Forced Duction Test Research Articles

Supramaximal Horizontal Rectus Recession–Resection Surgery for Complete Unilateral Abducens Nerve Palsy

PurposeTo review the surgical procedures and outcomes of supramaximal horizontal rectus recession–resection surgery for abduction deficiency and esotropia resulting from complete unilateral abducens nerve palsy.MethodsA total of 36 consecutive cases diagnosed as complete abducens nerve palsy, receiving supramaximal medial rectus recession (8.5 ± 1.4 mm, range: 6–10) combined with a supramaximal lateral rectus resection (11.1 ± 1.7 mm, range: 8–14) as performed over the period from 2017 to 2020, were reviewed retrospectively. All surgeries were performed by a single surgeon. Pre- and post-operative ocular motility, ocular alignment, forced duction test, binocular vision, abnormal head posture, and surgical complications were assessed.ResultsOf these 36 cases, 23 (63.8%) were followed up for greater than 2 months (Mean ± SD = 8.4 ± 6.0, range: 2–24) after surgery and the collected data was presented. Mean ± SD age of these patients was 41.7 ± 14.4 (range: 12–67) years with 73.9% being female. Trauma (52.2%, 12/23) and cerebral lesions (21.7%, 5/23) were the primary etiologies for this condition. Esodeviation in primary position improved from 55.5 ± 27.2 prism diopters (PD) (range: +25 to +123) to 0.04 ± 7.3 PD (range: −18 to +12) as assessed on their last visit. Pre-operative abduction deficits of −5.6 ± 1.0 (range: −8 to −4) reduced to −2.4 ± 1.4 (range: −4 to 0) post-operatively. The mean dose-effect coefficient of 2.80 ± 1.20 PD/mm (range: 1.07–6.05) was positively correlated with pre-operative esodeviation. Rates of overcorrection and ortho were 69.6 and 26.1%, respectively, on the first day after surgery, while on their last visit the respective levels were 4.3 and 82.6%.ConclusionSupramaximal horizontal rectus recession–resection surgery is an effective treatment method for complete abduction deficiency. The dose-effect was positively correlated with pre-operative esodeviation. Overcorrection on the first day post-operatively is required for a long-term satisfactory surgical outcome.

Medial rectus disinsertion for management of chronic complete sixth nerve palsy.

To report the outcomes of the medial rectus (MR) disinsertion procedure for the management of refractory esotropia (ET) with or without Abnormal head posture (AHP) in chronic complete sixth nerve palsy. This is a retrospective case series of patients with sixth nerve palsy who suffered from residual ET and diplopia following the conventional strabismus surgeries and underwent MR disinsertion procedure between April 2017 and February 2020. This procedure was offered to the patients who declined to use prism and did not wish to perform surgery on the fellow eye. The demographic and clinical data, including sex, age, visual acuity, pre and postoperative angle of strabismus, duction limitations, results of forced duction and force generation tests, details of prior strabismus surgeries, orbital CT scan findings, and follow up duration were collected from the medical records. Six patients were enrolled in this study. Mean age was 35.0 ± 14.0 years, and mean follow-up was 15.3 ± 5.9 months. The ET at the Primary position (PP) was 35.0 ± 18.4 prism dioptre (PD) before MR disinsertion, which decreased to 14.2 ± 17.4 PD after MR disinsertion procedure. Four cases needed additional complementary surgeries to improve residual ET in PP. No case developed overcorrection. Abduction deficiency was -5.0 ± 1.3 before MR disinsertion, which improved to - 2.8 ± 0.5 units at last follow-up. The mean of induced adduction deficiency was - 2.9 ± 0.4 at last follow-up. MR disinsertion can be considered in patients with chronic complete sixth nerve palsy and refractory diplopia when the conventional methods have failed.

Influence of fractures in different inferior orbital wall locations on ocular motility disorders.

Influence of fractures in different inferior orbital wall locations on ocular motility disorders.

Clinical observation of anterior tucking of the superior oblique tendon for correction of excyclotropia in adults

Objective: To investigate the clinical effect of anterior 1/3 superior oblique tendon tucking in acquired symptomatic excyclotropia adults. Methods: Retrospective case series. Seven patients (7 eyes) with acquired symptomatic excyclotropia who underwent an anterior 1/3 superior oblique tendon tuck procedure in Tianjin Eye Hospital from January 2019 to December 2019 were included. There were 5 male patients and 2 female patients, with an average age of (49±12) years old. All the patients had a history of a closed head injury. There was torsional diplopia in primary position, and eye movement examination showed paralysis of the superior oblique muscle in the affected eye, without obvious hyperactivity of the inferior oblique muscle. The anterior 1/3 tendon of the superior oblique muscle was tucked during surgery according to the relaxation of the superior oblique tendon in the forced duction test. The paired-sample nonparametric rank sum test was used to analyze the preoperative and postoperative (at 1 day after surgery and the last follow-up) excyclotropia angle. Results: The mean tuck amount was (7.7±1.8) mm (range, 6.0 to 10.0 mm). During operation, patients complained that excyclotropia improved markedly. The excyclotropia angle with the double Maddox rod test improved significantly from preoperative 10° (8°, 15°) to 2° (0°, 3°) at 1 day (Z=-2.379; P<0.05) and 2° (2°, 5°) at the last follow-up (Z=-2.375; P<0.05). The follow-up period was (112+38) days. All patients had no complaints of excyclotropia at the last follow-up. Conclusions: The anterior 1/3 superior oblique tendon tucking can effectively improve clinical symptoms in the primary position in adults with acquired excyclotropia and diplopia. The short-term postoperative results seem to be stable, without significant regression. (Chin J Ophthalmol, 2021, 57: 685-688).

Quantitative intraoperative torsional forced duction test in a pediatric population

Quantitative intraoperative torsional forced duction test in a pediatric population

Superior oblique tendon thinning as a surgical treatment for Brown syndrome

To evaluate the results of a superior oblique thinning technique for the treatment of congenital Brown syndrome. The medical records of consecutive patients at a single institution who were diagnosed with congenital Brown syndrome and underwent superior oblique thinning were retrospectively reviewed. In all cases, the prism cover test was used to assess ocular alignment. Standardized nine-gaze photographs were used to evaluate ocular rotations. Ocular torsion was measured using fundus retinography. Intraoperatively, all patients showed a positive forced duction test for elevation from adduction that became negative after a strongly maintained traction test maneuver. A total of 21 eyes of 20 consecutive patients (mean age, 5.8±2.5years) were included. Preoperatively, 16 patients were orthotropic in primary position; 4, hypotropic. Postoperatively, all patients were orthotropic in primary position. Limitation of elevation in adduction improved from -3.4±-0.6 (range, -2 to -4) to 0.6±1 (range, 0 to -3; P<0.01). Fundus retinography showed >1° change in ocular torsion after surgery in 3 of 6 patients (P>0.5). Superior oblique underaction or hypertropia did not occur. No superior oblique palsy appeared in any patient. There were no changes beyond 3months postoperatively except for 1 patient who relapsed 9months after surgery and 1 patient who improved after 4years. Superior oblique thinning is effective in improving elevation in adduction and hypotropia in primary position in patients with Brown syndrome associated with a thickened superior oblique tendon.

Clinical analysis and surgical treatment of atypical acute acquired concomitant esotropia

Objective: To investigate the clinical characteristics, possible etiology and surgical efficacy of acute acquired concomitant esotropia (AACE) with atypical etiology. Methods: Case-control study. Twelve patients, including 7 males and 5 females, who complained of diplopia and were diagnosed with AACE in Tianjin Eye Hospital from January to December 2019 and underwent surgical treatment were included. The duration of the disease was (8.83±3.71) months. All patients underwent routine ocular examination except amblyopia and ocular organic lesions. MRI examination of the orbits and the brain was performed in all the patients in order to screen orbital and craniocerebral diseases, and patients denied that the existence of common causes of AACE (such as occlusion of one eye, mental or psychological factors, medium to high myopia, etc. during medical examination). The characteristics of the disease, the difference of deviation angle at 33 cm and 5 m, and the changes of deviation angle and stereopsis before and after surgery were analyzed. The forced duction test was performed before operation, and the distance between the sclera margin and the midpoint of the medial rectus muscle attachment was measured and compared with the patients with intermittent exotropia (10 cases) and comitant esotropia (10 cases). Paired sample t-test and one-way analysis of variance were used for statistical analysis. Results: The mean spherical equivalent was (1.70±0.88) D in all AACE patients, and the deviation angle was (22.42±5.82) prism diopter (PD) at 33 cm and (20.00±4.86) PD at 5 m in primary gaze, which were not statistically significant (P=0.371). The force duction test showed no obvious tension or contracture of the medial rectus and no paralysis. In patients with AACE, the horizontal distance from the midpoint of the medial rectus to the limbus was (5.20±0.27) mm, versus (5.30±0.25) mm in intermittent exotropia patients and (5.30±0.31) mm in concomitant esotropia patients. All the differences were not statistically significant (P=0.618). All the patients with AACE had residual esotropia (mean, 3.42 to 6.33 PD) at 6 weeks, 3 months, and 6 months postoperatively, and their stereopsis improved more than before, with no stereopsis in 2 patients before surgery and stereopsis in all 12 patients after surgery. Conclusions: AACE patients with atypical etiology do not have high myopia and hyperopia. There is no significant difference between the distance and near angles. The occurrence of esotropia is related to decompensation of esophoria, which may result in clinical symptoms of diplopia. Conventional surgery can reduce esotropia and restore stereoscopic vision, but there is still a small amount of esophoria after surgery. There is no abnormality in the attachment point of the medial rectus muscle. (Chin J Ophthalmol, 2021, 57: 348-352).

Superior oblique split tendon elongation for Brown's syndrome: Long-term outcomes.

To report the outcomes of superior oblique split tendon elongation in Brown's syndrome. Charts of 17 consecutive Brown's syndrome patients who underwent superior oblique split tendon elongation were reviewed and clinical data regarding preoperative, intraoperative, and postoperative data were collected. About 17 eyes of 17 children with congenital Brown's syndrome underwent superior oblique split tendon elongation between January 2012 and March 2020 by a single surgeon. Mean age at surgery was 5.47 ± 2.82 (range 1.50-13.2). Eight (47.1%) were female. Preoperative deficit of elevation in adduction was -4 in all children. At the end of surgery, all eyes were freely elevated on adduction, on forced duction test. Mean follow-up time of 26.24 ± 11.22 (range 11-53) months. In 15 of 17 children (88.2%), motility improved, orthotropia in primary position was achieved, and head posture eliminated (p < 0.001). Superior oblique palsy occurred in two children, who after reoperation, achieved an acceptable outcome. No intraoperative complications were recorded. The superior oblique split tendon elongation procedure is a useful surgical technique with stable and satisfying outcomes for the treatment of severe congenital Brown's syndrome.

The presence of anomalous extraocular bands in Duane retraction syndrome

To determine the prevalence of anomalous extraocular bands in patients who underwent surgery for Duane syndrome and to compare the clinical findings in patients with and without bands. Thirty-one patients with Duane syndrome who had their first surgery on rectus muscles to correct the primary deviation and abnormal head posture were included in this retrospective study. Patients were divided into two groups depending on the identification of anomalous extraocular bands intraoperatively. Baseline clinical characteristics were compared between the groups. A total of 31 patients were included. Anomalous bands were found in 6 of 19 (32%) patients with esotropic Duane syndrome and 9 of 12 (75%) with exotropic Duane syndrome (P=0.02). In esotropic Duane syndrome, the bands were localized under the medial rectus muscle in 5 patients and under the lateral rectus muscle in 1 patient. All of the bands in patients with exotropic Duane syndrome were under the lateral rectus muscle. The amount of preoperative primary deviation, globe retraction, and up- or downshoot were similar between groups. All of the bands had distinct tight insertion on the sclera, requiring a sharp dissection for disinsertion. In 7 cases, the anomalous band was a translucent structure that could be identified under the surgical microscope as scleral indentation during forced duction testing. Histological examination of 6 cases revealed only fibrous tissue in 4 and accompanying striated muscle tissue in 2 patients. The present study highlights the incidence of anomalous bands in Duane syndrome.Repeating forced duction testing after disinsertion of the affected muscle and excision of the anomalous band is helpful for intraoperative identification of these structures.

Extraocular Muscle Enlargement in Bilateral Diffuse Uveal Melanocytic Proliferation Associated with Hepatocellular Carcinoma

A 64-year-old man with bilateral diffuse uveal melanocytic proliferation (BDUMP) (Figs A and B) associated with hepatocellular carcinoma presented with painless ocular movement limitations. Visual acuity was count fingers and 20/100, respectively. The eyelids and orbital changes were not observed. Extraocular muscle restriction was not presented on the forced duction test in both eyes. Orbit magnetic resonance imaging demonstrated tendon sparing extraocular muscle enlargement on the rectus and oblique muscles (Fig C), and the test for thyroid function and antibodies were within normal ranges.

Augmented superior rectus muscle transposition in management of defective ocular abduction

BackgroundSuperior rectus muscle transposition (SRT) is one of the proposed transposition techniques in the management of defective ocular abduction secondary to chronic sixth nerve palsy and esotropic Duane retraction syndrome (Eso-DRS). The aim of the current study is to report the outcomes of augmented SRT in treatment of Eso-DRS and chronic sixth nerve palsy.Methodsa retrospective review of medical records of patients with Eso-DRS and complete chronic sixth nerve palsy who were treated by augmented full tendon SRT combined with medial rectus recession (MRc) when intraoperative forced duction test yielded a significant contracture. Effect on primary position esotropia (ET), abnormal head posture (AHP), limitation of ocular ductions as well as complications were reported and analyzed.Resultsa total of 21 patients were identified: 10 patients with 6th nerve palsy and 11 patients with Eso-DRS. In both groups, SRT was combined with ipsilateral MRc in 18 cases. ET, AHP and limited abduction were improved by means of 33.8PD, 26.5°, and 2.6 units in 6th nerve palsy group and by 31.1PD, 28.6°, and 2 units in Eso-DRS group respectively. Surgical success which was defined as within 10 PD of horizontal orthotropia and within 4 PD of vertical orthotropia was achieved in 15 cases (71.4%). Significant induced hypertropia of more than 4 PD was reported in 3 patients (30%) and in 2 patients (18%) in both groups, respectively.Conclusionaugmented SRT with or without MRc is an effective tool for management of ET, AHP and limited abduction secondary to sixth nerve palsy and Eso-DRS. However, this form of augmented superior rectus muscle transposition could result in high rates of induced vertical deviation.

Surgical strategy for third nerve palsy with aberrant regeneration: Harnessing the aberrant power.

Purpose:Our study aimed to evaluate the outcome of contralateral eye (CE) fixation duress squint surgery (FDSS) in third nerve palsy (3rd NP) with aberrant regeneration and compare the postoperative ptosis correction with preoperative ptosis improvement on adduction.Methods:Patients of 3rd NP with aberrant regeneration who underwent CE FDSS between December 2012-July 2015 in a tertiary-care eye hospital with a follow-up period of 1-year were retrospectively studied to analyze preoperative and postoperative details. Surgical success was defined as the correction of ptosis within 1 mm of preoperative ptosis improvement during maximal adduction of the affected eye, postoperative alignment ≤10Δ, and resolution of subjective diplopia in primary position.Results:A total of 14 eyes in 14 patients (mean age 23.6 ± 13.6 years) were included. Mean preoperative exotropia and ptosis in primary position in 14 patients was 53.4 ± 20pd and 4.89 ± 2.9 mm, respectively, and mean hypotropia in 6 patients was 23.67 ± 5.89pd. The mean improvement of ptosis on adduction and supraduction in all patients was 4.07 ± 2.64 mm and 2.89 ± 2.22 mm, respectively (P = 0.213). All patients underwent large recession of CE lateral rectus (mean 12.4 ± 2.7 mm), 9 patients underwent CE medial rectus resection/plication (mean 6.0 ± 0.9 mm) and 6 patients underwent CE superior rectus recession (mean 6.6 ± 0.67 mm). Postoperatively, mean ptosis and exotropia correction was 3.7 ± 2.4 mm (P = 0.000) and 15 ± 9.6pd (P = 0.000), respectively, and mean hypotropia was 2.17 ± 4.02pd (P = 0.000). Surgical success was achieved in 6 patients. Postoperative ptosis correction showed strong positive correlation with preoperative improvement of ptosis on adduction (r = 0.87; P = 0.00).Conclusion:Preoperative lid excursion on adduction in 3rd NP can be regarded as a prognostic sign of the success of CE FDSS which can simultaneously correct both ptosis and squint.

Large-angle hypertropia managed by modified Nishida's procedure

Treating vertical squints especially large-angle hypertropia caused by inferior rectus palsy is a challenge. Superior rectus recession in presence of positive forced duction tests is the first step in surgical management. Following this, full tendon transposition of horizontal recti inferiorly (Inverse Knapp's procedure) is the standard procedure of choice. Modified Nishida's procedure has been described to treat vertical deviations like MED and inferior rectus aplasia. We describe a case of large-angle hypertropia treated by Modified Nishida's procedure.

A rare case of neurofibromatosis with proptosis-orbital neurofibroma

Neurofibromatosis, an oculo-­?neuro-­?cutaneous syndrome is characterized by multisystem involvement. A 65 years old male patient came to the dept. of ophthalmology, S. V. R. R. Govt. General Hospital, Tirupati with the complaints of protrusion of his left eye, noticed by him 20 days back, with a history of drooping of left upper eyelid. On physical examination, the patient was short statured (Ht: 148cm) with scoliosis, there were multiple neurofibromas on the skin all over the body and face, freckles in the axillary region and cafe-­?au-­?lait spots over his trunk. On ocular examination, the patient had eccentric proptosis of left eye where the eyeball was shifted downwards (Hypotropia of 450) and forwards (24mm on exophthalmometry) with severe ptosis of left upper eyelid with restriction of extraocular movements. No palpable mass was noted. Finger insinuation between the orbital margin and the globe was possible. Right eye was normal. Slitlamp examination showed multiple Lisch nodules on the surface of iris in both eyes. Fundoscopy showed inferior coloboma choroid of left eye with normal fundus picture in Right eye Binocular diplopia was noted on elevating the upper eyelid of left eye. Forced duction test was positive. CT scan showed proptosis of left eye. Ultrasound B-­?scan of left eye showed a well defined mass lesion of 1.5x2cm size, slightly hyperechoic, with minimal vascularity, situated away from the globe, along the lateral aspect of the orbit suggestive of Orbital neurofibroma. The rare entity in the present case is the Localized form of orbital neurofibroma. Diagnosis in the present case is clinical. Linkage analysis using polymorphic DNA markers can be performed, allowing prenatal diagnosis or presymptomatic diagnosis. Keyword: Oculoneurocutaneous syndrome, Orbital neurofibroma, Lisch nodules

SURGICAL OUTCOME OF INFERIOR RECTUS RECESSION IN MANAGEMENT OF MONOCULAR ELEVATION DEFICIT

Background: Monocular Elevation Deficiency (MED) is an inability to elevate one eye in all field of gazes usually resulting in one eye that is pointed downward relative to the other eye. Objective: To evaluate the efficacy of inferior rectus recession in management of monocular elevation deficit (MED) with +ve or –ve forced duction test (FDT). Patients and Methods: Our study was carried out on 20 patients complaining of MED who were selected from out-patients clinic in Sayed Galal and Al-Hussein University Hospitals. From January 2017 to May 2019. The patients were divided into 2 equal groups. Group A with +ve FDT, and group B with -ve FDT. Both groups had inferior rectus recession (IRR). Results: Preoperatively, 40% of patients in group A were -4 (limited elevation), and 60% of patients were -3. All those patients improved to -1 postoperatively. On the other hand, 90% of patients in group B were -4, and 10% of patients were -3 (limited elevation). They improved postoperatively to -3 and -2 respectively. In group (A), the average of preoperative hypotropia was 19.40 ± 1.43PD. All the patients had IRR: the postoperative average of hypotropia was 1.10 ± 1.91PD with average of correction 18.30 ± 1.42PD. In group (B) having MED with -ve FDT were operated by IRR. A reliable and effective correction of hypotropia in 7 patients with preoperative mean deviation of 19.86 ± 1.68PD, and postoperative mean deviation of 2.71 ± 2.56 PD with average of correction 17.14 ± 1.86PD. Partial correction of hypotropia in 3 patients underwent Knapp’s procedure with preoperative mean deviation of 50.0 ± 5.00, postoperative average of correction of 18.00 ± 0.00 PD, post Knapp procedure the deviation was 3.00 ± 2.65 with average of correction of 29.00 ± 2.65. Conclusion: Although the MED is etiologically multifactorial, satisfactory surgical results can be achieved by IRR as a simple and reliable 1ry intervention for both types (+ve FDT and –ve FDT).

Suture loop myopexy versus silicone band loop myopexy in the management of myopic strabismus fixus

To compare two different modalities of superior rectus-lateral rectus loop myopexy; suture (SLM) and silicone band loop (SBM), in the treatment of myopic strabismus fixus. The medical records of patients with myopic strabismus fixus who underwent surgical management with either SLM or SBM at a single institution over a period of 4years were retrospectively reviewed. In cases with positive intraoperative forced duction test, the medial rectus muscle was recessed. The primary outcome measures were improvement of primary position esotropia, hypotropia, and limitations of abduction and elevation. The angle between the displaced superior rectus and lateral rectus muscles (angle of globe dislocation) was also assessed by orbital imaging before and after surgery. A total of 21 patients were identified, of whom 10 underwent SLM and 11 underwent SBM. Mean age at surgery was 65.4±5.7years in the SLM group and 68.5±6.4years in the SBM group. Both procedures significantly improved esotropia, hypotropia, angle of globe dislocation, and limitation of abduction and elevation (P<0.0001), with no significant statistical difference between procedures (P>0.05). Intraoperative muscle splitting occurred in 2 cases in the SLM group, and transient foreign body sensation was documented in 3 cases in the SBM group. In this study cohort, both techniques achieved significant correction of ocular deviation, limitation of ocular ductions, and angle of globe dislocation associated with myopic strabismus fixus, with no statistically significant difference between procedures. Operative complications in both groups were mild and innocuous.

Use of neuromuscular blocking drugs in strabismus surgery: systematic review and ophthalmology survey study

ObjectiveNondepolarizing neuromuscular blocking drugs have been advocated for accurate forced duction testing (FDT) during strabismus surgery. The purpose of this study was to evaluate the literature on use of muscle relaxants (MRs) in strabismus surgery and to evaluate the current practice of pediatric ophthalmologists. DesignSystematic review and survey study. ParticipantsSeventy-seven pediatric ophthalmologists. MethodsMEDLINE, EMBASE, CENTRAL, Web of Science, and OpenGrey were searched to August 2019. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Primary studies on depolarizing or nondepolarizing MRs in patients undergoing strabismus surgery were included. Primary outcomes included indications and prevalence of use. A 23-question survey was emailed to pediatric ophthalmologists worldwide to collect practice pattern information involving MRs in strabismus surgery. ResultsThree studies were included in the systematic review. MRs were used in 34%–45% of patients undergoing strabismus surgery in one 1999 study for FDT. No evidence exists to support the use of MRs for facilitating FDT. Seven of 77 (9.1%) pediatric ophthalmologists requested MRs for FDT. Those who use MRs were more likely to be practicing outside the United States (p < 0.05) and in academic hospitals or private centres rather than in community settings. Drawbacks appeared to outweigh benefits, with the biggest drawback identified as increased turnover time between surgical cases (44%). ConclusionsInadequate evidence exists in the literature to support the use of nondepolarizing MRs to maintain paralysis of extraocular muscles during strabismus surgery, and this is an uncommon practice among pediatric ophthalmologists.

Duane-minus (Duane sine retraction and Duane sine limitation): possible incomplete forms of Duane retraction syndrome.

To report ocular motility patterns that mimic, but do not fulfil the full clinical picture of Duane retraction syndrome (DRS) and to describe their clinical features and surgical management. This is a retrospective case series study conducted on patients with DRS, mimicking non-comitant exotropia or esotropia and a face turn. Patients were included only if they lacked either globe retraction on adduction (sine retraction) or limitation of adduction or abduction on ductions (sine limitation not >0.5). Any overshoots or pattern strabismus was recorded. The ocular motility and alignment, details of surgery and their surgical outcomes were analysed. Twenty-one patients were identified; 13 in the sine retraction and 8 in the sine limitation group. All patients presented with a compensatory face turn. Overshoots were present in 10 (77%) and 7 patients (88%) in the sine retraction and sine limitation groups, respectively. Forced duction test showed tightness of the ipsilateral medial and the ipsilateral lateral rectus muscle in esotropic (n = 3) and exotropic patients (n = 18), respectively. Orthotropia was achieved in 82% of patients following ipsilateral medial or lateral rectus muscle recession. There is a subset of patients who present with motility pattern similar to DRS but lack its complete diagnostic criteria. The presence of a face turn, overshoots on adduction or an ipsilateral tightness of the affected muscle should make one consider DRS sine retraction/sine limitation. The patients in our study responded well to lines of management similar to those of DRS.

Vertical restrictive strabismus associated with proptosis: Similar clinical signs, different etiopathogenetic causes. A report of three patients.

To report the different uncommon pathogenesis of three cases of severe vertical restrictive strabismus associated with progressive unilateral proptosis with similar clinical features. Case series of three patients who presented to the Orbit Outpatient Service of Policlinico Gemelli with a history of left progressive unilateral proptosis, slowly worsening vertical strabismus and the left eye fixed in downward position. A thorough hematologic work up was performed. All patients underwent complete abdomen ultrasonography, orbital contrast enhanced magnetic resonance imaging, forced duction test under general anesthesia, and orbital biopsy. Patients were 30, 60, and 46 years old respectively. MRI showed left inferior rectus enlargement in two cases and superior rectus enlargement in one case, with contrast enhanced combined muscle belly and tendon enlargement in all cases. Patients underwent forced duction test, muscle weakening (in two cases), and muscle biopsy with histopathologic examination. The superior rectus appeared infiltrated by an undifferentiated high-grade pleomorphic sarcoma, whereas the two inferior recti were positive for idiopathic orbital inflammatory disease with fibrosis areas and neuromuscular choristoma, respectively. Although proptosis and acquired vertical restrictive strabismus are most commonly associated with thyroid associated orbitopathy (TAO), they can also be a manifestation of many other conditions and the differential diagnosis can be particularly challenging. The three reported cases presented indeed with similar clinical features but had three distinct underlying orbital etiologies, two of which were extremely uncommon.

Novel compact device for clinically measuring extraocular muscle (EOM) tension

Accurate knowledge of extraocular muscle (EOM) tension is important for the diagnosis of and surgical planning for strabismus, such as choosing which eye to operate or determining the amount of muscle displacement. Previous evaluations of passive EOM tension have relied extensively on the experience and skill of ophthalmic surgeons, who generally perform such evaluations by gripping the eyeball and then pushing and pulling it. This methodology, named the forced duction test, has the significant limitation that the tension is felt subjectively via the forceps, with the results therefore not being quantifiable. Previous quantitative analyses have utilized several different types of equipment with implanted force transducers or have involved connecting the muscle tendon to a strain gauge. However, the associated equipment setups and recording systems are highly complex and rarely used outside research settings. This situation prompted the present study to develop a novel compact, quantifiable and clinically applicable device for measuring the passive tension in human EOMs for use in clinical practice. The device employs locking forceps and a tilting sensor to rule out effects of the gripping force and to compensate for changes in the force due to tilting, which improves the measurement accuracy. The performance of the device was investigated in 60 eyes of 30 consecutive anaesthetized patients immediately prior to ophthalmic surgery. The results showed that the measured EOM tension in each rectus muscles agreed with previous findings: 48.3 ± 14.5 g (0.82 ± 0.28 g/deg, mean ± SD) for the lateral rectus, 45.6 ± 13.2 g (0.82 ± 0.23 g/deg) for the medial rectus, 48.6 ± 14.7 g (0.71 ± 0.21 g/deg) for the inferior rectus and 53.4 ± 13.7 g (0.77 ± 0.25 g/deg) for the superior rectus.