at the apex
- Present in the lesser wing
of sphenoid
TRANSMITS:
- Optic nerve with its
meninges
- Ophthalmic artery
ROOF
Left orbit
24. Cribra orbitalia:
- apertures apparent on the medial side of anterior
portion of the lacrimal fossa
- for veins from diploë to the orbit
- Best marked in the fetus and infant
Frontosphenoidal suture:
- between frontal and the lesser wing of the sphenoid
- usually obliterated in the adults
ROOF
25. CLINICAL SIGNIFICANCE
Thin and fragile
Easily fractured by direct
violence (penetrating orbital
injuries)
Frontal lobe injury
ROOF
26. Reinforced
- Laterally- greater wing of sphenoid
- Anteriorly- superior orbital margin
So, fractures tend to pass towards medial side
At junction of the roof and medial wall, the suture line lies
in proximity to cribriform plate of ethmoid
rupture of dura mater
CSF escapes into orbit/nose/both
ROOF
27. Since the roof is perforated neither by major
nerves nor by blood vessels, so it can be easily
nibbled away in transfrontal orbitotomy.
ROOF
28. MEDIAL WALL
Thinnest orbital wall
Formed(Antero-posteriorly)
1. Frontal process of
Maxilla
2. Lacrimal bone
3. Orbital plate of Ethmoid
4. Body of the sphenoid
Almost parallel to each other Left orbit
29. LANDMARKS
LACRIMAL FOSSA:
- Formed by:
- frontal process of
maxilla
- lacrimal bone
- Boundaries:
- Anterior- anterior
lacrimal crest
- Posterior- posterior
lacrimal crest
Right orbit
30. - Dimensions-
- Length≈ 14 mm
- Depth≈ 5 mm
- Continuous below with bony nasolacrimal canal
- Content-
- Lacrimal sac
MEDIAL
WALL
31. ANTERIOR LACRIMAL CREST*-
- upward continuation of the inferior orbital margin
- Ill defined above but well marked below
- Surface anatomy-
- Palpable along the medial orbital margin (anteriorly)
POSTERIOR LACRIMAL CREST*-
- downward extension of the superior orbital margin
- Surface anatomy-
- Palpable along the medial orbital margin, posterior to
the lacrimal fossa
*significant landmarks in lacrimal sac surgery
MEDIAL WALL
32. FRONTO ETHMOIDAL SUTURE LINE
- Marks the approximate level of ethmoidal sinus
roof
- Breach of this suture may open the frontal sinus,
or the cranial cavity
- Anterior and posterior ethmoidal foramina are
present in the suture line
MEDIAL WALL
33. Anterior ethmoidal foramen
- 20-25 mm posterior from the anterior lacrimal crest
- Opens in the anterior cranial fossa at the side of the
cribriform plate of ethmoid
- Transmits-
- anterior ethmoidal nerve & vessels
MEDIAL WAL
34. Posterior ethmoidal
foramen
- 32-35 mm posterior from
anterior lacrimal crest
- 7 mm anterior to the
anterior rim of optic
canal
- Transmits
- posterior ethmoidal
nerve & vessels
MEDIAL
WALL
Left orbit
35. Weber’s suture
Lies anterior to lacrimal fossa
Also known as sutura longitudinalis imperfecta
Runs parallel to anterior lacrimal crest
Branches of infraorbital artery pass through this
groove to supply the nasal mucosa
Bleeding may occur from these vessels during
DCR surgeries
MEDIAL WAL
36. CLINICAL SIGNIFICANCE
Anteriorly located suture indicates predominance
of lacrimal bone
Posteriorly located suture indicates the
predominance of maxillary bone*
*If maxillary component is predominant, it
becomes difficult to perform osteotomy to reach
the sac during DCR, because the maxillary bone
is very thick.
MEDIAL
WALL
37. Medial wall extremely fragile (presence of
ethmoidal air cells and nasal cavity)
Accidental lateral displacement of medial wall-
traumatic hypertelorism
Medial wall provides alternate access route to
the orbit through the sinus
MEDIAL WALL
38. Ethmoid
- Thinnest bone of the orbit
- Vascular connections with ethmoid sinus through foramina
- Inflammation in the ethmoid sinus spreads readily to the
orbit
Tumours of the nasal cavity can breach the lamina
papyracea to involve the orbit
Lacrimal bone can be easily penetrated during
endoscopic DCR
During surgery, hemorrhage is most troublesome due to
injury to ethmoidal vessels.
MEDIAL WAL
39. FLOOR
• Shortest orbital wall
• Roughly triangular
• Formed by-
• Orbital plate of maxilla
(major)
• Orbital surface of
Zygomatic bone
(anterolateral)
• Orbital plate of Palatine
bone
Right orbit
40. Bordered laterally by inferior orbital fissure and
medially by maxilloethmoidal suture
Overlies maxillary sinus
FLOOR
42. CLINICAL SIGNIFICANCE
BLOW OUT FRACTURES:
◦ Fractures of the orbital floor
◦ Infraorbital nerves and
vessels are almost invariably
involved
◦ Patient presents with
Diplopia
Restricted
movements(upgaze)
Paresthesia
FLOOR
43. LATERAL WALL
Formed by-
◦ 1. Zygomatic bone
◦ 2. Greater wing of
sphenoid
Thickest orbital wall
Separates orbit from-
◦ Middle cranial fossa
◦ Temporal fossa
At an angle of about 90°
with each other
Right orbit
44. LANDMARKS
LATERAL ORBITAL
TUBERCLE OF
WHITNALL:
- 4-5 mm behind the
lateral orbital rim
- 11 mm inferior to the
frontozygomatic
suture line
LATERAL
WALL
Right orbit
45. - Gives attachment to:
- Check ligament of lateral rectus
- Lockwood’s ligament
- Lateral canthal tendon
- The aponeurosis of the levator palpebrae
superioris
- Orbital septum
- Lacrimal fascia
LATERAL
WALL
46. CLINICAL SIGNIFICANCE
In resection of maxilla, the Whitnall’s tubercle is
spared, otherwise
Damage to Lockwood’s ligament
Inferior dystopia of eye ball
Diplopia
LATERAL
WALL
47. SPINA RECTI LATERALIS:
- at the junction of wide & narrow portions of the
superior orbital fissure
- Produced by a groove lodging superior ophthalmic
vein
- Gives origin to a part of Lateral Rectus
LATERAL WAL
48. ZYGOMATIC GROOVE:
- EXTENT:
- From the anterior end of the inferior orbital fissure to a
foramen in the zygomatic bone
- CONTENTS:
- Zygomatic nerve
- Zygomatic vessels
LATERAL WAL
49. CLINICAL SIGNIFICANCE
Lateral wall protects only the posterior half of the
eyeball, hence palpation of retrobulbar tumours is
easier.
Frontal process of zygoma & zygomatic process of
frontal bone protect the globe from lateral trauma-
known as facial buttress area.
Just behind the facial buttress area, is the
zygomaticosphenoid suture, which is the preferred
site for lateral orbitotomy.
LATERAL WAL
50. Anteriorly, superior margin of inferior
Orbital fissure joins suture between
zygomatic and greater wing of sphenoid
(line of relative weakness)
extends to frontozygomatic suture
Frequently involved in zygomatic bone
fracture
LATERAL WAL
52. SUPERIOR ORBITAL MARGIN
- formed by- Frontal bone
- concave downwards, convex forwards
- sharp in lateral 2/3rd ,rounded in medial 1/3rd
- at the junction- supraorbital notch (sometimes
foramen)*
- *Site for nerve block.
53. Sometimes-
o Arnold’s notch/foramen
Present medial to supraorbital notch
Transmits
medial branches of supraorbital nerve & vessels
o Supraciliary canal
Near the supraorbital notch
Transmits
nutrient artery
a branch of supraorbital nerve to frontal air sinus
SUPERIOR ORBITAL
MARGIN
54. SURFACE ANATOMY:
- Well marked prominence
- More prominent laterally than medially
- Eyebrow corresponds to the margin only in a part
- Head- under the margin
- Body- along the margin
- Tail- above the margin
SUPERIOR ORBITAL
MARGIN
55. LATERAL ORBITAL MARGIN:
- formed by
- zygomatic process of frontal
- the zygomatic bone
- strongest portion of margin
56. CLINICAL SIGNIFICANCE
Lateral orbital rim is recessed on its deep aspect ≈
0.75 cm above the rim margin to accommodate the
lacrimal gland
Prone to fracture
LATERAL ORBITAL
MARGIN
57. Narrowest and weakest part- frontozygomatic
suture
Prone for separation following blunt trauma
LATERAL ORBITAL MAR
58. INFERIOR ORBITAL MARGIN:
Formed by-
- Zygomatic
- Maxilla
- suture between the two is sometimes marked by a
tubercle- felt 4-5 mm above the infraorbital foramen
SURFACE ANATOMY:
- Palpable as a sharp ridge, beyond which the finger can
pass into the orbit
59. CLINICAL SIGNIFICANCE
At the junction of lateral 2/3rd & medial 1/3rd just within
the rim- small depression- origin of Inferior oblique
Prone to fracture
Disruption of Inferior oblique
Diplopia
Penetrating injuries may severe lacrimal passages
INFERIOR ORBITAL MAR
60. MEDIAL ORBITAL MARGIN:
- Formed by
- Frontal process of maxilla (anterior lacrimal crest)
- Lacrimal bone (posterior lacrimal crest)
63. OPTIC CANAL
Leads from the middle cranial fossa to the apex of
the orbit
Orbital opening- vertically oval
In the middle- circular (≈5mm)
Intracranial- horizontally oval
Length ≈ 8-12 mm
- Attained at 4-5 years of age
Boundaries-
- Medially- Body of the sphenoid
- Laterally- Lesser wing of the sphenoid
Right orbit
64. Directed- forwards, laterally and downwards
Distance between
◦ Intracranial openings≈ 25mm
◦ Orbital openings≈ 30mm
Transmits-
◦ Optic nerve & its meninges
◦ Ophthalmic artery
OPTIC
CANAL
65. Processus falciformis: The roof of the canal
reaches farther forwards than the floor
anteriorly, while posteriorly, the floor projects
beyond the roof. Fold of dura mater filling the
gap in the roof is called Processus falciformis.
OPTIC CANA
66. CLINICAL SIGNIFICANCE
Optic nerve glioma or Meningioma may lead to
unilateral enlargement of Optic canal
OPTIC CANA
Strut view of Optic
Canal
(Normal)
CT-Scan showing lesion in Left
optic nerve
67. SUPERIOR ORBITAL FISSURE
Also known as Sphenoidal
fissure
Lateral to the optic foramen
at the orbital apex
comma-shaped gap between the
roof and the lateral wall
Bounded by- Lesser and greater
wings of the sphenoid
Left orbit
69. 22 mm long
Largest communication between the orbit and
the middle cranial fossa
Its tip lies 30-40 mm from the frontozygomatic
suture
SUPERIOR ORBITAL
FISSURE
70. Lateral superior part of the fissure is narrower
than the medial inferior part.
- At the junction of the two lies spina recti
lateralis
SUPERIOR ORBITAL
FISSURE
71. LANDMARK
Annulus of Zinn
- Spans both superior orbital fissure & the optic
canal
- Gives origin to the four recti muscles
SUPERIOR ORBITAL
FISSURE
72. CLINICAL SIGNIFANCE
Inflammation of the superior orbital fissure and
apex may result in a multitude of signs
including ophthalmoplegia and venous outflow
obstruction
TOLOSA HUNT SYNDROME
SUPERIOR ORBITAL
FISSURE
73. SUPERIOR ORBITAL SYNDROME
(Rochon-Duvigneaud syndrome)
Fracture at superior orbital fissure
Involvement of cranial nerves
Diplopia, Ophthalmoplegia,
Exophthalmos, Ptosis,
SUPERIOR ORBITAL
FISSURE
74. Manner of involvement of nerves may be helpful in
predicting the site and extent of the lesion.
Divisions of III’rd nerve ± VI’th nerve
Annulus of Zinn (Purely intraconal lesion)
III’rd, IV’th and VI’th nerve
Entire length of the fissure involved
SUPERIOR ORBITAL
FISSURE
75. INFERIOR ORBITAL FISSURE
Also known as sphenomaxillary
fissure
Between floor and the lateral wall
Bounded by-
oMedially- Maxilla and orbital
process of palatine
oLaterally- Greater wing of the
sphenoid
oAnterior aspect- closed by
Zygomatic bone Left orbit
76. Transmits-
- Venous drainage from the inferior part of the
orbit to the pterygoid plexus
- neural branches from the pterygopalatine
ganglion
- the zygomatic nerve
- the infraorbital nerve
Closed in the living by the periorbita & the
Muller’s muscle
Serves as the posterior limit of surgical
subperiosteal dissection along the orbital floor
INFERIOR ORBITAL
FISSURE
78. PERIORBITA (Orbital periosteum)
Loosely adherent to the bones
Sensory innervation by branches of V’th nerve
Fixed firmly at
- Orbital margins (Arcus marginale)
- Suture lines
- Various fissures & foramina
- Lacrimal fossa
79. CLINICAL SIGNIFICANCE
Surgery in the orbital roof in the areas of
fissures and suture lines may be complicated
by cerebrospinal fluid leakage .
PERIORBITA
80. ORBITAL SEPTAL SYSTEM
Includes the connective tissue septa which are
suspended from the periorbita to form a
complex radial and circumferential
interconnecting slings.
These septa surround Extraocular muscles,
Optic nerve, neuro-vascular elements and the
fat lobules.
81. TENON’S CAPSULE
Also known as Fascia bulbi or bulbar sheath.
Dense, elastic and vascular connective tissue that
surrounds the globe (except over the cornea).
Begins anteriorly at the perilimbal sclera, extends around
the globe to the optic nerve, and fuses with the dural
sheath and the sclera.
Separated from the sclera by periscleral lymph space,
which is in continuation with subdural and subarachnoid
spaces.
82.
83. CONTENTS OF THE ORBIT
Eye ball
Muscles
◦ 4 Recti
◦ 2 obliques
◦ Levator palpebrae superioris
◦ Muller’s muscle (Musculus orbitalis)
Nerves
◦ Sensory- branches of V’th Nerve
◦ Motor- III’rd, IV’th & VI’th Nerve
◦ Autonomic- Nerves to the Lacrimal gland
◦ Ciliary ganglion
Left orbit
84. Vessels
◦ Arteries-
Internal carotid system- branches of ophthalmic artery
External carotid system- a branch of internal maxillary
artery
◦ Veins-
Superior ophthalmic vein
Inferior ophthalmic vein
◦ Lymphatics-
none
Lacrimal gland
Lacrimal sac
Orbital fat, reticular tissue & orbital fascia
CONTENTS OF THE
ORBIT
87. CILIARY GANGLION
- Peripheral parasympathetic
ganglion
- Lies between Optic nerve and
Lateral Rectus muscle
- ≈1cm anterior to the optic
foramen
- 3 posterior roots
- Sensory root
- Nasociliary Nerve
- Motor root
- Nerve to inferior oblique
- Sympathetic root
- Branches from internal
NERVES
88. SURGICAL SPACES
SUBPERIOSTEAL SPACE:
◦ Between orbital bones and the periorbita
◦ Limited anteriorly by strong adhesions of periorbita to
the orbital rim
89. PERIPHERAL ORBITAL SPACE (ORBITAL SPACE)
- Bounded:
- peripherally by periorbita
- internally by the four recti with their intermuscular
septa
- anteriorly by the septum orbitale
- Posteriorly, it merges with the central space
SURGICAL
SPACES
91. CENTRAL SPACE
- Also known as muscular cone or retrobulbar space
- Bounded:
- Anteriorly by Tenon’s capsule
- Peripherally by four recti with their intermuscular septa
- In the posterior part, continuous with the peripheral orbital
space
SURGICAL
SPACES
92. CONTENTS:
Central orbital fat
Nerves
◦ Optic nerve (with its meninges)
◦ Oculomotor
Superior and inferior divisions
◦ Abducent
◦ Nasociliary
◦ Ciliary ganglion
Vessels
◦ Ophthalmic artery
◦ Superior ophthalmic vein
SURGICAL
SPACES
93. SUBTENON’S SPACE*
- Between the sclera and the Tenon’s capsule
- *Pus collected in this space is drained by incision of
Tenon’s capsule through the conjunctiva
- *Site for drug instillation
SURGICAL
SPACES
94.
95. AGE RELATED VARIATIONS
Infantile orbits are more divergent (≈115°) than
those of adults (≈40-45°)
Orbital axes
- Lie in horizontal plane in infants
- slope downwards (≈15-20°) in adults
96. Orbital fissures are relatively larger in childhood than
in adults (owing to the narrowness of the greater
wing of sphenoid)
Orbital index- higher in children than in adults
(transverse diameter increases relatively more in
the later life)
Interorbital distance is smaller in children- may give
false impression of squint
AGE RELATED
VARIATIONS
97. Roof much larger than floor in infancy
Optic canal has no length at birth- a foramen
- at 1 year of age≈ 4 mm
Periorbita much thicker and stronger at birth than in
adults
AGE RELATED
VARIATIONS
98. SENILE CHANGES-
Holes, particularly in the roof due to absorption of
the bony wall
Orbital fissures become wider
AGE RELATED
VARIATIONS
99. GENDER RELATED VARIATIONS
MALES
• Glabella &
supraciliary ridges
more marked
FEMALES
• Larger
• More elongated
• Rounder
• Upper margins
sharper
• Frontal eminences
more marked
100. TAKE HOME
MESSAGE…………………...
Knowledge of orbital anatomy and its variations
helps to determine the pathology as well as the
site, direction and extent of the incision during
elective exploration of the orbit.
It is also must for understanding the clinical
course and planning the management in cases
of accidental incisions/explorations.