Correlation of retrobulbar volume change with resected orbital fat volume and proptosis reduction after fatty decompression for Graves ophthalmopathy

Graves-Basedow ophthalmopathy surgical approaches: Open vs Endoscopic

Graves-Basedow's disease (GBD) is an autoimmune pathology that affects the thyroid and is characterized by the presence of goiter, hyperthyroidism, ophthalmopathy, and dermopathy. Graves-Basedow ophthalmopathy (GBO) is a set of inflammatory and infiltrative alterations of the orbital tissue that affects 40-90% of subjects suffering from GBD. Our study aims to investigate the differences in the clinical outcomes of patients treated with two different techniques: the classic open and the more modern endoscopic. A retrospective clinical study was carried out from the year 2011 until the year 2020 to evaluate the clinical outcomes of two different surgical techniques for the treatment of GBO. Eighteen patients were given surgical indications, 12 males and 6 females aged between 37 and 69 years (average age 48.5 years), for a total of 36 orbits. From the year 2011 to the year 2014, all patients were treated with the open orbital decompression technique; from 2015 onwards, patients were subjected to orbital decompression with the endoscopic transnasal approach. Pre- and postoperative ophthalmometry, reduction of proptosis, and reduction of oculo-orbital index were compared for the two techniques. As evidenced by the statistical analysis carried out on the sample before and after surgical treatment, there is a statistically significant difference between ophthalmometry and the Oculo-Orbital Index (IOO) values; this indicates that surgical orbital decompression with two walls (floor and medial wall) is effective in reducing exophthalmos. The positive result is also confirmed by the reduction of proptosis, measured in millimeters, averaging 1.7 mm. In the analysis of data relating to the two different patient groups, treated respectively with endoscopic orbital decompression (Technique 1) and classical open orbital decompression (Technique 2), the results obtained show that there is no statistically significant difference between the results of the two techniques. Therefore, the choice of surgical approach is at the discretion of the surgeon. It is our opinion that orbital decompression with the endoscopic transnasal technique should be an absolute indication in all patients who have clinical and radiographic signs of involvement of the optic nerve at the orbital apex (crowded apex syndrome) thanks to the ability of this technique to add and decompress the optical channel at the apex. For all other patients with GBO, the endoscopic technique of orbital decompression can be indicated as a first-line surgical approach considering the absence of skin scars and the best aesthetic results.

Prediction of exophthalmos by body mass index for craniofacial reconstruction: consequences for cold cases

It is inconvenient for a forensic practitioner to gather population-specific data before performing a facial reconstruction. The inconvenience may defeat the point of creating the reconstruction. The objective of this study was to evaluate a non-population-dependent method of determining exophthalmos. The protrusion of the eyeball is known to vary with the contents of the orbital cavity based on bony orbital resorption or increased or decreased fat contents, as well as according to relative eyeball size. Of use are available statistics on body mass index, and this is discussed within the context of eyeball protrusion. A weak positive correlation (0.3263) between the body mass index of the country where the study originated, and the degree of exophthalmos was found. The results suggest that eyeball protrusion rates can be established according to body mass index, and this framework may be more useful considering conventional police practices.

Dysthyroid Optic Neuropathy

PURPOSE

Dysthyroid optic neuropathy (DON) is a sight-threatening complication of thyroid eye disease (TED). This review provides an overview of the epidemiology, pathogenesis, diagnosis, and current therapeutic options for DON.

METHODS

A literature review.

RESULTS

DON occurs in about 5% to 8% of TED patients. Compression of the optic nerve at the apex is the most widely accepted pathogenic mechanism. Excessive stretching of the nerve might play a role in a minority of cases. Increasing age, male gender, smoking, and diabetes mellitus have been identified as risk factors. Diagnosis of DON is based on a combination of ≥2 clinical findings, including decreased visual acuity, decreased color vision, relative afferent pupillary defect, visual field defects, or optic disc edema. Orbital imaging supports the diagnosis by confirming apical crowding or optic nerve stretching. DON should be promptly treated with high-dose intravenous glucocorticoids. Decompression surgery should be performed, but the response is incomplete. Radiotherapy might play a role in the prevention of DON development and may delay or avoid the need for surgery. The advent of new biologic-targeted agents provides an exciting new array of therapeutic options, though more research is needed to clarify the role of these medications in the management of DON.

CONCLUSIONS

Even with appropriate management, DON can result in irreversible loss of visual function. Prompt diagnosis and management are pivotal and require a multidisciplinary approach. Methylprednisolone infusions still represent first-line therapy, and surgical decompression is performed in cases of treatment failure. Biologics may play a role in the future.

The Changes in Ocular Biomechanical Response Parameters and Intraocular Pressure After Surgical Treatment for Thyroid Eye Disease

Purpose

To investigate changes in ocular biomechanical response parameters and intraocular pressure (IOP) in patients with thyroid eye disease (TED) undergoing orbital decompression or anterior blepharotomy.

Methods

Eighty-three eyes from 46 patients receiving orbital decompression (the orbital decompression group) and 45 eyes from 28 patients receiving anterior blepharotomy (the anterior blepharotomy group) were retrospectively enrolled from a tertiary center. Corvis ST tonometry was used to assess ocular biomechanical response and biomechanically corrected IOP (bIOP) pre- and postoperatively. Non-contact tonometry (IOP-NCT) was also performed.

Results

In the anterior blepharotomy group, the margin reflex distance decreased (P < 0001). The highest concavity radius (P = 0.026) and whole eye movement (P = 0.003) increased. Neither IOP-NCT nor bIOP had a significant change. In the orbital decompression group, the extent of exophthalmos decreased (P < 0.001). The A2 length (P = 0.009) decreased. The bIOP did not show a significant change (16.4 ± 2.7 vs. 16.7 ± 4.5; P = 0.415), but the IOP-NCT decreased significantly (17.5 ± 3.3 vs. 16.0 ± 3.3; P < 0.001). Higher baseline IOP-NCT (β = -0.40, P < 0.001) and greater reduction in stiffness parameter A1 (SP-A1; β = 0.05, P = 0.002) were associated with more significant IOP-NCT reduction after the orbital decompression.

Conclusions

Ocular biomechanical response parameters may change after TED surgery, potentially affecting IOP measurements, particularly in patients receiving orbital decompression.

Effects of Androgen Deprivation Therapy on Extraocular Muscles, Retrobulbar Orbital Fat, and the Optic Nerve in Patients with Prostate Cancer

INTRODUCTION

The aim of this study was to evaluate radiologically the effects of long-term luteinizing hormone-releasing hormone (LHRH) agonist therapy on extraocular muscle thickness, retrobulbar orbital fat (ROF), and the optic nerve (ON) in prostate cancer (PCa) patients.

METHODS

The retrospective study included patients with primary or recurrent PCa who received androgen deprivation therapy (ADT) for at least 12 months. Each patient underwent gallium-68 prostate-specific membrane antigen positron emission tomography-computed tomography both before and at the end of the 12-month treatment. Thickness of the ON, lateral rectus muscle, medial rectus muscle, superior rectus muscle, and inferior rectus muscle were measured by using the coronal CT sections in soft tissue window. ROF, ocular protrusion, and ON length were measured in sagittal and coronal planes. Changes in these anatomical structures induced by LHRH analogs were investigated by comparing pre- and post-treatment measurements.

RESULTS

A total of 57 patients were included in the study. Median PSA and TT values ​​of the patients before treatment were 36.5 (range, 19.6-51.2) ng/mL and 614.0 (range, 472.0-743.0) ng/dL, respectively, and these values ​​decreased significantly after the treatment (10.6 [range, 5.2-14.2] ng/mL and 36.5 [range, 19.6-51.2] ng/dL, respectively, p < 0.001 for both). After the treatment, there was a statistically significant decrease in the areas of inferior rectus muscle, superior rectus muscle, lateral rectus muscle, and medial rectus muscle (p < 0.001 for all), while significant increases were observed in ROF (11.9%, p < 0.001) and ON thickness (14.3%, p = 0.004). The amount of ocular protrusion also showed a significant increase of approximately 14% after the treatment (14.0 [range, 12.0-16.0] mm vs. 16.0 [range, 14.0-17.2] mm, p < 0.001).

DISCUSSION/CONCLUSION

Our findings, for the first time in the literature, indicated that ADT causes a decrease in extraocular muscle mass and an increase in ROF with ocular protrusion. It can be asserted that these changes are similar to the changes in skeletal muscle and fat mass in other body parts. Further studies with a higher level of evidence are needed to clinically evaluate the increase in ocular protrusion and ON enlargement, which are likely to be caused by the increase in ROF.

Different Characteristics of Orbital Soft Tissue Expansion in Graves Orbitopathy: Extraocular Muscle Expansion is Correlated to Disease Activity While Fat Tissue Volume With Duration

This study aimed to describe the correlation between some clinical features and orbital soft tissue volume in Graves orbitopathy (GO). The authors collected computed tomography scans from 56 untreated GO patients and measured fat volume (FV), intraorbital and extraorbital FV (IFV, EFV), bony cavity volume (BV), and extraocular muscle volume (MV) of the 112 orbits by using Mimics software. The ratio of soft tissue volume and BV were used to eliminate the individual variations. Outcomes were compared among groups and were correlated with clinical data, including age, sex, clinical activity score, duration, serum TSH receptor antibody (TRAb) level, body mass index and smoking status. Multivariate linear regression showed that higher MV/BV is associated with higher CAS and TRAb level ( P< 0.001, 0.005, res p ectively). No relationship was found between MV/BV and duration, sex, age, and body mass index. IFV/BV was related to duration (β=0.138, 95% confidence interval: 0.076-0.201, P <0.001), and did not correlate to clinical activity. IFV and MV are positively associated with exophthalmometry ( P =0.009, <0.001, respectively), while orbital bony volume (BV) is negatively correlated with exophthalmometry ( P =0.025). Results suggested TRAb level can impact the severity of GO mainly by affecting extraocular muscle rather than fat tissue. MV of GO is associated with disease activity, whereas IFV is correlated with duration and increases over time.

Adjunctive Middle Turbinectomy for Endoscopic Medial Orbital Wall – Thyroid Eye Disease Decompression

Introduction Middle turbinate resection (MTR) is commonly performed during endonasal endoscopic sinus and skull base surgery.

Objective The purpose of this study was to characterize the additional orbital soft-tissue volume expansion during endoscopic medial orbital wall decompression with adjunctive MTR.

Methods A retrospective review of patients who underwent endoscopic medial wall decompression with MTR was performed. The imaging software AW (GE Healthcare, Chicago, IL, USA) was used to overlay pre and postoperative orbital computed tomography (CT) images to visualize the preoperative position of the middle turbinate and the postoperative orbital soft tissue in the ethmoid bed. The imaging software Vitrea (Vital Images Inc., Minnetonka, MN, USA) was used to manually segment postoperative scans to determine the volume of orbital tissue which had filled the space previously occupied by the middle turbinate or medial to it.

Results Nine orbits from 5 patients were included in this study; all patients were female with a history of hyperthyroidism. The average age was 55.6 years (range 32–74). Of the 9 orbits, 7 (78%) had orbital soft tissue within the space of the resected middle turbinate postoperatively. The average volume of orbital tissue within or medial to this space was 0.83 +/− 0.67 cc. No patients had any postoperative complications.

Conclusions In this patient cohort, adjunctive middle turbinate resection for endoscopic medial orbital wall decompression added ∼ 0.83 cc of volume for orbital soft tissue after medial wall decompression. Middle turbinate resection is a useful adjunct to the orbital surgeon's armamentarium to augment the results of a medial orbital decompression for select patients.

A new radiological measurement method used to evaluate the modified transconjunctival orbital fat decompression surgery

Purpose

A new radiological method was used to evaluate the plastic effect of modified transconjunctival orbital fat decompression surgery in patients with inactive thyroid-associated ophthalmopathy.

Methods

In this study, 10 inactive patients (14 eyes) with moderate to severe thyroid-associated ophthalmopathy were selected. The patients underwent modified transconjunctival orbital fat decompression surgery. According to the results of a spiral CT scan before and 6 months after the surgery, the INFINITT system workstation was used to measure the eyeball protrusion value. According to the results obtained by the PHLIPS IntelliSpace Portal elliptical area and line segment measurement tools, the standard elliptical vertebral volume formula was used to calculate the muscular cone inner volume. Changes in eyeball protrusion and the inner volume of the muscular cone before and after surgery were examined. Statistical analysis of the correlation between the two parameters was performed.

Results

Radiological measurement results confirmed that removing the orbital fat in the muscle cone during surgery was effective for alleviating eyeball protrusion in patients with thyroid-associated ophthalmopathy (P < 0.05). This surgery caused an obvious change in the muscle cone inner volume (P < 0.05). And there was significant correlation between changes in eyeball protrusion and muscle cone inner volume (r = 0.797, P = 0.0006, P < 0.05).

Conclusion

The radiological assessment method used in this study is simple and easy to implement. For inactive patients with moderate to severe thyroid-associated ophthalmopathy who just want to improve their appearance, the modified orbital fat decompression surgery is worth considering.

Strategies in Surgical Decompression for Thyroid Eye Disease

Surgical management of thyroid eye disease- (TED-) associated morbidity has been plagued by the complex interplay of different operative techniques. Orbital decompression is the well-recognized procedure for disfiguring exophthalmos and dysthyroid optic neuropathy (DON). There are numerous published techniques described for the removal of the orbital bone, fat, or a combination. The diverse studies are noncomparative as they include different indications, stages of disease, and methods of evaluation. Thus, it is difficult to conclude the most efficient decompression technique. To obtain effective and predictable results, it is therefore important to propose a logical and acceptable clinical guideline to customize patient treatment. Herein, we developed an algorithm based on the presence of DON, preoperative existing diplopia, and severity of proptosis which were defined by patient's disabling symptoms together with a set of ocular signs reflecting visual function or cosmesis. More specifically, we aimed to assess the minimal but effective surgical technique with acceptable potential complications to achieve therapeutic efficacy. Transcaruncular or inferomedial decompressions are indicated in restoring optic nerve function in patients with DON associated with mild or moderate to severe proptosis, respectively. Inferomedial or fatty decompressions are effective to treat patients with existing diplopia associated with mild or moderate to severe proptosis, respectively. Fatty or balanced decompressions can improve disfiguring exophthalmos in patients without existing diplopia associated with mild to moderate or severe proptosis, respectively. Inferomedial or 3-wall decompressions are preferred to address facial rehabilitation in patients associated with very severe proptosis but without preoperative diplopia.

Semi-automatic magnetic resonance imaging based orbital fat volumetry: reliability and correlation with computed tomography

Post-processing analysis can provide valuable information for diagnosis and planning of orbital disorders. This cross-sectional study aims to evaluate the reliability of semi-automatic, orbital fat volumetry using magnetic resonance imaging (MRI). Two observers assessed the orbital fat volume using a standard MRI protocol (3T, T1w sequence) in 12 orbits diagnosed with Graves' orbitopathy (GO) and 10 healthy control orbits. MRI and computed tomography (CT) based analysis were compared. Intra-observer variability was good (intraclass correlation coefficient (ICC) 0.88; 95% confidence interval (CI) [0.70, 0.95]) and interobserver agreement was moderate (ICC 0.55; 95% CI [-0.09, 0.81]), which corresponds to a mean percentage difference of 1.3% and 17.9% of the total orbital fat volume. Mean differences between MRI and CT measurements were, respectively, 1.1 cm³ (P= 0.064, 95% CI [-0.20, 2.43]) and 1.4 cm³ (P=0.016, 95% CI [0.21, 2.56]) for the control and the GO group. MRI volumetry was strongly correlated with CT (Pearson's r= 0.7, P<0.001). We conclude that orbital fat volumetry is feasible with a semi-automatic segmentation procedure and standard MRI protocol. Correlation with CT volumetry is good, but considerable bias may derive from observer variability and these errors should be taken into account for the purpose of volumetric analysis. Better definition of error sources may increase measurement accuracy.

Orbital anatomical parameters affecting outcome of deep lateral orbital wall decompression

PURPOSE

To determine orbital anatomical parameters that affect surgical outcome of deep lateral orbital wall decompression.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Endoscopic orbital fat decompression for the management of proptosis in Grave's orbitopathy using a laryngeal skimmer blade

BACKGROUNDS/OBJECTIVES

Intraoperative handling and manipulation of orbital fat remains a challenge to orbital surgeons. We present a case series of endoscopic orbital fat decompression with medial orbital wall decompression for proptosis management in Grave's orbitopathy, describing a technique for fat excision using a laryngeal skimmer blade, reporting clinical and surgical outcomes, and complications.

SUBJECTS/METHODS

All patients who underwent endoscopic orbital fat decompression, with medial orbital wall decompression, for proptosis management in Grave's orbitopathy between 2011 and 2018, under the care of a single surgeon, were included in this retrospective interventional case series.

RESULTS

Nineteen patients were included in this study. Using a laryngeal skimmer blade, orbital fat was excised endoscopically at the time of medial orbital wall decompression. The mean volume of orbital fat excised was 1.45 ± 0.63 ml and the mean reduction in proptosis was 4.5 ± 1.02 mm. There were no intraoperative complications.

CONCLUSIONS

In this study, we describe our experience of using a laryngeal skimmer blade as a method of excising orbital fat for orbital decompression in patients with proptosis secondary to Grave's orbitopathy.

Double Vision After Minimally Invasive Orbital Decompression

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

DISCUSSION

Double vision following minimally invasive orbital decompression is rare and the mechanisms are poorly understood.

Orbital decompression for thyroid eye disease: methods, outcomes, and complications

PurposeTo determine the safety and effectiveness of orbital decompression for thyroid eye disease (TED) in our unit. To put this in the context of previously published literature.Patients and methodsA retrospective case review of all patients undergoing orbital decompression for TED under the care of one orbital surgeon (SMS) between January 2009 and December 2015. A systematic literature review of orbital decompression for TED.ResultsWithin the reviewed period, 93 orbits of 55 patients underwent decompression surgery for TED. There were 61 lateral (single) wall decompressions, 17 medial one-and-a-half wall, 11 two-and-a-half wall, 2 balanced two wall, and 2 orbital fat only decompressions. For the lateral (single) wall decompressions, mean reduction in exophthalmometry (95% confidence interval (CI) was 4.2 mm (3.7-4.8), for the medial one-and-a-half walls it was 2.9 mm (2.1-3.7), and for the two-and-a-half walls it was 7.6 mm (5.8-9.4). The most common complications were temporary postoperative numbness (29% of lateral decompressions, 17% of other bony decompressions, OR 0.50, 95% CI 0.12-2.11) and new postoperative diplopia (9% of lateral decompressions, 39% of other bony decompressions, OR 6.8, 95% CI 1. 5-30.9). Systematic literature searching showed reduction in exophthalmometry for lateral wall surgery of 3.6-4.8 mm, with new diplopia 0-38% and postoperative numbness 12-50%. For other bony decompressions, reduction in exophthalmometry was 2.5-8.0 mm with new diplopia 0-45% and postoperative numbness up to 52%.ConclusionDiffering approaches to orbital decompression exist. If the correct type of surgery is chosen, then safe, adequate surgical outcomes can be achieved.

Fat-removal orbital decompression for thyroid associated orbitopathy: The right procedure for the right patient

Orbital decompression is an effective and invaluable procedure for addressing some of the chronic manifestations of Graves’ Ophthalmopathy (GO) such as exophthalmos and orbital congestion. Fat–removal orbital decompression (FROD) started to gain popularity after its introduction in the late 20th century. Among the therapeutic armamentarium of techniques and approaches available for orbital decompression, FROD has proven its efficacy and safety in addition to its ability to reduce proptosis in a relatively predictable manner. In addition, postoperative complications occurring after FROD are generally considered to be less frequent and less serious compared to bone-removal orbital decompression (BROD). Nevertheless, despite of FROD’s high benefit-to-risk ratio, proper selection of patients based on meticulous preoperative assessment, including imaging, is of paramount importance to achieve optimal functional and aesthetic results. Although up till now there is still no consensus regarding the procedure of choice in GO patients, FROD is an important option to consider in this subset of patients.

Long-term outcomes of orbital fat decompression in Graves’ orbitopathy

Purpose

To evaluate the long-term clinical efficacy of orbital fat decompression in treating proptosis in Graves' ophthalmopathy (GO).

Methods

Retrospective review of 1604 eyes of 845 patients with symmetric (1518 eyes) and asymmetric (86 eyes) proptosis who received orbital fat decompression between 2003 and 2014. Changes in Hertel values were evaluated at baseline, 6 months postoperatively and yearly thereafter. Recurrence of proptosis, diplopia and other complications that required additional surgeries were documented and analysed. The surgical outcome was defined as complete success if there was proptosis reduction with no recurrence and improved or no diplopia. Partial success was considered if there was proptosis reduction without recurrence yet persistent or new-onset diplopia. Failure was considered if there was recurrence of proptosis regardless of diplopia. The patient’s quality of life was also evaluated as a long-term outcome.

Results

After follow-up for 37.9±24.4 months, 1365 eyes (85.1%) achieved complete success, 219 eyes (13.7%) achieved partial success and 20 eyes (1.2%) had failure. Newly onset diplopia and secondary decompression occurrence rate remained low at 3.3% and 0.6%, respectively. The total proptosis reduction was 4.1±1.3 mm, which was consistent all through the intermediate and long-term (5–10 years) follow-up. The amount of orbital fat removal (4.5±1.1 mL) played a significant role in the long-term Hertel change. Importantly, the overall quality of life increased significantly for GO patients after undergoing orbital fat decompression.

Conclusions

Orbital fat decompression has a long-term efficacy in correcting disfiguring proptosis with a low complication rate and without the need of secondary decompression procedures. This was also associated with a significant improvement in quality of life.

Orbital decompression for thyroid eye disease

The literature regarding orbital decompression for thyroid eye disease is vast, spanning multiple specialty areas including neurosurgery, head and neck, maxillofacial, and ophthalmic plastic surgery. Although techniques have advanced considerably over the more than 100 years during which this procedure has been performed, the 4 major approaches remain: transorbital, transcranial, transantral, and transnasal. The explosion in literature related to orbital decompression has mostly involved minor technical variations on broader surgical themes. The purpose of this review is to organize the major approaches in terms of bony anatomy and to contextualize variation in transdisciplinary techniques within a common conceptualization.

Endoscopical Orbital Fat Decompression with Medial Orbital Wall Decompression for Dysthyroid Optic Neuropathy

OBJECTIVE

To describe a novel approach to orbital decompression for dysthyroid optic neuropathy (DON).

METHODS

An augmented endoscopic transethmoid medial orbital wall decompression (ETMOWD) was performed on 43 consecutive patients (72 eyes) with DON in order to access the orbital apex adequately. Concurrently, endoscopic transethmoid fat decompression (ETFD) using a novel aspiration/cutting instrument to remove orbital fat was performed for further reduction of proptosis. All patients were followed up periodically for at least 6 months. Outcomes such as improvement of visual acuity (VA), color vision, degree of proptosis reduction as well as the incidence of surgical induced diplopia were analyzed at the final review.

RESULTS

Sixty-nine out of 72 eyes (95.8%) had a statistically significant improvement in VA from -0.65 ± 0.30 to -0.25 ± 0.22 postoperatively, with a mean improvement of 0.55 ± 0.17 (p < 0.001). Thirty-four out of 45 eyes had an improvement in color vision (p < 0.001). The range of proptosis reduction was 4 to 9 mm (mean 6.2 ± 1.2 mm). Postoperative symmetry was achieved to within 2 mm using an exophthalmometer in 39 of 43 patients (90.7%). Five patients developed diplopia in the postoperative phase, but had complete resolution within 3 months. Two patients had further deterioration in their diplopia following surgery.

CONCLUSION

Our technique of a combined ETFD with ETMOWD appears to be effective in managing patients with DON, with minimal morbidities and a low incidence of postoperative diplopia.

Endoscopic medial orbital fat decompression for proptosis in type 1 graves orbitopathy

PURPOSE

To describe the surgical technique for endoscopic medial orbital fat decompression in type 1 (lipogenic) Graves orbitopathy and report outcomes.

DESIGN

Retrospective interventional case review.

METHODS

We reviewed 108 patients (206 orbits) with inactive, type 1 Graves orbitopathy without diplopia, who underwent endoscopic medial orbital fat decompression solely for proptosis reduction. Following endoscopic transethmoid medial orbital wall decompression, extraconal and intraconal orbital fat was removed with a low-suction cutting instrument. All patients were followed up for at least 12 months. Surgical time, preoperative and postoperative Hertel exophthalmometry, incidence of postoperative diplopia within 30-degree visual field in the primary gaze, and other complications were analyzed.

RESULTS

The mean surgical time was 97.7 ± 16.7 minutes (67-136 minutes). The mean follow-up was 16.0 ± 4.2 months (12-24 months). Preoperative and postoperative proptosis values at final review were 21.1 ± 2.3 mm (17-26 mm) and 13.0 ± 0.9 mm (12-15 mm), respectively (P < .001). Median reduction in proptosis was 8.0 mm with mean of 8.2 ± 1.8 mm (4-11 mm). Symmetry to within 2 mm was achieved in 106 of 108 patients (98.1%). Twenty-five of 108 patients (23.1%) had diplopia within 30-degree visual field of the gaze, and 23 of these had complete resolution within 3 months, while the remaining 2 patients required squint surgery.

CONCLUSIONS

Endoscopic medial orbital fat decompression may be an effective technique for proptosis in selected patients with type 1 Graves orbitopathy and is associated with a low rate of surgically induced diplopia.

Surgical effects of various orbital decompression methods in thyroid-associated orbitopathy: computed tomography-based comparative analysis

OBJECTIVES

To evaluate the surgical effects of orbital fat decompression and bony decompression in each orbital wall using computed tomography (CT) in thyroid-associated orbitopathy (TAO).

METHODS

In 27 TAO patients (48 orbits) with exophthalmos who underwent orbital wall decompression combined with fatty decompression, we recorded the resected orbital fat volume intraoperatively and estimated the decompression volume of the orbital wall in the deep lateral, medial and inferior walls using postoperative orbit CT images. Then, the correlation between exophthalmos reduction by Hertel reading and decompression volume in each area was analyzed to validate the surgical predictability, surgical efficiency and contribution level to total exophthalmos reduction.

RESULTS

The decompression volume in orbital fat and the deep lateral wall showed relatively high correlation with exophthalmos reduction (surgical predictability) compared to medial and inferior wall. The surgical efficiency was highest at deep lateral wall (2.704 ± 0.835 mm/cm(3)), followed by medial wall (0.892 ± 0.527 mm/cm(3)), orbital fat (0.638 ± 0.178 mm/cm(3)) and inferior wall (0.405 ± 0.996 mm/cm(3)). The actual contribution level to total exophthalmos reduction was highest in fatty decompression, followed by deep lateral decompression.

CONCLUSION

In TAO patients with exophthalmos, orbital fat and deep lateral orbital wall are more predictable and contributory surgical targets for postsurgical exophthalmos reduction.

Graded decompression of orbital fat and wall in patients with Graves' orbitopathy

Purpose

To investigate the results of graded decompression of orbital fat and walls in Graves' orbitopathy (GO) considering the degree of proptosis reduction at surgery and preoperative computed tomography (CT) findings.

Methods

This is a retrospective interventional case series. Graded orbital fat and wall decompression was performed in 90 orbits of 55 patients. In patients with enlarged extraocular muscles and minimal orbital fat proliferation in preoperative CT scans, one- or two-wall decompression of posterior orbit was performed with minimal fat excision. In other cases, the maximal amount of fat tissue was removed from the post-septal area to the apex. If the proptosis was not satisfactorily symmetrically reduced at surgery, one- or two-wall decompression was performed successively. Symmetric reduction of proptosis was consistently confirmed intraoperatively to assure that a desired amount of exophthalmos reduction was achieved.

Results

Four types of decompression were performed: fat only (group 1), fat and one-wall (group 2), fat and two-wall (group 3), and two-wall and minimal fat decompression (group 4). The mean preoperative Hertel value (20.6 ± 2.8 mm) was reduced significantly at six months postoperatively (16.1 ± 2.3 mm). Proptosis significantly decreased with a mean of 4.3 ± 1.7 mm, and the reduction was greatest (5.1 ± 2.1 mm) in group 3. In group 1, a significant correlation between Hertel change and the volume of resected orbital fat was found (r = 0.479). Diplopia was newly developed or aggravated postoperatively in eight patients, and six of these patients were in group 3. With the exception of one patient, visual acuity improved to nearly normal postoperatively in all patients with optic neuropathy.

Conclusions

Graded orbital decompression of orbital fat and bony walls, as assessed by the degree of proptosis reduction during surgery, was effective and predictable with minimal complications in GO patients with vision-threatening or cosmetically disfiguring proptosis.

Long-term outcomes of unilateral orbital fat decompression for thyroid eye disease

BACKGROUND

The aim of this study was to evaluate the long-term outcomes after unilateral orbital fat decompression in patients with thyroid eye disease.

DESIGN

Retrospective, comparative, cross-sectional study

PARTICIPANTS

Thirty-three orbits of 33 patients were included in this study. Of the 33 patients, 13 underwent fat decompression (group A), and the other 20 had bony decompression (group B).

METHODS

The medical records of patients who underwent orbital decompression to reduce proptosis for thyroid eye disease were retrospectively reviewed. The degrees of proptosis were measured by Hertel exophthalmometry preoperatively and over a follow-up period of more than 3 years. We evaluated the change in proptosis after surgery.

MAIN OUTCOME MEASURES

Postoperative change in exophthalmos.

RESULTS

A recurrence in proptosis from fat decompression was seen in ten patients (76.9 %) in group A and in only two patients (10 %) in group B. The amount of regression due to surgery after 3 years was 2.3 ± 1.4 mm and 0.7 ± 0.9 mm in groups A and B respectively. The tendency of regression was more prominent in group A than in group B.

CONCLUSION

The long-term effect of unilateral orbital fat decompression for the reduction of proptosis in patients with thyroid eye disease may be weak, leading to regression. Care should be taken when determining the extent of fat decompression with consideration for this tendency.

Predicting dysthyroid optic neuropathy using computed tomography volumetric analyses of orbital structures

OBJECTIVE

To evaluate the ability of orbital apex crowding volume measurements calculated with multidetector-computed tomography to detect dysthyroid optic neuropathy.

METHODS

Ninety-three patients with Graves' orbitopathy were studied prospectively. All of the patients underwent a complete neuro-ophthalmic examination and computed tomography scanning. Volumetric measurements were calculated from axial and coronal contiguous sections using a dedicated workstation. Orbital fat and muscle volume were estimated on the basis of their attenuation values (in Hounsfield units) using measurements from the anterior orbital rim to the optic foramen. Two indexes of orbital muscle crowding were calculated: i) the volumetric crowding index, which is the ratio between soft tissue (mainly extraocular muscles) and orbital fat volume and is based on axial scans of the entire orbit; and ii) the volumetric orbital apex crowding index, which is the ratio between the extraocular muscles and orbital fat volume and is based on coronal scans of the orbital apex. Two groups of orbits (with and without dysthyroid optic neuropathy) were compared.

RESULTS

One hundred and two orbits of 61 patients with Graves' orbitopathy met the inclusion criteria and were analyzed. Forty-one orbits were diagnosed with Graves' orbitopathy, and 61 orbits did not have optic neuropathy. The two groups of orbits differed significantly with regard to both of the volumetric indexes (p<0.001). Although both indexes had good discrimination ability, the volumetric orbital apex crowding index yielded the best results with 92% sensitivity, 86% specificity, 81%/94% positive/negative predictive value and 88% accuracy at a cutoff of 4.14.

CONCLUSION

This study found that the orbital volumetric crowding index was a more effective predictor of dysthyroid optic neuropathy than previously described computed tomography indexes were.