Jianhua Yan

Purpose Research on strabismus surgery for Thyroid Eye Disease (TED) is limited, with insufficient data on surgical dose–response. This study aimed to assess outcomes and dose–response in initial strabismus surgeries using a large TED sample. Methods A retrospective review of TED patients undergoing initial strabismus surgery (2013–2023) at Zhongshan Ophthalmic Center included data on demographics, ocular deviation, motility, surgical techniques, and outcomes. Surgeries involved rectus recession and tenotomy, with traction sutures (TS) applied for deviations > 35 prism diopters (PD). Success was defined as no diplopia and deviation ≤ 10 PD horizontally, ≤ 5 PD vertically. Dose–response (deviation change per mm rectus recession, DPR) and influencing factors were analyzed. Results Among 104 patients, rectus recession had a 70.65% success rate, while tenotomy achieved 12.5%. Success was highest for superior rectus (SR) recession (88.00%), followed by inferior rectus (IR) (70.00%) and medial rectus (MR) (38.46%). Two-muscle recessions succeeded in 55.56%. In single rectus recession with TS, DPR for IR, SR, and MR was 6.96 ± 2.18, 5.92 ± 1.14, and 9.78 ± 5.80 PD/mm, respectively, versus 4.26 ± 0.78, 3.95 ± 0.83, and 3.86 ± 0.29 PD/mm without TS. Preoperative deviation significantly affected DPR, especially in IR/SR surgeries (P < 0.001). Simultaneous MR recession did not alter IR/SR DPR in TS (P = 0.266) or non-TS (P = 0.138) groups. However, in non-TS cases, IR/SR recession impacted MR DPR (P = 0.034), but this effect was absent with TS (P = 0.741). Conclusions Single rectus recession achieves high success for TED vertical strabismus, with TS enhancing correction. Preoperative deviation is key to dose–response, while vertical recession influences horizontal dose–response when deviation is < 35PD.

Purpose Strabismus, including esotropia and exotropia, significantly affects binocular vision and presents challenges in clinical management and surgical correction. Although previous studies have explored the anatomical characteristics of horizontal rectus extraocular muscles (EOMs) in strabismus, large-scale analyses of insertional anatomy remain limited. This study investigates anatomical variations in the insertions of horizontal rectus EOMs in patients with esotropia and exotropia, aiming to understand their impact on strabismus management. Methods A retrospective case-control study was conducted using clinical records from 4781 patients diagnosed with strabismus who underwent surgery at the Zhongshan Ophthalmic Center, Sun Yat-sen University, from June 2014 to August 2020. Anatomical measurements of horizontal rectus EOM insertions were taken using a Castroviejo caliper. Statistical analyses, including regression analysis, were performed to examine the relationship between EOM characteristics and clinical outcomes. Results Significant anatomical differences were observed among esotropia, exotropia, and control groups. Esotropia patients exhibited shorter medial rectus (MR) insertion distances (mean: 4.81 mm) than both exotropia (5.09 mm) and controls (5.08 mm, p < 0.001), with moderate effect sizes. Exotropia subtypes showed wider MR and lateral rectus (LR) insertions, particularly in constant and pattern types (MR width p = 0.001, LR width p = 0.002). Regression analysis indicated that shorter MR insertion distance was significantly associated with greater esodeviation at both near (β = -13.60, p < 0.001) and distance (β = -12.76, p < 0.001), though with small effect sizes. Refractive error (SE) and age were also significant predictors of deviation magnitude and AC/A ratio. Conclusion Anatomical variations in the horizontal rectus EOMs are significantly associated with esotropia and exotropia. These findings enhance our understanding of strabismus pathophysiology and may help guide surgical strategies for severe cases, though further research is needed to refine clinical applications.

AIM: To describe the clinical manifestations, imaging features and surgical treatments in 5 cases of extraocular muscle (EOM) dysplasia presenting as orbital space-occupying lesions (SOL). METHODS: Records from the 5 cases with EOM dysplasia between 2004 and 2016 were retrospectively reviewed and clinical data were recorded including family history, age at onset, age at surgery, visual acuity, cycloplegic refraction, ocular alignment and motility, stereoacuity, exophthalmos, anterior segment and fundus, orbital computed tomography (CT) or magnetic resonance imaging (MRI) scan, surgical methods and final outcomes. RESULTS: All 5 cases (1 male, 4 females) were unilateral (3 right, 2 left eyes). The average age was 5.4y (range 4-6y) with no family history. Patients had unilateral strabismus (horizontal and vertical), restricted eye movement, and eyelid changes (abnormal fissures, lagophthalmos, and/or entropion) in the affected eye. None had proptosis; 1 had 2-mm enophthalmos. Orbital CT/MRI showed irregular, ill-defined masses in EOM. Two anterior orbitotomies and 3 strabismus surgeries were performed, and pathology confirmed EOM dysplasia. After surgery, horizontal deviations, which ranged from exotropia (XT) 10 prism diopter (PD) to esotropia (ET) 10 PD (average 6 PD), decreased by an average of 18 PD, while vertical deviations, which ranged from 4 PD to 20 PD (mean 9.8 PD), decreased by an average of 23.2 PD. CONCLUSION: SOL from EOM dysplasia is non-familial and typically presenting unilaterally characterized by an irregular, diffusely infiltrating mass within the EOM. EOM involvement causes strabismus, restricted eye movement, eyelid changes, and enophthalmos likely due to cicatricial processes.

AIM: To investigate the potential mechanisms of A-V pattern and evaluate the surgical outcomes used in the treatment of sensory exotropia. METHODS: The medical records of patients with sensory A-V pattern exotropia who underwent strabismus surgery between May 2014 to June 2019 was retrospectively reviewed. The control group included sensory exotropia patients without A-V pattern and concomitant A-V pattern exotropia patients with normal vision who undergone strabismus surgery over this same time period. Ocular alignment, best corrected visual acuity, oblique muscle function, and stereopsis records were collected. RESULTS: Among the 843 eligible patients, 91 (10.79%; 39 males and 52 females) had A-pattern (54, 6.4%) or V-pattern (37, 4.4%). Age at onset of vision impairment was 4±5y and at the time of surgery was 25±9y. Statistically significant negative correlations were present between impaired visual acuity and the pre-operative exodeviation (r=-0.198, P=0.016) and patterns (r=-0.207, P=0.015). Age at surgery and exodeviation in patients with concomitant A-V pattern exotropia was significantly earlier as compared with that of sensory A-V pattern exotropia and sensory exotropia (both P<0.0001). There were no significant differences in these clinical variables between sensory exotropia with or without A-V pattern. Deviation and pattern were significantly reduced in patients receiving horizontal rectus surgery with or without oblique muscle surgery (both P<0.0001). CONCLUSION: The prevalence of sensory A-V pattern exotropia in our study is 10.79%. Visual acuity represents an important factor contributing to the occurrence and development of A-V pattern. Isolated horizontal rectus surgery can provide a good option for the correction of sensory A-V pattern exotropia.

A 6-year-old male involving a coexistence of congenital fibrosis of the superior rectus muscle (SR) with Marcus Gunn Jaw-Winking phenomenon presented with an elevation of the upper eyelid along with a chronically open mouth that had been present since early infancy. There was extropia and hypertropia, a limitation of elevation and depression in the right eye, and an abnormal head posture (AHP) with a left head tilt, right face turn, and a chin-up head position. He also displayed an upper eyelid retraction and a 2-mm lagophthalos in the right eye. Results of the forced duction test indicated a constricted SR of the right eye. A dissection of the SR from the levator palpebrae superioris and a 5-mm SR recession was performed within the right eye. At 2 months post surgery, there was a 3 prism diopters (PD) hypertropia in the right eye when the left eye was fixated on the target and a 10 PD hypotropia in the left eye when the right eye was fixated on the target, along with an improvement in his AHP. In this rare case with a coexistence of congenital fibrosis of the SR and Marcus Gunn jaw-winking phenomenon, we found that the performance of an individualized surgical protocol proved effective in reducing the vertical deviation and improving AHP.

Purpose: The purpose of this study was to design an objective method for measurement of head positions as achieved with use of a microelectromechanical systems (MEMS) sensor. In addition, to use this system to observe the abnormal head position (AHP) in patients with congenital superior oblique palsy (SOP) before and after their surgery. Methods: An MEMS sensor was designed for recording of the pitch, roll, and yaw values of the head position in real time. The MEMS sensor was then fixed on the synoptophore from –30 degrees to +30 degrees positions horizontally and vertically to test the accuracy of these measurements. Then, we tested 13 participants with AHP using the MEMS method and the photographic method and compared their correlations. Finally, the pitch, roll, and yaw values of head positions were measured using this MEMS sensor in 31 patients with congenital SOP as performed before and after their surgery. Results: The MEMS sensor (LPMS-B2; Alubi, Guangzhou, China; 400 hertz [Hz]), as based on the theory of a gyroscope, was designed and connected to a smartphone via Bluetooth. It was able to conveniently record the patient’s pitch, roll, and yaw head positions in real time, recordings which were consistent with the scales of the synoptophore (P > 0.05) and good correlations with the photographic method (P < 0.001). The main preoperative AHP in patients with SOP was roll (22/31, 71%). Pre- and postoperative vertical deviations were 16.4 ± 7.3 prism diopters (PD) and 4.1 ± 4.2 PD, respectively (P = 0.001). The AHP in patients with SOP was positively correlated with the angle of extorsion in the dominant eye (P = 0.01), rather than that of the vertical deviation. Conclusions: The MEMS sensor described in this report is a simple, practical, and accurate objective device for use in head position measurements. In patients with SOP, the AHP is related to the angle of extorsion in the dominant eye. Translational Relevance: The MEMS sensor was designed as a micro-wireless dynamic high-precision device for AHP measurement, which has the potential for use in a clinic.

The traumatic rupture of the superior oblique tendon with ptosis is extremely rare, and the surgical treatment is very challenging. We reported a case of a 41-year-old man with superior oblique tendon rupture and ptosis due to an iron hook injury. The ocular movement disorders were not obvious except for mild superior oblique underaction but were accompanied by severe extorsion. The distal stump of the superior oblique tendon was shortened and anchored to the periosteum of the supra-nasal orbital margin near the trochlea. Post-operative follow-up revealed the surgical outcome was better than expected, which resulted in significant improvement in binocularity and cosmetic outcomes without complication in the present case. The exploration of the levator palpebral superioris (LPS) in the early post-traumatic stage might not be necessary in circumstances without eyelid laceration. Shortening and anchoring of the ruptured superior tendon could restore almost normal binocularity, decrease the extorsion, and avoid acquired Brown syndrome.