Influence of orbital morphology on proptosis reduction and ocular motility after decompression surgery in patients with Graves' orbitopathy

Lateral Rectus Muscle Resection for New-Onset Esotropia Following Medial Orbital Wall Decompression in Thyroid Eye Disease

Background and Objectives: The purpose of this study was to evaluate the outcome of lateral rectus (LR) muscle resection for new-onset or worsening esotropia after medial orbital wall decompression in patients with thyroid eye disease. Materials and Methods: This retrospective observational study included 20 patients. Preoperative and postoperative measurements of ocular deviation angles and fields of binocular single vision (BSV) were performed one day before and three months after surgery. Surgical success was defined as postoperative horizontal ocular deviation ≤ 5° and BSV including the primary position. Factors influencing a reduction in the esodeviation angle were analyzed using univariate and multivariate linear regression analyses. Results: Eighteen patients (90.0%) were deemed as successful surgical cases. The esodeviation angle decreased from 19.4 ± 11.2° to 1.0 ± 2.6°. In multivariate analysis, a reduction in the esodeviation angle was correlated with the presence of dysthyroid optic neuropathy (p = 0.027), amounts of LR muscle resection in mild eyes (p = 0.014), and amounts of additional medial rectus muscle recession in severe eyes (p < 0.001). Conclusions: LR muscle resection showed a high success rate in correcting new-onset or worsening esotropia which developed after medial orbital wall decompression. Several factors influencing a reduction in the esodeviation angle were found.

Effects of orbital decompression on duction, cyclotorsion and diplopia

BACKGROUND

Orbital decompression is commonly performed to correct proptosis in patients with Graves' orbitopathy (GO). In literature, the incidence of new-onset constant diplopia after orbital decompression varies. Few studies have evaluated changes in duction and cyclodeviation after orbital decompression. We evaluated the changes in duction, cyclodeviation, eye position and degree of diplopia after orbital decompression.

METHODS

We retrospectively analysed data from patients who underwent orbital decompression at our hospital between January 2016 and July 2020. Data regarding the type of decompression, eye position, duction, cyclodeviation and level of diplopia according to the Gorman score were recorded.

RESULTS

Data from 281 eyes/orbits of 156 patients were analysed. Proptosis decreased from 23.8±2.5 to 20.9±2.5 mm. Horizontal and vertical duction range decreased (horizontal d=0.40 and vertical 0.30; p=0.000) after surgery; however, the change was not clinically significant (≤5°). Horizontal deviation changed towards esodeviation (d=-0.45; p=0.000), whereas vertical deviation remained stable (d=0.15; p=0.161). Preoperative cyclotorsion in the primary and downgaze positions changed towards incyclodeviation (primary: d=0.30, p=0.021; downgaze d=0.30, p=0.039). Diplopia improved in 22% (18 patients), whereas new-onset constant diplopia developed in 11% (12 patients). Elevation has an excellent predictive value of causing new-onset constant diplopia when measured preoperatively as <19°, sensitivity 88.0%, specificity 41.7% (area under the curve 0.812 (95% CI 0.660 to 0.963); p=0.000).

CONCLUSION

After orbital decompression, incidence of new-onset constant diplopia was 11% and 22% of the patients had partial or complete improvement of their diplopia. The changes in duction, cyclodeviation and horizontal deviation showed a statistical but not clinical difference. Patients with GO and a preoperatively restricted elevation of <19° are at risk of developing new-onset constant diplopia. In addition, preoperative incyclodeviation may worsen after decompression surgery.

Postoperative drift and dose-response of strabismus surgery in thyroid eye disease: predicting desired outcomes with intraoperative adjustable sutures

OBJECTIVE

To report outcomes of strabismus surgery in thyroid eye disease using intraoperative bow-knot adjustable sutures under topical anaesthesia and calculate prediction models for surgical correction and postoperative drift depending on surgical dose-response.

METHODS

We retrospectively reviewed patients operated on from 2016 to 2021. A satisfactory outcome was defined as no diplopia with maintenance of vertical (<5 PD) and horizontal (<10 PD) stable alignment at primary gaze. Subjective diplopia corrected with prisms within successful motor alignment was defined as a fair result. Otherwise, the result was considered to be poor.

RESULTS

A total of 73 patients were included (60 females, 82%). Mean preoperative horizontal and vertical deviations were 26.9 PD (19.1 SD), and 11.8 PD (7.6 SD), respectively. Mean horizontal drift was -3.2 PD (5.2 SD), whereas mean vertical drift was -3.4 PD (3.3 SD). A linear regression established a dose-response of 2.37 PD/mm for each medial rectus recession (p < 0.0001; r2 = 0.777) and 3.75 PD/mm for unilateral inferior rectus recession (p < 0.0001; r2 = 0.922). Final success rate was satisfactory in 62 patients (85%), fair in 7 patients (10%), and poor in 4 patients (5%).

CONCLUSIONS

Muscle recession with intraoperative adjustable sutures is effective for the treatment of thyroid eye disease strabismus. Predictable dose-responses could be achieved with a drift toward overcorrection. Undercorrection proportional to the planned surgical dose should be the immediate postoperative target of choice. Other variables such as orbital decompression and concurrent vertical and horizontal surgery do not correlate with dose-response and postoperative drift. However, further studies are necessary to validate our findings.

How Age Affects Graves' Orbitopathy-A Tertiary Center Study

PURPOSE

Graves' orbitopathy (GO) is an autoimmune disorder leading to inflammation, adipogenesis, and fibrosis. The severity of GO can vary widely among individuals, making it challenging to predict the natural course of the disease accurately, which is important for tailoring the treatment approach to the individual patient. The aim of this study was to compare the clinical characteristics, course, treatment, and prognosis of GO patients under 50 years with older patients.

METHODS

We reviewed the medical records of a random sample of 1000 patients in our GO database Essen (GODE) comprising 4260 patients at our tertiary referral center. Patients were divided into two groups: Group 1 (≤50 years) and Group 2 (>50 years). Only patients with a complete data set were included in the further statistical analysis.

RESULTS

The results showed that younger patients (n = 484) presented significantly more often with mild GO (53% vs. 33%, p < 0.0001), while older patients (n = 448) were more likely to experience moderate-to-severe disease (44% vs. 64%, p < 0.0001). Older patients showed more severe strabismus, motility, and clinical activity scores (5.9 vs. 2.3 PD/310° vs. 330° both p < 0.0001, CAS: 2.1 vs. 1.7, p = 0.001). Proptosis and occurrence of dysthyroid optic neuropathy (DON) showed no significant difference between groups (both 3%). Multiple logistic regression revealed that the need for a second step of eye muscle surgery was most strongly associated with prior decompression (OR = 0.12, 95% CI: 0.1-0.2, p < 0.0001) followed by orbital irradiation and age. The model showed good fitness regarding the area under the curve (AUC = 0.83).

DISCUSSION

In conclusion, younger GO patients present with milder clinical features such as a lower rate of restrictive motility disorders and less pronounced inflammatory signs. Therefore, older patients tend to need more steroids, irradiation, and lid and eye muscle surgery. Still, the risk of DON and the necessity of secondary eye muscle surgery are not or only slightly associated with age, respectively.

The effect of rim-off deep lateral orbital decompression on the lateral rectus shape and oculomotor balance

PURPOSE

The purpose of the study was to measure the effect of rim-off deep lateral decompression for Graves orbitopathy on the lateral rectus muscle path and oculomotor balance.

METHODS

Retrospective analysis of the medical records and pre- and postoperative computed tomography scans of 34 orbits of 23 patients who underwent deep lateral decompression alone. The oculomotor balance of these 23 patients was measured with the alternate cover test and prisms before and after surgery. Bezier functions were used to measure the postoperative path of the lateral rectus in all decompressed orbits.

RESULTS

Deep lateral decompression induced a curvilinear deformation of the lateral rectus. There was no significant correlation between the position of the point of maximum muscle displacement and the size of the residual lateral wall. The changes in the lateral rectus path had no adverse effects on the oculomotor balance of the patients.

CONCLUSIONS

The location of the curvilinear deformation of the lateral rectus does not depend on the residual segment of the lateral wall. The changes of the lateral rectus path have no deleterious effect on the oculomotor balance.

Risk Factors for New Onset Diplopia After Graduated Orbital Decompression

PURPOSE

The aim of the study was to identify possible risk factors for new onset diplopia in 20° of primary position (NOD PP) after orbital decompression. A predisposition for NOD has been established for patients with pre-existing diplopia in secondary gaze; therefore, the authors focused on patients without preoperative diplopia.

METHODS

Retrospective chart review of patients who underwent balanced orbital decompression between 2012 and 2019 due to Graves orbitopathy at the authors' institution. Exclusion criteria were incomplete clinical data set, revision surgery, and medial or lateral decompression only. The following clinical parameters were evaluated preoperatively and postoperatively: Hertel exophthalmometry, objective measurement of misalignment using the prism-cover-test, assessment of the field of binocular single vision, and measurement of monocular excursions. In addition, the diameter of the extraocular eye muscles was measured in all preoperative CT scans.

RESULTS

We included 327 patients (612 orbits), 126 patients (242 orbits) had no preoperative diplopia. In patients with NOD PP (34%, n = 43/126), enlargement of the medial rectus muscle and restriction of abduction and elevation were significantly more frequent than in patients with no NOD PP. The degree of exophthalmos decrease positively correlated with postoperative squint angle.

CONCLUSION

We were able to identify the diameter of the medial rectus muscle, restriction of abduction, and elevation as well as an extensive reduction of exophthalmos as risk factors for NOD PP in patients with no preoperative diplopia.

Comparison of degree of medial rectus muscle misalignment after medial orbital wall decompression with or without periosteal flap

PURPOSE

To compare the degree of postoperative medial rectus (MR) muscle misalignment in patients who underwent medial orbital wall decompression with or without a periosteal flap along the MR muscle.

METHODS

This retrospective, observational study included 40 sides from 26 patients. The following parameters were measured on axial computed tomographic images taken post- and/or preoperatively: the distance of the anteroposterior line between the posterior lacrimal crest and the junction of the ethmoid and sphenoid sinuses from the most medial point of the medial margin of the MR muscle; the angle created at the point of the MR globe insertion, the most medial point of the MR muscle, and the junction of the ethmoid and sphenoid sinuses; and the MR muscle cross-sectional area. Postoperative changes in the distance (MR muscle shift) and area (MR muscle expansion) were calculated, and MR muscle shift, MR muscle angle, and the rate of MR muscle expansion were compared between the groups with (22 sides) and without (18 sides) a periosteal flap.

RESULTS

MR muscle shift (P = 0.325), MR muscle angle (P = 0.219), and the rate of MR muscle expansion (P = 0.904) were not significantly different between the groups.

CONCLUSIONS

Preservation of the periosteum along the MR muscle is thought to prevent MR muscle misalignment after medial orbital wall decompression. However, the results of this study indicate that preservation of a periosteal flap may not contribute to lessening MR muscle shift after surgery.

18 F-FDG-PET/MRI in patients with Graves' orbitopathy

PURPOSE

Currently, therapeutic management of patients with Graves' orbitopathy (GO) relies on clinical assessments and MRI. However, monitoring of inflammation remains difficult since external inflammatory signs do not necessarily represent the orbital disease activity. Therefore, we aimed to evaluate the diagnostic value of ¹⁸F-FDG-PET/MRI to assess the inflammation of GO patients.

METHODS

Enrolled patients with new onset of GO underwent ophthalmological examinations to evaluate the activity (CAS) and severity of GO (NOSPECS), as well as an ¹⁸F-FDG-PET/MRI (Siemens Biograph mMR) with dual time point imaging (immediately post-injection and 60 min p.i.). A subset of PET parameters including maximum standardized uptake value (SUVmax), metabolic target volume (MTV), and total lesion glycolysis (TLG) were obtained separately per eye and per extraocular eye muscle (EOM). EOM thickness was measured on the co-registered MRI.

RESULTS

Of 14 enrolled patients, three showed mild, seven moderate-to-severe, and four sight-threatening GO. Patients with severe GO showed statistically significant higher TLG than patients with mild GO (p = 0.02) and higher MTV than patients with mild (p = 0.03) and moderate (p = 0.04) GO. Correlation between NOSPECS on one hand and MTV and TLG on the other was significant (R² = 0.49-0.61).

CONCLUSION

TLG and MTV derived from FDG-PET appear to be good discriminators for severe vs. mild-to-moderate GO and show a significant correlation with NOSPECS. As expected, PET parameters of individual eye muscles were not correlated with associated eye motility, since fibrosis, and not inflammation, is mainly responsible for restricted motility. In conclusion, ¹⁸F-FDG-PET/MRI can be used for assessment of GO inflammation.

Proposing a surgical algorithm for graduated orbital decompression in patients with Graves' orbitopathy

PURPOSE

To determine the outcome after orbital decompression using a graduated technique, adapting the surgical technique according to individual patients' disease characteristics.

METHODS

We retrospectively examined the postoperative outcome in patients treated with a graduated balanced orbital decompression regarding reduction of proptosis, new onset diplopia and improvement in visual function. 542 patients (1018 orbits) were treated between 2012 and 2020 and included in the study. Clinical examinations including visual acuity, exophthalmometry (Hertel) and orthoptic evaluation were performed preoperatively and at minimum 6 weeks postoperatively. Mean follow-up was 22.9 weeks.

RESULTS

Mean proptosis values have significantly decreased after surgery (p < 0.01). In 83.3% of the patients Hertel measurement normalized (≤ 18 mm) after surgery, New onset diplopia within 20° of primary position occurred in 33.0% of patients, of whom 16.0% had preoperative double vision in secondary gaze. Patients suffering from dysthyroid optic neuropathy (DON) had a significant increase in visual acuity (p < 0.01).

CONCLUSION

We demonstrated that individually adapted graduated orbital decompression successfully improves key disease parameters of Graves' orbitopathy with low morbidity.

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.

Changes in Field of Binocular Single Vision and Ocular Deviation Angle After Balanced Orbital Decompression in Thyroid Eye Disease

PURPOSE

To evaluate influential factors for changes in the binocular single vision (BSV) and ocular deviation angle in the medial direction after bilateral balanced orbital decompression in thyroid eye disease.

METHODS

This retrospective study included 41 patients. The areas of BSV and the angles of medial ocular deviation on the Hess chart were measured. The percentages of pre- and postoperative areas against the normal area (%BSV) and the change in BSV after surgery were calculated. Postoperative change in the angle was calculated by subtraction of the preoperative angle from the postoperative one. Influential factors for the change in BSV and that in the medial deviation angle were evaluated via multivariate linear regression analysis.

RESULTS

The maximum cross-sectional area of the medial rectus muscle, preoperative %BSV, and preoperative medial ocular deviation angle were significant factors of change in BSV (adjusted r2 = 0.449, p < 0.001), although age, history of anti-inflammatory treatment, volume of removed orbital fat, findings on CT images, maximum cross-sectional areas of the other rectus muscles, and presence or absence of a periosteal flap did not affect change in BSV (p > 0.050). On the contrary, all variables did not influence postoperative changes in the medial ocular deviation angle (p > 0.050).

CONCLUSIONS

In balanced orbital decompression, the maximum cross-sectional area of medial rectus muscle, preoperative field of BSV, and medial ocular deviation were significant influential factors for postoperative changes in field of BSV.

Deep lateral orbital decompression for Graves orbitopathy: a systematic review

PURPOSE

To systematically review the literature on the deep lateral orbital decompression (DLD).

METHODS

The authors searched the MEDLINE, Lilac, Scopus, and EMBASE databases for all articles in English, Spanish, and French that used as keywords the terms orbital decompression and lateral wall. Two articles in German were also included. Data retrieved included the number of patients and orbits operated, types of the approach employed, exophthalmometric and horizontal eye position changes, and complications. The 95% confidence intervals (CI) of the mean Hertel changes induced by the surgery were calculated from series with 15 or more data.

RESULTS

Of the 204 publications initially retrieved, 131 were included. Detailed surgical techniques were analyzed from 59 articles representing 4559 procedures of 2705 patients. In 45.8% of the reports, the orbits were decompressed ab-interno. Ab-externo and rim-off techniques were used in 25.4% and 28.8% of the orbits, respectively. Mean and 95% CI intervals of Hertel changes, pooled from 15 articles, indicate that the effect of the surgery is not related to the technique and ranges from 2.5 to 4.5 mm. The rate of new onset of diplopia varied from zero to 8.6%. Several complications have been reported including dry eye, oscillopsia, temporal howling, lateral rectus damage, and bleeding. Unilateral amaurosis and subdural hematoma have been described in only one patients each.

CONCLUSIONS

The low rate of new-onset diplopia is the main benefit of DLD. Prospective studies are needed to compare the rate of complications induced by the 3 main surgical techniques used.

Impact of the ethmoid volume on endoscopic medial wall decompression outcomes in Graves' orbitopathy

BACKGROUND

Endoscopic orbital decompression is a well-established technique for Graves orbitopathy treatment.

AIMS

Measurement of the ethmoid volume and its correlation with proptosis reduction in patients undergoing endoscopic orbital decompression for Graves' orbitopathy.

METHODS

We retrospectively reviewed clinical charts of 209 patients (319 orbits) operated by a surgeon at our institution between 1998 and 2019.

RESULTS

Average age was 46.9 years. About 83.3% of the patients were female, 54.6% were smokers, 93.8% were euthyroid at the time of decompression, 3.8% were hypothyroid and 2.4% were hyperthyroid. About 77.5% of the patients underwent bilateral surgery, the remainder and unilateral. Subsequent stages included strabismus surgery in 22.5% patients, Müllerectomy 37.8%, with or without canthoplasty (14.8 vs. 23%). Mean proptosis reduction was 4.61 mm. Mean ethmoid volume was 5.57 mm³. Ethmoid volume had a moderate positive correlation with proptosis reduction (r _s = 0.49, p < .001). Further investigation, statistically significant moderate correlation was found only in the small (SE) and big (BE) ethmoid groups.

CONCLUSION

We advise evaluating ethmoid sinus pneumatization on computed tomography before decompression to estimate possible anatomical limitations. Additional wall decompression might be advocated in most severe cases.

Bony Orbital Decompression in Patients with High Myopia and Pseudoexophthalmos

INTRODUCTION

High myopic eyes grow in length (> 0.35 mm/dpt) more than in height and width leading to a disturbing unilateral exophthalmos in patients with anisomyopia and - more rarely - a bilateral exophthalmos in high myopia affecting both eyes. Secondary consequences are sicca symptoms and painful eye mobility due to a large bulbus in a too small bony orbit. The aim of the work was to evaluate the effectiveness of bony orbital compression in cases of high myopia.

MATERIAL AND METHODS

Four patients underwent bony orbital decompression between the years 2012 and 2019. Two of the patients received lateral and two of them balanced (medial endonasal endoscopic and lateral) decompression. The decompression effect, complications and the influence of decompression on eye position and motility were evaluated.

RESULTS

Significant decompression effect was achieved in all patients. As a result, symmetry was restored in all unilaterally affected patients. No complications occurred. The lateral decompression had a positive effect on the preexisting convergent strabismus (reduction of the "eso" position, neutral to the vertical deviation). The carefully dosed medial decompression did not lead to any change of the horizontal position in one patient and in the other exotropic patient it resulted in a 10 pdpt of "exo" reduction without developing an "eso" position.

DISCUSSION

The bony orbital decompression provides a sufficient decompression effect in the four patients to reduce the myopic pseudoexophthalmos. The alignment anomalies associated with a high myopia ("heavy eye") was favourably influenced by the lateral decompression.