This document provides information on orbital surgeries and anatomy. It describes the average dimensions of the adult orbit and its topographic relations. The seven bones that make up the four orbital walls - roof, lateral wall, medial wall, and floor - are identified along with key landmarks. The document also discusses the five surgical spaces of the orbit and different surgical techniques for orbitotomy, orbital decompression, and fracture repair.

1. ORBITAL SURGERIES
DR.PRAKRITI YAGNAM .K
MODERATOR : DR. CH. MOHANRAO

2. Orbit :
 Bony cavities that contain globes , EOM ,
, fat and blood vessels
 Each orbit is pear shaped ( quadrilateral
pyramid ) tapered posteriorly to the apex and
the optic canal
 Medial orbital walls are parallel and separated
by 25 mm. in an average adult
 Widest dimension of the orbit is approximately
1 cm. behind the anterior orbital rim

4. Average dimensions of adult orbit :
 Volume – 30 cc.
 Entrance height – 35 mm.
 Entrance width – 40 to 45 mm.
 Medial wall length – 40 to 45 mm.
 Distance from posterior globe to optic foramen – 18 mm.
 Length of orbital segment of optic nerve – 25 to 30 mm.

6. Topographic relations :
Orbital septum arises
anteriorly from orbital rim
The paranasal air sinuses are
either rudimentary or small
at birth and they increase in
size through adolescence
They lie adjacent to floor ,
medial wall and anterior
portion of orbital floor

8. Orbital walls :
 Composed of 7 bones
 Ethmoid , frontal ,lacrimal , maxilla , palatine ,
sphenoid and zygomatic bones
 They constitute the four walls of the orbit –
, floor , medial and lateral walls
 The walls meet at the apex and the anterior
opening constitutes the base

10. Roof :
Composition – Orbital plate of
frontal bone
Lesser wing of
sphenoid bone
Location – Adjacent to anterior
cranial fossa and frontal sinus
Landmarks
Fossa of lacrimal gland –
contains orbital lobe of lacrimal
gland
Fossa for trochlea of SO
– 5 mm. behind superomedial
orbital rim
Supraorbital notch or foramen
Transmits supraorbital vessels
and supraorbital branch of
frontal nerve

12. Lateral wall :
•Thickest and strongest
Composed of – Zygomatic bone
Greater wing of sphenoid
•Separated from the roof by superior orbital fissure
Location – Adjacent to middle cranial fossa and temporal fossa
Extends anteriorly to the equator of the globe helping to protect
posterior half of the eye while still allowing wide peripheral vision

13. Landmarks
- Lateral orbital tubercle of Whitnall - Attachment to lateral canthal tendon
Lateral horn of levator aponeurosis
Check ligament of lateral rectus
Lockwood ligament
- Whitnall ligament inserts onto lateral orbital wall mm. above lateral orbital
tubercle in attachment to lacrimal gland fascia
- Frontozygomatic suture is located 1 cm. above the tubercle

15. Medial wall :
Composition – Orbital plate of ethmoid
Lacrimal bone
Frontal process of maxillary bone
Lesser wing of sphenoid bone
- Only the lacrimal bone is wholly within the orbital confines
Location – Adjacent to ethmoid and sphenoid sinuses and nasal cavity

16. Landmarks
- Frontoethmoid sutures – Approximate level of cribriform plate
Roof of ethmoids
Floor of anterior cranial fossa
Exit of anterior and posterior ethmoidal vessels

17. Lamina papyracea - Thinnest walls of the orbit
 Between orbits and ethmoidal sinuses along medial wall and maxillary bone ( posterior
medial portion )
 Frequently fractured as a result of indirect or blow out fractures
 Acute bacterial infections of ethmoidal sinus may extend through lamina papyracea or
neurovasular perforation to form subperiosteal abscess and extend into. Orbital soft tissues

19. Floor :
Composition – Maxillary bone
Palatine bone
Orbital plate of zygomatic bone
- Forms the roof of maxillary sinus
- Does not extend to orbital apex but ends at pterygopalatine fossa – shortest
of all walls
Landmark
- Infraorbital groove and canal which transmits infraorbital artery and maxillary
division of trigeminal nerve

21. Apertures :
Ethmoidal foramina
- Anterior and posterior ethmoidal foramina present in the medial wall along
frontoethmoidal suture
- Anterior and posterior ethmoidal arteries pass through corresponding
foramina
Importance
- Surgical landmark for superior extent of medial wall surgery
- Damage to medial wall above this level may disrupt a plane superior to
cribriform plate

22.  Potential route of entry into orbit for pathogens
and neoplasms from the sinus
Others :
 Superior orbital fissure
 Inferior orbital fissure
 Zygomatico facial and Zygomatico temporal
canals
 Nasolacrimal canal
 Optic canal

24. Other important features :
 Periorbita is the periosteal lining of orbital bones
 At orbital apex fuses with dura mater covering the optic nerve
 Anteriorly continuous with orbital septum and periosteum of facial bones
 Line of fusion of these layers at orbital rim forms arcus marginalis
 Periorbita adheres loosely to bone except at orbital margin , sutures , fissures , foramina , tubercles and
canals
 During exenteration can be separated except at these layers

26. Surgical spaces of orbit :
- Five in number
1. Sub periosteal space
2. Extraconal or peripheral space
3. Sub tenons space
4. Sub arachanoid space
5. Intra conal or central space
- A single orbital lesion may involve more than one surgical space and a
combination of approaches may be necessary for pathological process affecting
the orbit

28. The different surgical techniques to orbit include
1. Orbitotomy
2. Orbital decompression
3. Fracture repair

29. 1. Orbitotomy :
- It is procedure of making a surgical incision into the orbit
Indications :
- Complete removal ( excision biopsy ) of orbital tumor
- Incision biopsy of tumor
- Removal of IOFB
- Drainage of orbital abscess or hematoma

30. Specific incision of orbitotomy is selected depending on the exact location of orbital
pathology
Types :
- Anterior
- Lateral
- Transcranial

31. Approaches :
- Trans cutaneous – preferred site is skin crease
- Trans caruncular
- Trans conjunctival – preferred wherever feasible

33. Trans cutaneous incisions :
If lesion in anterior two thirds of the orbit , placed superiorly
- Subbrow Benedicts incision
- Upper eyelid crease incision
Supero medial orbit – Lid split incision
Medial orbit – Lynch incision
Sea gull incision

34. Inferior orbit – Lower lid subciliary incision
Superotemporal orbit – Stallard – wright incision
Extension of upperlid crease incision
Berkes incision

37. Anterior orbitotomy :
- Most commonly superior approach is done
- Most orbital lesions are focused in superoanterior part of the orbit than in any
other location
- In transcutaneous approach – must avoid damaging the
LPS muscle , SO muscle
Trochlea
Lacrimal gland
Sensory nerves or vessels entering or exiting the orbit along superior orbital rim

38. Upper eyelid crease incision
Sub periosteal space extraconal space medial intraconal
space

39. Sub periosteal space :
- Dissection is performed superiorly towards orbital rim in a plane between
orbicularis oculi muscle and orbital septum
- Incision is made at arcus marginalis where periosteum of the frontal bone
to become orbital septum entering the sub periosteal space
Extra conal space :
- Dissection is carried posteriorly through orbital septum after skin incision

40. Medial intraconal space :
 Dissection is kept medial to medial edge of levator muscle after opening the orbital septum
 Proceed between medial and central pad of fat pads through inter muscular septum extending from
superior rectus to medial rectus
 It is used for - biopsy of optic nerve
for optic nerve sheath fenestration in cases of IIH
for accessing intraconal lesions medial to optic nerve

41. Technique :
- Via upper lid crease incision
- It provides better cosmosis than incision over superior orbital rim
- Sub periosteal and extraconal spaces are approached
General anaesthesia
Skin incision in upper lid crease
Dissection is carried in plane between orbicularis anteriorly and
orbital septum posteriorly

42. Periorbita of the roof is lifted off with Freer elevator and is pushed inferiorly
If inadequate exposure
Small amount of superior orbital rim is nibbled away
T shaped incision is placed on periorbita with sharp Westcott scissors
Corners retracted to expose superior orbit
Lesion is visualized and incision biopsy is taken

43. If circumscribed lesion – Blunt dissection done all around and lesion removed
Traction may be placed on tumor with cryoprobe also
Orbital rim periosteum is repaired
Lid crease is reformed
Skin incision is sutured

46. Trans conjunctival approach :
 Incisions in superior conjunctiva can be used to reach
superomedial , subtenon , intraconal or extraconal
surgical spaces
 Dissection must be performed medial to the LPS
muscle to prevent post operative blepharoptosis
 Care should be taken in superolateral fornix to avoid
damage to lacrimal ductules

47. Other approaches :
Vertical eyelid splitting :
- Via a full thickness incision which allows an extended trans conjunctival
exposure for removal of superomedial intraconal tumors
- Careful realignment of tarsal plates , levator aponeurosis prevents post
operative blepharoptosis , eyelid notching and eyelid retraction

49. Lateral orbitotomy :
- To access
Lateral intraconal Fossa of lacrimal gland
space behind equator of the
globe
- In children as orbit is relatively shallower extensive exposure may be achieved
without the need for bone removal

50. Technique :
- Via lateral extension of upper lid crease incision
General anaesthesia
Incision – Upper lid crease in lateral one third and extended laterally
to lateral orbital rim
Soft tissue is dissected to expose lateral orbital rim with
reflection of temporalis muscle and periosteum of orbit
Periosteum is incised and retracted

51. Orbital rim bone , zygomatic process of frontal bone and frontal process
of zygomatic bone are exposed
Periorbita is lifted and pushed medially pushing orbital contents
away from the rim
Metal guard is placed between periorbita or orbital contents and
bony rim before cutting the bone
Bone in incised just below the frontozygomatic suture and inferiorly
at lower end of lateral orbital rim

52. Cut segment is held with bone holding rongeur and fractured away
temporally to give exposure to orbit – MARGINOTOMY
T shaped incision is placed on periorbita to expose orbital contents
LR is needed to be identified and retracted for an intraconal mass
Incision or excision biopsy is done

53. Fragment of orbital rim may be replaced by wiring
Periosteum is closed with 6 – 0 vicryl sutures
Skin is repaired in layers
- Complete hemostasis is achieved before closure
- To help prevent post operative intra orbital hemorrhage an external drain may
be placed in the deep orbit

58. Medial orbitotomy :
Indications – repair of
medial wall trauma
orbital decompression
access to lacrimal sac or
sino – nasal tumors with
orbital involvement
Avoid damage to medial
canthal tendon , lacrimal
canaliculi and sac
SO tendon and muscle ,
trochlea , IO muscle
sensory nerves and
vessels along medial
aspect of
superior orbital rim

59. Incisions – Trans
cutaneous Trans conjunctival Retrocanalicular
Trans cutaneous
incision :
• For tumors within or near
lacrimal sac
frontal sinus ethmoidal sinus

60. Technique :
- Approached through frontoethmoidal skin incision placed vertically just medial
to insertion of medial canthal tendon
- Enter the sub periosteal space by reflecting medial canthal tendon in
with periosteum preserving lacrimal drainage apparatus

61. Trans conjunctival :
 Bulbar conjunctiva incision
 To approach – Extra conal space
Subtenons space
Intra conal space – If MR is detached
In the region of anterior optic nerve
for exploration or biopsy

63. Retro caruncular incision :
Indications – Medial wall fractures
Medial orbital bone decompression
Medial sub periosteal abscess
Technique :
- Incision posterior to caruncle – excellent exposure of medial orbit
Blunt dissection carried medially followed by incision and elevation of
periosteum sub periosteal space

66.  Retro caruncular + Inferior trans conjunctival incision gives panoramic exposure of
inferior and medial orbit
 IO muscle may be divided at its origin along infero medial orbital rim and reattached at
the end of the surgery
 Has better cosmesis than transcutaneous incision
 Care must be taken to remain posterior to lacrimal drainage apparatus

68.  Combined lateral and medial orbitotomies can be done for posterior optic nerve
approach or muscle cone assessment
 Lateral orbitotomy with removal of lateral orbital wall allows globe to be displaced
temporally maximizing medial exposure to deeper orbit

69. Inferior orbitotomy :
Indications – Masses that are visible or palpable in the inferior conjunctival
fornix of lower eyelid
Deep inferior extra conal or intra conal orbital masses
To approach orbital floor for fracture repair or decompression
Tran cutaneous
Approaches
Trans conjunctival

70. Trans cutaneous :
Sub ciliary blepharoplasty incision in lower eyelid skin
Septum is exposed through preseptal orbicularis oculi muscle towards
inferior orbital rim
Septum is opened to expose extraconal surgical space
- Other cutaneous incision is lower eyelid crease incision directly over inferior
orbital rim

72. Trans conjunctival :
- Incision through inferior conjunctiva and lower eyelid retractors where extra
space and orbital floor are exposed
- Incision below inferior tarsal border in conjunctival fornix is given for
extraconal space
sub periosteal space
intra conal space and sub tenons spaces
- Avoid injury to IO muscle , IR muscle and infra orbital neuro vascular bundle

73. Extra conal space :
 Via lateral canthotomy and inferior cantholysis
 Dissection in a preseptal plane inferiorly
towards orbital rim
 Can be accessed by incising orbital septum
Sub periosteal space :
- By incising at arcus marginalis and elevating
periosteum

74. Intra conal space :
By dissection between
rectus and lateral rectus
Sub tenon space :
Incision of bulbar conjunctiva
and tenon capsule
Also used to gain access to
intraconal space by
or reflecting inferior rectus
muscle from the globe

78. Orbital decompression :
 It is the bony decompression of the orbit that allows
orbital contents to prolapse into new space created
 Used to improve the volume to space discrepancy that
occurs primarily in patients with thyroid eye disease
Goal – To allow enlarged muscles and orbital fat to
expand into additional space that is created during the
surgery
 Expansion relieves pressure on optic nerve and its
blood supply
 Reduces proptosis and orbital congestion

79. Methods :
Historical – Removal of medial
orbital wall and much of
orbital floor extending to apex
including maxilla ethmoidal
strut
It allows orbital tissues to
expand into ethmoid and
maxillary sinuses
Approach is by maxillary
vestibular or transcutaneous
incisions

80. Post operative complaints :
 Globe ptosis and upper eyelid retraction could
be exacerbated in patients with large restricted
inferior rectus muscle
 Could also disrupt globe excursion due to
prolapse of muscles into sinus space and
displacement of orbital content

81. Current approach :
- Combination of one or more discrete incisions that allow access to lateral , inferior
and / or medial walls
- Lateral and inferior orbit – Upper eyelid crease incision
Extended lateral canthotomy incision
Inferior trans conjunctival incision combined
with a lateral canthotomy or inferior cantholysis

82. - Decompression of lateral wall includes removal of bone along the sphenoid wing
by using rongever and / or a drill
- Medial wall – Retrocaruncular + trans conjunctival incision
Trans nasal endoscopic approach via ethmoid sinus
Balanced decompression :
- Removing bones from opposite walls
- Will reduce the risk of worsening or new onset diplopia

84. For further decompression – removal of lateral orbital rim and / or reposition it anteriorly at time of closure is done
Anterior displacement of lateral canthus aid in reduction of eyelid retraction
Each additional wall provides 2 mm. reduction in proptosis
The generalized technique –
After reaching orbital rim periosteum is incised and lifted off and orbital wall is removed
Periosteum is incised at each area

88. Fat decompression :
Removal of retrobulbar fat
further aids in reduction of
proptosis
Beneficial in patients with
compressive optic neuropathy
May allow 3mm. reduction of
proptosis
Intra conal fat is removed
preserving extra conal fat
It causes minimal disturbance in
EOM balance reducing the risk
inducing strabismus and
Decompression through orbital
roof into anterior cranial fossa is
inadvisable

92. 3. Fracture repairs :
Orbital floor or blow out fracture repair –
General anaesthesia
FDT to confirm entrapment of IR or surrounding soft tissue in the fracture
Lateral canthotomy and inferior cantholysis
Mobilize lower lid away from globe as swinging flap

93. Incision – inferior fornix ( others – transcutaneous )
separation of tissue in the plane between orbicularis and orbital septum
Inferior orbital rim periosteum is exposed and retracted
Incision is placed on the periosteum along the rim of the orbit
Periorbita is lifted proceeding posteriorly till fractured area is reached

94. Entire fracture is visualized upto posterior extent
Soft tissue entering the fracture is gradually teased up with elevator
- In trap door fractures hinged door of bone traps comparatively larger bulk of
tissue in small opening
- Must lift the bone fragment away to release the tissue adequately
Complete reduction of soft tissue back into orbit is done
Confirmed by FDT

95. - Reduced tissue is supported by retractor to prevent prolapse back into fracture
while floor is repaired
Depending on size of defect plate size is selected
- Plate materials – silicone
Bone grafts
Titanium mesh
Porous polyethylene sheet – can be shaped easily to
conform the curvature of the floor
- Soft tissue grows into pores over time and fixes the plate
reduces the chance of slippage and extension

96. - Plate must be large enough to extend into intact bone beyond the defect
- If there is large defect in periorbita – barrier plate is used
Plate is placed and retractor is removed and tissue is replaced
- If anterior rim is projecting or FDT is positive
Plate may be too large or placed too superficially
Trimmed or position is corrected

97. Finally fixed with metal screws to orbital rim
- If silicone plate is used tissue adhesives can be used
Periosteum is repaired with interrupted 6 – 0 vicryl sutures
Lower lid retractors and inferior fornix is also repaired with interrupted
6 - 0 vicryl suturing
Lateral canthus is repaired
- Some surgeons use lower lid skin crease which is a more direct route to floor
but leaves visible scar

99. Porous polyethylene Silicone

103. Special surgical techniques in the orbit :
1. Fine Needle Aspiration and Biopsy – Lymphoid lesions
Secondary tumors invading orbit from sinuses
Suspected metastatic tumors
Blind eyes with optic N. tumors
- Not effective for obtaining tissue from fibrous inflammatory lesions because of
difficulty in successfully aspirating cells
- Lymphoproliferative disorders – FNAB + flow cytometry + monoclonal antibody
or PCR analysis

105. 2. Endoscopic trans nasal surgery :
 Utilizing the anatomic relationship of ethmoid and maxillary
sinus to medial and inferior respectively
 Permits biopsy or resection of intraconal pathology
 May also be combined with open orbitotomy to allow
improved access to apical processes
 Used in TED or non traumatic compressive optic neuropathy
for decompression of orbit or optic canal
 May also be used for drainage of medial sub periosteal orbital
abscess in patients with sinusitis or for debridement of
tissue in patients with fungal sinusitis

106. 3. Tumors or traumatic injuries of skull base involving superior and posterior orbit
- Access via frontal cranitotomy or fronto temporal orbito zygomatic approach
- Requires a multidisciplinary team
- Neuro surgeon gives access to deep superior and lateral orbit by removing
frontal bone and orbital roof
- Indications – Decompression of optic canal
Resection of meningioma , fibrous dysplasia , schwannomas
gliomas , cavernous venous malformations and solitary fibrous
tumors

107. Post operative care for orbital surgeries :
To reduce postop edema – Elevation of head
Ice compressors over eyelids
Administration of systemic corticosteroids
optimal placement of drain
- Ice packs minimize swelling and allow for observation of operative site and
monitoring of visual acuity
- Prophylactic systemic antibiotics may also be given

108. Preoperative and intraoperative requisites :
 Complete preoperative evaluation
 Orbital imaging
 Choosing appropriate surgical approach
 Obtaining adequate exposure
 Manipulating the tissues carefully
 Employing proper illumination and instrumentation
 Maintaining excellent hemostasis and team approach

109. Complications :
Decreased or complete loss of vision
- Most dreaded complication
- May be due to - Excessive traction on the globe or optic nerve
- Contusion of optic nerve
- Post op hemorrhage
Raised orbital pressure Ischemic injury to ON
- Post op infection

110. - Patient with severe orbital pain post op must be evaluated immediately for
possible orbital hemorrhage
- Pain + decreased vision + proptosis + ecchymosis + increased IOP + afferent
pupillary defect
Surgeon should open the wound to minimize the effect of orbital
compression syndrome
Any hematoma is evacuated or any active bleeding is controlled

111. Other complications :
 Blepharoptosis
 CSF leak
 Ciliary ganglion dysfunction with loss of accommodation
 Cranial neuropathy resulting in EOM weakness or palsy
 Hypoaesthesia in the distribution of trigeminal nerve ( V1 and
V2 )- seen in floor decompression due to damage to
infraorbital nerve
 Infraplacement of globe after decompression – preservation
medial strut of bone between medial wall and floor may help
preventing it

112.  Keratitis sicca
 Motility disturbance – diplopia
 Neuroparalytic keratopathy
 Orbital cellulitis
 Pupillary dysfunction
 Retinal detachment
 Vitreous hemorrhage

113. Instruments used in orbital surgery :
- Quality of surgery depends on availability of appropriate instruments
- Operating light – External surgical lamp – ceiling or stand mounted
- Magnification – Microscope or surgical loupe is used
2.5 X or 3.0 X
- Suction apparatus
- Cautery – standard bipolar cautery for hemostasis
- Surgical unit – Monopolar radiofrequency or electrosurgical hand piece

114. Others :
- Cryoprobe
- Microdrill
- Oscillating saw

115. Others :

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