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.

Primary and secondary superior rectus recessions to correct vertical deviations in Graves' orbitopathy patients.

PURPOSE: Patients with vertical strabismus and consecutive diplopia due to Graves' orbitopathy (GO) might need recession of the rectus superior muscle. The aim of this retrospective analysis is to provide dose-effect values and motility analysis for these patients. METHODS: Dose-effect relations (deviation reduction in primary position per amount of recession in mm), monocular excursions and size of the field of binocular single vision (BSV) were evaluated in three different groups of patients. Group 1 (n = 33) patients with primary fibrosis of superior rectus muscle undergoing recession of the ipsilateral rectus superior, Group 2 (n = 14) superior rectus muscle recession after recession of inferior rectus on the contralateral eye and Group 3 (n = 15) simultaneous ipsilateral superior rectus recession and contralateral inferior rectus muscle recession. Surgery was performed using the dose-effect for inferior rectus recession of 4 prism dioptre (PD,Δ ) reduction/per mm recession and the intraoperative traction test. RESULTS: Restoration of BSV in the central 20° of gaze could be reached in 88%, 79% and 67% of patients in the three groups, respectively. Restoration of BSV in downgaze (up to 30°) was a little less successful, 79%, 57% and 53%, respectively. The median dose-effect was 3.2Δ reduction/mm recession in Group 1 (Spearman correlation r = 0.75, p < 0.0001) and 3.3Δ /mm in Group 2 (n.s.) and 4Δ /mm in Group 3 (r = 0.67, p = 0.016). The basis for the improvement was the symmetrization of ductions. CONCLUSION: If superior rectus recession is necessary in GO, higher dosing around 3Δ reduction/per mm recession should be applied. In case of large deviations, combined vertical surgery (inferior rectus and superior rectus contralateral) is required and reasonable (low cyclotorsion). Single-step or two-step procedures lead to similar results.

Quality of life improves after strabismus surgery in patients with Graves' orbitopathy.

OBJECTIVE: To evaluate the influence of strabismus surgery on quality of life (QoL) in Graves' orbitopathy (GO) patients. DESIGN: Prospective study of case series. METHODS: Consecutive GO-patients who were scheduled for their first strabismus surgery were included in the study. The patients completed the GO-QoL questionnaire within 3 months before the surgery and 2-4 months after the surgery. A complete orthoptic examination, including the field of binocular single vision (BSV), was performed. Clinically relevant response (CRR) in the QoL was also evaluated. RESULTS: In this study, 28 patients were included. The GO-QoL score for visual functioning was 46.3±24.2 before surgery and 65.7±30.5 after surgery (P=0.009). The GO-QoL score for appearance changed from 60.6±25.9 to 69.5±24.2 (P=0.005). After surgery, the field of BSV increased from 24.3±34.8 to 68.5±36.0 points (P=0.000). A weak correlation was found between the field of BSV and the visual functioning score after surgery (r=0.417; P=0.034). CRR was found in 20 (71%) patients. Those with a CRR showed a larger field of BSV (P=0.002) and better GO-QoL scores (P=0.008). CONCLUSIONS: GO-QoL score increases significantly for both visual functioning and appearance after the first strabismus surgery in GO-patients, showing the highest improvement for the visual functioning questions. Both the GO-QoL and field of BSV outcomes correlate well with the CRR.