ophthalmic and facial veins are not valveless

Original Article

Ophthalmic and facial veins are not valveless_ 502..510

John Zhang and Mark D Stringer MS FRCSDepartment of Anatomy and Structural Biology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand

ABSTRACT

Background: The ophthalmic and facial veins are fre-quently stated to be devoid of valves, facilitating thespread of infection from the mid-face to the cavern-ous sinus.

Methods: Twelve superior and eight inferior oph-thalmic veins together with 13 angular and facialveins were harvested from adult cadavers. Each veinwas opened longitudinally and examined by stere-omicroscopy; the number, location and geometry ofvalve cusps were recorded.

Results: Ten valves were identified in nine (75%)superior ophthalmic vein specimens: four valveswere in the superior ophthalmic vein and theremainder were located near its origin from angularand supra-orbital tributaries. No valves were seen inthe inferior ophthalmic vein. Seventeen bicuspidvalves were identified in tributaries of the angularvein or in the facial vein, but none were in theangular vein itself. Four of seven facial vein seg-ments extending to the lower border of the mandiblehad valves. The orientation of valve cusps predictedthe following blood flow: in the facial vein, inferi-orly; in the superior ophthalmic vein, towards thecavernous sinus; and in the angular vein, to thefacial or superior ophthalmic vein.

Conclusions: This study demonstrates, for the firsttime, the existence of valves in the superior oph-thalmic vein and its two main tributaries. Valveswere also seen in the facial vein. It is not the absenceof venous valves but the existence of communica-tions between the facial vein and cavernous sinusand the direction of blood flow that is important inthe spread of infection from the face.

Key words: cavernous sinus thrombosis, facial vein,ophthalmic vein, venous valve.

INTRODUCTION

According to modern clinical and anatomical refer-ence texts, the superior and inferior ophthalmicveins (IOVs)1–3 and the facial veins1,4–6 are devoid ofvalves. This is understood to facilitate the spread ofinfection from the mid-face, specifically from the‘dangerous triangle’ bounded by the bridge of thenose and angle of the mouth, which may lead tolife-threatening septic cavernous sinus thrombosis.Venous valves are now understood to be more wide-spread than previously believed. They can even befound in microscopic veins and venules.7 The aim ofthis study was to investigate whether there arevalves in the ophthalmic, angular and facial veinsand whether indeed the absence of valves is a factorthat predisposes to the intra-cranial spread ofinfection.

METHODS

Ophthalmic veins

Twelve intact orbits in eight cadavers (5 male, 3female; age range 44–91 years) with no macroscopicorbital pathology were dissected. The orbital roofwas carefully removed using rongeurs, exposing thefascial sheath of the eyeball and orbital fat. Thefrontal nerve, ophthalmic artery and superior oph-thalmic vein (SOV) were identified. The latter wasdissected along its length from its origin connectingwith the supra-orbital and angular veins, to the cav-ernous sinus (Fig. 1). Dissection was performedusing optical loupes (magnification ¥2.5) andmicroinstruments. Towards the apex of the orbit, thelevator palpebrae superioris and superior rectusmuscles were divided to expose the SOV and its

� Correspondence: Professor Mark D Stringer, Department of Anatomy and Structural Biology, Otago School of Medical Sciences, University of Otago,

PO Box 913, Dunedin 9054, New Zealand. Email: [email protected]

Received 24 January 2010; accepted 26 April 2010.

Clinical and Experimental Ophthalmology 2010; 38: 502–510 doi: 10.1111/j.1442-9071.2010.02325.x

© 2010 The AuthorsJournal compilation © 2010 Royal Australian and New Zealand College of Ophthalmologists

connection with the IOV. The latter was traced ante-riorly until it was replaced by a network of minuteveins. Small tributaries of the SOV, such as lacrimaland muscle branches, were divided.

The SOV was harvested in continuity with tribu-taries connecting with the supra-orbital and angularveins, the IOV (when present) and its junction withthe cavernous sinus. Each vein was then openedlongitudinally, under a Nikon SMZ 445 stereomicro-scope at magnification ¥10, and the edges werepinned out on to a cork board using stainless steelinsect pins (Fine Science Tools Inc., Foster City, CA,USA) (Fig. 2). The lumen of the vein was examinedunder the dissection microscope at up to ¥35 mag-nification and the following measurements were

taken with electronic digital calipers (Tresna, Guilin,China; accuracy � 0.03 mm): the length of the SOVfrom its origin (union of supra-orbital and angulartributaries or from point of emergence from thefrontal bone if only a single root was present) to itstermination (junction with the cavernous sinus); thecircumference of the SOV at its origin and termina-tion; and the circumference and length of majortributaries. The number, location and geometry ofany valve cusps were also recorded; the pocket depthof three larger valves was measured. Representativephotographs were taken using a Canon G10 digitalcamera fitted with a Canon LA-DC58K microscopelens adaptor.

Angular and facial veins

The angular vein, external nasal vein and facial veinwere harvested in continuity from sides of the facethat had not been extensively dissected previouslyin the eight cadaver specimens above-mentioned andin an additional four cadavers (3 male, age range71–87 years). The length of facial vein that was har-vested was variable as a result of previous dissectionin some cases. Dissection began with the angularvein medial to the medial canthus of the eye, whichwas then traced caudally.

We also had access to a single fresh cadaver(49 years, female) that had been injected with Bat-son’s resin through the internal carotid artery. Theresidual vascular resin cast demonstrated some fillingof orbital veins and these were examined further.

Infra-orbital veins

During our dissections, it became apparent that therewas no readily identifiable infra-orbital vein. Conse-quently, the infra-orbital neurovascular bundle wasremoved intact from its canal by a trans-maxillaryapproach. The samples were post-fixed in 10%neutral buffered formalin overnight, embedded inparaffin, sectioned (3 mm) and stained with Verhoeff-Van Gieson’s stain before viewing on an OlympusBX51 light microscope (original magnification ¥40).

Cadaver specimens

All cadaver specimens were obtained in accordancewith the New Zealand Human Tissue Acts (1964,2008) and embalmed with a phenoxyethanol mix orwith Dodge anatomical mix (Dodge Anatomical,Dodge Co., Cambridge, MA, USA).

RESULTS

Ophthalmic veins

A total of 12 SOVs and eight IOVs were analy-sed (Table 1). The mean length of SOV was

Figure 1. Left superior ophthalmic vein in a cadaver afterpartial removal of surrounding orbital fat. A, anterior; P, poste-rior; L, lateral; M, medial.

Figure 2. Opened superior ophthalmic vein with inferior oph-thalmic tributary after harvesting and pinning out ontocorkboard. A, anterior; P, posterior; L, lateral; M, medial.

Ophthalmic and facial vein valves 503


49.2 � 16.2 mm. Its mean diameter at origin and ter-mination was 1.4 � 0.7 mm and 1.8 � 0.5 mm, res-pectively. The diameter of the smallest SOV was0.6 mm at its origin. Seven SOVs originated from theunion of tributaries communicating with both theangular and supra-orbital vein. Three SOVs origi-nated solely from a communicating branch to thesupra-orbital vein and two SOVs had a single originfrom the communicating branch to the angular vein.

No valves were identified in the IOV segments.Ten valves were identified in nine (75%) of the 12SOV specimens. Four of these valves were in theSOV and the remaining were located near the originof the SOV in the angular and supra-orbital veintributaries. Also present were juxtaostial endolumi-nal folds (termed unicuspid ‘valves’ by Maros8) atsome junctions between the SOV and its sidebranches; these were not recorded. The majority ofvalves were bicuspid but two in the tributaries ofone SOV were tricuspid. In all cases the directionof blood flow indicated by the orientation of thevalve cusps was towards the cavernous sinus. All ofthe SOV valves were within 10 mm of the origin ofthe SOV (Fig. 3). Valve pocket depth varied between0.5 and 0.7 mm in the three different valves wemeasured.

In four cadavers we were able to harvest bilateralSOVs. In two of these, valves were present bilater-ally in either the SOV or its communicating brancheswith the angular and supra-orbital veins, and in theother two valves were present on one side only.

Angular and facial veins

A total of 13 angular veins were retrieved from 10cadavers; an external nasal tributary was present in

10 (77%) cases. The angular vein becomes the facialvein at its junction with the superior labial vein,3 butthe latter is not invariably present and so, for thepurposes of our measurements, the facial vein supe-rior to the external nasal tributary was taken as theangular vein, and its caudal continuation the facialvein. In the 10 specimens with an external nasal veintributary, the mean length of the angular vein was19.1 � 5.5 mm and the mean length of the externalnasal vein was 13.2 � 5.8 mm. The mean diameter of

Table 1. Ophthalmic vein results

Specimen Length ofSOV (mm)

Length ofIOV (mm)

No. of valvesin SOV

Distance of valve(s) tocavernous sinus (mm)

Direction ofblood flow

1 65.7 9.5 0 NA2 60.0 7.2 1 53.5 Towards CS3 52.6 13.6 1 42.9 Towards CS4 54.4 31.7 1 54.0 Towards CS5 34.2 – 0 NA6 47.1 – 1 37.2 Towards CS7 47.8 – 2 49.5, 49.8 Towards CS8 50.6 5.4 1 50.6 Towards CS9 52.0 26.8 0 NA

10 43.9 9.7 1 54.6 Towards CS11 47.7 6.0 1 47.7 Towards CS12 33.9 – 1 34 Towards CSMean � SD 49.2 � 16.2 13.7 � 9.8 0.9 � 0.5 47.4 � 7.1

NB. Some of the valves to CS distances exceed the measured length of the SOV because the valves were near the termination of thecommunicating branches with the angular and supra-orbital veins. –, no data; CS, cavernous sinus; IOV, inferior ophthalmic vein; NA, notapplicable; SD, standard deviation; SOV, superior ophthalmic vein.

Figure 3. Axial valve in superior ophthalmic vein consistentwith blood flow towards cavernous sinus. A, anterior; P, poste-rior; L, lateral; M, medial.

504 Zhang and Stringer


the origin of the angular vein (formed by the unionof supratrochlear and supra-orbital veins)6 was1.3 � 0.8 mm and the mean length of available facialvein was 48.7 � 53.0 mm. In the three specimenswithout an identifiable external nasal tributary andno obvious demarcation between the angular andfacial vein, the mean length of vein studied was104.6 � 29.0 mm.

A total of 17 valves, all bicuspid, were identifiedin these specimens. Six axial valves were found inthe external nasal vein, at a mean distance of 2.4 �0.5 mm from its termination, and five in other tribu-taries of the angular vein near their junction (Fig. 4).Four of seven facial vein segments extending to thelower border of the mandible had valves; these weremostly clustered around the level of the body of themandible (Fig. 5).

The direction of blood flow indicated by theorientation of the valve cusps is shown in Figure 4.For supra-orbital, supratrochlear and external nasalveins this was towards the angular vein. For thefacial vein, the direction of blood flow was inferiorlytowards the internal jugular vein.

In nine cadavers, the SOV, angular and facial veinswere all harvested. Four had both intra-cranial andextra-cranial valves and four had either intra-cranialor extra-cranial valves; only one cadaver had anabsence of valves in the veins sampled.

The single vascular cast clearly showed a bicuspidvalve in the angular tributary of the SOV (Fig. 6).The direction of the cusps indicated blood flow

towards the cavernous sinus, consistent with theresults of our microdissection study.

Infra-orbital veins

A total of 11 infra-orbital neurovascular bundleswere examined histologically. The number of mus-cular veins identified in each specimen ranged from3–84. The diameter of the largest vein was 0.7 mmin a specimen with eight other veins within the

Figure 4. Schematic representa-tion of valve locations and arrowsshowing predicted direction ofblood flow. Small superior oph-thalmic vein tributaries such as lac-rimal and muscle branches are notshown for simplicity. IOV, inferiorophthalmic vein; SOV, superiorophthalmic vein.

Figure 5. Bicuspid axial valve in the facial vein consistent withcaudal blood flow towards the internal jugular vein. I, inferior;L, lateral; M, medical; S, superior.



neurovascular bundle. The majority of the veinscould be considered as either venae comitantes orvasa vasora and vasa nervora (Fig. 7).

DISCUSSION

Three main findings emerge from this study. First,the superior ophthalmic veins are not devoid ofvalves as stated in major reference texts.1–3 Ourstudy demonstrates, for the first time, the presenceof valves in the SOV and its two main tributaries,the communicating branches from the angular andsupra-orbital veins. Valves were present in 75% ofthis sample of 12 SOVs. In almost all cases thegeometry of the valve cusps would predict bloodflow towards the cavernous sinus. Second, despitethe persistent assertion that the facial vein isvalveless,1,4–6 we can confirm the existence ofvenous valves in the facial vein, corroborating aprevious study from Japan.9 Our study alsorevealed the presence of previously unknownvalves within the supra-orbital and supratrochleartributaries of the angular vein, all of which werecompatible with venous drainage to the facial vein.Finally, we found no evidence of a discrete infra-orbital vein within the infra-orbital canal asdescribed in anatomy reference texts.3,10 Instead, wefound multiple small veins. Interestingly, Terminolo-gia Anatomica lists the supra-orbital vein but there isno entry for an infra-orbital vein.11 Our study islimited by a relatively small sample size dictated bythe availability of cadavers but a larger number of

specimens is unlikely to substantially change ourfindings.

The anatomy of ophthalmic andfacial veins

The SOV is generally described as being formed atthe superomedial margin of the orbit immediatelyposterior to the trochlea from the union of twocontributing ‘roots’: a superior root from thesupra-orbital vein that enters the orbit through thesupra-orbital notch/foramen, and an inferior rootfrom a branch of the angular vein that pierces theorbital septum.12–14 The course of the SOV withinthe orbit is relatively constant,13,14 passing posteri-orly within the orbital fat to the medial border ofthe superior rectus muscle15 and then posterolater-ally under the superior rectus muscle above theoptic nerve, before continuing along the lateralborder of the superior rectus muscle through thesuperior orbital fissure to the cavernous sinus;12,14

the vein traverses the orbit along a connectivetissue septum located just below the superior rectusmuscle.16 The SOV may pass through14 or outsidethe common tendinous ring.17 Our findings are con-sistent with this description except that five of 12SOVs in our study arose from a single root, eitherfrom the supra-orbital or angular vein. A similarvariation has been reported previously.14

The IOV is formed by small tributaries in the floorof the mid-orbit above the inferior rectus muscle andinferior to the optic nerve.14,15 It passes posteriorly

Figure 6. Vascular resin cast showing a biscuspid valve (arrows) in the angular tributary of the superior ophthalmic vein. I, inferior;L, lateral; M, medical; S, superior.



along the lateral border of the inferior rectus muscle,receiving numerous branches before joining theSOV, which drains into the cavernous sinus.17 Thiswas the pattern in our samples. Rarely, the IOV candrain directly into the cavernous sinus.18 A connect-ing vein passes through the inferior orbital fissure tothe pterygoid plexus in about 50% of individuals.3,19

The angular vein is formed by the union of thesupra-orbital and supratrochlear veins, and runs infe-riorly across the nasal margin of the medial palpebralligament approximately 8 mm from the medialcanthus of the eye.20 It communicates directly with theSOV and becomes the facial vein at its junction withthe superior labial vein.3 Thus, the orbital veins haveabundant connections with extra-orbital veins.

Venous valves in the facial andophthalmic veins

In a microdissection study of facial veins in 20cadavers, Nishihara et al. found a total of 222 valvesbetween the medial angle of the eye and the inter-nal jugular vein.9 Valves were concentrated aroundthe lower border of the mandible and were fre-

quently related to branches or junctions; none werefound in the angular vein. An average of threevalves was seen in each cadaver facial vein and94% were bicuspid. At least one valve was foundin every cadaver. In a qualitative follow-up study,the same group of authors investigated facial veinsin 13 adult cadavers using vascular resin corrosioncasts and scanning electron microscopy.21 Valveswere identified in the lingual, labial and facialveins; all were bicuspid. In a similar but larger dis-section study of cadaver facial veins, Molinari et al.reported similar results to the Japanese study,except that valves could not be found in the facialvein in 18% of cases.22 Our results confirm thatthere are valves in the facial vein, particularlyaround the level of the mandible. We found novalves in the angular vein but numerous valveswere seen in its tributaries.

Previous studies have suggested that there are novalves in the human pterygoid venous plexus23 orin the emissary veins of the skull connecting intrac-ranial venous sinuses with extracranial veins.21 Ourresults indicate that for some emissary veins at leastthis is wrong.

Figure 7. Photomicrograph of infra-orbital neurovascular bundle at original magnification ¥12.5 and ¥40 (Verhoeff-Van Gieson stain).Muscular veins have been labelled with a ‘V’ in the lumen.



Direction of venous blood flow

The direction of venous flow in the SOV has longbeen contentious, some authors arguing that bloodflow was towards the face,24 others that flow wastowards the cavernous sinus,18 and still others thatblood flow may be bidirectional.25,26 Studies usingorbital venography have yielded conflictingresults12,27 although, in most cases, SOV filling canoccur from the angular vein.12,28

Erickson et al. used colour Doppler flow imagingto examine 26 normal orbits in 16 supine subjects.29

The SOV was seen in 22 orbits, with blood flowtowards the cavernous sinus. In six subjects whowere asked to perform a Valsalva manoeuvre,transient retrograde flow (away from cavernoussinus) was seen during the manoeuvre associatedwith distention of the SOV, followed by absentflow, and then accentuated antegrade flow after ces-sation of the manoeuvre; these observations areconsistent with competent valves near the origin ofthe SOV. Both Lieb and Chen et al. examinednormal orbits in supine adults and found bloodflow with a mean maximum velocity of about7.8 cm/s towards the cavernous sinus.30,31 The influ-ence of gravity on the direction of blood flow wasnot discussed in these papers. A physiologicalstudy appeared to contradict these findings suggest-ing that flow was bidirectional, dominantlytowards the face in normothermic conditions andtowards the cavernous sinus in hyperthermia.32 Thedistribution of venous valves in our study suggeststhat blood flow is: (i) caudal towards the internaljugular vein in the inferior part of the facial vein;(ii) normally towards the cavernous sinus in theSOV; and (iii) into either the facial vein or the SOVfrom the angular vein.

The ‘dangerous triangle’ and theintra-cranial spread of facial infection

Spread of infection from the face to the cavernoussinus was described in 1852.33 Treves subsequentlyemphasized the route of spread via venous commu-nications with the facial vein.34 He also consideredthat the absence of valves in the facial vein was afactor in the spread of infection, a view that becameentrenched in the literature by 1922 and extended toinclude the angular and ophthalmic veins.35 Theclinical concept of a ‘dangerous triangle’ was popu-larized by Maes who considered that there was atriangular-shaped region extending from ‘the anglesof the mouth to the bridge of the nose’, critical to thespread of infection from the face to the intracranialvenous sinuses.36 Maes argued that the spread ofinfection was because the facial veins are in directcommunication with the cavernous sinus via the

pterygoid plexus, angular and ophthalmic veins; theabsence of valves in the facial veins facilitated thisprocess.36 This concept remains popular even inmodern clinical and anatomical texts.1,2,5,6 However,our study demonstrates that the facial and SOVs dopossess valves. Thus, it is not the absence of venousvalves but the consistent communication betweenthe facial vein and cavernous sinus that is importantin the spread of infection. This communication canbe via the angular and SOV, or via the deep facialvein, pterygoid plexus and then the IOV or emissaryveins in the foramen ovale.

If the absence of venous valves was important inthe spread of infection from the face then infectionwould only occur in valveless individuals or viavalveless veins such as the IOV. This is unlikely forseveral reasons. Firstly, in none of the 20 cadaversstudied by Nishihara et al. were valves completelyabsent.9 Secondly, there is no known associationbetween cavernous sinus thrombosis and othervenous disorders related to congenital absence ofvenous valves which is very rare. Finally, the largest,most consistent and direct communication betweenthe facial veins and the cavernous sinus is via theSOV.

In the pre-antibiotic era, spread of infection fromthe dangerous triangle was one of the commonestcauses of septic cavernous sinus thrombosis.37 Thisremains an important source in economically poorercountries.38 However, in recent years, the sphenoidand ethmoid sinuses have become more frequentprimary sites of infection.39–41 Indeed, the potentialprimary source of septic cavernous sinus thrombo-sis encompasses a much wider catchment area ofinfection sites in addition to the ‘dangerous tri-angle’. This includes the nasal cavity,42 paranasalsinuses,38,43 middle ear, tonsils and soft palate37 andupper teeth.44,45

ACKNOWLEDGEMENTS

We wish to thank Associate Professor Greg Jones(Dunedin School of Medicine) for the image of thevascular corrosion cast, Robbie McPhee, MedicalIllustrator and Graphic Artist (Dunedin School ofMedicine), for his expertise with Figure 5, andMandy Fisher (Histology Services Unit, DunedinSchool of Medicine) for her assistance withhistology. JZ was supported by an Otago MedicalResearch Foundation Summer Scholarship.

REFERENCES

1. Rosse C, Gaddum-Rosse P. Hollinshead’s Textbook ofAnatomy, 5th edn. Philadelphia, PA: Lippincott-Raven,1997; 756.



2. Snell RS, Lemp MA. Clinical Anatomy of the Eye, 2nd edn.Oxford: Blackwell Science Inc., 1998; 286–9.

3. Standring S, ed. Gray’s Anatomy: the Anatomical Basis ofClinical Practice, 40th edn. Edinburgh: Churchill Living-stone, 2008; 492, 656, 666.

4. Goldenberg D, Karam M, Netzer A et al. Facial veinthrombophlebitis: a rare but potentially lethal entity.Otolaryngol Head Neck Surg 2000; 122: 769–71.

5. Drake RL, Vogl AW, Mitchell AWM. Gray’s Anatomy forStudents, 2nd edn. Baltimore, MD: Lippincott Williams& Wilkins, 2010; 871.

6. Moore KL, Dalley AF, Agur AMR. Clinically OrientedAnatomy, 5th edn. Baltimore, MD: Lippincott Williams& Wilkins, 2006; 857–8, 875.

7. Caggiati A, Phillips M, Lametschwandtner A, AllegraC. Valves in small veins and venules. Eur J Vasc Endo-vasc Surg 2006; 32: 447–52.

8. Maros T. Data regarding the typology and functionalsignificance of the venous valves. Rom J MorpholEmbryol 1981; 27: 195–214.

9. Nishihara J, Takeuchi Y, Miki T, Itoh M, Nagahata S.Anatomical study on valves of human facial veins.J Craniomaxillofac Surg 1995; 23: 182–6.

10. Dalley AF, Agur AMR. Grant’s Atlas of Anatomy, 12thedn. Baltimore, MD: Lippincott Williams & Wilkins,2008; 656.

11. Federative Committee on Anatomical Terminology.Terminologia Anatomica. Stuttgart: Thieme, 1998; 93.

12. Brismar J. Orbital phlebography II. Anatomy of supe-rior ophthalmic vein and its tributaries. Acta RadiolDiagn 1974; 15: 481–96.

13. Bergen M. A literature review of the vascular system inthe human orbit. Acta Morphol Neerl-Scand 1981; 19:273–305.

14. Cheung N, McNab AA. Venous anatomy of the orbit.Invest Ophthalmol Vis Sci 2003; 44: 988–95.

15. Henry JGM. Contribution à l’étude de l’anatomie desvaisseaux de l’orbite et de la loge caverneuse – parinjection de matieres plastiques – du tendon de Zinn etde la capsule de Tenon. Thèse de Paris; 1959.

16. Ettl A, Koornneef L, Daxer A, Kramer J. High-resolution magnetic resonance imaging of the orbitalconnective tissue system. Ophthalmic Plast Reconstr Surg1998; 14: 323–7.

17. Spektor S, Piontek E, Umansky F. Orbital venousdrainage into the anterior cavernous sinus space:microanatomic relationships. Neurosurgery 1997; 40:532–40.

18. Natori Y, Rhoton ALJ. Microsurgical anatomy of thesuperior orbital fissure. Neurosurgery 1995; 36: 762–75.

19. Gurwitsch M. Üeber die anastomosen zwischen dengesichts- und orbitalvenen. A v Graefes Arch Ophthalmol1883; 29: 31–83.

20. Wolff E. Anatomy of the Eye and Orbit, 6th edn. London:H. K. Lewis & Co. Ltd., 1968; 413–15.

21. Miyake M, Ito M, Nagahata S, Takeuchi Y, Fukui Y.Morphological study of the human maxillofacialvenous vasculature: examination of venous valvesusing the corrosion resin cast technique. Anat Rec 1996;244: 126–32.

22. Molinari S, Navarro J, Hubner de Miranda-Neto M,Chopard R, Didio L. Morphology and incidence ofvalves in the facial vein of humans. Rev Chil Anat 2000;18: 103–7.

23. Racz L, Maros TN, Maros TG. Some aspects of con-cerning the peculiarities of the pterygoid venousplexus in man related to age. Morphol Embryol 1984; 30:11–16.

24. Sesemann E. Die orbitalvenen des menschen und ihrzusammenhang mit den oberflachlichen venen deskopfes. Arch Anat Physiol Wiss Med 1869; 2: 154–73.

25. Festal AF. Recherches anatomiques sur les veines del’orbite. Thèse de Paris; 1887.

26. Whitnall S. Anatomy of the Human Orbit and AccessoryOrgans of Vision, 1921 edn. New York: Robert E KriegerPublishing Company Inc., 1979; 310–19.

27. Hanafee WN. Orbital venography. Radiol Clin North Am1972; 10: 63–81.

28. Tornow K, Piscol K. The evaluation of the superiorophthalmic vein on the carotid angiogram. Neuroradi-ology 1971; 2: 30–4.

29. Erickson S, Hendrix L, Massaro B et al. Color Dopplerflow imaging of the normal and abnormal orbit. Radi-ology 1989; 173: 511–16.

30. Lieb W. Color Doppler imaging of the eye and orbit.Radiol Clin North Am 1998; 36: 1059–71.

31. Chen CC, Luo CL, Wang SJ et al. Colour Dopplerimaging for diagnosis of intracranial hypotension.Lancet 1999; 354: 826–9.

32. Hirashita M, Shido O, Minoru T. Blood flow throughthe ophthalmic veins during exercise in humans. Eur JAppl Physiol 1992; 64: 92–7.

33. Ludlow H. On carbuncular inflammation of lips andother parts of face. Med Times 1852; 5: 287–90.

34. Treves F. Surgical Applied Anatomy. Philadelphia, PA:Lea Brothers & Co, 1888; 99.

35. Wheeler WI. The danger of sepsis about the lips. Ir JMed Sci 1926; 1: 369–71.

36. Maes U. Infections of the dangerous areas of the face.Ann Surg 1937; 106: 1–10.

37. Southwick F, Richardson EPJ, Swartz M. Septicthrombosis of the dural venous sinuses. Medicine 1986;65: 82–106.

38. Thatai D, Chandy L, Dhar K. Septic cavernous sinusthrombophlebitis: a review of 35 cases. J Indian MedAssoc 1992; 90: 290–2.

39. Watkins LM, Pasternack MS, Banks M, Kousoubris P,Rubin PAD. Bilateral cavernous sinus thromboses andintraorbital abscesses secondary to Streptococcus milleri.Ophthalmology 2003; 110: 569–74.

40. Absoud M, Hikmet F, Dey P, Joffe M, Thambapillai E.Bilateral cavernous sinus thrombosis complicatingsinusitis. J R Soc Med 2006; 99: 474–6.

41. Goawalla A, Mansell N, Pearson A. Septic cavernoussinus thrombosis with bilateral secondary orbitalinfection. Orbit 2007; 26: 113–16.

42. Sanchez T, Cahali M, Murakami M, Butugan O,Miniti A. Septic thrombosis of orbital vessels due tocutaneous nasal infection. Am J Rhinol 1997; 11: 429–34.



43. Ebright JR, Pace MT, Niazi AF. Septic thrombosis ofthe cavernous sinuses. Arch Intern Med 2001; 161:2671–6.

44. Pavlovich P, Looi A, Rootman J. Septic thrombosis ofthe cavernous sinus: two different mechanisms. Orbit2006; 25: 39–43.

45. Udaondo P, Garcia-Delpech S, DÃaz-Llopis M, SalomD, Garcia-Pous M, Strottmann JM. Bilateral intraor-bital abscesses and cavernous sinus thromboses sec-ondary to Streptococcus milleri with a favorable outcome.Ophthal Plast Reconstr Surg 2008; 24: 408–10.



ophthalmic and facial veins are not valveless

Documents