Deep Lateral Wall Research Articles

Elemgasem nubilus: a new brachyrostran abelisaurid (Theropoda, Ceratosauria) from the Portezuelo Formation (Upper Cretaceous) of Patagonia, Argentina

AbstractAbelisaurids are medium–large‐sized theropod dinosaurs that were predominant in the carnivorous fauna during the Late Cretaceous of Gondwana. These predators are abundant in the Cretaceous fossil strata of Patagonia, which yield the best record for this group. In the Late Cretaceous, abelisaurids appear in almost all regions of Gondwana and in all stages, except for the Coniacian, in which they are globally unknown. Here we describe a new abelisaurid,Elemgasem nubilusgen. et sp. nov., from the Portezuelo Formation (Turonian–Coniacian), Patagonia, Argentina. The palaeohistology of the appendicular bones ofElemgasemshows that the holotype was a subadult individual, but had achieved sexual maturity. This taxon is based on several axial and appendicular elements, and is diagnosed by the presence of a marked pattern of rugosity on the lateral surface of the fibula and a dorsoventrally deep lateral wall of the calcaneum. Moreover, the posterior caudal vertebrae have a morphology slightly different from any other abelisaurid.Elemgasem nubilusis recovered as an unstable taxon within Brachyrostra, given that it was recovered as sister taxon of Furileusauria or in several positions within this clade. Despite the problematic phylogenetic relationships ofElemgasem nubilus, it is important because it is the first abelisaurid from the Turonian–Coniacian interval and it increases the diversity of this theropod family at a time of marked turnover in the tetrapod fauna of South America, global climate change, and mass extinction events recorded worldwide in the marine realm.

Endoscopic Transconjunctival Deep Lateral Wall Decompression for Thyroid-associated Orbitopathy: A Minimally Invasive Alternative: Transconjunctival Endoscopic with Wall Decompression for TAO

To investigate the feasibility, efficacy, and safety of endoscopic transconjunctival transorbital deep lateral wall decompression for thyroid-associated orbitopathy (TAO). Prospective single-surgeon interventional case series. Twenty-two patients (39 orbits) diagnosed with thyroid-associated orbitopathy without dysthyroid optic neuropathy were enrolled in this study. All patients underwent endoscopic transconjunctival transorbital deep lateral wall decompression for proptosis reduction. The data, including measurement on exophthalmometry, volumetric change on computed tomography, and surgery-related complications, were analyzed. We observed a proptosis reduction (mean, 3.42 ± 0.87 mm; range, 2.10-5.52 mm) and a corresponding decrease in the bony volume of the greater wing of the sphenoid bone (mean, 1.89 ± 0.81 cm3; range, 0.56-3.79 cm3) postoperatively. Preexisting diplopia improved in 5 patients (22.73%). Transient zygomaticotemporal hypoesthesia developed in all patients, and cerebrospinal fluid leakage occurred in 1 orbit (2.56%). No patient complained of temporal hollowing, oscillopsia, or new-onset or worsening diplopia during follow-up. Endoscopic transconjunctival transorbital deep lateral wall decompression is an effective and minimally invasive treatment for proptosis reduction in patients with thyroid-associated orbitopathy. The surgery-related complications with this technique were fewer compared with traditional approaches.

Correlation between uniocular deviation and duction changes following different decompression surgeries in thyroid eye disease

BackgroundPostoperative ocular imbalance is an important problem for orbital decompression surgery in thyroid eye disease (TED). The aim of this study was to evaluate the changes in unilateral ocular deviation and duction following orbital decompression and discuss the biomechanics of ocular imbalance.MethodsFifty-four TED patients who underwent unilateral orbital decompression were included. Fifteen patients underwent 1-wall (deep lateral wall) decompression, 18 patients underwent 2-wall (deep lateral and medial wall) decompression and 21 patients underwent 3-wall (deep lateral, medial and inferior wall) decompression. Objective and subjective deviation of the operated eyes were evaluated using the prism test and synoptophore, respectively. Ocular ductions were measured using Hirschberg’s method. The diameters of the extraocular rectus were measured by computed tomography.ResultsOcular deviation and duction showed no significant difference after 1-wall decompression (p = 0.25–0.89). Esotropia increased after 2-wall decompression (p = 0.001–0.02), and hypotropia increased after 3-wall decompression (p = 0.02). Adduction increased but abduction decreased following 2-wall and 3-wall decompression (p < 0.05). Infraduction increased following 3-wall decompression (p < 0.001). Additionally, the increase in esotropia was significantly correlated with the increase in adduction and with the decrease in abduction (r = 0.37–0.63, p < 0.05). There were significant correlations between the diameter of the medial rectus and the increase in esotropia, the increase in adduction and the decrease in abduction postoperatively (r = 0.35–0.48, p < 0.05).ConclusionsThe changes in ocular deviation and duction were different after 1-wall, 2-wall and 3-wall orbital decompression. The increased contractile force of the rectus may be an important reason for strabismus changes after orbital decompression surgery.

Orbitadekompression bei endokriner Orbitopathie – Erfahrungen und Ergebnisse

HintergrundDie endokrine Orbitopathie ist die häufigste extrathyreoidale Manifestation des Morbus Basedow und tritt bei schätzungsweise 25–50 % der betroffenen Patienten auf. Krankheitsbedingt kommt es zu einer entzündlichen Schwellung der Orbitaweichteile. Die Behandlung erfolgt meist konservativ. Bei schweren Fällen mit beeinträchtigendem Exophthalmus oder akuter, steroidrefraktärer Visusbedrohung kann eine chirurgische Orbitadekompression die Beschwerden der Patienten lindern oder das Sehvermögen erhalten. Ein wesentlicher Aspekt der Versorgungsqualität besteht in der Vermeidung postoperativer Doppelbilder.Ziel der ArbeitErfahrungs- und Ergebnisbericht von 100 chirurgischen Orbitadekompressionen bei 62 Patienten an einem interdisziplinären Orbitazentrum. Patienten mit Kompression der Orbitaspitze wurden mittels pterionaler Dekompression behandelt. Patienten ohne Hinweise auf Orbitaspitzenbeteiligung wurden mittels tiefer lateraler Wandresektion oder pterionaler Dekompression behandelt.MethodikRetrospektive Datenanalyse.ErgebnisseDie mittlere Exophthalmusreduktion betrug 2,9 mm. Augen mit visusbedrohendem Schweregrad gewannen im Mittel 2,2 Zeilen an Sehschärfe, der Visus bei rehabilitativer Indikation blieb stabil. Die Komplikationsrate betrug 4 %. Neue Doppelbilder wurden nach 2 Eingriffen beobachtet. Bei einem Patienten kam es zu einer Visusminderung von 0,8 auf 0,1. In 9 Fällen führte die Operation zu einem vollständigen Rückgang zuvor beklagter Doppelbilder.DiskussionVisusgewinn, Exophthalmusreduktion und Komplikationsrate sind in diesem Kollektiv vergleichbar mit zuvor publizierten Arbeiten. Diese Studie bestätigt die Rolle der Orbitadekompression bei visusbedrohender und schwer beeinträchtigender endokriner Orbitopathie.

Orbital anatomical parameters affecting outcome of deep lateral orbital wall decompression.

To determine orbital anatomical parameters that affect surgical outcome of deep lateral orbital wall decompression. Twenty orbits of 20 patients with moderate proptosis (maximum 25 mm) due to thyroid eye disease who were stable for at least 6 months were included in this prospective cohort study. Four parameters including lateral orbital wall distance (LOWD), removable surface area (RSA), removable surface length (RSL), and sphenoid door jamb thickness (SDJ) were evaluated by computed tomography (CT) scan prior to surgery in these patients. Deep lateral orbital wall decompression without fat removal was done in all patients. Relationship between all these factors and proptosis reduction, 6 months after surgery was assessed. Mean proptosis before decompression surgery (mean ± SD) was 23.22 ± 1.19 mm and reduction in Hertel exophthalmometry (mean ± SD) was -3.27 ± 1.03 mm (p = 0.006). Pearson correlation showed that LOWD, RSL, and SDJ had statistically significant correlation with proptosis reduction (p = 0.017, 0.002, and 0.001, respectively.). Linear multivariate regression analysis showed SDJ as the only independent factor in predicting surgical outcome. several orbital anatomical factors have significant role in predicting surgical outcome following deep lateral wall orbital decompression. Among these parameters, SDJ is an independent factor, whereas LOWD and RSL are dependent factors. Preoperative assessment of the bony sphenoid anatomy may be helpful in predicting the amount of potential decompression.

Deep Lateral Wall Partial Rim-Sparing Orbital Decompression with Ultrasonic Bone Removal for Treatment of Thyroid-Related Orbitopathy.

Purpose To describe the results of thyroid-related orbitopathy (TRO) treated by ultrasonic deep lateral wall bony decompression with partial rim sparing (DLW-PRS). Methods A review was carried out, from January 2015 to September 2017, of all patients treated with ultrasonic DLW-PRS decompression using a SONOPET® (Stryker, Kalamazoo, MI, USA) ultrasonic aspirator, using a lateral, small triangle flap incision for access. The primary outcome was the change in proptosis (measured by the difference in Hertel exophthalmometry measurements). Other secondary outcomes were changes in visual acuity (VA) (using Snellen scale, decimal fraction), presence of lagophthalmos, eyelid retraction (measured by upper eyelid margin distance to the corneal reflex (MRD1) and lower eyelid margin distance to the corneal reflex (MRD2), and presence of exposure keratopathy). Results A total of 58 orbital decompressions in 35 patients were reviewed, with 23 patients (65.7%) having bilateral decompressions. There was a female preponderance with 26 patients (74.2%), and the mean age ± standard deviation was 52.6 ± 13.9 years. Mean proptosis was 24.51 ± 1.76 mm preoperatively, reduced to 19.61 ± 1.27 mm in final follow-up. The mean reduction was 4.9 ± 1.54 mm. VA improved from 0.8 ± 0.14 to 0.9 ± 0.12, p=0.039. 5 of 13 patients (38.4%) with preoperative diplopia reported improvement or complete resolution after surgery. MRD1 was reduced from 5.25 ± 0.88 mm to 4.49 ± 0.7 mm. MRD2 was also reduced from 6.3 ± 0.88 mm to 5.0 ± 0.17 mm. Presence of lagophthalmos was reduced from 35 eyes (60.3%) to five (8.6%); the presence of epiphora was also reduced from 20 patients (57.1%) to 3 (8.5%) following decompression. Complications of the surgery included zygomatic hypoaesthesia in 14 (40%) patients in the early postoperative period and chewing alterations in 10 (28.5%) of the patients. All of these complications were resolved at the 6-month follow-up visit. We noted no surgical complications such as ocular or soft tissue damage, infection, inflammation, or visual loss. Conclusions The SONOPET® ultrasonic bone curette can be used safely and effectively for DLW orbital decompression surgery. The main benefits were good visualization and handling of tissues and speed and ease of use of the equipment. This trial is registered with ClinicalTrials.gov identifier: NCT04025034.

Deep lateral rim-sparing orbital wall decompression in spontaneous globe subluxation associated with shallow orbits and eyelids laxity

ABSTRACTPurpose: To share our experience on deep lateral wall rim-sparing orbital decompression for the prevention of further spontaneous globe subluxation, in patients with shallow orbits and eyelid laxity.Methods: This is a retrospective, interventional case series review. We report the results of deep lateral wall rim-sparing orbital decompression in 7 patients with recurrent spontaneous globe subluxation, operated in our department between 2010 and 2016. The orbital morphology was established by computed tomography scan images, and all patients with shallow orbit configuration and who in addition had eyelid laxity were included. Patients with thyroid eye disease were excluded.Results: No significant intraoperative and postoperative complications were encountered. In all cases, the patients were satisfied with the aesthetic result and none reported further episodes of globe subluxation.Conclusions: Deep lateral wall rim-sparing orbital decompression is a safe and effective decompressive procedure associated with minimal complications, which can be performed successfully in patients with spontaneous globe subluxation associated with shallow orbits with enough eyelid laxity.

Deep Lateral Wall Partial Rim-Sparing Orbital Decompression for Treatment of Thyroid-Related Orbitopathy

Deep Lateral Wall Partial Rim-Sparing Orbital Decompression for Treatment of Thyroid-Related Orbitopathy

Comparative electron microscopy study of the bone surfaces relief after ultrasonic and mechanical high-speed bone removal in orbital decompression

To compare the results of scanning electron microscopy studies of the surface of bone fragments of orbital lateral wall formed by mechanical and ultrasonic bone removal devices. The surfaces of 7 bone fragments have been investigated after bony orbital decompression in patients with thyroid eye disease (TED). Electron microscopy of the bone relief was performed after exposure to an ultrasonic surgical system or a high-speed drill. Electron microscopy revealed that relief of the bony surface within a compact substance after application of an ultrasonic aspirator had parallel grooves of the same type up to 100 μm in depth and 80-100 μm wide, with relatively smooth edges. In the area of impact on spongy substance the bone surface became more amorphous, rougher due to the exposure of cellular structures at different depths. High-speed drill used in the area of compact substance left monotonous, almost flat relief with individual compact conglomerates of bone 'dust'. Removal of thinned fragments of the compact substance of the specimen led to appearance of the cellular structure typical for a spongy substance. Data on features of the relief of the edges of bone 'window' obtained for the first time, as well as specifics of working in conditions of limited surgical access allowed the conclusion that modern ultrasonic bone aspiration is promising for deep lateral wall decompression and some other orbital interventions.

Comparison of rim-sparing versus rim-removal techniques in deep lateral wall orbital decompression for Graves’ orbitopathy

The aim of this study was to compare the surgical outcomes of deep lateral orbital decompression using the rim-sparing technique versus the rim-removal technique in Graves’ orbitopathy (GO). A retrospective cohort study of 75 orbits in 50 patients with GO was performed. Proptosis, best corrected visual acuity (BCVA), intraocular pressure (IOP), upper and lower lid margin to reflex distances (MRD-1 and MRD-2, respectively), diplopia, ocular restriction, and GO quality of life (GO-QOL) questionnaire results were analyzed pre- and postoperatively. The average proptosis reduction ranged from 3.5mm to 6.7mm with the rim-sparing technique and from 3.6mm to 6.7mm with the rim-removal technique (P>0.05). All orbits with dysthyroid optic neuropathy in the rim-sparing group and 87.5% of such orbits in the rim-removal group showed improved BCVA (P=0.321). Reductions in IOP, MRD-1, and MRD-2 were observed with both techniques. Patients in the rim-sparing group had greater improvements in GO-QOL appearance score (P=0.043). In conclusion, rim-sparing orbital decompression provides efficacious outcomes with greater improvements in patient quality of life than the rim-removal technique. The rim-sparing technique should be considered as a preferable option because it preserves the integrity of the lateral vertical maxillary buttress and bony protection for the orbital contents.

Orbital decompression for thyroid associated ophthalmopathy: transnasal endoscopic approach or external orbital approach?

External orbital decompression, including medial wall, inferior wall, lateral wall and orbital fat decompression alone or in combination, has long been considered to be the standard treatment for thyroid related eye diseases. Deep lateral wall orbital decompression has better effect in the balance of eye position, correction of serious exophthalmos and severe oppression optic neuropathy. Recently, however, endoscopic orbital decompression is becoming increasingly popular with the development of endoscopic surgery technique in naso-orbit related diseases. Endoscopic orbital decompression has the advantages of avoiding an external incision scar. Nevertheless, the new method also has some disadvantages, for example, application limited to medial and inferior orbital wall orbital decompression, high incidence of esotropia, need for external lateral wall decompression and expensive cost for equipment. Both surgical approaches have advantages and disadvantages respectively for medial wall and inferior wall decompression. The operative result depends on the individualized surgical design and the experience of the surgeon rather than the choice of the surgical approach. As a result, the choice of the surgical approaches should be specifically based on the patient's conditions, patient's acceptance of the operation, experience of the surgeon and available resources. (Chin J Ophthalmol, 2018, 54: 484-487).

Lateral Rectus Muscle Expands More Than Medial Rectus Following Maximal Deep Balanced Orbital Decompression.

It has been reported that extraocular muscles can enlarge following orbital decompression in thyroid eye disease. In this article, the authors studied the changes in extraocular muscles size following maximal deep lateral and medial balanced decompression in a large sample of thyroid eye disease patients. Imaging data were reviewed preoperatively and postoperatively. Radiologic proptosis was assessed. Maximal axial muscle width of the medial and lateral recti was measured. Data from 48 consecutive patients (75 orbits) were included. There was a significant increase in the width of both the lateral and medial recti after decompression (p < 0.01). The mean (standard deviation [SD]) change was less for the medial rectus (0.7 mm) than for the lateral (2.7 mm). This difference was significant (p < 0.01). For the lateral rectus, 80% of all decompression surgeries were associated with an increase in width of >1 mm. Mean (SD) proptosis reduction was 8.2 mm (3.4 mm). These results suggest that the extraocular muscles enlarge in the most deep lateral wall decompressions. For decompression as performed in this article, expansion tends to be more commonly found and of a greater magnitude in the lateral rectus compared with medial.

Ethnic variation in deep lateral orbital anatomy and its implications on decompression surgery

ABSTRACTAim: To describe differences in the deep lateral orbital wall (specifically, trigone) between Chinese, Malay, Indian and Caucasian subjectsMethods: Single-centre retrospective Computed Tomogram (CT)-based study; 20 subjects of each ethnicity were used from existing databases, matched for gender, average age and laterality. Subjects below 16 years of age were excluded. DICOM image viewing software CARESTREAM Vue PACS (Carestream Health Inc., USA) and OsiriX version 7.5 (Pixmeo., Switzerland) were used to measure deep lateral wall length, thickness and volume, as well as orbital depth and statistical analyses performed using Statistical Package for Social Sciences version 21 (IBM, USA).Results: In each group, there were 12 males (60%) and average age was not significantly different (p = 0.682–0.987). Using Chinese subjects as a reference, in Chinese, Malay, Indian and Caucasian subjects, mean trigone thickness was 13.68, 14.02, 11.60 (p < 0.001) and 13.80 mm, curved total wall length 45.23, 42.29 (p = 0.048), 41.91 (p = 0.020) and 45.00 mm, curved trigone length 23.03, 22.61, 17.19 (p = 0.011) and 18.76 mm (p = 0.030) and trigone volume 3120.97, 3221.01, 1613.66 (p < 0.001), 2498.46 mm3 (p = 0.059) respectively. Similarly, perpendicular orbital depth was 27.54, 24.97, 22.12 (p = 0.001) and 25.93 mm and diagonal orbital depth was 34.19, 33.27, 29.48 (p = 0.01) and 34.63 mm respectively.Conclusions: Indian and, to a lesser extent, Caucasian subjects have smaller trigones compared to their Chinese and Malay counterparts. Indian subjects also have shallower orbits and due care should be taken during decompression surgery.

Deep lateral wall orbital decompression following strabismus surgery in patients with Type II ophthalmic Graves’ disease

ABSTRACTPurpose: Surgical management of ophthalmic Graves’ disease traditionally involves, in order, orbital decompression, followed by strabismus surgery and eyelid surgery. Nunery et al. previously described two distinct sub-types of patients with ophthalmic Graves’ disease; Type I patients exhibit no restrictive myopathy (no diplopia) as opposed to Type II patients who do exhibit restrictive myopathy (diplopia) and are far more likely to develop new-onset worsening diplopia following medial wall and floor decompression. Strabismus surgery involving extra-ocular muscle recession has, in turn, been shown to potentially worsen proptosis. Our experience with Type II patients who have already undergone medial wall and floor decompression and strabismus surgery found, when additional decompression is necessary, deep lateral wall decompression (DLWD) appears to have a low rate of post-operative primary-gaze diplopia.Methods: A case series of four Type II ophthalmic Graves’ disease patients, all of whom had already undergone decompression and strabismus surgery, and went on to develop worsening proptosis or optic nerve compression necessitating further decompression thereafter. In all cases, patients were treated with DLWD. Institutional Review Board approval was granted by the University of Kansas.Results: None of the four patients treated with this approach developed recurrent primary-gaze diplopia or required strabismus surgery following DLWD.Conclusions: While we still prefer to perform medial wall and floor decompression as the initial treatment for ophthalmic Graves’ disease, for proptosis following consecutive strabismus surgery, DLWD appears to be effective with a low rate of recurrent primary-gaze diplopia.

Double Vision After Minimally Invasive Orbital Decompression.

New onset Diplopia following orbital decompression in thyroid eye disease patients is estimated to occur in up to 30% to 40% of decompression patients, mostly related to deep lateral and medial wall decompressions. A retrospective chart review of all minimally invasive (fat and minimal bone orbital decompression performed at the UCLA Stein Eye Institute between 2005 and 2015. Inclusion criteria were thyroid eye disease patients older than 18 years undergoing fat only orbital decompression with no previous muscle surgery. The chart review revealed only 5 patients with new onset diplopia after this surgery. The cases are discussed and a possible mechanism for the diplopia is proposed. Double vision following minimally invasive orbital decompression is rare and the mechanisms are poorly understood.

Surgical Outcomes of Balanced Deep Lateral and Medial Orbital Wall Decompression in Korean Population: Clinical and Computed Tomography-based Analysis.

PurposeTo evaluate the clinical outcomes of balanced deep lateral and medial orbital wall decompression and to estimate surgical effects using computed tomography (CT) images in Korean patients with thyroid-associated ophthalmopathy (TAO).MethodsRetrospective chart review was conducted in TAO patients with exophthalmos who underwent balanced deep lateral and medial orbital wall decompression. Exophthalmos was measured preoperatively and postoperatively at 1 and 3 months. Postoperative complications were evaluated in all study periods. In addition, decompressed bone volume was estimated using CT images. Thereafter, decompression volume in each decompressed orbital wall was analyzed to evaluate the surgical effect and predictability.ResultsTwenty-four patients (48 orbits) with an average age of 34.08 ± 7.03 years were evaluated. The mean preoperative and postoperative exophthalmos at 1 and 3 months was 18.91 ± 1.43, 15.10 ± 1.53, and 14.91 ± 1.49 mm, respectively. Bony decompression volume was 0.80 ± 0.29 cm3 at the medial wall and 0.68 ± 0.23 cm3 at the deep lateral wall. Postoperative complications included strabismus (one patient, 2.08%), upper eyelid fold change (four patients, 8.33%), and dysesthesia (four patients, 8.33%). Postsurgical exophthalmos reduction was more highly correlated with the deep lateral wall than the medial wall.ConclusionsIn TAO patients with exophthalmos, balanced deep lateral and medial orbital wall decompression is a good surgical method with a low-risk of complications. In addition, deep lateral wall decompression has higher surgical predictability than medial wall decompression, as seen with CT analysis.

Comparison of lateral orbital decompression with and without rim repositioning in thyroid eye disease

Rim-off lateral wall decompression may be associated with functional and cosmetic deficit. Our objective, therefore, was to describe the functional and cosmetic results of deep lateral orbital decompression with and without anterior rim repositioning for thyroid eye disease. In this retrospective comparative case series all consecutive thyroid eye disease patients who underwent deep lateral wall decompression at the Royal Victorian Eye and Ear Hospital between 1990-2007 and the Goldschleger Eye Institute, Sheba Medical Center between 2008-2011 were included. Patients were divided into two groups: the "rim-on" group in which the anterior lateral orbital rim was repositioned and the "rim-off" group in which it was left off. Main outcome measures were: proptosis reduction, postoperative oscillopsia and diplopia, presence of visible or palpable lateral orbit depression. One hundred and twelve patients who underwent 186 orbital decompressions were included in the final analysis. The average proptosis reduction for two- and three-wall decompressions ranged between 4.6-4.9mm in the rim-on and 4.6-5.7mm in the rim-off group respectively. The prevalence of postoperative oscillopsia was similar in both groups. The preoperative diplopia worsened in 17 patients (32.1%) in the rim-on group and in seven patients (12.3%) in the rim-off group (P = .02, chi-square test). None of the patients developed visible or palpable lateral orbit depression. Deep lateral orbital decompression without anterior rim repositioning may be an effective approach to enhance functional and cosmetic outcomes in thyroid eye disease patients without increasing the risk of lateral wall depression or postoperative oscillopsia.

Critical Appraisal on Orbital Decompression for Thyroid Eye Disease: A Systematic Review and Literature Search.

IntroductionOrbital decompression is the indicated procedure for addressing exophthalmos and compressive optic neuropathy in thyroid eye disease. There are an abundance of techniques for removal of orbital bone, fat, or a combination published in the scientific literature. The relative efficacy and complications of these interventions in relation to the specific indications remain as yet undocumented. We performed a systematic review of the current published evidence for the effectiveness of orbital decompression, possible complications, and impact on quality of life.MethodsWe searched the current databases for medical literature and controlled trials, oculoplastic textbooks, and conference proceedings to identify relevant data up to February 2015. We included randomized controlled trials (RCTs) comparing two or more interventions for orbital decompression.ResultsWe identified only two eligible RCTs for inclusion in the review. As a result of the significant variability between studies on decompression, i.e., methodology and outcome measures, we did not perform a meta-analysis. One study suggests that the transantral approach and endonasal technique had similar effects in reducing exophthalmos but the latter is safer. The second study provides evidence that intravenous steroids may be superior to primary surgical decompression in the management of compressive optic neuropathy requiring less secondary surgical procedures.ConclusionMost of the published literature on orbital decompression consists of retrospective, uncontrolled trials. There is evidence from those studies that removal of the medial and lateral wall (balanced) and the deep lateral wall decompression, with or without fat removal, may be the most effective surgical methods with only few complications. There is a clear unmet need for controlled trials evaluating the different techniques for orbital decompression. Ideally, future studies should address the effectiveness, possible complications, quality of life, and cost of each intervention.

CT-based measurements of the sphenoid trigone in different sex and race.

In thyroid orbitopathy, surgical treatment of exophthalmos and compressive optic neuropathy is orbital decompression. Deep lateral wall decompression has been advocated alone or combined with the medial wall for a "balanced" decompression. The degree of lateral decompression is dependent on the volume of the sphenoid trigone comprising the deep lateral orbital wall. This study aims to compare the volume of the trigone in various races in men and women. After Institutional Review Board approval, patients with normal sinus CT scans (Siemens Somatom 40-slice) were retrospectively reviewed. Inclusion criteria were men and women aged 30 to 60 years, no orbital disease or surgery, normal orbital CT scans, and self-reported race (Asian, black/African American, white). Scans were measured with imaging software (Synapse, Fujifilm USA). The superior and inferior extents of the measured trigone were the superior and inferior orbital fissures, respectively. In the axial CT plane, the areas of each slice of the right and left trigone were manually outlined with the software and volume subsequently calculated based on the slice thickness (2 mm). Comparisons between groups were made via repeated measures analysis of variance. One hundred twenty subjects were included, 20 from each subgroup, yielding 240 measured orbits. The overall volume of the sphenoid trigone for all groups combined was 1.53 cm (standard deviation 0.72 cm). Mean male volume was significantly larger than mean female volume (1.71 ± 0.83 cm vs. 1.35 ± 0.55 cm; p = 0.004). Average left side volume was larger than paired right side volume (1.58 ± 0.74 cm vs. 1.49 ± 0.71 cm; p = 0.02). There were no significant differences in average volumes between races (p = 0.17). The mean sphenoid trigone volume was larger in men than in women. There were no significant differences in volume between racial groups. The data showed significant interindividual and intraindividual variability. When analyzing these data for the purposes of orbital decompression, planning should be based on each side of each patient, as the expected degree of lateral decompression may vary greatly.

Characterization and Outcomes of Repeat Orbital Decompression for Thyroid-Associated Orbitopathy

Orbital decompression for thyroid-associated orbitopathy (TAO) is commonly performed for disfiguring proptosis, congestion, and optic neuropathy. Although one decompression typically achieves goals, a small percentage requires repeat decompression. We performed a 10-year retrospective chart review of all orbital decompressions for TAO at a single tertiary referral institution. Four-hundred and ninety-five orbits (330 patients) were decompressed for TAO, with 45 orbits (37 patients) requiring repeat decompression. We reviewed the repeat cases for indications, clinical activity scores, approach, walls decompressed, and outcomes. Nine percent of orbits required repeat decompression for proptosis (70%), optic neuropathy (25%) or congestion (45%). Sixty-four percent were for recurrence of disease, 36% were for suboptimal decompression. Three incisional approaches were used: lateral upper eyelid crease, inferior transconjunctival, and transcaruncular, with inferior transconjunctival being most common. Of the three walls removed, deep lateral, inferior, and medial, the deep lateral wall was most common (51%). A repeat lateral decompression was the most frequent pattern. Of 37 patients requiring repeat decompression, 40% had diplopia prior to repeat, and an additional 24% developed diplopia after the repeat. Whereas previous studies published by our group cited only 2.6% of deep lateral wall orbital decompressions leading to new-onset primary gaze diplopia, repeat orbital decompressions have a much higher rate of post-operative diplopia. The new onset primary gaze diplopia after repeat decompression group had a higher average preoperative CAS (3.3 vs. 2.4, p < 0.01), higher mean blood loss (56 vs. 19 mL, p = 0.04), more frequent medial wall decompressions (47% vs. 29%, p = 0.33), and greater proptosis reduction (2.4 vs. 1.7 mm, p = 0.24).