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PubMed2005

[An analysis of orbital fracture in open-clinic practice of Department of Ophthalmology Medical University of Gdansk 1990-1991 and 2000-2001 years].

Orbital fractures are common in midface trauma. The aim of our study was the retrospective analysis of patients with eye injuries. According to a prospective protocol we studied 82% adults and 18% children with orbital fractures. Men compared 72% of the patients. Men aged 21-35 years the most affected (mean age 29 years). These patients were divided into two groups: these who was treated in Emergency Department of our Clinic in 1990-1991 years (group I) and these who was treated in 2000-2001 (group II). Patients were analysed for age, sex, cause of injury and types of orbital fracture. In a patient with orbital trauma and orbital fractures visual acuity and ocular muscle motility are two most important ophthalmologic functions to be evaluated emeregently. Inclusion criteria were clinically suspected orbital injuries defined by reduced bulbus motility or diplopia We determined visual function: visual acuity, intraocular pressure, biomicroscopy and ophthalmoscopy, X- ray and CT examination. X- ray and CT has come to play a major role in the orbital examination of trauma patients with orbital fractures. Our cases of the orbital margin fractures classified into: blow-out (orbital floor fracture), Le Fort III (orbital- zygomatic fracture), roof fracture (fracture of the inferior orbital rim) and complex orbital fracture. The blow-out orbital fracture was the most common fracture type and orbital roof was the least common site of fracture of the orbital bony covering of the eye. In whole orbital fractures there were single wall fracture in 43% of cases in group I and 41% of cases in group II., two-wall fracture in 31% of cases in group I and 30% of cases in group II, Three wall-fracture in 15% of cases in group I and 17% of cases in group II. and four wall-fracture in 11% of cases in group I and 12% of cases in group II. Of whole orbital fractures had an associated eye injury. Common mechanisms included assaults (37% of cases in group I and 46% of cases in group II) and car or motor vehicle accidents (43% of cases in group I and 44% of cases in group II). We believe that further studies on this subject are necessary because the mechanism which produces the orbital fractures is subject to debate, they are acknowledged to be difficult to diagnose solely through clinical means.

Adult↗

PubMed1996

Orbital involvement by Wegener's granulomatosis: imaging findings.

OBJECTIVE: The purpose of this study was to define patterns of Wegener's granulomatosis (WG) orbital disease involvement. SUBJECTS AND METHODS: We evaluated the orbital examinations of 14 WG patients (CT for nine, MR imaging for three, and both CT and MR imaging for two) for the number of involved orbits, intraconal or extraconal location, involvement of the orbital apex, sinus involvement, bony erosion, and optic nerve compression. MR images were analyzed for signal characteristics and enhancement patterns. RESULTS: We found orbital disease to be unilateral in 12 patients (86%) and bilateral in two patients (14%) (total of 16 orbits). In 11 orbits (69%), coexistent orbital and sinus diseases with bony erosion were present. Orbital disease without sinus disease was seen in five orbits (31%). Intraorbital disease distribution was as follows: solely extraconal--seven orbits (44%) (four with involvement of muscle); intraconal with muscular involvement--one orbit (6%); combined intra- and extraconal--seven orbits (44%); and primarily orbital apex--one orbit (6%). Involvement of the apex was seen in six orbits. The WG mass was hypointense relative to orbital fat on three standard T2-weighted MR images. We saw homogeneous MR contrast enhancement in all four orbits studied on enhanced T1-weighted images. CONCLUSION: Intraorbital WG involvement is usually accompanied by paranasal sinus disease. A hypointense signal on T2-weighted MR images is helpful in suggesting the diagnosis.

Aged↗

PubMed2002

Orbital preservation in surgical management of sinonasal malignancy.

OBJECTIVE: To determine the oncological and functional outcome when applying defined criteria for orbital preservation during surgical treatment of sinonasal malignancy encroaching on the orbital structures. STUDY DESIGN: Retrospective consecutive review of patients in tertiary care center setting. METHODS: Analysis of 66 patients undergoing surgical treatment for sinonasal malignancy encroaching on the orbit. Orbital preservation was performed in all patients with tumor extension up to and including resectable periorbital involvement. Minimum follow-up was 2 years. Detailed analysis of oncological and functional outcomes is included. RESULTS: Of 66 tumors abutting or invading into the orbit, 54 were amenable for surgical treatment with orbital preservation and the remaining 12 underwent orbital exenteration. Histopathological findings were divided into five subgroups: squamous cell carcinoma, adenomatous carcinomas, sinonasal undifferentiated carcinoma, sarcoma, and other. Squamous cell carcinoma represented the largest subgroup (24 patients), and 5-year overall actuarial survival was not statistically different (P = 1.4; relative risk, 0.713) between patients treated with orbital preservation (53%) versus those undergoing exenteration (46%). Similarly, no difference in survival was found in the adenomatous carcinoma subgroup. Within the orbital preservation group as a whole, local recurrence occurred in 30% patients (16 of 54) compared with 33% patients (4 of 12) treated with orbital exenteration. Of note, eye-sparing surgery was associated with local recurrence at the original site of orbital involvement in only 7.8% of cases (4 of 54). Overall eye function was graded as functional without impairment in 54% of patients (29 of 54), functional with impairment in 37% (20 of 54), and nonfunctional in 9% (5 of 54). The most common abnormality was globe malposition (enophthalmos or hypophthalmos) that was seen in 34 patients (63%) and was associated with the lack of adequate rigid reconstruction of subtotal or total orbital floor or multisegment orbital defects. However, enophthalmos was asymptomatic in the majority of cases, and persistent diplopia occurred in only five patients (9%). Various ocular sequelae were present in 20 of the 49 patients (41%) with functional eyes. Radiation therapy increased the risk of ocular complications, in particular, optic atrophy, cataract formation, excessive dryness, and ectropion. CONCLUSIONS: Selective orbital preservation is oncologically safe and is a worthwhile undertaking in attempting to maintain a functionally useful eye with surgical management of sinonasal malignancy encroaching on the orbit. Consideration should be given to rigid orbital reconstruction in larger defects resulting from subtotal or total orbital floor resection or resections involving two or more orbital walls.

Adolescent↗

PubMed1996

Orbital dysmorphology in unilateral coronal synostosis.

Unilateral coronal synostosis (UCS) produces overt craniofacial dysmorphology. UCS surgery in infancy aims to release the osseous restriction and normalize the fronto-orbital deformity. The quantitative effect of this surgery on the orbit and its contents is unknown. This study was conducted to quantify the preoperative orbital dysmorphology and its surgical outcome in patients with unilateral coronal synostosis. Twenty-eight UCS patients had preoperative three-dimensional computerized tomographic (CT) scans (at mean age 4.0 months), cranio-orbital reconstructive surgery (at 4.7 months), and postoperative scans (at 18.1 months). The CT data were analyzed using a computer workstation and AnalyzeTM biomedical imaging software. Four measurements were performed on both ipsilateral (same side as synostosis) and contralateral (opposite to synostosis) orbits of each scan: orbital index (OI, 100 x height/width of orbit), orbital cavity volume (OV), ocular globe volume (GV), and ventral globe Index (VGI, 100 x globe volume ventral to the anterior surface of orbital cavity/GV). The data were analyzed for statistical significance using Student's ttest. Preoperatively, the OI was significantly greater on the ipsilateral than on the contralateral side (113.7 vs. 87.3). There was a significant improvement on both sides of the orbit postoperatively, with ipsilateral 99.1 and contralateral 92.1. However, the difference between both sides remained significant. The OV was smaller in the ipsilateral orbits both pre- and postoperatively, with ipse/contralateral ratios of 95.8 and 95.2, respectively. Importantly, the GV was consistently smaller in the ipsilateral orbits preoperatively, with an ipse/contralateral ratio of 93.3. The ratio increased to 97.1 postoperatively, a statistically significant change. In the ipsilateral orbits, the preoperative VGI was significantly greater. The VGI improved postoperatively. These data indicate that UCS affects the development of the osseous orbit as well as its soft-tissue contents. After cranio-orbital surgery, there is diminution of asymmetry of both the bony orbit and its soft-tissue contents. Partial normalization of orbital dysmorphology occurred during the first postoperative year. UCS surgery in infancy does not prevent growth of orbital hard or soft tissues, and it seems to permit normalization of previously impaired growth.

Cephalometry↗

PubMed1996

Neuronal connections of orbital cortex in rats: topography of cortical and thalamic afferents.

The cortical and thalamic afferent connections of rat orbital cortex were investigated using fluorescent retrograde axonal tracers. Each of the four orbital areas has a distinct pattern of connections. Corticocortical connections involving the ventral and ventrolateral orbital areas are more extensive than those of the medial and lateral orbital areas. The medial orbital area has cortical connections with the cingulate, medial agranular (Fr2) and posterior parietal (PPC) cortices. The ventral orbital area has connections with the cingulate area, area Fr2, secondary somatic sensory area Par2, PPC, and visual areas Oc2M and Oc2L. The ventrolateral orbital area (VLO) receives cortical input from insular cortex, area Fr2, somatic sensory areas Par1 and Par2, PPC and Oc2L. The lateral orbital area has cortical connections limited to the agranular and granular insular areas, and Par2. Thalamic afferents to the four orbital fields are also topographically organized, and are focused in the submedial and mediodorsal nuclei. The ventrolateral orbital area receives input from the entirety of the submedial nucleus, whereas the other orbital areas receive input from its periphery only. Each orbital area is connected with a particular segment of the mediodorsal nucleus. The medial orbital area receives its principal thalamic afferents from the parataenial nucleus, the dorsocentral portion of the mediodorsal nucleus, and the ventromedial portion of the submedial nucleus. The ventral orbital area receives input from the lateral segment of the mediodorsal nucleus, the rostromedial portion of the submedial nucleus, and the central lateral nucleus. Thalamic afferents to the ventrolateral orbital area arise from the entirety of the submedial nucleus and from the lateral segment of the mediodorsal nucleus. The lateral orbital area receives thalamic afferents from the central segment of the mediodorsal nucleus, the ventral portion of the submedial nucleus, and the ventromedial nucleus. The paraventricular, ventromedial, rhomboid and reuniens nuclei also provide additional input to the four orbital areas. The connections of the ventrolateral orbital area are interpreted in the context of its role in directed attention and allocentric spatial localization. The present findings provide anatomical support for the view that areas Fr2, PPC and VLO comprise a cortical network mediating such functions.

Animals↗

PubMed1999

Direct orbital manometry in healthy patients.

PURPOSE: To determine orbital tissue tension and orbital compartment compliance in normal patients. METHODS: An orbital manometer was designed to directly measure orbital tissue tension before, during, and after a 5-ml retrobulbar injection of anesthetic in patients undergoing ocular surgery. Tissue tension was recorded for 5 minutes after the injection. Orbital compliance was calculated as change in volume divided by change in pressure. Data were collected from 18 normal orbits. RESULTS: Resting orbital tissue tension was 4.0 +/- 1.5 mmHg (mean +/- standard deviation). After retrobulbar injection, orbital tissue tension rose to 11.6 +/- 2.6 mmHg (p = 0.00000000009 compared with baseline). After 5 minutes, tissue tension declined to 6.6 +/- 1.9 mmHg (p = 0.00000001 compared with preinjection and p = 0.00002 compared with postinjection). Orbital compartment compliance was 0.74 +/- 0.31 ml/mmHg. No adverse events occurred. CONCLUSIONS: The authors' orbital manometer safely determined orbital tissue tension and orbital compartment compliance in normal orbits. Retrobulbar injection causes consistent measurable changes in orbital tissue tension. Directly assessing orbital dynamics in vivo may prove useful both as an adjunct in the clinical evaluation of patients with disorders resulting in an orbital compartment syndrome as well as in assessing the risk of retrobulbar injection in orbits at greater risk for complications from this procedure.

Anesthetics, Local↗

PubMed1994

Color Doppler imaging of orbital venous flow in dysthyroid optic neuropathy.

Color Doppler imaging was performed to evaluate the venous stasis in 39 orbits, including 9 optic neuropathy orbits, of 20 patients with dysthyroid ophthalmopathy and 22 orbits of 11 healthy subjects. The superior ophthalmic vein (SOV) was detected in 26 dysthyroid ophthalmopathy orbits and in 13 control orbits. The blood flow in the SOV was in the anteroposterior direction in 20 dysthyroid ophthalmopathy orbits and in 13 control orbits. Reversed flow, ie, the flow in the posteroanterior direction, was seen in 6 dysthyroid ophthalmopathy orbits and in none of the control orbits. In dysthyroid ophthalmopathy orbits, the blood flow in the SOV was reversed in 5 (36%) of the 14 orbits with apical orbital crowding observed on computed tomography, which means there was compression of the optic nerve by enlarged extraocular muscles, as compared to in 1 (4%) of the 25 orbits without apical orbital crowding (P < 0.05). The percentage of the orbits having reversed flow in SOV was 44% of dysthyroid ophthalmopathy orbits with optic neuropathy as opposed to 7% of those without optic neuropathy (P < 0.05). Reversed blood flow in the SOV strongly supported the existence of severe venous stasis in the orbits, which may be related to the development of dysthyroid optic neuropathy.

Adolescent↗

PubMed1999

Intraocular and intraorbital compartment pressure changes following orbital bone grafting: a clinical and laboratory study.

Visual loss is an uncommon but catastrophic complication after intraorbital bone grafting for the reconstruction of acute traumatic defects or long-standing enophthalmos. Increased intraocular or intraorbital compartment pressure may be pathogenic in this setting. A two-part study was designed to test the null hypothesis that intraocular and intraorbital compartment pressure values remain constant despite orbital volume reduction with graft material. Laboratory study: Intraocular and intraorbital compartment pressures were measured during sequential orbital volume reduction in New Zealand White rabbits that had been randomized to one of three groups: intact orbits (n = 10), acute orbital wall defects (n = 8), and chronic (3 months) orbital wall defects (n = 11). Intraocular pressure was significantly (p<0.05) elevated in all three groups of orbits undergoing orbital volume reduction compared with control, nonoperated orbits. Intraorbital compartment pressure values did not change significantly from control levels throughout the grafting sequence. Although no significant differences existed between groups in the maximum levels of intraocular pressure attained, the chronic group demonstrated a greater rate of rise and slower rate of decline. Clinical study: Using applanation tonometry, intraocular pressure was measured before and serially after orbital floor exploration and intraorbital placement of split calvarial bone grafts in 19 patients who presented with orbital-zygomatic complex fractures that required surgery. A separate group of 16 patients with orbital-zygomatic complex fractures that required exploration of the orbital floor but not bone grafting was used for comparison. A significant (p<0.05) elevation of intraocular pressure was observed immediately after bone grafting compared with nongrafted orbits, but values returned to normal within 30 minutes and remained stable through the third postoperative day. There were no cases of visual impairment in any patients in either group as the result of surgical treatment. These data indicate that orbital volume reduction with graft material results in significant, temporary elevation of intraocular pressure. No significant elevations of intraorbital compartment pressure were detected in the rabbit orbits. Data from this study may have direct relevance in defining guidelines for "tolerable" changes in orbital tissue and globe pressures after surgery.

Adult↗

PubMed2003

Orbit deformities in craniofacial neurofibromatosis type 1.

BACKGROUND AND PURPOSE: The possible relationship of orbit deformities in neurofibromatosis type 1 (NF1) to plexiform neurofibromas (PNFs) have not been fully elucidated. Our purpose was to review orbital changes in patients with craniofacial NF1. METHODS: We retrospectively reviewed CT and MR imaging abnormalities of the orbit in 31 patients (18 male, 13 female; mean age, 14 years; age range 1-40 years) with craniofacial NF1. RESULTS: Orbital abnormalities were documented in 24 patients. Six had optic nerve gliomas with enlarged optic canals. Twenty had PNFs in the orbit or contiguous to the anterior skull. The posterior orbit was distorted by encroachment from an expanded middle cranial fossa in 13 patients, and 18 had enlargement of the orbital rim. Other changes included focal decalcification or remodeling of orbital walls adjacent to PNFs in 18 patients and enlargement of cranial foramina resulting from tumor infiltration of sensory nerves in 16. These orbital deformities were sometimes progressive and always associated with orbital infiltration by PNFs. CONCLUSION: In our patients with craniofacial neurofibromatosis, bony orbital deformity occurred frequently and always with an optic nerve glioma or orbital PNF. PNFs were associated with orbital-bone changes in four patterns: expansion of the middle cranial fossa into the posterior orbit, enlargement of the orbital rim, bone erosion and decalcification by contiguous tumor, and enlargement of the cranial foramina. Orbital changes support the concept of secondary dysplasia, in which interaction of PNFs with the developing skull is a major component of the multifaceted craniofacial changes possible with NF1.

Adolescent↗

PubMed2001

Orbital growth retardation in retinoblastoma survivors: work in progress.

BACKGROUND: Orbital growth retardation, after enucleation and/or external beam radiation for retinoblastoma (RB), is a serious late effect. We measured orbital volumes of RB survivors treated at Hadassah University Hospital, Jerusalem, between 1980-1998. PROCEDURE: Forty-five orbits of 28 children with RB (17 bilateral, 11 unilateral) were examined. Thirty-six orbits were irradiated, 19 enucleated, and 10 both enucleated and irradiated. The orbital volumes were calculated from a three-dimensional orbital CT reconstruction. The orbits of RB survivors were compared to age-matched controls. RESULTS: The mean age at diagnosis was 13 months, mean follow-up time was 56 months. The mean volume of RB orbits (14.4 cc) was statistically significantly smaller than control orbits (17.8 cc). There was no difference between the mean volume of orbits treated with enucleation, irradiation or both. The orbital volume of children treated before the age of 12 months was statistically significantly smaller than those treated later. There was no difference between mean volume of fellow orbits in unilateral RB and controls. The mean orbital asymmetry index in control children (2.6%) was statistically significantly smaller than in RB survivors (14%). CONCLUSIONS: There was a significant orbital growth retardation after enucleation and/or irradiation for RB. There was no difference between mean orbital volumes after enucleation, radiation or both. Orbital growth retardation was most prominent in children treated in the first year of life. Although small in number, our study suggests that deferring enucleation and/or irradiation until after the age of 12 months may reduce long-term complications.

Age Factors↗

PubMed2006

The prenatal development of the human orbit.

During the 1970s, as part of his work for a doctor's thesis in which he described the development of the human orbit in great detail, the first author established the largest anatomical collection of embryonic and fetal orbits ever. Unfortunately, he died before the thesis could be finished. The thousands of sections have now been scanned at high resolution and made publicly available on the Internet at www.visible-orbit.org; 3-D reconstruction software is being developed. The Discussion and part of the 'Methods' section of this thesis are published in translation in this article. The conclusions of the first author at the time read as follows: (1) initially, the developing orbit is vaguely indicated by condensations in the mesenchymal connective tissue area; (2) in this connective tissue area, chondral, osseous and muscular structures develop and grow until, in the fully developed stage, the orbital content is surrounded by bony surfaces with a thin layer of connective tissue as periosteum, and by a muscle fragment; (3) the embryonic and early fetal phase, during which one can only speak of a 'regio orbitalis,' is followed by a period in which we can speak of a primordial orbit; (4) the phase of the primordial orbit extends until after birth; (5) the surface area of all orbital walls increases more or less linearly; (6) the 'musculus orbitalis Mülleri' occupies a special place in the orbital wall; (7) the so-called 'regio craniolateralis' is the primordium, which, in the fully developed stage, is occupied by the thick intersection of the frontolateral and the horizontal part of the frontal bone; (8) in the frontal plane, the shape of the primordial orbit, as well as that of the fully developed orbit, is more or less round; (9) the prenatal development of an eye socket is a complex event, characterized by changes in composition, shape and size of the orbital wall; and (10) the orbit can only be denoted by the term "eye socket" when it is fully developed. At the end of the thesis, he also presented the following postulates: (1) in the prenatal orbit, the development of the so-called 'periorbita' is at the forefront; (2) the mutual rotation of the orbital axes and the frontalization of the eyes from approx. 180 degrees in the early prenatal stages to approx. 50 degrees in adulthood do not seem to be caused by mechanical influences of the surrounding tissue; (3) the pterygopalatine fossa and the 'cavum cerebri' are not part of the orbit at any developmental stage; (4) in the prenatal skull, the inferior nasal concha, which forms part of the maxilla in the fully developed skull, is part of the 'capsula nasalis'; and (5) in order to achieve normal development of the eye socket in microphthalmus and anophthalmus, the normal orbital content should be restored.

Female↗

PubMed2001

Surgical management of the anophthalmic orbit, part 1: congenital.

Congenital microphthalmos and anophthalmos are rare conditions in which orbital growth is deficient. Hypoplasia of the globe affects the bony orbit (micro-orbitism), the conjunctival sac, and eyelids (microblepharism), and it may be associated with abnormalities of the entire hemifacial skeleton (hemifacial microsomia). In the present article, the authors review a series of 19 patients with microphthalmos (nine had right-sided, one had bilateral, and nine had left-sided microphthalmos) who were treated in the Orbitopalpebral Unit at Hospital Foch over a period of 15 years (follow-up, 5 months to 18 years).Orbital expansion was achieved using spherical implants (n = 13), orbital osteotomies (n = 4), and orbital expanders (n = 2). Both expanders were removed within 6 months because of failure (one infection and one rupture). The current preferred method for orbital expansion is to use serial implants in the growing orbit and osteotomies in cases of late referral or insufficient orbital volume in the older child. The target proportions of the reconstructed orbit are not planned to mirror the healthy side exactly. The inferior orbital rim is kept higher to support the orbital implant, and the orbit is kept shallow to avoid a sunken appearance. Cranial bone grafts were used to augment deficient orbital contours; they were assisted by anterior transposition of the temporalis muscle (n = 5) when additional orbital volume was required. Conjunctival sac reconstruction was achieved by the use of serial conformers placed in the conjunctival sac during the neonatal period, followed by grafts of buccal mucosa and full-thickness skin maintained in place with a tarsorrhaphy for 3 to 6 months. Eyelid reconstruction using local flaps and skin grafts proved to be necessary in cases treated by osteotomy expansion, although reconstruction was not required after expansion using serial solid shapes. The results illustrate an evolution in approach and concepts of reconstruction of the microphthalmic orbit and emphasize the need for an integrated craniofacial approach for this complex deformity.

Anophthalmos↗

PubMedDate not supplied

Orbital volumetric analysis of allergic fungal sinusitis patients with proptosis before and after endoscopic sinus surgery.

BACKGROUND: The aim of this study was to examine the changes of orbital volumes in allergic fungal sinusitis (AFS) patients with proptosis who undergo endoscopic sinus surgery. METHODS: A retrospective study of operative patients with proptosis due to AFS was performed. Normative data were obtained using patients with chronic sinusitis without orbital involvement. Orbital volume measurements were obtained using digitized images and computer software to calculate volumes (cm3) of outlined regions on 1.3-mm axial computed tomography images. Orbital volumes were measured as total volumes and volumes within the bony orbit. Bony orbits were defined using two techniques: (1) the region posterior to a line from ipsilateral zygoma to contralateral zygoma and (2) the region posterior to a line from zygoma to ipsilateral lacrimal bone. Four affected orbits in three AFS patients with proptosis were evaluated. Twenty-eight unaffected orbits in 14 patients were used as normal comparisons. RESULTS: Orbital involvement by AFS resulting in proptosis decreased orbital volumes within the bony orbit to a mean of 70% of normal. After successful endoscopic sinus surgery, bony orbital volumes normalize or approach normal ranges to a mean 90% of normal with resolution of clinically apparent proptosis. Total volumes remained stable before and after surgery. CONCLUSION: Massive AFS may affect the orbit resulting in proptosis. Spontaneous orbital remodeling with clinical resolution of proptosis and normalization of bony orbital volumes can be seen in AFS patients several months after sinus surgery and aggressive medical treatment. Surgical orbital reconstruction typically is not needed once the sinus disease is adequately addressed.

Adolescent↗

PubMed2006

[Study on the growth of orbital volume in individuals at different ages by computed tomography].

OBJECTIVE: To study the growth aspects of orbital volume and to establish the normal value of orbital volume by computed tomography (CT). METHODS: One hundred and twenty three individuals without eye diseases (64 males, 59 females) were divided into 5 groups according to the age. Orbital volume and length of horizontal transverse axis and anterior-posterior axis of the eye were measured at different levels in original or reconstructive CT images. The relationship between orbital volume and age, gender and eyeball volume was analyzed. RESULTS: There was no difference between the left and right orbital volume in all age groups. Orbital volume grew rapidly before 20 years of old. Mean orbital volume in males aged 17 and females aged 13 was 23.54 and 21.75 ml, respectively, which reached 95% of the adult orbital volume. In normal adult, orbital volume in the male was larger than that of the female. The mean orbital volume of adult male and female was (25.04 +/- 2.37) ml and (22.89 +/- 2.67) ml, respectively. A strong linear correlation was presented between the age and orbital volume (P < 0.05). The difference of orbital volume between the male and female was statistically non-significant before 14 years old (P = 0.315). The growth of eyeball volume was consistent with that of the orbital volume, the ratio of eyeball/orbit volume was decreased with age from 0.40 to 0.26. CONCLUSIONS: There is no difference between the right and left orbital volume. Orbital volume is correlated with age and gender. Orbital volume grows rapidly before 20 years of old and still grows slowly after 40 years old.

Adolescent↗

PubMed2006

Sino-orbital fistula: a complication of exenteration.

PURPOSE: To report the incidence, characteristics, and management of sino-orbital fistulas, a complication of orbital exenteration. DESIGN: Retrospective interventional case series. PARTICIPANTS: One hundred ten patients who underwent orbital exenteration at 2 orbital units. METHODS: Retrospective chart review of all cases of orbital exenteration between 1993 and 2005 at one orbital unit and between 1999 and 2005 at a second orbital unit. MAIN OUTCOME MEASURES: Incidence of sino-orbital fistulas. RESULTS: Seventy-three and 37 orbital exenterations were performed at the first and second orbital units, respectively. Five patients developed sino-orbital fistulas, 1 of whom developed 2 fistulas at separate sites. In the first unit, 4 fistulas developed in 3 of 73 (4.1%) patients who underwent orbital exenteration. In the second unit, 2 fistulas developed in 2 of 37 (5.4%) exenterated orbits. The majority (5/6) of fistulas occurred medially to the ethmoid sinus, whereas 1 occurred superiorly to the frontal sinus. Risk factors that may have contributed to fistula formation include radiotherapy (3/6), sinus disease (3/6), intraoperative penetration into a sinus (3/6), and immunocompromise (1/6). Management was tailored to the individual case and ranged from conservative socket hygiene to surgical repair with grafts or flaps. Four of the 6 fistulas recurred after repair. Three of these subsequently were closed successfully. Only 1 fistula persisted until the patient died from malignant disease. CONCLUSIONS: Sino-orbital fistulas are uncommon but not rare complications of orbital exenteration that may be predicted by several risk factors. Bothersome symptoms may necessitate treatment, which can range from conservative management to surgical repair with various grafts or flaps. Despite repair, fistulas may be difficult to eradicate.

Adult↗

PubMed1989

Electrical properties and innervation of fibers in the orbital layer of rat extraocular muscles.

1. The inferior rectus muscle of rat, one of the extraocular muscles, contains two populations of multiply innervated fibers (MIFs): orbital MIFs, located in the orbital layer of the muscle and global MIFs, found in the global layer. The electrical properties and the responses to nerve stimulation of orbital MIFs were studied with single intracellular electrodes and compared with those of twitch fibers of the orbital layer, MIFs of the global layer, and tonic fibers of the frog. 2. About 90% of the orbital MIFs did not produce overshooting action potentials. In these fibers the characteristics and time course of the responses to nerve stimulation varied along the length of the fibers. Within 2 mm of the end-plate band of the muscle, the responses consisted of several small end-plate potentials (EPPs) and a nonovershooting spike. Distal to 2 mm, the responses in most fibers consisted of large and small EPPs with no spiking response. Some fibers produced very small spikes surmounted on large EPPs. 3. Overshooting action potentials were observed in approximately 10% of the orbital MIFs recorded between the end-plate band and 2 mm distal. The presence or absence of action potentials was not related to the magnitude of the resting potential of the fibers. 4. The threshold of nerve stimulated responses in orbital MIFs was the same as that in orbital twitch fibers. A large number of orbital MIFs had latencies equal to those for the orbital twitch fibers recorded at the same distance from the end-plate band, but the average latency was greater in the MIFs. The latency of orbital MIFs was about one-half of that for the MIFs of the global layer. The values for the effective resistance and membrane time constant of orbital MIFs fell between those for orbital twitch fibers on the one hand, and global MIFs and frog tonic fibers on the other. 5. In order to compare electrical properties with innervation patterns, fibers identified electrophysiologically as orbital MIFs were injected with the fluorescent dye Lucifer yellow and then traced in Epon-embedded, serial transverse sections. In addition to numerous superficial endings distributed along the fibers, a single "en plaque" ending was also found in the end-plate band that resembled the end plates of the adjacent orbital twitch fibers. 6. From these results we conclude that the electrical activity of orbital MIFs varies along the length of the fibers.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed2004

Restoration of the orbital aesthetic subunit in complex midface defects.

OBJECTIVES/HYPOTHESIS: Although various options exist for restoration of the orbital defect in complex craniofacial resections, the aesthetic appearance and functional result of the orbit are optimized when the bony orbital architecture, orbital volume, and facial contour are specifically addressed. The study describes an approach using free tissue transfer for restoration of the native orbital aesthetic subunit. STUDY DESIGN: Retrospective case series. METHODS: Nineteen patients (male-to-female ratio, 14:5; mean age, 52 y [age range, 8-79 y]) in the study period between 1997 and 2001 had orbital defects that could be classified into one of the following categories: 1) orbital exenteration cavities only, 2) orbital exenteration cavities with resection of less than 30% of the bony orbital rim, or 3) radical orbital exenteration cavities with resection of overlying skin and bony malar eminence. Group 1 had reconstructions with fasciocutaneous forearm flaps; group 2, with osseocutaneous forearm flaps; and group 3, with osseocutaneous scapula flaps. RESULTS: Eighteen of 19 patients achieved a closed orbital reconstruction with restoration of the orbital aesthetic subunit. Among 16 patients with more than 4 months of follow-up, 10 patients had minimal or no resulting facial contour deformity and 8 patients engaged in social activities outside the home on a frequent basis. Five of the nine patients who were working before their surgery were able to return to work. CONCLUSION: Patients with complex midface defects involving the orbit can undergo free tissue transfer and have successful restoration of the native orbital aesthetic subunit without an orbital prosthesis.

Adolescent↗

PubMed2002

Changes in orbital volume during childhood in cases of craniosynostosis.

OBJECT: Controversy remains concerning the timing of frontoorbital advancement (FOA) surgery performed for craniosynostosis. Reduced orbital volume and degree of exorbitism are often cited as reasons for early surgical intervention. To date, however, little attention has been given to orbital volume and its changes during the first few years of life as an indicator of orbital growth in children with craniosynostosis. Knowledge of orbital volume and growth patterns in individuals with craniosynostosis and those with normal cranial structures will enable surgeons to refine both the type and timing of surgical intervention required, thus obtaining the optimum outcome for their patients. METHODS: Using the procedure of segmentation, orbital volumes in 50 children with various forms of craniosynostosis were measured on preoperative computerized tomography scans. Changes in average volume that occur with increasing age were calculated and compared with a model of normal orbital volume growth. At presentation the children with craniosynostosis ranged in age from 1 to 29 months, with 82% of them within the 1st year of life. Several interesting observations emerged from this study. Excluding patients with unilateral coronal synostosis, there was no difference between orbital volumes measured on the right and left sides, allowing mean orbital volume measurements to be used for comparative purposes. Although children with craniosynostosis begin life with significantly smaller orbital volumes, overall normal mean volumes for both sexes are attained by 13 months of age, with volumes approaching normal by 6 months of age in male infants and by 8 months of age in female infants. Changes in orbital volume associated with age generally appear to be similar in most forms of craniosynostosis. There appears to be no significant difference in changes in orbital volume between children with syndromic or nonsyndromic forms of bicoronal synostosis. Orbital volume is significantly reduced on the ipsilateral affected side in cases of unicoronal synostosis in comparison with the contalateral side, but it is not significantly lower than that of normal. Finally, FOA surgery appears to restore normal growth of orbital volume. CONCLUSIONS: The results of this study indicate that the underlying mechanism leading to craniosynostosis and restriction of orbital volume "burns out" and begins to lose its major effects within the first few months of life. It would appear that FOA surgery should be delayed until the end of the second half of the 1st year of life, thus maximizing the effects of accelerated normal orbital growth and reducing the risks of relapse.

Aging↗