Approach to orbital surgery.

simplified slide for orbital surgery.

1. Approach to orbital surgery Bipin bista Resident ophthalmology

2. introduction Requires delicacy of a neurosurgeon, the strength of an orthopaedic surgery, and the 3-dimensional sense of a general surgeon. Comfort & success are based on surgeon’s knowledge of the relationships among the orbital structures & ability to approach the orbit from different directions & angles.

3. Surgical spaces Subperiosteal ( subperiorbital ) surgical space Extraconal surgical space Episcleral (sub- tenon ) surgical space Intraconal surgical space (central) Subarachnoid surgical space

4. instruments Stryker saw with finger twitch, bony rongeurs

5. instruments Sewall, wright

6. Orbitotomy – superior approach Trancutaneous incisions Transconjunctival incision

7. Orbitotomy – superior approach Transcutaneous incisions : an incision through the upper eyelid crease offers good access to the superior orbital rim & periosteum , with a HIDDEN scar. Cosmetic result is better with an eyelid crease incision >> supraorbital rim. Eyelid crease incision leds to access to orbital rim by superior dissection in the postorbicularis fascial plane anterior to orbital septum. After rim exposure, incision is made in arcus marginalis,then periosteum is separated from the frontal bone of the orbital roof.

8. Orbitotomy – superior approach Upper eyelid crease may also be used for entry into the medial intraconal space, which requires exposure of the medial edge of the levator muscle & dissection through the intermuscular septum Used for exposure & fenestration of the retrobulbar ON, in case of IIH.

9. Orbitotomy – superior approach A coronal flap is used to expose superior orbital lesions. Useful for transcranial orbitotomies & for extensive lesions of the superior orbit & sinuses which requires bone removal.

10. Orbitotomy – superior approach Transconjunctival approach to reach the SN, episcleral , intraconal , or the extraconal surgical spaces but dissection must be performed medial to levator muscle to prevent ptosis. Vertical eyelid splitting of upper lid at the junction of the medial & central thirds allows extended exposure to removal of SM intraconal tumors . Vertical incision of eyelid & levator aponeurosis to expose SM intraconal space. Less chance postop ptosis & eyelid retraction syndrome.

11. Orbitotomy – inferior approach Suitable for masses that are visible or palpable in the inferior conjunctival fornix of the lower eyelid, as well as for deeper extraconal orbital masses. Access by dissecting between the inferior & lateral recti. Also used for orbital floor # repair or decompression.

12. Orbitotomy – inferior approach Trancutaneous approach :Minimal scarring by use of an infraciliary blepharoplasty incision in the lower eyelid & dissection beneath the orbicularis muscle to expose orbital septum & inferior orbital rim. Extended subciliary incision or an in incision in the lower lid crease allows exposure to the rim. Orbital floor # are reached by the subperiosteal route.

13. Orbitotomy – inferior approach Transconjunctival incisions has largely replaced transcutaneous route. Incision made through the inferior conjunctiva & lower eyelid retractors. Exposure of the floor is optimised when incision is combined with lateral canthotomy & cantholysis . Incision of the bulbar conjunctiva & tenon capsule allows to episcleral space. If Inferior Rectus is retracted, intraconal space can be accessed.

14. Orbitotomy – medial approach Careful to avoid damaging the medial canthal tendon, lacrimal canaliculi & sac, trochlea, superior oblique tendon & the muscle, inferior oblique muscle, and the sensory nerves & vessels along the medial aspect of superior orbital rim.

15. Orbitotomy – medial approach Transcutaneous incision : Tumors within or near the lacrimal sac, the frontal or ethmoidal sinus & the medial rectus can be approached.(Lynch/ Frontoethmoidal incision) ; 9-10 mm medial from medial canthal angle.

16. Orbitotomy – medial approach

17. Orbitotomy – medial approach Transconjunctival incision : incision in bulbar conjunctiva, allows entry into extraconal or episcleral surgical space to expose the region of the ant. ON for examination, biopsy, or sheath fenestration. If the posterior ON or muscle cone needs to be seen, a lateral/medial orbitotomy . Lateral orbitotomy with removal of the lateral orbital wall allows the globe to be displaced temporally, thus maximising medial access to the deeper orbit.

18. Orbitotomy – medial approach

19. Orbitotomy – medial approach Transcaruncular approach : incision through the posterior third of the caruncle or the conjunctiva immediately lateral to the caruncle allows excellent exposure of the medial periosteum Advantage of better cosmetic result than Lynch incision, but the surgeon must be careful to protect the lacrimal canaliculi & remain posterior to lacrimal apparatus. Combination of transcaruncular & inferior transconjunctival incision allows exposure of the inferior & medial orbit : medial wall #, medial orbital bone decompression, & for drainage of medial subperiosteal abscesses.

20. Orbitotomy – medial approach

21. Orbitotomy – lateral approach Used when a lesion is located within the lateral intraconal space, behind the equator of the globe, or in the lacrimal gland fossa. Previously, traditional S-shaped Stallard -Wright skin incision, extending from beneath the eyebrow laterally & curving down along the zygomatic arch, allowed good exposure of the rim but a noticeable scar. Newer approach, upper eyelid crease incision or a lateral canthotomy : Both allowed exposure of the lateral orbital rim & anterior portion of zygomatic arch Dissecting through the periorbita & then intermuscular septum, above/below lateral rectus posterior to globe provides access to the retrobulbar space.

22. Stallard -Wright skin incision

23. Fronto – zygomatic approach

24. Orbitotomy – lateral approach If not adequately exposed through a soft-tissue lateral incision, an oscillating saw/ bony rongeurs to remove the bone of the lateral rim. Good exposure by retraction of the lateral rectus muscle. Tumours can be prolapsed into the incision by gentle traction on eyelid. Maintain hemostasis – cryo , Allis, suture (cavernous hemangioma ),placing a drain. Lateral orbital rim is usually replaced & sutured through predrilled tunnels in the rim or rigid fixation with plating systems

25. Orbitotomy – lateral approach

26. Orbital decompression Surgical procedure to improve the volume- to- space discrepancy, occurs primarily in TED. Goal is to allow the enlarged muscles & orbital fat to expand into periorbital spaces Relieves pressure on the ON & its blood supply & reduces proptosis . Historically, removal of the medial orbital wall & much of orbital floor. Approach currently used is transconjunctival incision combined with a lateral cantholysis Burring down the medial surface of the lateral wall further causes decompression. Removal of retrobulbar fat further reduces proptosis .

27. Orbital decompression

28. Orbital decompression

29. Post operative care for orbital surgery Elevation of the head Ice compression Administration of steroids Placement of drain (24-36 hrs ) Regular check-up of VA Avoid patching

30. Special surgical techniques Fine needle aspiration biopsy : lymphoid lesions, secondary tumours, suspected metastatic tumors , blind eyes with ON tumors . Masses or traumatic injuries : frontal craniotomy or Frontotemporal OR Orbitozygomatic approach.

31. Complications of orbital surgery Decreased or lost vision : excessive traction on the globe or ON, contusion of the ON, postop infxn , hemorrhage which leads to increased intraorbital pressure & consequent ischaemic injury to the ON. Severe pain should be evaluated for orbital hemorrhage . Decreased VA, proptosis , ecchymosis, increased IOP , afferent pupillary defect : Consideration for reopening. Hypoaesthesia following orbital floor repair, along with downward displacement of globe & postop exacerbation of upper eyelid retraction. Motility disorder 3 rd CN injury : Superior orbital tumor resection, risk of ciliary ganglion injury. Other : ptosis, neuroparalytic keratopathy , pupillary changes, VH, detached retina, forehead hypothesia , keratitis sicca , CSF fluid leak, & infection.

32. References AAO 2014-15 section 07 - Orbit, eyelids & lacrimal system. Oculoplastic Surgery - Leatherbarrow _ Brian.