Dr. Ahmed M. Adawy Professor Emeritus, Dept. Oral & Maxillofacial Surg. Former Dean, Faculty of Dental Medicine Al-Azhar University The term “blow out” refers to partial herniation of the orbital contents through one of its walls. This usually occurs via blunt force trauma to the eye. Most often, the orbital floor is fractured in conjunction with the inferior orbital rim “impure” blowout fracture, but “pure” orbital floor fractures, with intact orbital rim can be seen. An extensive and careful history, physical examination, together with CT scans is vital for the diagnosis of orbital floor fractures. The timing of treatment, surgical approaches, and reconstruction of the orbital floor are presented.

2. Dr. Ahmed M. Adawy
Professor Emeritus, Dept. Oral & Maxillofacial Surg.
Former Dean, Faculty of Dental Medicine
Al-Azhar University

3. The orbit is a bony pyramid with the apex pointing
posteriorly and the base situated anteriorly and is bounded
by the roof, floor, medial and lateral walls. The orbital
roof is formed primarily by the frontal bone and the lesser
wing of the sphenoid. The frontal bone separates the orbit
from the anterior cranial fossa. The floor is formed by the
maxilla, palatine and zygomatic bones. The maxilla
separates the orbit from the underlying maxillary sinus.
The medial wall is formed by the ethmoid, maxilla,
lacrimal and sphenoid bones. The ethmoid bone separates
the orbit from the ethmoid sinus.

4. The lateral wall is formed anteriorly by the zygomatic
bone and posteriorly by the greater wing of the sphenoid.
The sphenoid bone houses the orbital canal. Lateral to the
orbital canal lies the superior orbital fissure housing
cranial nerves III, IV, V, and VI. Located around the
globe of the eye and attached to it are 6 extraocular
muscles; the 4 rectus muscles and the superior and
inferior oblique muscles. The fat and connective tissue
around the globe help to reduce the pressure exerted by
the extraocular muscles (1,2).

5. Anatomy of the orbit.

6. Extraocular muscles.

7. Fractures involving the orbit are frequently observed. In
more than 40% of all the facial fractures parts of the
orbital rim and/or the internal orbit are injured with a
variety of fracture patterns ranging from simple to
complex comminuted fractures. Even if orbital fractures
may occur in isolation, they commonly occur in multiple
walls and they are also usually associated with the
involvement of extra orbital bone structures. In one study
of the orbital walls, four walls were involved in 5% of
cases, three walls in 17% and two walls in 30% of the
cases (3). Another study reported that 62% of cases (of a
total of 73 patients with head trauma) had orbital fractures
involving multiple sites (4).

8. When the orbital floor is involved, this is often referred to
as a “blowout” fracture. The term refers to partial
herniation of the orbital contents through one of its walls.
This usually occurs via blunt force trauma to the eye. The
medial and inferior walls are the weakest, with the
contents herniating into the ethmoid and maxillary sinuses
respectively. Most often, the orbital floor is fractured in
conjunction with the inferior orbital rim “impure” blowout
fracture, but “pure” orbital floor fractures, with intact
orbital rim (5) can be seen in 22 to 47 percent of orbital
injuries.

9. Since the first description of blow-out fractures by Lang
(6), there has been controversy over the exact mechanism
causing these injuries and various theories have been
proposed. There are two main theories: the first one,
known as the hydraulic theory proposed by Smith and
Regan (7), who postulate that trauma directed to the globe
results in the transmission of hydraulic pressure to the
walls of the orbit, with consequential fracture of the thin
orbital floor. The second one is the hypothesis of buckling
(8), which states that trauma to the infraorbital rim may
transmit force directly to the thinner orbital floor, causing
disruption of the bone without fracture of the rim.

10. Theories of mechanism of blow-out orbital fractures;
a) Hydraulic theory. b) Buckling theory.

11. More recently, experimental studies have shown that both
mechanisms can produce orbital blowout fractures, but
with different characteristics (9). Buckling tends to produce
smaller, linear fractures along the anterior orbital floor,
with little or no periorbital herniation and a lower
likelihood of clinical enophthalmos. In contrast, the
hydraulic mechanism tends to produce larger, more
posterior fractures of both the floor and medial wall, with
frequent herniation and a higher likelihood of
enophthalmos. When these two mechanisms combine, the
resulting fracture is significantly larger than with either
mechanism acting independently (10).

12. An extensive and careful history, physical examination,
is vital for the diagnosis of orbital floor fractures. CT
scans has become a key tool for the initial evaluation of
orbit fractures. The etiology for ocular trauma is
commonly a motor vehicle accident, interpersonal
altercation, and sport-related injuries. Commonly,
patients will complain of periorbital pain and a change in
vision; blurriness or possibly diplopia. Physical
examination findings associated with an orbital floor
fracture should include palpation of the orbital rim for
bony defects or step-offs. Moreover, the presence of
hypoesthesia in the inferior orbital nerve distribution,
eyelid ecchymosis, subconjunctival hemorrhage should
be recognized.

13. Coronal CT with fracture through the left orbital floor with herniation
of the orbital fat and inferiorly displaced inferior rectus muscle.

14. Sagittal CT showing blow-out fracture with inferior
displacement of orbital content.

15. Periorbital ecchymosis and subconjunctival hemorrhage
following orbital fracture.

16. Left orbital floor fracture leads to inferior rectus muscle
entrapment.

17. If the patient does complain of visual changes, a thorough
ocular examination, including light projection, two-point
discrimination, and the presence of an afferent pupillary
defect should be performed. It is highly recommended to
obtain an ophthalmology consultation for further ocular
examination. Enophthalmos and exophthalmos can be
determined by viewing the profiles of the corneas from
over the brow. Enophthalmos can be seen after a large
orbital floor fracture because of the increase in orbital
cavity volume. Exophthalmos can be a presenting sign of
a retro-bulbar hematoma.

18. Posterior displacement of the globe.
Traumatic enophthalmos.

19. Traumatic exophthalmos,
proptosis was due to edema.

20. If extraocular muscle limitation is found, a forced duction
test under anesthesia should be performed to evaluate for
muscle entrapment. The examiner uses forceps to grasp
the conjunctiva near the attachment of the inferior rectus
muscle and attempts to move the globe through a full
range of motion. Restricted movements of the extraocular
muscles may result in diplopia and sometimes
oculocardiac reflex. The condition is manifested in
bradycardia, nausea, vomiting, and arrhythmia (11).

21. Forced duction test for evaluation of extraocular muscle
entrapment.

22. The oculocardiac reflex is thought to be caused by an
increase in vagal tone, with afferent signal being carried
by the ophthalmic division of the trigeminal nerve by
means of the ciliary ganglion, and the vagus nerve
carrying the efferent signals to the heart and stomach (12).
Nonresolution of these symptoms can be fatal. If severe,
the condition warrant immediate surgical exploration of
orbital floor fractures to reduce entrapped periorbital
tissues.

23. The timing of treatment is probably the most controversial
in the management of orbital blowout fractures. Generally,
treatment of orbital floor fractures can be divided into four
categories; conservative treatment, immediate surgical
intervention, early surgical intervention, and delayed
surgical intervention. It should be mentioned however, that
many orbital blowout fractures have no sequelae if they
are left untreated, however, others may result in diplopia,
enophthalmos, or even complete loss of vision if not
treated promptly and adequately. The decision to observe a
fracture or proceed with surgery is based however, on the
clinical examination findings, orbital imaging, and
assessment of the risk and benefit of either option.

24. Conservative treatment may be considered in cases of
small fractures without entrapment or diplopia.
Spontaneous clinical improvement has been documented
in patients with orbital blowout fractures who have been
treated conservatively. In a recent study, Young et al (13)
reported that a large proportion of patients showed
improvement in radiologic findings in terms of reduction
in orbital content herniation, and features of new bone
formation, despite being treated conservatively. They
further added that results showed improvement in clinical
findings of ocular motility restriction, diplopia, and
infraorbital hypoesthesia from initial to follow-up visit.

25. Immediate surgical repair (within 24–48 h) is highly
recommended for emergent conditions of diplopia with
radiological evidence of inferior rectus muscle or peri-
muscular soft tissue entrapment and a non-resolving
oculocardiac reflex. Immediate repair is also
recommended for “white-eyed blowout fractures,”(14) in
patients less than 18 years of age with vertical limitation
of eye movement and radiological evidence of inferior
rectus muscle or peri-muscular soft tissue entrapment.
Individuals with diplopia, limited versions, but without
radiological evidence of entrapment, should be monitored
closely 5–7 days after the injury and improvement should
be observed in 1–2 weeks. If the motility dysfunction does
not improve or stabilize, surgery should be considered (15).

26. Early repair within 2 weeks is recommended for a variety
of clinical settings; (1) Mechanical restriction of globe
mobility with a positive forced duction test of computed
tomography evidence of inferior rectus muscle or peri-
muscular soft tissue entrapment. (2) Large floor defect
typically is greater than half the surface in CT scan or with
prolapsed orbital soft tissue. (3) Clinical enophthalmos
(>2 mm) or hypophthalmos with serial examinations in
following 2 weeks and minimal clinical improvement.
Progressive infraorbital hypoesthesia also warrants early
intervention. In recent literature, early surgical repair has
been recommended because it was associated with better
outcomes (16).

27. Large orbital floor fracture greater than 50% of the surface,
warrants early intervention.

28. Longer delays decrease the likelihood of successful repair
of enophthalmos because of progressive scarring and fat
atrophy. Dulley and Fells (17) reported that 72% of the
patients operated upon greater than 6 months after the
injury developed residual enophthalmos. In contrast, only
20% of the patients operated within 14 days of trauma
developed enophthalmos. Of the early treated patients,
31% of those treated non-surgically due to lack of
symptoms or signs were left with permanent
enophthalmos or diplopia. More recently, however, Simon
et al (18), concluded that post-operative outcomes were
similar between those patients with orbital floor fractures
who had early repair when compared to those with late
repair.

29. Approaches to the repair of orbital floor fractures
include transcutaneous or transconjunctival approaches.
Traditionally, transcutaneous approaches, namely
subciliary, subtarsal, and infraorbital, have been employed
to access the orbital floor and infraorbital rim (19).
Subciliary incisions are performed through in the lower
eyelid 2 mm below the edge of the eyelid. The incision for
the subtarsal (also known as mid-lid) approach, is made 5
to 7 mm inferior to the lower lid margin. Whereas, the
infraorbital incision is made directly over the infraorbital
rim. Major drawbacks of these techniques are the esthetic
outcome and lower eyelid malposition (20).

30. Transcutaneous approaches;
A - subciliary,
B - subtarsal,
C - infraorbital.

31. Incisions used to expose the infraorbital rim; subciliary (dashed line)
and subtarsal incision (dotted line).

32. The transconjunctival approach is currently regarded as
the mainstream method for reduction of blowout fractures
of the inferior orbital wall. It is cosmetically preferred and
is performed by pulling the lower eyelid forward with the
incision made on the internal (conjunctival) surface of the
eyelid, thereby preserving the integrity of the orbital
septum and orbicularis muscle. Orbital floor fractures may
be reached through 2 types of conjunctival approaches, the
preseptal one and the retroseptal one. While the retroseptal
approach offers a more direct and easier route to the
orbital rim and floor, it is associated with a significantly
higher rate of lower lid complications compared to the
preseptal approach.

33. Compared to the transcutaneous approach the trans-
conjunctival approach is surgically similar in providing
adequate exposure and access to the orbital floor and
shows low rates of complications and leaves no visible
scar (21). However, this approach often requires lateral
canthotomy for complete exposure. Moreover, Holtmann
et al (22) confirmed the impressions that the technique
takes longer operating times compared with the dermal
approaches to the orbit. They concluded that trans-
conjunctival approach took almost 3 times longer to
perform and recommended the use of the subtarsal
approach.

34. Transconjunctival approach.

35. A recent comprehensive review of incision techniques
found insufficient high-level evidence to suggest one
pattern over another, but did show a low incidence of
complications with transconjunctival approaches, the
highest rate of complications and revisions in subciliary
approaches, and the lowest revision rate with subtarsal
incisions (21). Over the past three decades, both trans-
cutaneous and transconjunctival approaches have been
widely used in the management of orbital fractures.
However, there is still controversy regarding which is the
best surgical approach associated with the lowest rate of
lower lid malposition.

36. Several other approaches have been employed, these
include incisions via existing facial lacerations, upper
buccal sulcus, bicoronal, and Gillies incisions. More
recently, endoscopic approaches have been described.
Ducic and Verret (23) presented endoscopic transantral
repair of isolated orbital floor fractures. The technique
involves a standard Caldwell-Luc approach to the
maxillary sinus undertaken through a gingivobuccal
incision. They concluded that the technique represents a
precise method of fracture repair that results in excellent
outcomes with minimal morbidity in the majority of
patients. Further, it allows for immediate fracture repair
without the need to wait for periorbital edema to settle.

37. Endoscopic transantral
approach.

38. As an alternative, transantral endoscopic technique has
been described in the repair of orbital blow-out fractures
(24). Although the superiority of traditional versus
endoscope-assisted surgery of orbital fractures is unclear,
there are advantages to the use of endoscopes in select
cases. Such new or modified routes of access may provide
better exposure, improved morbidity and a more
minimally invasive surgery overall. These improvements
were designed to offer additional options for orbital
access.

39. Following exposure of the fracture site, reduction should
be attempted. Care is taken during elevation of soft tissue
and muscle that has prolapsed through the orbital floor
fracture. Gentle manipulation will prevent possible
disruption of the neurovascular structures, namely the
inferior orbital nerve. Forced duction test is performed to
ensure that there is no evidence of soft tissue
incarceration. Once full exposure and reduction is
achieved, the orbital floor can be reconstructed using a
variety of implant materials. Biological materials e.g. split
calvarial, rib, or iliac crest bone grafts offer the potential
advantages of better biocompatibility, but come at the cost
of donor site morbidity. Conversely, synthetic grafts have
the advantages of being readily available.

40. Alloplastic implants are available as restorbable or
nonresorbable plates , each with their own distinct
advantages and disadvantages. Resorbable alloplasts,
composed of polylactic acid , polyglycolic acid , or
composite polymers, are readily available and able to offer
long-term support to allow bony healing. However, they
may be associated with delayed enophthalmos and/or
intense inflammation as the implant degrades (25). An
added disadvantage of the current biodegradable materials
available to repair defects of the inferior orbital wall is the
premature loss of mechanical properties before the healing
process is complete.

41. Nonresorbable alloplasts offer long-term rigid support for
orbital floor reconstruction, but have a higher risk of
implant-associated infections. Porous polyethylene
(Medpore) is easy to mold and adapt and allows rigid
fixation and vascular ingrowth. Titanium mesh implants,
in contrast, are biocompatible and easy to contour, but are
not easy to place, especially with deep orbital fractures, as
the plate edges often catch on periorbital tissues. Titanium
also has a high ability to be osseointegrated into
surrounding tissues and is particularly useful for large
orbital floor fractures requiring significant rigidity and
strength. However, titanium can be associated with intense
fibrosis, making secondary surgery a challenge (26).

42. Reconstruction of orbital floor
using titanium mesh.

43. Postoperative coronal and sagittal CT scan showing
repositioning of the soft tissue in orbital floor and a
good adaptation of the titanium mesh.

44. Newer materials, consisting of titanium mesh coated with
porous polyethylene, are available and aim to capture the
strengths of both materials. It has the malleability, strength,
memory, and radiopacity of titanium, with the potential for
fibrous ingrowth of porous polyethylene. It is also coated
on one side to prevent inflammation and adhesion of
orbital tissue. A recent survey of practicing plastic
surgeons found that porous polyethylene/titanium and
titanium mesh were the two most commonly used
materials for orbital floor reconstruction (16).

45. Porous polyethylene/titanium implant with medial
and lateral wings for fixation.

47. 1. Shin JW, Lim JS, Yoo G, Byeon JH. An analysis of pure blowout fractures and associated
ocular symptoms. J Craniofac Surg; 24: 703, 2013.
2. Noda M, Noda K, Ideta S, Nakamura Y, et al. Repair of blowout orbital floor fracture by
periosteal suturing. Clin. Experiment. Ophthalmol; 39: 364, 2011.
3. Manolidis S, Weeks BH, Kirby M, Scarlett M, et al. Classification and management of
orbital fractures: experience with 111 orbital reconstructions. J Craniofac Surg; 13: 726,
2002.
4. Lee HJ, Jilani M, Frohman L, Baker S. CT of orbital trauma. Emerg Radiol; 10: 168,
2004.
5. Converse JM, Smith B. Blowout fracture of the floor of the orbit. Trans Am Acad
Ophthalmol Otolaryngol; 64: 676, 1960.
6. Lang W. Traumatic enophthalmos with retention of perfect acuity of vision. Trans
Ophthalmol Soc U K; 9: 41, 1889.
7. Smith B, Regan WF. Blow-out fracture of the orbit: Mechanism and correction of internal
orbital fracture. Am J Ophthalmol; 44: 733,1957.
8. Phalen JJ, Baumel JJ, Kapkin PA. Orbital floor fractures: A reassessment of pathogenesis.
Nebr Med J; 25: 100, 1990.
9. Ahmad F, Kirkpatrick NA, Lyne J, Urdang M, et al. Buckling and hydraulic mechanisms
in orbital blowout fractures: Fact or fiction? J Craniofac Surg; 17: 438, 2006.
10. Nagasao T, Miyamoto J, Jiang H, Tamaki T, et al. Interaction of hydraulic and buckling
mechanisms in blowout fractures. Ann Plast Surg. 64: 471, 2010.

48. 11. Kim BB, Qaqish C, Frangos J, Caccamese JF Jr. Oculocardiac reflex induced by an
orbital floor fracture: report of a case and review of the literature. J Oral Maxillofac
Surg; 70: 2614, 2012.
12. Sires BS, Stanley RB Jr, Levine LM. Oculocardiac reflex caused by orbital floor
trapdoor fracture: An indication for urgent repair. Arch Ophthalmol; 116: 955, 1998.
13. Young SM, Kim Y-D, Kim SW, et al. Conservatively treated orbital blowout
fractures: Spontaneous radiologic improvement. Ophthalmology; 125: 938, 2018.
14. Jordan DR, Allen LH, White J, et al. Intervention within days for some orbital
floor fractures: the white-eyed blowout. Ophthal Plast Reconstr Surg; 14: 379, 1998.
15. Lelli GJ, Milite J, Maher E. Orbital floor fractures: Evaluation, indications,
approach, and pearls from an ophthalmologist’s perspective. Fac Plas Surg; 23: 190,
2007.
16. Aldekhayel S, Aljaaly H, Fouda-Neel O, et al. Evolving trends in the management
of orbital floor fractures. J Craniofac Surg; 25: 258, 2014.
17. Dulley B, Fells P. Long-term follow-up of orbital blow out fractures with and
without surgery. Mod Probl Opthalmol; 14: 467, 1975.
18. Simon GJB, Syed HM, McCann JD, et al., 2008. Early versus late repair of orbital
blowout fractures. Ophthal. Surg. Lasers Imaging; 40: 141, 2009.
19. Wilson S, Ellis E III. Surgical approaches to the infraorbital rim and orbital floor :
The case for the subtarsal approach. J Oral Maxillofac Surg; 64: 104, 2006.

49. 20. Ridgway EB, Chen C, Colakoglu S, et al. The incidence of lower eyelid malposition
after facial fracture repair: a retrospective study and meta-analysis comparing subtarsal,
subciliary, and transconjunctival incisions. Plast Reconstr Surg; 124:1578, 2009.
21. Kothari NA, Avashia YJ, Lemelman BT, et al. Incisions for orbital floor exploration.
J Craniofac Surg; 23 (Suppl 1): 1985, 2012.
22. Holtmann B, Wray RC, Little AG: A randomized comparison of four incisions for
orbital fractures. Plast Reconstr Surg; 67: 731, 1981.
23. Ducic Y, Verret DJ. Endoscopic transantral repair of orbital floor fractures.
Otolaryngol Head Neck Surg; 140: 849, 2009.
24. Bonsembiante A, Luisa Valente L, Andrea Ciorba A, et al. Transnasal endoscopic
approach for the treatment of medial orbital wall fractures. Ann Maxillofac Surg; 9:
411, 2019.
25. Jank S, Emshoff R, Schuchter B, et al. Orbital floor reconstruction with flexible
Ethisorb patches: A retrospective long-term follow-up study. Oral Surg Oral Med Oral
Pathol Oral Radiol Endod; 95: 16, 2003.
26. Lee HB, Nunery WR. Orbital adherence syndrome secondary to titanium implant
material. Ophthal Plast Reconstr Surg; 25: 33, 2009.