Reversal of dysthyroid optic neuropathy following orbital fat decompression

Evaluation of lamina cribrosa and peripapillary vascular density in thyroid orbitopathy and effect of intravenous methylprednisolone therapy

OBJECTIVE

To evaluate optic nerve head changes in patients with thyroid orbitopathy (TO) and investigate the effects of intravenous methylprednisolone (IV MTP) on these changes.

METHODS

Eighty-two eyes of 41 patients with TO with and without dysthyroid optic neuropathy (DON) and 40 eyes of 40 healthy control subjects were included in the study. Lamina cribrosa thickness (LCT) and depth (LCD) measurements, peripapillary retinal nerve fibre layer thickness (RNFLT), and radial peripapillary capillary vascular density were measured using optical coherence tomography and optical coherence tomography angiography. Visual field examination and proptosis were evaluated. Patients with DON and active non-DON received IV MTP for 12 weeks, and the effect of this treatment was evaluated.

RESULTS

Peripapillary vascular density decreased in patients with DON compared with the other groups (p < 0.001 for all); there was no difference in the total, superior hemi-sector, and inferior hemi-sector of the RNFLT between the groups. LCT was decreased in the TO group (p < 0.001). After IV MTP treatment, the LCT and best-corrected visual acuity were increased. Thyroid-stimulating hormone receptor antibody levels, intraocular pressure, the superior hemi-sector of the RNFLT, and proptosis were decreased compared with the control subjects (p = 0.012, p = 0.008, p = 0.043, and p < 0.001, respectively).

CONCLUSIONS

The RNFLT may not always increase in DON. Lamina cribrosa morphology may change in patients with TO. IV MTP therapy has a positive effect on the LCT but not on radial peripapillary capillary vascular density or LCD.

Dysthyroid Optic Neuropathy Dramatically Improved by Sheath-Guided Triamcinolone Orbital Injection: A Case Report

Thyroid eye disease is an autoimmune disorder caused by thyroid-stimulating hormone receptor autoantibodies stimulating the thyroid-stimulating hormone receptor, resulting in proptosis, extraocular muscle dysfunction, diplopia, retro-orbital pain, optic nerve compression, and visual impairment. Dysthyroid optic neuropathy (DON), believed to result from direct compression by enlarged extraocular muscles, represents a severe complication with the potential for irreversible vision loss. Currently, the treatment options for DON are limited to highly invasive procedures, such as orbital decompression surgery and systemic steroid pulse therapy. There are consequently significant challenges in the management of this condition. This report presents a case where a significant improvement in DON was achieved solely through the novel technique of sheath-guided orbital triamcinolone injection, which was utilized with the aim of reaching the deeper part of the orbit under sheath guidance. In this case, the best corrected visual acuity improved from 20/32 (decimal visual acuity: 0.7) to 20/20 (1.2) in the right eye and from 20/500 (0.04) to 20/20 (1.2) in the left eye. Critical flicker frequency values also improved, from 20.3 Hz to 35.0 Hz in the right eye and from 9.3 Hz to 31.5 Hz in the left eye. The cross-sectional areas of the extraocular muscles decreased by an average of 55.5%.

Optical coherence tomography and shear wave elastography findings in Graves ophthalmopathy

PURPOSE

The main feature of Graves ophthalmopathy (GO) is revealed by determining the activity and severity of the disease. We aimed to evaluate the use of imaging methods can also provide additional information about the severity of this disease.

METHODS

Optical coherence tomography (OCT) and shear wave elastography (SWE) findings were compared in 32 patients with mild GO group and in the healthy control group. Measuring for TSH receptor antibody (TRAb) serum level is used third-generation assay.

RESULTS

In Graves group, optic nerve sheath diameter (ONSD) values were increased in both eyes (p < 0.001, p < 0.001). SWE measurements showed a significant increase both eye optic nerve (ON) and right eye soft tissue elasticity values in GO group (p < 0.001, p < 0.001, p < 0.001, respectively). There was a significant thinning in left temporal retinal nerve fiber layer (RNFL) thickness and left RNFL peripapillary thickness in GO group (p < 0.001, p < 0.025, respectively). There was a correlation between left eye OCT and SWE findings. Also, there was a significant difference between the median left eye ON and soft tissue elasticity results in the TRAb-positive GO group (p = 0.049, p = 0.048, respectively).

CONCLUSION

SWE measurements showed a significant increase both eyes ONSD, ON and right eye soft tissue elasticity values in GO group. GO group was significant thinning in some left eye regions in OCT measurements. There was a correlation between left eye OCT and SWE findings. In addition to clinical activity score and TRAb, SWE and OCT can be used to monitor in patients with GO.

Surgical management of dysthyroid optic neuropathy: A systematic review

OBJECTIVE

There is currently no recommendation on the optimal surgical management for dysthyroid optic neuropathy (DON). The aim of this study is to systematically review the surgical management of DON and its outcome on visual acuity (VA).

DATA SOURCES

MEDLINE, Cochrane Library, and clinicaltrials.gov REVIEW METHODS: A systematic review of studies about the surgical management of DON was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Articles were included if preoperative and postoperative VA in logMAR (Logarithm of the Minimum Angle of Resolution) were available.

RESULTS

Fifteen articles were included in the study accounting for 669 orbits. The mean VA improvement was of 0.44 logMAR overall, 0.41 logMAR for 1-wall, 0.41 logMAR for 2-wall, and 0.55 logMAR for 3-wall decompressions. The mean reduction in exophthalmos was 4.9 mm overall, 4.3 mm for 1-wall, 4.54 mm for 2-wall, and 6.02 for 3-wall decompressions. The mean new onset diplopia (NOD) rate was 19.84% overall, 19,12% for 1-wall, 20.75% for 2-wall, and 19.83% for 3-wall decompressions.

CONCLUSION

The results are limited due to the high number of biases in the included studies. It seems that 3-wall decompression offers the best VA improvement and proptosis reduction although also the highest NOD and complications rate. Two-wall balanced decompression or 1-wall inferomedial decompression seems to be effective with less morbidity.

Extraocular muscle volume index at the orbital apex with optic neuritis: a combined parameter for diagnosis of dysthyroid optic neuropathy

OBJECTIVES

To evaluate the diagnostic performance of the extraocular muscle volume index at the orbital apex (AMI) and the signal intensity ratio (SIR) of the optic nerve in dysthyroid optic neuropathy (DON).

METHODS

Clinical data and magnetic resonance imaging were collected retrospectively from 63 Graves' ophthalmopathy patients, including 24 patients with DON and 39 without DON. The volume of these structures was obtained by reconstructing their orbital fat and extraocular muscles. The SIR of the optic nerve and axial length of eyeball were also measured. The posterior 3/5 of the retrobulbar space volume was used as the orbital apex to compare parameters in patients with or without DON. Area under the receiver operating characteristic curve (AUC) analysis was used to select the morphological and inflammatory parameters with the highest diagnostic value. A logistic regression was performed to identify the risk factors of DON.

RESULTS

One hundred twenty-six orbits (35 with DON and 91 without DON) were analyzed. Most of the parameters in DON patients were significantly higher than in non-DON patients. However, the SIR 3 mm behind the eyeball of the optic nerve and AMI had the highest diagnostic value in these parameters and are independent risk factors of DON by stepwise multivariate logistic regression analysis. Combining AMI and SIR had a higher diagnostic value than a single index.

CONCLUSIONS

Combining AMI with SIR 3 mm behind the eyeball's orbital nerve can be a potential parameter for diagnosing DON.

CLINICAL RELEVANCE STATEMENT

The present study provided a quantitative index based on morphological and signal changes to assess the DON, allowing clinicians and radiologists to monitor DON patients timely.

KEY POINTS

The extraocular muscle volume index at the orbital apex (AMI) has excellent diagnostic performance for dysthyroid optic neuropathy. A signal intensity ratio (SIR) of 3 mm behind the eyeball has a higher AUC compared to other slices. Combining AMI and SIR has a higher diagnostic value than a single index.

Orbital Decompression: Conceptual Approach for Orbital Volume Expansion

PURPOSE

To review the advances in the surgical techniques of orbital decompression.

METHODS

A literature review of orbital decompression surgery and experience-based consideration of bony areas for decompression.

RESULTS

In the 100-year-plus span of orbital decompression literature, multiple incisions and multiple bone and fat removal strategies have been described. In general, bone removal has been conceptualized as consisting of 4 walls of the orbit. However, the orbital bony anatomy is more subtle than a simple box, and considering 6 areas of potential bony removal allows a more nuanced paradigm for clinical decision-making and for understanding various technique descriptions. Historical and current techniques, and surgical planning and decision-making, are described from the perspective of a 6 area paradigm. Potential complications are reviewed.

CONCLUSION

A conceptual framework for orbital decompression focusing on 6 potential areas of bone removal provides a nuanced and flexible paradigm for understanding and describing surgical techniques, and for designing individualized surgery. Orbital decompression surgery should be customized to the patient's anatomy and symptoms.

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.

A 46-Year-Old Woman with a 4-Year History of Graves Disease, with Severe Corticosteroid-Unresponsive Thyroid Eye Disease, Successfully Treated with Tocilizumab

BACKGROUND Tocilizumab is a therapeutic biologic antagonist of the interleukin-6 (IL-6) receptor that has been approved to treat some autoimmune and chronic inflammatory diseases. This report is of a patient with a history of Graves disease and severe corticosteroid-unresponsive thyroid eye disease that included edema of the optic nerve and choroid, which was successfully treated with tocilizumab. CASE REPORT A 46-year-old woman with a 4-year history of Graves disease presented with acutely progressive bilateral severe optic nerve compression, severe bilateral optic nerve edema, bilateral restriction of eye movement, and bilateral choroidal folds. The patient was managed with an initial high dose of systemic steroid without any success. She then underwent bilateral orbital wall decompression without any noticeable amelioration. She subsequently received 4 doses of a tocilizumab (8 mg/kg) infusion. This resulted in a considerable decrease in inflammatory signs and improvement in optic nerve function, thereby improving her quality of life. The patient did not have any adverse reactions to the tocilizumab. CONCLUSIONS The findings from this case support recent case reports and clinical trials indicating that tocilizumab may be effective in corticosteroid-resistant thyroid eye disease associated with autoimmune hyperthyroidism.

Update on the surgical management of Graves' orbitopathy

Graves' orbitopathy (GO) is a complex autoimmune disorder of the orbit that causes the eye to appear disfigured. GO is typically associated with Graves' disease, an inflammatory autoimmune condition that is caused by thyrotropin receptor autoantibodies. Although our knowledge of the pathophysiology of GO has improved, its exact pathogenesis remains unclear. Some patients suffer from disfigurement, double vision, and even vision loss rather than hyperthyroidism. The disease severity and activity prompt different treatments, as the signs of GO are heterogeneous, so their management can be very complex. Despite medical advances, the first-line treatment for moderate-to-severe active GO is still glucocorticoids, while surgery can be critical for the treatment of chronic inactive GO. Surgery is sometimes required in the acute phase of the disease when there is an immediate risk to vision, such as in dysthyroid optic neuropathy. Most surgeries for GO are rehabilitative and subdivided into three categories: decompression, strabismus repair, and lid surgery. This review is a basic overview of the field, with up-to-date knowledge of the surgical techniques for GO. We review and summarize recent literature on the advances in surgery for GO to provide up-to-date insights on the optimal surgical treatment for GO.

Management of Thyroid Eye Disease: A Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this consensus statement.

Management of thyroid eye disease: a Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this Consensus Statement.

Diagnostic Ability of Barrett’s Index and Presence of Intracranial Fat Prolapse in Dysthyroid Optic Neuropathy

Background

Dysthyroid optic neuropathy (DON) is one of the most serious visual loss threats for patients with Graves’ ophthalmopathy (GO). Barrett’s index (BI) and intracranial-fat prolapse have been used in diagnosing DON. However, these parameters are rarely used in Southeast Asian populations with a variety of cut-off values.

Objective

To evaluate the performance of BI and fat prolapse in diagnosing of DON, and to study the correlation between their parametric values with visual acuity (VA) and visual field defect (VF).

Methods

Between January 2011 and December 2020, orbits affected by GO were retrospectively reviewed and classified into 2 groups based on the presence or absence of DON. All orbital-computed-tomography (CT) scans were measured for BI and fat prolapse. Diagnostic performance of BI and fat prolapse was analyzed and evaluated in relation to visual outcome.

Results

We included orbits with DON (23 orbits) and the absence of DON (61 orbits). BI was significantly higher in patients in the DON group (47.68 ± 12.52%) compared to the absence of DON (37.55 ± 10.88%), p < 0.001. The presence of fat prolapse was significantly higher in the DON group (p = 0.003). BI at 40% provided best diagnostic performance with sensitivity of 78.3%/specificity of 63.9%. The presence of fat prolapse 4.5 mm via the superior-ophthalmic-fissure (SOF) had a lower sensitivity compared with fat prolapse 2.5 mm. Comparison between area under the curve (AUC) of BI and fat prolapse revealed no statistically significant difference (AUC 0.742 and 0.705 in BI and fat prolapse, respectively, p = 0.607). A negative correlation between the BI and fat prolapse with VA and VF was observed (p < 0.001).

Conclusion

Measurement of BI is a simple diagnostic method for detecting DON in Thai populations. The presence of fat prolapse (2.5 mm) provides a lower sensitivity compared with a BI at 40%. A slightly larger BI or fat prolapse should be suspected of DON for early treatment.

Insights into Current Management Strategies for Dysthyroid Optic Neuropathy: A Review

Dysthyroid optic neuropathy (DON) is a potentially sight-threatening eye disease associated with Graves’ orbitopathy (GO). DON is not common in GO patients, reportedly occurring in only about 5% of patients. The pathogenesis of severe DON is considered to involve both muscular nerve strangulation and impaired blood flow. There is some objective grading of physical examination findings and the severity of GO, including a clinical activity score (CAS) and EUropean Group On Graves’ Orbitopathy (EUGOGO), but no specialized protocol completely characterizes DON. Most clinicians have decided that the combination of clinical activity findings, including visual acuity, color vision, and central critical fusion frequency, and radiological findings, including magnetic resonance imaging (MRI), can be used to diagnose DON. MRI has the most useful findings, with T2-weighted and fat-suppressed images using short-tau inversion recovery (STIR) sequences enabling detection of extraocular changes including muscle and/orbital fat tissue swelling and inflammation and, therefore, disease activity. The first-choice treatment for DON is intravenous administration of steroids, with or without radiotherapy. Unfortunately, refractoriness to this medical treatment may indicate the need for immediate orbital decompression within 2 weeks. Especially in the acute phase of DON, thyroid function is often unstable, and the surgeon must always assume the risk of general anesthesia and intra- and post-operative management. In addition, there are currently many possible therapeutic options, including molecular-targeted drugs. The early introduction and combination of these immunomodulators, including Janus kinase inhibitors and insulin-like growth factor-1 receptor antibody (teprotumumab), may be effective for GO with DON. However, this is still under investigation, and the number of case reports is small. It is possible that these options could reduce systemic adverse events due to unfocused glucocorticoid administration. The pathophysiology of DON is not yet fully understood, and further studies of its treatment and long-term visual function prognosis are needed.

The method of the exophthalmos value predicted calculation when planning the orbital decompression procedure in patients with endocrine ophthalmopathy

BACKGROUND: The most effective method of surgical treatment of lipogenic and mixed forms of edematous exophthalmos is currently the internal orbital decompression. During this surgical procedure, the excessive pathologically altered adipose tissue is removed from the external and the internal surgical spaces of the orbit. Many scientists are developing methods for calculating the volume of orbital fat, but the question on developing a method for predicted exophthalmos after internal orbital decompression, which could be used without attracting additional equipment and software, is easy to learn and does not require a long calculation time, remains actual. This method has to take into account the individual features of the patients orbital structure and be used for calculations in the bilateral proptosis correction. AIM: To develop and evaluate the effectiveness of a new method for calculating the eyeball position after orbital decompression. MATERIALS AND METHODS: 64 patients (126 orbits) with lipogenic and mixed forms of endocrine ophthalmopathy were examined. All patients underwent internal orbital decompression, during which the orbital fat was removed, the volume of which was calculated according to the developed original method. Patients underwent ophthalmological examination and MSCT before surgery and 6 months after it. . RESULTS: As a result of orbital decompression in the examined group, a decrease in proptosis was observed in all patients, and the exophthalmos calculated by the method corresponded to the eyeball position in patients in 6 months after surgery. The level of statistical significance of the planned postoperative eyeball position in relation to the actual postoperative exophthalmos calculated according to the Students t-test was 0.98 (p 0.05), that is, it can be argued that the groups do not differ, and no statistically significant differences were found. CONCLUSIONS: The developed method for calculating the estimated postoperative exophthalmos is effective without using additional software. This technique allows you to achieve a symmetrical eyeball position in the postoperative period and to reduce the risk of complications.

Intraocular Pressure and Glaucoma in Thyroid Eye Disease

PURPOSE

Current literature lacks a summary of knowledge on intraocular pressure (IOP) elevation and glaucoma in thyroid eye disease (TED). This review aims to augment existing literature by providing such a summary. It qualitatively evaluates current knowledge on the pathogenesis, prevalence, and management of concomitant ocular hypertension or glaucoma in TED patients.

METHODS

In this narrative review, relevant publications were identified through a computerized database search. Search results were screened for relevance. Correspondence, Editorials, and Letters to the Editors were excluded. References cited within the identified articles were used to further augment the search. Information extracted for qualitative analysis included epidemiologic data, methods of IOP assessment, management protocols, and response to treatment.

RESULTS

Studies in current literature are relatively heterogenous, differing in country of origin, TED cohort sizes, and IOP measurement techniques. Further studies are required to elucidate the true epidemiologic relationship between TED and ocular hypertension or glaucoma. Proposed models of IOP elevation include elevation of episcleral venous pressure, mucopolysaccharide deposition within the trabecular meshwork, restrictive myopathy, steroid-induced glaucoma, and secondary glaucoma. IOP-reducing effects of TED treatment options are discussed.

CONCLUSIONS

While raised IOP in TED is a common phenomenon, the diagnosis of glaucoma in TED requires a high index of suspicion before any intervention.

Graded transantral orbital decompression outcomes in stable thyroid eye disease: a series of 47 orbits

Purpose: To provide outcome data for transantral orbital decompression for functional and aesthetic rehabilitation for exophthalmos in stable thyroid eye disease (TED).Methods: Retrospective, non-comparative chart review of consecutive TED patients who underwent primary-graded transantral orbital decompression for exophthalmos by a single surgeon (MAB) between 2005 and 2018. Additional inclusion criteria included follow-up >90 days and no prior orbital surgery. Outcome data collection included millimeters of proptosis reduction, postoperative complications, and patient satisfaction.Results: A total 30 patients (47 orbits) were included. Average reduction in proptosis: 2.8 mm (range 0-9 mm, median 2.5 mm). Post-operatively, new onset diplopia occurred in four patients, V2 numbness in 15 patients (17 orbits), and sinusitis in 2 patients (2 orbits). Phone surveys reached 9/30 patients (14 orbits): cosmetic improvement was reported in 14/14 orbits, relief of orbital ache reported in 10/10 orbits with pre-operative ache, relief of dry eye in 8/13 orbits with preoperative dry eye, and overall satisfaction score: 8.9/10 (range 4-10, median 10).Conclusions: Graded transantral orbital decompression is a viable option for stable TED patients with orbital ache, exophthalmos, and exposure keratopathy, resulting in a high degree of functional and cosmetic satisfaction in our cohort.

Modified endoscopic transnasal orbital apex decompression in dysthyroid optic neuropathy

BACKGROUND

To describe the surgical technique and assess the clinical efficacy and safety of modified endoscopic transnasal orbital apex decompression in the treatment of dysthyroid optic neuropathy.

METHODS

In this retrospective research, forty-two subjects (74 orbits) who underwent modified endoscopic transnasal orbital apex decompression for the treatment of dysthyroid optic neuropathy were enrolled. Preoperative and postoperative best-corrected visual acuity (BCVA), visual field mean deviation (MD), Hertel exophthalmometry, and new onset diplopia were assessed before and after the intervention. The Wilcoxon test was used for differential analysis. Linear mixed-models' analyses were conducted to assess the potential predictors for BCVA change.

RESULTS

Postoperatively, the mean BCVA improved from 0.70 ± 0.62 logMAR to 0.22 ± 0.33 logMAR. BCVA significantly improved in 69 eyes (93%), remained stable in 4 eyes (5%) and deteriorated in 1 eye (1%). MD of visual fields improved from -13.73 ± 9.22 dB to -7.23 ± 7.04 dB. Proptosis decreased from 19.57 ± 3.38 mm to 16.35 ± 3.01 mm. Preoperative BCVA, MD of visual fields and medical rectus diameter were independent factors associated with improvements in BCVA (P < 0.05) by linear mixed-models' analyses. Eighteen patients (42.9%) developed new diplopia postoperatively.

CONCLUSION

Modified endoscopic transnasal orbital apex decompression effectively restores vision in dysthyroid optic neuropathy.

Endoscopic Orbital Decompression for Graves' Orbitopathy - A Vietnam Study

Purpose

To evaluate the efficacy and safety of endoscopic orbital decompression in patients with Graves' orbitopathy.

Patients and Methods

This is a prospective study in Hanoi Medical University and a Military Hospital from December 2017 to December 2018. Twenty-eight orbits of fifteen patients were undergoing endoscopic orbital decompression for Graves' orbitopathy. Indications for surgery were proptosis in twenty-two orbits and compressive optic neuropathy in six orbits. The outcome measures were proptosis reduction, visual acuity, visual field test and diplopia. Post-operative complications including cerebrospinal fluid leakage, haemorrhage, lacrimal duct impairment, worsening diplopia, sinusitis and cellulitis were collected.

Results

The mean proptosis reduction was 2.23 mm. Visual acuity and medium deviation in the Humphrey visual field were significantly improved in four of six eyes with compressive optic neuropathy. There was one patient with intra-operative excessive bleeding which resolved without affecting visual outcome. Post-operatively, two patients developed a new onset of diplopia and two others worsened diplopia; three have already undergone successful strabismus surgery and moderate proptosis reduction.

Conclusion

Endoscopic orbital decompression surgery was effectively and safely to manage compressive optic neuropathy of Graves' orbitopathy and moderately reduce proptosis in a group of Vietnamese patients.

Dysthyroid optic neuropathy: evaluation and management

BACKGROUND

Dysthyroid optic neuropathy (DON) is a serious complication of Graves orbitopathy (GO) from optic nerve dysfunction that may result in permanent loss of vision.

PURPOSE

This paper reviews the current knowledge of DON, including its pathogenesis and epidemiology, clinical and radiologic features, and management choices and outcomes.

METHODS

Literature review and author retrospective case series.

RESULTS

Over 90% of DON cases are related to nerve compression by enlarged extraocular muscles (EOM) while the remainder are caused by stretching of the optic nerve without compression. DON's incidence is 5-8% of GO cases. Risk factors include advancing age, male gender, smoking and diabetes mellitus, and these cases should be referred promptly to an ophthalmologist or GO clinic to rule out DON and for ongoing care. Clinical features of DON may include reduction in central and colour vision (unexplained by other ocular disorders), afferent pupil defect and/or optic disc edema. Since most cases are associated with enlarged EOM, restricted motility and soft tissue venous congestion are common. Visual fields and optical coherence tomography (OCT) help confirm the diagnosis while CT or MRI Scans show apical optic nerve compression or proptosis with optic nerve stretch. Standard therapy includes iv/oral corticosteroids (CS) with partial response in most cases, but often relapse with tapering. Radiotherapy may delay or avoid surgery and may prevent the onset of DON when combined with CS in high-risk individuals. The benefits of newer biologic targeted therapy are not clear. Orbital decompression surgery often has positive outcomes, even in cases of severe vision loss or delayed surgery. The most common surgical complication is worsening strabismus, which may worsen visual function and quality of life. In rare cases, permanent vision loss from DON may occur despite full therapy.

CONCLUSIONS

Although DON may cause vision loss, most cases are reversible if recognized and managed in a timely manner.

Thyroid eye disease: Redefining its management-A review

Thyroid eye disease (TED) is a debilitating, vision threatening disease that dramatically alters patients' quality of life. Until recently, the management of TED is a long arduous course with supportive therapy, followed by an extensive surgical treatment plan to reverse the disease endpoints. Teprotumumab offers an early, safe therapeutic intervention to help reverse disease end points such as diplopia and proptosis and improve quality of life.

[Efficacy of transethmoidal orbital decompression in patients with dysthyroid optic neuropathy]

OBJECTIVES

To estimate efficacy and safety of endoscopic orbital decompression in patients with dysthyroid optic neuropathy (DON).

MATERIAL AND METHODS

19 patients aged 54.8±7.1 y.o. with DON were enrolled into the study.

RESULTS

Visual acuity was from counting fingers till 0.9 (0.4±0.28) before surgery, it increased till 0.7±0.2 (p<0.05) after surgery. The amount of correct Ishihara plates increased from 5.8±7 till 13.3±7.6 (p<0.05). Exophthalmos reduced by 1.7 mm (p<0.05). Significant reduce of orbital inflammation was noted as well.

CONCLUSIONS

This study is the first study of this kind in Russian Federation. Obtained results showed high efficacy and safety of endoscopic orbital decompression in patients with DON.

Gaze-evoked deformations of the optic nerve head in thyroid eye disease

PURPOSE

To assess gaze evoked deformations of the optic nerve head (ONH) in thyroid eye disease (TED), using computational modelling and optical coherence tomography (OCT).

METHODS

Multiple finite element models were constructed: one model of a healthy eye, and two models mimicking effects of TED; one with proptosis and another with extraocular tissue stiffening. Two additional hypothetical models had extraocular tissue softening or no extraocular tissue at all. Horizontal eye movements were simulated in these models. OCT images of the ONH of 10 healthy volunteers and 1 patient with TED were taken in primary gaze. Additional images were recorded in the same subjects performing eye movements in adduction and abduction. The resulting ONH deformation in the models and human subjects was measured by recording the 'tilt angle' (relative antero-posterior deformation of the Bruch's membrane opening).

RESULTS

In our computational models the eyes with proptosis and stiffer extraocular tissue had greater gaze-evoked deformations than the healthy eye model, while the models with softer or no extraocular tissue had lesser deformations, in both adduction and abduction. In healthy subjects, the mean tilt angle was 1.46°±0.25 in adduction and -0.42°±0.12 in abduction. The tilt angle measured in the subject with TED was 5.37° in adduction and -2.21° in abduction.

CONCLUSION

Computational modelling and experimental observation suggest that TED can cause increased gaze-evoked deformations of the ONH.

Pterional Orbit Decompression in Grave Disease with Dysthyroid Optic Neuropathy

OBJECTIVE

The choice of surgical technique in sight-threatening Grave orbitopathy remains controversial. Available data are mostly derived from mixed cohorts with multiple surgical indications and techniques. The authors assessed predictors for visual outcome after standardized pterional orbital decompression for dysthyroid optic neuropathy.

METHODS

Retrospective analysis of 62 pterional orbital decompressions performed on 40 patients with dysthyroid optic neuropathy.

RESULTS

Visual acuity improved by an average of 3.8 lines in eyes with preoperative visual impairment (95% confidence interval [CI]: 1.8-5.8 lines, P < 0.001) and remained stable in eyes without prior visual impairment (95% CI -1.3 to 1 line, P = 0.81). Proptosis was reduced by an average of 3.1 mm (95% CI 1.8-4.3 mm, P < 0.001). Higher degrees of proptosis were predictive of worse visual outcomes (P = 0.017). New-onset diplopia developed in 2 patients, while previous diplopia resolved after surgery in 6 patients.

CONCLUSIONS

This cohort is the largest series of pterional orbit decompressions and the first to focus exclusively on dysthyroid neuropathy. Complication rates were low. Decompression surgery was highly effective at restoring and maintaining visual acuity in patients with dysthyroid optic neuropathy.

Abnormal functional connectivity density in patients with dysthyroid optic neuropathy

[Objective] Functional connectivity density (FCD) mapping was used to investigate abnormalities and factors related to brain functional connectivity (F.C.) in cortical regions of patients with dysthyroid optic neuropathy (DON) and to analyze the pathogenesis of DON further. [Methods] Patients diagnosed with thyroid-associated ophthalmopathy (TAO) in the Eye Hospital were enrolled. All patients underwent comprehensive eye examinations and best-corrected visual acuity, visual field(V.F.) test. MRI data collection and analysis were completed in the 2nd Affiliated Hospital of Wenzhou Medical University. The patients were divided into two groups: the DON group, with an average visual field, mean deviation (M.D.) of both eyes < -5 dB, and the non-DON group (nDON group), with an average visual field M.D. of both eyes ≥ -2 dB. [Results] A total of 30 TAO patients (14 men, 16 women) with complete data who met the experimental requirements were enrolled. The average age was 48.79 (40~ 57) years. There were 16 patients in the DON group and 14 patients in the nDON group. No significant differences in age, gender, education level, and the maximum horizontal diameter of either medial rectus muscle were found between the two groups. The difference of brain FCD between the two groups showed significant abnormal connectivity in the right orbital gyri of the frontal lobe (Frontal_Inf_Orb_R) and the left precuneus in the DON group compared with the nDON group. As demonstrated by decreased FCD values in the right inferior frontal gyrus/orbital part, the relevant brain regions were the left middle temporal gyrus, left precuneus, left middle frontal gyrus, right postcentral gyrus, and brain gyri (excluding the supramarginal gyrus and angular gyrus) below the left parietal bone. The FCD associated with the left precuneus was increased, and the relevant brain areas were the left middle temporal gyrus, right cuneus, superior occipital gyrus, and right fusiform gyrus. A significant correlation was identified between the MD. of the binocular visual field and brain FCD. [Conclusion] The abnormal FCD in the cortex of DON patients suggests that a central nervous system mechanism may be related to the pathogenesis of the DON.

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.

Vision loss associated with orbital surgery - a major review

Purpose: Vision loss after orbital surgery is one of the most dreaded complications faced by the orbitofacial surgeon. This literature review was conducted in an attempt to determine the risk factors for severe vision loss and discuss the applied anatomy related to various types of orbital surgery - orbital tumor excisions, orbital decompression, and post-traumatic orbital reconstruction.Methods: A literature search was conducted via PubMed and Google Scholar. All cases of vision loss following orbital tumor biopsy or excision, orbital decompression, and orbital trauma reconstruction were reviewed.Results: The incidence of postoperative blindness appears to be more after orbital tumor excisions (4.7%), compared to post-traumatic orbital reconstruction (2.08%) and orbital decompressions for thyroid orbitopathy (0.15%).The causes of vision loss include ischemic optic neuropathy, traumatic optic neuropathy, retinal and ophthalmic artery occlusions, and orbital compartment syndrome.Conclusion: Apart from careful patient selection, proper counseling about the risk of postoperative blindness is of utmost importance. Detailed preoperative treatment planning, meticulous atraumatic intraoperative dissection under direct visualization, with attention to the danger zones and vital structures, close intraoperative and postoperative monitoring, and urgent management of potentially reversible compressive causes of vision loss can improve outcomes.

Augmented endoscopic orbital apex decompression in dysthyroid optic neuropathy

PURPOSE

To describe a modified technique of endoscopic orbital decompression for dysthyroid optic neuropathy nonresponsive to pulsed corticosteroids.

METHODS

Retrospective, interventional single centre case series included 17 consecutive patients with dysthyroid optic neuropathy (DON) who were refractory to pulse corticosteroids. Removal of the posteromedial floor and the orbital process of palatine bone (OPPB) was performed in addition to the endoscopic transethmoidal medial orbital wall decompression (ETMOWD), to achieve maximal orbital apex decompression. Main outcome measures were change in visual acuity (VA), color vision, degree of proptosis reduction, incidence of new-onset diplopia, and any complications.

RESULTS

Seventeen eyes (100%) had a statistically significant improvement in VA from 1.0 ± 0.44 LogMAR to 0.0 ± 0.15, with an average improvement of 0.41 ± 0.30 LogMAR (p 0.05, paired t-test). Fourteen out of 16 eyes had a complete improvement in color vision and two eyes had partial recovery. Afferent pupillary defect (76.5%) resolved in all cases. Five out of 10 cases with preoperative visual field defects demonstrated no residual field defects following surgery. The range of proptosis reduction was 0-5 mm (mean 2.7 ± 1.3 mm). No patients with diplopia (12/17) had worsening or developed new-onset diplopia following surgery.

CONCLUSION

Combined removal of the posterior medial floor including the OPPB with ETMOWD may be a viable alternative in the surgical management of DON.

Insulin-like Growth Factor-I Receptor and Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a complex disease process presumed to emerge from autoimmunity occurring in the thyroid gland, most frequently in Graves disease (GD). It is disfiguring and potentially blinding, culminating in orbital tissue remodeling and disruption of function of structures adjacent to the eye. There are currently no medical therapies proven capable of altering the clinical outcome of TAO in randomized, placebo-controlled multicenter trials. The orbital fibroblast represents the central target for immune reactivity. Recent identification of fibroblasts that putatively originate in the bone marrow as monocyte progenitors provides a plausible explanation for why antigens, the expressions of which were once considered restricted to the thyroid, are detected in the TAO orbit. These cells, known as fibrocytes, express relatively high levels of functional TSH receptor (TSHR) through which they can be activated by TSH and the GD-specific pathogenic antibodies that underpin thyroid overactivity. Fibrocytes also express insulin-like growth factor I receptor (IGF-IR) with which TSHR forms a physical and functional signaling complex. Notably, inhibition of IGF-IR activity results in the attenuation of signaling initiated at either receptor. Some studies suggest that IGF-IR-activating antibodies are generated in GD, whereas others refute this concept. These observations served as the rationale for implementing a recently completed therapeutic trial of teprotumumab, a monoclonal inhibitory antibody targeting IGF-IR in TAO. Results of that trial in active, moderate to severe disease revealed dramatic and rapid reductions in disease activity and severity. The targeting of IGF-IR with specific biologic agents may represent a paradigm shift in the therapy of TAO.

Evolution of thyroid eye disease decompression-dysthyroid optic neuropathy

Orbital decompression surgery and medical therapy for thyroid eye disease (TED) have evolved over the past 150 years and afforded the opportunity to restore pre-disease appearance and visual function. This manuscript explores the past 150 years of surgical innovation for the treatment of TED. The "Age of Surgical Heroism" spans the time from 1888 to 1979 during which the pioneers of orbital decompression developed lateral orbitotomy, transcranial decompression, paranasal sinus decompression, and transantral decompression despite an incomplete understanding of the pathophysiology of both TED and a limited ability to non-invasively assess their patients. The "Age of Surgical Refinement" dawned with the development of computed tomography and represents the years 1979-2000. During this time, the "swinging eyelid" approach for two- and three-wall decompressions was introduced, a combined orbital-extradural four wall decompression procedure was developed, fat decompression was explored, and endoscopic decompression techniques were advanced. At the beginning of the 21st century, our understanding of the orbital pathophysiology of TED evolved significantly. Clinicians recognized the age-related phenotype of TED based largely on the relative contribution of extraocular muscle enlargement vs. orbital fat expansion. The "Modern Age" of Customized Orbital Decompression features both "medical decompression" during the active phase of TED and, in the stable phase, customized surgical plans incorporating individual patients' anatomy, orbital pathology, and surgical goals that collectively maximize therapeutic benefit while minimizing therapeutic morbidity.

Orbital decompression in the system of treatment for complicated thyroid eye disease: case report and literature review

Orbital decompression is a surgical procedure aimed at increasing the orbital volume and/or decreasing the volume of the orbital fat. The indications for orbital decompression are determined in the course of thorough eye examination. An important objective of examination of a patient with thyroid eye disease (TED) is determination of inflammation activity and severity. Orbital decompression is a surgical procedure that can be performed in both the active and nonactive stages of the disease. However, the indications for the surgery in these cases are different. Optic neuropathy and severe corneal disease are threatening complications that may lead to permanent visual loss and generally occur in the presence of active orbital inflammation. If treatment with high-dose corticosteroids has proven ineffective, an urgent surgical procedure consisting of orbital decompression and, in case of involvement of the cornea, eyelid and corneal surgery has to be performed. Owing to significant progress in technology, improvement of methods and accumulated experience over the past decade, the indications for bone orbital decompression have extended compared to the time when this procedure was used only in patients with extremely severe TED. The most common complication of the orbital decompression is the development or deterioration of previously existing binocular diplopia and strabismus. In addition, other parameters may change as well, including the position of the globe, the eyelids, the angle of deviation of the eye, and intraocular pressure. Thus, bone orbital decompression is a major step of a comprehensive, often multistage, system of rehabilitation of patients with severe refractory TED.

Dysthyroid Optic Neuropathy

PURPOSE

Dysthyroid optic neuropathy (DON) is a serious complication of Graves orbitopathy that can result in irreversible and profound visual loss. Controversy exists regarding the pathogenesis and management of the disease. The authors provide an overview of the current understanding of DON and present a therapeutic guideline.

METHODS

A review of the literature.

RESULTS

The mechanism of DON appears to be multifactorial: direct compression of the optic nerve by enlarged extraocular muscles, stretching of the optic nerve by proptosis, orbital pressure, vascular insufficiency, and inflammation. Some or all of these factors may be involved in an individual patient. There has only been one controlled trial comparing high-dose intravenous methylprednisolone to bony orbital decompression for DON. Both 2-wall and 3-wall decompression techniques successfully improve visual functions of patients with DON. There are few case reports/case series that suggest biologic agents may improve visual function in DON.

CONCLUSIONS

DON is a serious complication of Graves orbitopathy, the diagnosis and management of which is complex and requires a multidisciplinary approach. There is little evidence regarding the optimum management strategy. Based on the current literature, the first line of treatment is intravenous methylprednisolone, with the exact timing and indication of bony orbital decompression still to be determined. In addition, there may be a role for the use of biologic agents that will require a systematic program to determine efficacy.

Complications and outcomes of grafting of posterior orbital fat into the lower lid-cheek junction during orbital decompression

PURPOSE

To report the complications of grafting of excised posterior orbital fat into the lower lid-cheek junction at the time of orbital decompression surgery.

METHODS

Retrospective review of consecutive patients undergoing orbital decompression combined with grafting of posterior orbital fat to the pre-malar and lateral canthal area (FG). A second group of consecutive patients undergoing orbital decompression but no orbital fat grafting (NoFG) were also studied as a form of comparative control. Standard patient data, including age, sex, visual acuity, degree of proptosis, operative details, diplopia or any other complications was collected. Independent assessment of pre- and post-operative photographs graded the lower lid-cheek junction.

RESULTS

Thirty-four orbits of 29 patients, of which 21 orbits underwent orbital decompression with orbital fat grafting (FG). There were no intraoperative complications, postoperative infections, or visual loss. Complications relating to fat grafting included prolonged swelling in 3 (17%) patients at 3 months, in 1 case lasting 6 months, lower lid lumps in 3 (17%), and fat seepage in 1 (6%). The FG group achieved a greater improvement in the appearance of the lower-lid-cheek junction at 12 months in comparison to NoFG. Mean grade improvement 1.24 ± 1.09 vs 0 ± 0.82 (p = 0.025). Median follow-up was 20 months (range 6-30 months).

CONCLUSION

Grafting of excised orbital fat during orbital decompression can improve the appearance of the lower lid-cheek junction in patients being treated for thyroid orbitopathy. However, 24% of patients will experience swelling and/or lumpiness requiring several months to settle or further fat excision.

Cutting-edge endonasal surgical approaches to thyroid ophthalmopathy

Objective

Thyroid orbitopathy is a poorly understood extrathyroidal manifestation of Graves' disease that can cause disfiguring proptosis and vision loss. Orbital decompression surgery for Graves' orbitopathy (GO) can address both cosmetic and visual sequelae of this autoimmune condition. Endonasal endoscopic orbital decompression provides unmatched visualization and access to inferomedial orbital wall and orbital apex. This review examines the state of the art approaches employed in endonasal endoscopic orbital decompression for GO.

Methods

Review of literature evaluating novel surgical maneuvers for GO.

Results

Studies examining the efficacy of endonasal endoscopic orbital decompression are heterogenous and retrospective in design; however, they reveal this approach to be a safe and effective technique in the management of GO.

Conclusion

Subtle variations in endoscopic techniques significantly affect postsurgical outcomes and can be tailored to the specific clinical indication in GO making endonasal endoscopic decompression the most versatile approach available.

Level of Evidence

NA.

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.

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.

Dysthyroid optic neuropathy: update on pathogenesis, diagnosis, and management

INTRODUCTION

Dysthyroid optic neuropathy (DON) is a severe manifestation of thyroid eye disease (TED) that can result in permanent vision loss. Management is complex, multidisciplinary, and involves medical and/or surgical therapies. This review describes current concepts in the epidemiology, pathophysiology, diagnosis, and treatment of DON.

AREAS COVERED

An extensive review of the literature was performed to detail current concepts on the diagnosis and management of DON. This includes utilization of various medical and surgical modalities for disease management.

EXPERT COMMENTARY

DON can result in permanent blindness and often requires the use of corticosteroids and surgical decompression. We favor the use of intravenous corticosteroids and a transcaruncular approach when surgical decompression is indicated. The use of orbital radiation for DON is often reserved for patients that are poor surgical candidates and/or patients with refractory disease.

Minimally invasive surgery for thyroid eye disease

Thyroid eye disease (TED) can affect the eye in myriad ways: proptosis, strabismus, eyelid retraction, optic neuropathy, soft tissue changes around the eye and an unstable ocular surface. TED consists of two phases: active, and inactive. The active phase of TED is limited to a period of 12–18 months and is mainly managed medically with immunosuppression. The residual structural changes due to the resultant fibrosis are usually addressed with surgery, the mainstay of which is orbital decompression. These surgeries are performed during the inactive phase. The surgical rehabilitation of TED has evolved over the years: not only the surgical techniques, but also the concepts, and the surgical tools available. The indications for decompression surgery have also expanded in the recent past. This article discusses the technological and conceptual advances of minimally invasive surgery for TED that decrease complications and speed up recovery. Current surgical techniques offer predictable, consistent results with better esthetics.

Combined Endoscopic Medial and External Lateral Orbital Decompression for Progressive Thyroid Eye Disease

OBJECTIVE: To compare the efficacy of endoscopic medial and lateral orbital wall surgery to 3-wall decompression in patients with thyroid eye disease.

STUDY DESIGN AND SETTING: A retrospective study of patients with thyroid eye disease with severe proptosis, exposure keratitis, or compressive optic neuropathy was conducted.

RESULTS: Mean reduction in proptosis was 4.37 mm in the 2-wall approach and 4.59 mm in the 3-wall group. Seventy-five percent of patients in the 2-wall group demonstrated improved visual acuity; 50% improved after 3-wall decompression. Vertical palpebral fissure height decreased by an average of 2.50 mm in the 2-wall group and by 2.03 mm in the 3-wall group. New onset diplopia was 11.8% and 12.5%, respectively.

CONCLUSIONS: Improvement in the degree of proptosis, visual acuity, and palpebral fissure height was seen in the majority of our patients and compared favorably to our results with 3-wall orbital decompression.

EBM rating: C-4

Compressive Optic Neuropathy and Repeat Orbital Decompression: A Case Series

PURPOSE

To characterize the presenting characteristics, preoperative clinical activity score (CAS), surgical approach, and visual outcomes in patients with thyroid eye disease undergoing repeat orbital decompression for recurrent or recalcitrant compressive optic neuropathy (CON).

METHODS

The medical records of patients with recurrent or recalcitrant CON undergoing repeat orbital decompressions were retrospectively reviewed. The primary outcome measures included pre- and postoperative Humphrey visual field mean deviation, visual acuity (VA) measured in logarithm of the minimal angle of resolution, color vision measured by Ishihara plates, and presence of relative afferent pupillary defect. Details of the surgical procedure and each patient's CAS at presentation were also recorded.

RESULTS

Six patients, 9 orbits, with a mean preoperative CAS of 3.8 were included in this review. The mean time between initial decompression and presentation to our center for recurrent or persistent CON symptoms was 8.6 years (range, 1 to 15 years). At presentation, the average Humphrey visual field mean deviation was -16.5 (standard deviation: 8.8), improving to -3.8 (2.4) postoperatively with a mean of 9.3 months follow up (mean improvement of 75%). Preoperative VA was 0.34 (0.23) LogMAR, improving to 0.05 (0.10) LogMAR with a mean follow up of 10.4 months. Pre- to postoperative comparisons of clinical measures all showed statistically significant improvement (p < 0.05). Eight eyes presented with decreased VA (any VA < 20/20), 4 with decreased color vision (any color vision < 11), and 1 with a relative afferent pupillary defect, and all these patients demonstrated improvement following repeat orbital decompression.

CONCLUSIONS

In patients with thyroid eye disease, symptoms of recurrent CON occurred up to 15 years following initial orbital decompression underscoring the smoldering, progressive nature of the disease. Repeat decompression that focused on the orbital apex resulted in visual improvement in all 6 patients. Despite clinical evidence of CON, the mean CAS of these patients at presentation was only 3.8, highlighting the importance of close monitoring of patients with thyroid eye disease following decompression regardless of the external manifestations of disease activity.

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

INTRODUCTION

Orbital 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.

METHODS

We 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.

RESULTS

We 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.

CONCLUSION

Most 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.

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.

Surgical Treatment of Dysthyroid Optic Neuropathy: Long-Term Visual Outcomes with Comparison of 2-Wall versus 3-Wall Orbital Decompression

PURPOSE

To compare the long-term visual outcomes after 2-wall (medial-lateral) versus 3-wall (medial-lateral-inferior) orbital decompression combined with fat removal in patients with dysthyroid optic neuropathy (DON).

METHODS

Records of 68 eyes of 42 patients were retrospectively reviewed. Two-and 3-wall decompression was performed in 41 and 27 eyes, respectively. Transcaruncular approach was used for medial wall decompression. Lateral canthotomy combined with upper eyelid crease incision was used for lateral wall removal, and combined with transconjunctival lower eyelid incision if floor decompression performed. Outcome measures were visual acuity (VA), color vision, Hertel measures, visual field mean deviation (MD) and pattern standard deviation (PSD) Result: The mean follow-up time was 39.3 months (range, 12-72 months). All indicators of visual function significantly improved after 2-and 3-wall decompression. The improvement in VA and color vision was similar between groups. (logMAR VA: 2-wall: 0.52 ± 0.68 versus 3-wall: 0.71 ± 0.86, p = 0.335); (color vision on Ishihara plates: 2-wall: 10.1 ± 8.1 versus 3-wall: 11.6 ± 7.8, p = 0.447). The improvement in MD and PSD were higher after 3-wall decompression (MD: 2-wall: 10.0 ± 5.5 versus 3-wall: 14.3 ± 7.5 dB, p = 0.020); (PSD: 2-wall: 3.5 ± 1.9 versus 3-wall: 4.8 ± 3.0 dB, p = 0.045). Proptosis reduction was higher after 3-wall decompression (2-wall: 5.1 ± 1.3 versus 3-wall: 7.2 ± 1.9 mm, p = 0.0001). New onset diplopia was seen 20% and 28.5% of cases in 2-and 3-wall decompression, respectively. No adnexal/orbital complications were seen in 2-wall group, however orbital hematoma (1 case) and persisting eyelid edema (1 case) were encountered in 3-wall group.

CONCLUSION

Both 2-and 3-wall orbital decompressions are safe and effective for management of visual dysfunction in DON. Although 3-wall decompression provide better improvement in the parameters of visual field analysis and Hertel measures, new onset diplopia, adnexal/orbital complications are more common with this technique.