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The cranio-orbital foramen, the groove on the lateral wall of the human orbit, and the orbital branch of the middle meningeal artery.

The cranio-orbital foramen, a foramen in the lateral wall of the orbit, contains an anastomosis between the anterior branch of the middle meningeal artery and the lacrimal artery. Previous workers have speculated that the groove starting either from the cranio-orbital foramen or the lateral extremity of the superior orbital fissure contains the anastomotic artery. We investigated the cranio-orbital foramen and the groove on the lateral wall of the orbit in a series of 170 dried adult human skulls, and the course of the orbital branch of the middle meningeal artery in 74 specimens from 37 cadavers. We observed the cranio-orbital foramen in 141 skulls (82.9%). It was unilateral in 55 (32.4%) and bilateral in 86 (50.6%) skulls. The groove on the lateral wall of the human orbit was observed in 122 skulls (71.8%). It was unilateral in 40 (23.5%) and bilateral in 82 (48.2%). The groove on the lateral wall of the orbit started from the cranio-orbital foramen in 20 skulls (11.8%). The orbital branch of the middle meningeal artery was found in 48 cadaveric specimens (64.9%): 32 (43.2%) passed through the cranio-orbital foramen and 12 (16.2%) passed through the superior orbital fissure. In four specimens (5.4%), orbital branches of the middle meningeal artery passed through both the superior orbital fissure and the cranio-orbital foramen. The anatomy of the cranio-orbital foramen and the course of the orbital branch should be well known by surgeons reconstructing the anterior base of the skull, the orbit after orbital base surgery, and during excision of meningiomas.

Cadaver↗

Rethinking orbital imaging establishing guidelines for interpreting orbital imaging studies and evaluating their predictive value in patients with orbital tumors.

PURPOSE: To establish guidelines for interpretation of orbital imaging by magnetic resonance imaging (MRI) and/or computed tomography (CT), and to apply these guidelines and examine their predictive value in 131 patients with biopsy-proven orbital tumors. DESIGN: Prospective evaluation of imaging studies. PARTICIPANTS: Imaging studies (CT and/or MRI) from 131 cases with biopsy-proven orbital tumors. METHODS: Guidelines for reviewing orbital imaging studies (MRI and/or CT) were established based on 5 major characteristics: (1) anatomic location, (2) bone and paranasal sinuses involvement, (3) content, (4) shape, and (5) associated features. In total, 84 features were established by an experienced orbital surgeon and a neuroradiologist. Applying these 84 features, imaging studies of 131 biopsy-proven orbital tumors were evaluated by 3 physicians. MAIN OUTCOME MEASURES: Imaging features: characteristics, sensitivity, specificity, and positive and negative predictive values in various groups of orbital tumors and kappa values. RESULTS: One hundred thirty-one cases of biopsy-proven orbital tumors were evaluated. Benign lesions were more likely to be smaller in size, round or oval in shape (29% of all benign tumors, 0% in malignant and inflammatory, P<0.001), and associated with hyperostosis (22% of all benign lesions, P<0.001). They were also more likely to be hyperdense or hypodense on CT imaging (15% and 11%, respectively; P<0.05 in comparison with inflammatory and malignant tumors). Inflammatory processes showed panorbital involvement (23% vs. 3%, and 0% in benign and malignant tumors, respectively; P<0.001). Orbital fat involvement and fat stranding were noticed only in inflammatory lesions (19% and 16%, respectively; P<0.001). None of the features occurred only in malignant tumors, but they tend to involve the anterior orbit more commonly (54% vs. 20%, and 29% in benign and malignant; P = 0.002), and were more likely to show bone erosion (31% vs. 6%, and 16% in benign and inflammatory tumors, respectively; P = 0.004) and molding around orbital structures (29% vs. 3% in benign, and 0% in inflammatory tumors, respectively; P<0.001). Features such as panorbital involvement, orbital fat, frontal sinus opacity, molding around orbital structures, perineural involvement, and fat stranding had specificity of 97% to 100%, but low sensitivity. CONCLUSIONS: Guidelines for analysis of orbital imaging studies (CT or MRI) are suggested. Based on these guidelines several imaging features showed significantly different occurrences in benign, malignant, and inflammatory processes; although this can help in differential diagnosis, tissue diagnosis may still be required.

Adult↗

The lacrimal keyhole, orbital door jamb, and basin of the inferior orbital fissure. Three areas of deep bone in the lateral orbit.

OBJECTIVES: To calculate the volume of bone in 3 areas of the deep lateral orbit that are available for removal in decompression surgery and to demonstrate these 3 areas within a 3-dimensional computed tomographic reconstruction of the orbit. DESIGN: The 3 areas of bone in the deep lateral orbit were designated the lacrimal keyhole, the sphenoid door jamb, and the basin of the inferior orbital fissure. By means of digitized computed tomographic scans, these 3 areas of bone were analyzed by measuring preoperative and postoperative orbital volumes and predicted bony expansion volumes in 9 patients (17 orbits) who underwent deep lateral orbital decompression surgery. We also calculated the volume of bone that could be removed from 11 normal orbits. A 3-dimensional computer reconstruction of an orbital computed tomographic scan was created, and the 3 areas of potential bone were delineated within it. RESULTS: The average volumes of the basin of the inferior orbital fissure, the sphenoid door jamb, the lacrimal keyhole, and the total of the 3 regions were 1.2, 2.9, 1.5, and 5.6 cm3, respectively. The 3 areas of bone contributed variably to the total, with the door jamb contributing the most volume of the 3, nearly twice the value of the other 2. There was, however, a significant amount of interpatient variability, especially for the door jamb region. CONCLUSION: Orbital decompression surgery of the deep lateral wall can provide adequate volume expansion because of the amount and location of potential space that exists in the 3 areas of deep bone.

Adult↗

The effect of buphthalmos on orbital growth in early childhood: increased orbital soft tissue volume strongly correlates with increased orbital volume.

PURPOSE: Our purpose was to evaluate the effect of increased orbital soft tissue volume on orbital growth. METHOD: Patients with unilateral or significantly asymmetric bilateral buphthalmos as determined by axial computed tomography scan were recruited. Volumetric determinations of the bony orbit with use of axial 1.5 mm sections on computed tomography were undertaken. Statistical analysis of the paired ocular length measurement and bony orbital volume measurements for each patient were performed. RESULTS: Eight patients (mean age 41 months) with a 15% or greater difference in axial length were enrolled. The mean axial length of the buphthalmic globes was 23% greater than that of the contralateral globes. Orbits harboring a buphthalmic globe had an orbital volume 11% greater than on the contralateral side. CONCLUSION: Increased orbital soft tissue volume as evidenced by buphthalmos was significantly associated with enlarged bony orbital volume. This indicates that soft tissue volume is a determinant of orbital volume and suggests that orbital tissue expanders might enhance bony development in patients with anophthalmos or microphthalmos and after early enucleation.

Bone Development↗

[Orbital diameter, inner and outer orbital distance. A growth model of fetal orbital measurements].

AIM: Aim of this study was to establish a growth model for the intrauterine growth of the following fetal parameters: orbital diameter, interorbital and biocular diameters. METHOD: Data were measured in a prospective cross-sectional study with real-time ultrasound. The study group consisted of 1090 healthy fetuses between 12 and 41 weeks gestation. For curve standardisation a growth model for all parameters was used. RESULTS: Using this growth model growth profiles (5., 50., and 95. percentiles) were established. All orbital parameters showed a nonlinear growth. CONCLUSION: Since ocular and orbital malformations (anophthalmia, microphthalmia, hypo- and hypertelorism) are often principal signs of generalised syndromes, orbital biometry is helpful for a detailed prenatal investigation of the fetal face. This is demonstrated in 2 cases with an orbital malformation (orbital hypoplasia, hypotelorism).

Cephalometry↗

Autogenous orbital reconstruction in a child with congenital abnormalities of the orbital roof and vertical orbital dystopia.

Congenital anomalies of the orbital roof are rare occurrences. The case of a 2-year-old child with vertical orbital dystopia and abnormalities of the right bony orbit is presented. The patient underwent right orbital reconstruction to restore facial symmetry. A coronal approach with a frontal craniotomy was used for intracranial exposure. The abnormal angulation of the roof was corrected, and the defect was reconstructed with a split-calvarial bone graft harvested from the parietal region. The bone graft was secured with resorbable plate fixation. To preserve vision, reconstruction of this type must be done at an early age, preferably before the age of 4 years. In this patient, there is good facial symmetry and normal globe positioning 5 years after surgery.

Bone Transplantation↗

Orbital socket contracture: a complication of inflammatory orbital disease in patients with Wegener's granulomatosis.

AIM: To describe the clinical characteristics of orbital socket contracture in patients with Wegener's granulomatosis (WG). METHODS: A retrospective cohort study The medical records of 256 patients with WG examined at the National Institutes of Health from 1967 to 2004 were reviewed to identify patients with orbital socket contracture. Details of the orbital disease including Hertel exophthalmometry readings, radiological findings, and results of eye examinations were recorded. Orbital socket contracture was defined as orbital inflammation with proptosis followed by the development of enophthalmos and radiographic evidence of residual fibrotic changes in the orbit. To examine for risk factors in the development of a contracted orbit, patients with orbital socket contracture were compared to patients without contracture with respect to multiple variables including history of orbital surgery, orbital disease severity, and major organ system involvement. The main outcome measures were the clinical characteristics of orbital socket contracture associated with inflammatory orbital disease in patients with WG. RESULTS: Inflammatory orbital disease occurred in 34 of 256 (13%) patients and detailed clinical data on 18 patients were available and examined. Orbital socket contracture occurred during the clinical course in six patients; the features included restrictive ophthalmopathy (five), chronic orbital pain (three), and ischaemic optic nerve disease (two) resulting in blindness (no light perception) in one patient. The orbital socket contracture occurred within 3 months of treatment with immunosuppressive medications for inflammatory orbital disease in five patients and was not responsive to immunosuppressive medications. The median degree of enophthalmos in the contracted orbit compared with the fellow eye was 2.8 mm (range 1.5-3.5 mm) by Hertel exophthalmometry. There were no risk factors that predicted development of orbital socket contracture. CONCLUSIONS: In six patients with WG and active inflammatory orbital disease, orbital socket contracture occurred during the treatment course with systemic immunosuppressive medications. The orbital socket contracture, presumably caused by orbital fibrosis, led to enophthalmos, restrictive ophthalmopathy, chronic orbital pain, and optic nerve disease and was not responsive to immunosuppressive therapy. Orbital socket contracture has not been previously reported as a complication of inflammatory orbital disease associated with WG and was an important cause of visual morbidity in our cohort of patients.

Adolescent↗

The effect of maturation on the ability to stimulate orbital growth using tissue expanders in the anophthalmic cat orbit.

Tissue expanders were used to stimulate orbital growth at different stages of maturity in the immature anophthalmic cat orbit. Twelve cats had the right globe enucleated at 2 weeks of age and tissue expanders implanted in the orbit. The cats were randomized into four groups (A, B, C, and D). The tissue expanders remained in the nonexpanded state for a preassigned length of time. Orbital volume was determined on each cat using computed tomography (CT) immediately prior to expansion of the implant. Expansion began at age 10 weeks for group A, 15 weeks for group B, and 25 weeks for group C and involved 0.7 cc injections of saline at 2-week intervals until a final volume of 4.5 cc was obtained. Group D remained as a nonexpansion control group. Four to 5 weeks after expansion was completed, a second orbital volume CT was obtained on each animal and compared with the pre-expansion CT. The right orbits of group A, had pre-expansion (week 10) orbital hypoplasia with a volume 26.2% smaller than the left control orbits. Postexpansion (week 25), the right orbital hypoplasia had decreased to a volume 10.3% less than the left control orbits. The right orbits of group B had pre-expansion (week 15) orbital hypoplasia with a volume 35.6% smaller than the left control orbits. Postexpansion (week 31), the right orbital hypoplasia had decreased to a volume 25.9% less than the left control orbits. The right orbits of group C had a preexpansion (week 25) orbital hypoplasia with a volume 39.8% smaller than the left control orbits. Postexpansion (week 41), the right orbital hypoplasia had decreased to a volume 29.3% less than the left control orbit. Tissue expanders, expanded in the hypoplastic immature cat orbit stimulated orbital growth and reversed orbital bony hypoplasia to varying degrees. The amount of growth stimulated was inversely proportional to the age at which expansion began. Orbital growth, stimulated by tissue expander expansion, was also demonstrated after the normal age of cat orbit maturation (weeks 28-30).

Animals↗

Orbital cellulitis: a rare complication after orbital blowout fracture.

PURPOSE: To report the incidence of orbital cellulitis after orbital blowout fracture. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: All patients with orbital cellulitis and a history of recent orbital fracture. METHODS: A medical record review of clinical history, imaging studies, and surgical and treatment outcome was performed. MAIN OUTCOME MEASURES: Resolution of orbital cellulitis and surgical and imaging findings. RESULTS: Four patients (3 male; mean age, 30 years [range, 4.5-58]) were treated for orbital cellulitis complicating orbital fracture. All patients had evidence of paranasal sinusitis before or after the orbital injury, and 2 also reported forceful nose blowing after sustaining orbital trauma. Although 3 patients received prophylactic oral antibiotics after the fracture, this failed to prevent infection. Sinusitis commenced 1 to 2 weeks before and as late as 5 weeks after orbital injury. All patients were treated with IV antibiotics. Two developed an orbital abscess that required surgical drainage; 1 patient improved after an endonasal maxillary antrostomy. One patient improved on IV antibiotics alone and underwent fracture repair at a later stage. These 4 patients represent 0.8% of all cases of orbital fractures treated in the study period. CONCLUSIONS: Orbital cellulitis is a rare complication of orbital fracture, and seems to be more common when paranasal sinus infection preexists or occurs within several weeks of the injury. Oral antibiotics given after the orbital injury may not prevent orbital cellulitis or abscess formation. Surgery may be required to drain orbital abscess or in nonresolving cellulitis to drain the paranasal sinuses. Fracture repair, if indicated, should be delayed, particularly if an alloplastic implant is used.

Acute Disease↗

Surgical correction of orbital and periorbital deformities using lamella and complex osteotomies in both orbital rim and wall.

PURPOSE: For dealing with the problems in orbital and periorbital deformities. METHODS: In orbital deformities such as hypertelorism, orbital dystopia, radiated orbit, and secondary deformities of traumatic orbit, the authors used lamella osteotomies of either orbital rim and wall or complex osteotomies in both adjacent orbital rims and walls with bicoronal incision and galea aponeurotica dissection. In most of the cases, the fragments of complex osteotomies were repositioned with rigid fixation. RESULTS: Best results with nearly normal orbital volumes, better contour of orbit and midface, and improved eyelids and vision were achieved in 44 cases. There were 5 cases of supraorbital osteotomy (intracranial routine), 8 cases of medial orbital osteotomy, 3 cases of inferior orbital osteotomy, and 28 cases of both lateral and inferior orbital osteotomy in the series. No complications occurred. Clinical measurement was achieved in both pre- and postoperative osteotomies. According to comparative recordings, such as cephalometric measurement of the interorbital distance, exophthalmic measurement with Hertel exophthalmometer, the angle between orbital horizontal level and bilateral tragus linkage, and the linear distance between lateral canthus and tragus, the gap difference between pre- and postoperative data were achieved. The orbital and midface appearance has improved significantly. CONCLUSIONS: Lamella and complex osteotomies of orbital rim and wall were proved to be save and effective for correction of most deformities of the orbital and periorbital region.

Adolescent↗

[Orbital development after enucleation without orbital implant in early childhood].

PURPOSE: To evaluate the development of orbital volume in five adults who underwent enucleation without orbital implant during early childhood, using reconstructed computed tomography(CT) images. MATERIALS AND METHODS: The orbital volume of 5 adults who underwent enucleation without orbital implants during early childhood was measured using CT images, and the results were compared between the anophthalmic orbit and the unaffected orbit in each case. The shape of maldevelopmental orbit and the relationship between orbital development and replacement of the prosthesis were also investigated. RESULTS: Orbital development in patients who underwent enucleation without orbital implant during early childhood was delayed in comparison with the unaffected orbit, and the delayed development was especially remarkable at the part of orbit corresponding to the equator of the eyeball. Maldevelopment of the orbit was severer in cases without replacement of the prosthesis than with it. CONCLUSION: For the development of orbital volume in anophthalmos after enucleation, orbital volume in place of the eyeball is required. Therefore, orbital implantation at the time of enucleation and replacement of the prosthesis with larger ones as the body grows are important.

Adult↗

Orbital tissue-derived T lymphocytes from patients with Graves' ophthalmopathy recognize autologous orbital antigens.

Lymphocytic and other mononuclear cell infiltration of the retro-bulbar space is observed in Graves' ophthalmopathy (GO). We investigated the antigenic character of orbital adipose/connective tissue and muscle from 21 euthyroid patients with severe GO after orbital surgery. Orbital tissue proteins were separated and recovered in soluble form by means of an electroelution technique. Twenty-two protein fractions, identified according to their molecular mass ranges, were used as antigens for orbital tissue-derived and peripheral blood T lymphocytes. Seventeen T cell lines from 6 patients were established from in vivo activated orbital T cells using interleukin-2 and anti-CD3 antibodies. T cell proliferation was measured as [3H] thymidine uptake. When screened for their reactivity to autologous adipose/connective tissue proteins, all T cell lines responded significantly to protein fractions 6-10 kDa [stimulation index (SI) = 32.9 +/- 9.8 (mean +/- SE)] and 19-26 kDa (17 +/- 5), but not to tuberculin, which was used as a control. Phenotypic analysis analysis of 10 orbital T cell lines indicated that 6 lines consisted predominantly of CD4+ cells. Incubation of a representative T cell line with allogeneic orbital protein fraction induced a very low response to protein fraction 19-26 kDa, but not to other fractions. Thyroid protein fraction 6-10 kDa also induced the proliferation of orbital T cell lines. Incubation of peripheral blood mononuclear cells with autologous orbital protein fractions gave similar results; positive responses to 6-10 and 19-26 kDa fractions were observed with orbital tissue from 12 of 14 patients (mean SI = 22 +/- 5.9 and 6.3 +/- 1.7, respectively), and positive responses were observed with orbital tissue from 3 of 4 patients to eye muscle fractions 6-10 and 19-26 kDa (13.8 +/- 6.9 and 6 +/- 2, respectively). When proteins from cultured orbital fibroblasts were used as antigens, autologous peripheral blood mononuclear cells from the 7 of the 9 patients tested responded to these 2 fractions (15.2 +/- 6.9 and 6.8 +/- 2.4, respectively), whereas a response to cultured orbital myoblasts was observed with the 19-26 kDa fraction only (SI = 8). Positive responses to abdominal adipose or muscle proteins, as controls, were not found. The demonstration of sensitized, orbital tissue-specific, T lymphocytes in the peripheral blood and orbit from patients with GO provides evidence for a role of cellular immunity in the pathogenesis of this eye disorder.

Adult↗

Molecule intrinsic minimal basis sets. I. Exact resolution of ab initio optimized molecular orbitals in terms of deformed atomic minimal-basis orbitals.

A method is presented for expressing the occupied self-consistent-field (SCF) orbitals of a molecule exactly in terms of chemically deformed atomic minimal-basis-set orbitals that deviate as little as possible from free-atom SCF minimal-basis orbitals. The molecular orbitals referred to are the exact SCF orbitals, the free-atom orbitals referred to are the exact atomic SCF orbitals, and the formulation of the deformed "quasiatomic minimal-basis-sets" is independent of the calculational atomic orbital basis used. The resulting resolution of molecular orbitals in terms of quasiatomic minimal basis set orbitals is therefore intrinsic to the exact molecular wave functions. The deformations are analyzed in terms of interatomic contributions. The Mulliken population analysis is formulated in terms of the quasiatomic minimal-basis orbitals. In the virtual SCF orbital space the method leads to a quantitative ab initio formulation of the qualitative model of virtual valence orbitals, which are useful for calculating electron correlation and the interpretation of reactions. The method is applicable to Kohn-Sham density functional theory orbitals and is easily generalized to valence MCSCF orbitals.

Journal Article↗

Pure orbital blowout fracture: new concepts and importance of medial orbital blowout fracture.

Pure orbital blowout fracture first occurs at the weakest point of the orbital wall. Although the medial orbital wall theoretically should be involved more frequently than the orbital floor, the orbital floor has been reported as the most common site of pure orbital blowout fractures. A total of 82 orbits in 76 patients with pure orbital blowout fracture were evaluated with computed tomographic scans taken on all patients with any suspicious clinical evidence, including nasal fracture. Isolated medial wall fracture was most common (55 percent), followed by medial and inferior wall fracture (27 percent). The most common facial fracture associated with medial wall fracture was nasal fracture (51 percent), not inferior wall fracture (33 percent). This finding suggests that the force causing nasal fracture is an important causative factor of pure medial wall fracture as the buckling force from the medial orbital rim. Of patients with medial wall fractures, 25 percent had diplopia and 40 percent had enophthalmos. On plain radiographs, diagnostic signs were found in 79 percent of medial wall fractures and in 95 percent of inferior wall fractures. On computed tomographic scans, late enophthalmos was expected in 76 percent of medial wall fractures. Therefore, the medial orbital blowout fracture may be an important cause of late enophthalmos, because it has a high incidence of occurrence, a low diagnostic rate, and a high severity of defect. Among the causes of limitation of ocular motility, muscle traction of the connective septa and direct muscle injury were found frequently, but true incarceration of the muscle was extremely rare in all fractures. The medial and inferior orbital walls are clearly demarcated by the bony buttress, which is an important structure supporting these orbital walls. Its buttress was closely correlated with the fracture of these orbital walls. Most orbital blowout fractures without collapse of the bony buttress had a trapdoor fracture with or without small fragments of punched-out fracture.

Adolescent↗

Transcaruncular approach to the medial orbit and orbital apex.

OBJECTIVE: To present a versatile approach to the medial orbit and orbital apex through the caruncle. DESIGN: Retrospective, noncomparative, case series with description of surgical technique. PARTICIPANTS: Twenty-five consecutive patients underwent orbital surgery by use of a transcaruncular approach. INTERVENTION: Inferior and medial wall fracture repair or orbital decompression by means of a transcaruncular or combined transfornix-transcaruncular approach. MAIN OUTCOME MEASURES: The surgical indications and complications were recorded for each patient. RESULTS: Ten patients (10 orbits) underwent combined inferior and medial orbital wall fracture repair through a combined transfornix-transcaruncular approach. In 8 of 10 (80%) orbits, the inferior oblique muscle was disinserted during surgery. Fifteen patients (24 orbits) underwent orbital decompression surgery for dysthyroid orbitopathy. An isolated transcaruncular approach was used in 5 of 24 orbits, and a combined transfornix-transcaruncular approach was used in 19 of 24 orbits. There were no complications related to either approach. CONCLUSIONS: Orbital bone removal and fracture reduction may be safely completed through a combined transfornix-transcaruncular approach. The transcaruncular approach provides excellent and safe exposure of the medial orbital wall, and it avoids scarring associated with the Lynch approach.

Decompression, Surgical↗

[Orbital volumetry as a planning principle for reconstruction of the orbital wall].

Before reconstruction of the orbital walls and other surgical procedures concerning the orbits leading to a modification of pathologically altered orbital volumes, it is useful to measure these volumes in order to allow preciser correction. Orbital volumetric studies on 22 patients and 6 dry skulls were performed using high resolution computer tomography. 14 patients presented enophthalmos of various origin, 3 patients fibrous dysplasia involving the orbits and 5 patients showed no orbital pathology. In 10 patients with unilateral posttraumatic enophthalmos an increase of the bony orbital volume of 20.1% in the average was found corresponding to an enophthalmos of 3.5 mm in the average. Correlation between the severity of the enophthalmos and the increase in orbital volume was found. Enophthalmos could not be correlated to the intraorbital fat volume, especially no atrophy of orbital fat could be demonstrated in these patients. Normal orbital volume measurements of patients and dry skulls were compared to those found in the literature. Planning of the surgery was therefore facilitated before correction of enophthalmos, reconstruction of bony orbital contour after tumor resection and in patients with fibrous dysplasia. Results suggest that the bony orbital enlargement, followed by a change in soft-tissue shape and position is the usual cause for posttraumatic enophthalmos. Changes in volume of soft-tissues themselves are less significant.

Cephalometry↗