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At least 19 recordsLinked to original sources
PubMed1998

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↗
PubMed1998

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↗
PubMed1995

[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↗
PubMed1997

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↗
PubMed2001

[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↗
PubMed1996

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↗
PubMed1999

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↗
PubMed2000

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↗
PubMed1994

[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↗
PubMed1992

Stimulation of orbital growth by the use of expandable implants in the anophthalmic cat orbit.

We evaluated the efficacy of expandable orbital implants to stimulate bone growth in the anophthalmic cat orbit. Eighteen cats unilaterally enucleated at 2 weeks of age received either expandable orbital implants (groups A1 and A2), solid silicone sphere implants of 12 mm or 8 mm (groups B1 and B2), or no implant (group C). Those cats with expandable implants (group A) had the implant size increased by 0.5 ml injections of saline at 2-week intervals starting at 8 weeks of age until a final volume of 4 cc was reached. Four of the expandable implants were found to be only partially inflated at 20 weeks and were subgrouped A2. At 20 weeks of age, the anophthalmic orbits with fully inflated expanders showed no significant difference in either orbital volume or orbital entrance area when compared with control orbits: volume (91.2%), area (95.7%) (p = 0.01). These same orbits also showed a significant increase in both orbital volume and orbital entrance area when compared with the growth obtained by any other group. These other groups showed growth, expressed as a percentage of normal growth, as follows: partially inflated implant: volume (63.0%), area (69.0%); 12-mm sphere implant: volume (57.0%), area (54.5%); 8-mm sphere implant: volume (46.5%), area (44.6%); no implant: volume (47.6%), area (43.6%) (p = 0.01). This study suggests that the use of expandable orbital implants stimulates bony growth in the immature cat orbit. Bony stimulation was proportional to volume implanted, and expandable orbital implants achieved maximum bony stimulation in the groups studied.

Animals↗
PubMed1992

Complex orbital fracture repair using rigid fixation of the internal orbital skeleton.

Large orbital fractures involving more than one orbital wall are frequently associated with enophthalmos and vertical globe dystopia. The authors repaired 22 orbits in 20 patients using the technique of rigid fixation of the internal orbital skeleton. Eleven orbits were reconstructed with titanium or vitallium implants that were custom-shaped to span the bony defect and fixed to the orbital rim. Seven orbits were reconstructed with bone grafts rigidly supported by a miniplate, and, in four cases, direct lag screw support of bone grafts was used. The intraoperative goal was to restore the native orbital anatomy and volume. Autologous calvarial bone grafts were used to supplement the repair to achieve the desired volumetric effect and to cover additional wall defects. A reoperation for additional orbital augmentation was needed in one enophthalmic and one anophthalmic orbit. There were no cases of overcorrection, migration, infection, or extraocular muscle entrapment. In complex orbital fractures, the technique of rigid internal orbital fixation appears to yield a stable and predictable result with the prevention of postoperative globe malposition.

Adult↗
PubMed2000

Dimensions and volumes of the orbit and orbital fat in posttraumatic enophthalmos.

OBJECTIVES: To estimate from 2D and 3D-CT the anatomical defects that are most likely to be responsible for posttraumatic enophthalmos. MATERIALS AND METHODS: The morphology and dimensions of the orbit and of fat content were investigated in 25 patients 6-12 months after treatment for complex orbital fractures by image analysis and volumetric estimation from 2D and 3D-CT. RESULTS: The shape of orbit was very often changed from conical to more rounded due to enlargement of the posterior segment. The retrobulbar fat appeared fragmented and dislocated posteriorly. No changes were observed in the structural appearance or radiodensity of either the orbital fat or muscles. There was reduced sagittal eye projection, increased width of the orbital rim, downward dislocation of the posteromedial orbital floor, and increased volume in the posttraumatic orbits which was significantly different (P < 0.05). Enophthalmos was correlated with orbital volume and height of the retrobulbar portion of the orbit. The volume of fat did not correlate with enophthalmos. CONCLUSIONS: Posttraumatic enophthalmos appears to be more commonly related to failure in correcting the orbital volume and in reducing the outward dislocation of the posterior orbital floor and not to changes in the fat content.

Adipose Tissue↗
PubMed2002

[Orbital volume measurement of enophthalmos of orbital blowout fractures].

OBJECTIVE: To measure the volumetric changes of enophthalmos of orbital blowout fractures, and to study the relation between the change of the orbital volume and the degree of enophthalmos. METHODS: In 16 patients with enophthalmos of orbital blowout fractures, the measurement of orbital volume was carried out during 3 months to 2 years after injury by using the computed tomography (CT), computer image processing and computer orbital three-dimensional measuring method. The relation between the orbital volume discrepancy and enophthalmos was assessed by using Pearson correlation coefficients. RESULTS: There were significant linear correlation between the increment of the orbital volume and the degree of enophthalmos (r = 0.95, P < 0.001), with each 1.0 cm(3) increment in bony volume causing approximately 0.9 mm of enophthalmos. CONCLUSIONS: Orbital blowout fractures can expand the orbital volume. The measurement of orbital volume may predict the risk and the final degree of the enophthalmos at the late stage, thus it may provide useful information in surgical intervention to estimate the size and volume of the orbital implant for an individual case.

Adolescent↗
PubMed1988

[A new technique for the removal of orbital tumors--combined fronto-orbital approach].

Advances in the surgical approach to the orbital fossa have resulted in an increase in the cure of tumors involving the optic nerve and the external ocular muscles. In the past 10 years we have encountered 12 cases with orbital fossa tumors, excluding ocular tumors and inflammatory disease case. After tumor removal surgery, new neurological deficits such as total ophthalmoplegia were caused in many cases, where surgery was performed by classical Krönlein's technique or Dandy's transfrontal approach. So we thought that a new method for tumor removal should be contrived to improve postoperative results. Recently we have had four cases with large orbital tumors (3 cavernous angiomas and one schwannoma). In order to protect visual acuity and external ocular muscle function, we have devised a modification of the frontal craniotomy technique, the "combined fronto-orbital approach". Using our new method, we have successfully removed these four orbital tumors and with good postoperative results. We have concluded that our new technique is superior to other transfrontal approaches on several points as follows: 1) Decreased avoidable compression against the orbital contents and a decrease in the risk of tearing the frontal lobe dura and the peri-orbital during fronto-orbital craniotomy. 2) Satisfactory external decompression and a wide operative field are obtained with simple and safe procedures. 3) Previously detaching the superior rectal muscle makes it easy to distinguish the orbital fossa pathoanatomy and to remove a tumor. 4) Good results are easily obtained in the reconstruction of the orbital roof and the orbital rim, especially in the prevention of postoperative bulbar pulsation and from cosmetic view point.

Frontal Bone↗