No-split, no-tenotomy transposition of only the superior rectus muscle combined with medial rectus recession in patients with complete abducens nerve palsy.

PURPOSE: To evaluate the outcomes of no-split, no-tenotomy transposition of only the superior rectus muscle combined with medial rectus recession in patients with complete abducens nerve palsy. METHODS: In this procedure, the temporal margin of the superior rectus muscle, 10 mm posterior to the insertion, was secured with a nonabsorbable suture and sutured to the sclera at a distance of 12 mm from the limbus in the superotemporal quadrant, halfway between the superior rectus and lateral rectus. Success was defined as distance and near alignment of ≤8Δ and no diplopia in primary position 6 months after surgery. RESULTS: A total of 8 patients with abducens nerve palsy underwent the procedure. At the last follow-up, the mean postoperative change in primary position deviation was 42.6Δ ± 8.1Δ (range, 34Δ-57Δ) for distance and 42.1Δ ± 7.5Δ (35Δ -57Δ) for near, a significant reduction (P = 0.012). Abduction deficit also improved significantly (P = 0.010). Postoperatively, no vertical deviation or torsional diplopia was induced. At the 6 months' follow-up, compared with the first postoperative visit, an esodrift at near developed in 1 patient. Of the 8 cases, 6 fulfilled the criteria for success. CONCLUSIONS: In our small study cohort, no-split, no-tenotomy superior rectus transposition and medial rectus recession improved esotropia and abduction limitation without inducing significant vertical deviations or torsional diplopia.

Superior Rectus Transposition Surgery: Safety, Efficacy, and Place in Therapy.

Abduction limitation in esotropic Duane retraction syndrome (DRS), esotropic Mobius syndrome, and sixth nerve palsy is one of the difficult-to-manage problems in strabismus surgery. The procedure of superior rectus transposition (SRT) was introduced by Johnston et al. In this procedure, the superior rectus (SR) muscle is disinserted and sutured adjacent to the insertion of lateral rectus (LR) muscle. The purpose of this review is to explore literature about efficacy and safety of SRT and its usage in strabismus surgery.

Retinal misregistration and effect of surgery on its improvement in patients with epiretinal membrane.

PURPOSE: To evaluate the prevalence of retinal misregistration, that is, misalignment of retinal elements that affect central and peripheral fusion, and the effect of surgery in patients with epiretinal membrane (ERM). METHODS: This prospective interventional case-series was performed on 32 patients with symptomatic ERM with the complaint of binocular diplopia or decreased visual acuity. After the diagnosis of ERM, optotype frame, synoptophore, and lights on-off tests were used to evaluate retinal misregistration. Patients with severe symptoms underwent surgery and were followed for 3 months. RESULTS: Of the 32 patients, 6 (19%) had preoperative diplopia. Optotype frame, synoptophore, and lights on-off tests had positive results in 20 (63%), 19 (63%), and 11 (34%) cases, respectively. Of the 6 diplopia cases, 5 showed positive results in all 3 tests and 1 was positive on optotype frame and synoptophore testing. Of the 26 cases without diplopia, 15 (58%) showed positive results in at least one test, including 6 (23%) in all three tests, 6 (23%) in two tests, and 3 (12%) in only one test. Ten patients underwent surgery. Postoperatively, all patients had negative lights on-off test, but optotype frame and synoptophore tests were negative in eight patients (80%). Two cases (20%) had postoperative diplopia, including 1 case with postoperative new-onset diplopia. CONCLUSIONS: The prevalence of retinal misregistration was higher than the rate of diplopia. Surgery improved diplopia and results of tests of retinal misregistration.

Comparison of the Accuracy of Anterior Segment Optical Coherence Tomography and Ultrasound Biomicroscopy in Localizing Rectus Muscle Insertions.

PURPOSE: To compare the accuracy of anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in localizing rectus muscle insertions. METHODS: The study was performed on 27 patients (39 rectus muscles) who required primary or secondary surgery. Using caliper function in the AS-OCT and UBM software, the distance from the insertion site to the anterior chamber angle was measured. The actual muscle insertion distance from limbus was considered as the measured distance plus 1 mm. The measurements by UBM and AS-OCT were compared with intraoperative measurements and with each other. RESULTS: AS-OCT and UBM were performed on 13 medial rectus, 24 lateral rectus, and 2 superior rectus muscles. Ninety two percent of UBM measurements (36 muscles) were within 1 mm, one was within 1-1.5 mm, and 2 were within 1.5-2 mm of surgery measurements. Eighty five percent of AS-OCT measurements (33 muscles) were within 1 mm, 5 were within 1-1.5 mm, and one was within 1.5-2 mm of surgery measurements. In all cases, the mean absolute error of the UBM (0.54 ± 0.44) and AS-OCT (0.51 ± 0.36) showed no significant difference (p = .76). CONCLUSION: AS-OCT and UBM can be used interchangeably to localize rectus muscle insertions and showed good agreement with intraoperative measurements.

Retinal displacement following pars plana vitrectomy with silicone oil tamponade for rhegmatogenous retinal detachment.

PURPOSE: To evaluate the frequency of retinal displacement after pars plana vitrectomy (PPV) using silicone oil tamponade in patients with rhegmatogenous retinal detachment (RRD). METHODS: Patients with fresh RRD were enrolled in this prospective interventional case series. A standard 3-port PPV with silicone oil tamponade was performed in all cases. A complete ocular examination, optical coherence tomography and fundus autofluorescence (FAF) imaging were performed at 1 and 3 months follow-up. Orthoptic examinations including synoptophore and light on-off tests were also performed at 3 months. RESULTS: Twenty-three eyes from 23 patients with mean age of 56.6 ± 11 (range: 38-82) years were included. All patients were pseudophakic. Downward retinal displacement was found in 2 eyes (8.7%) showing hyperautofluorescent lines parallel to retinal vessels in FAF image. The patients with retinal displacement did not complain of metamorphopsia and did not show abnormality in orthoptic tests. CONCLUSION: Unintentional retinal shift following PPV with silicone oil tamponade for RRD is uncommon and might have little clinical significance.

Superior Rectus Transposition and Medial Rectus Recession for Treatment of Duane Retraction Syndrome and Sixth Nerve Palsy.

Purpose: To evaluate the outcome of augmented superior rectus transposition (SRT) with medial rectus (MR) recession in patients with Duane Retraction Syndrome (DRS) and sixth nerve palsy.Methods: Twenty four patients (16 DRS and 8 sixth nerve palsy) that underwent the procedure were included. The superior rectus muscle was secured, detached, and re-attached to the sclera along the spiral of Tilaux, adjacent to lateral rectus insertion. A non-absorbable augmentation suture was passed through the sclera, 8 mm posterior to the insertion of the lateral rectus.Results: At the last follow-up, the effect of surgery in decreasing esotropia in both groups was significant (P = .001 for DRS group, P = .002 for sixth nerve palsy). In both groups, abduction deficit improved significantly (P < .001 for DRS and P = .008 for sixth nerve palsy). After the surgery, small, asymptomatic vertical deviation in primary position was induced in five patients (20.8%). Post-operatively, none of the patients complained of torsional diplopia. In the 6-month follow-up, compared with the first postoperative visit, an eso-drift at distance or near developed in 11 patients (45.8%). Of the 11 patients with eso-drift, overcorrection (exotropia of 3-14 PD) was present at the first post-operative visit in 5 cases. Four cases showed an exo-drift (2-5 PD) at distance or near over time.Conclusion: SRT with medial rectus recession improves esotropia and abduction limitation without inducing significant vertical deviations and torsional diplopia. Some of the cases that underwent SRT with MR recession may show an eso-drift. The eso-drift can correct initial exotropia in some cases.

Bupivacaine Injection without Electromyographic Guide for Correction of Residual Esotropia and Exotropia after Strabismus Surgery.

Purpose: To evaluate the effect of bupivacaine injection without electromyographic guide for correcting residual esotropia and exotropia after strabismus surgery. Methods: Thirty patients with residual esotropia or exotropia after strabismus surgery were included in the study. Three milliliters of bupivacaine 0.5% were injected into medial or lateral rectus muscle without electromyographic guide. Results: The mean pre-injection misalignments were 14.8 ± 3.4 (8-20) PD at distance and 14.7 ± 4.4 (6-25) PD at near. The 1 month post-injection alignment changes were 5.2 ± 2.6 (2-13) PD at distance and 6.5 ± 3.1 (2-18) PD at near. The 6 months post-injection alignment changes were 5.8 ± 2.6 (2-13) PD at distance and 7.0 ± 3.6 (2-18) PD at near. LogMAR of the worst eye had strong correlations with 6 months far alignment change (ρ = 0.39, p = .04), 6 months near alignment change (ρ = 0.41, p = .03), and 12 months near alignment change (ρ = 0.69, p = .01). Conclusion: The effect of bupivacaine injection without electromyographic guide for correcting residual esotropia or exotropia after strabismus surgery was between 2 and 18 PD, comparable with other studies on unoperated cases. The effect of bupivacaine may increase with decreasing visual acuity.

Strabismus Surgery in Thyroid-Associated Ophthalmopathy; Surgical Outcomes and Surgical Dose Responses.

PURPOSE: To investigate the success rate and surgical dose responses in strabismus surgery of thyroid-associated ophthalmopathy (TAO). METHODS: Thirty-three patients (26 men) were included in this study and underwent strabismus surgery. The mean follow-up time was 11.3 ± 6.5 months. Success was defined as the proportion of patients with a horizontal deviation of less than 10 PD, vertical deviation of less than 4 PD, and no subjective diplopia in primary and downgaze. RESULTS: After the final follow-up visit, strabismus surgery was successful in 87.8% of patients. Pre-operative factors (age, gender, smoking, corticosteroid usage, radioactive iodine, orbital decompression, optic neuropathy, baseline deviations, extorsion, type of strabismus, TAO duration) were not statistically correlated with success. Dose responses were calculated to be 3.44 ± 0.66 PD/mm of medial rectus recession and 4.83 ± 1.48 PD/mm for vertical rectus recession. Patients with deviation ≥25 PD had significantly larger surgical dose response compared to the group with deviation<25 PD (p value = .003 for horizontal and p-value <0.05 for vertical deviations). In eyes with predominant hypotropia, we found 1.64 ± 1.37 PD decrease in esotropia for each millimeter recession of inferior rectus muscle. CONCLUSIONS: Surgical dose responses in large deviations were significantly higher than the moderate angle of deviation. The reported mean for vertical dose responses may vary in different patients based on the laterality and involvement of superior rectus muscles. The recession of inferior rectus muscle may correct mild-to-moderate esotropia without the need for horizontal muscle surgery.

Management of Thyroid Eye Disease-Related Strabismus.

PURPOSE: To review various treatment methods in thyroid eye disease (TED) related strabismus. METHODS: We searched in PubMed and Google Scholar and Ovid MEDLINE for keywords including TED-related strabismus, strabismus in thyroid-associated ophthalmopathy, Graves' ophthalmopathy related strabismus or squint, and restrictive strabismus. Two expert strabismus specialists selected and evaluated the English articles that were related to our paper and had been published since 2000. Some articles were added based upon the references of the initial articles. RESULTS: One hundred fifteen articles were found, 98 of which were mostly related to the topic of this review. Management of TED-related strabismus was reviewed and categorized in non-surgical and surgical. Botulinum toxin A (BTA) is a useful non-surgical management of strabismus in an active TED and residual deviation after strabismus surgery. Postoperative under-correction is relatively more common in TED-related esotropia. Lateral rectus resection and BTA are the options to manage the problem. Muscle rectus muscle resection should be performed after maximum recession of restricted muscles. It should be avoided on a restricted or enlarged muscle. Management of TED-related vertical deviation is challenging. In these cases, the surgical treatment selected depends on forced duction test (FDT) (pre and intraoperative), orbital imaging (which muscle is enlarged), and the amount of vertical deviation (in both down-gaze and primary position). CONCLUSIONS: TED-related strabismus needs careful evaluation and management to achieve optimal outcome. Different surgical and non-surgical options are available for intervention in TED-related strabismus.

Surgical outcome of patients with unilateral exotropic Duane retraction syndrome.

PURPOSE: To describe the clinical features and surgical outcomes of patients with unilateral exotropic Duane retraction syndrome (DRS). METHODS: The medical records of patients with unilateral exotropic DRS who underwent surgery between March 2015 and February 2018 were reviewed retrospectively. RESULTS: A total of 40 patients (mean age, 18.75 ± 12.54 years; 21 males [53%]) were included. In 28 patients (70%) the left eye was involved. All patients had globe retraction and head turn toward the opposite side of the affected eye. Remarkable upshoot/downshoot movement was detectable in 11 patients (28%). The mean deviation for near and distance improved from 24.37Δ ± 12.34Δ (range, 6Δ-77Δ) and 19.67Δ ± 10.76Δ (range, 4Δ-60Δ) to 4.25Δ ± 8.61Δ (range, 0Δ-50Δ) and 2.62Δ ± 6.15Δ (range, 0Δ-35Δ) after the first surgery (P <0.001 for near and far deviation). Mean postoperative follow-up was 7.82 ± 9.45 months. Two patients required reoperation. Different types of surgeries, including lateral rectus recession (with or without Y-splitting), lateral and medial rectus recession (with or without Y-splitting of the lateral rectus muscle), bilateral lateral rectus recession, and lateral rectus recession with vertical rectus nasal transposition were performed. Twenty-four patients (60%) were successfully treated with only a single recession of the ipsilateral lateral rectus muscle. The mean lateral rectus recession was 7.45 ± 0.73 mm (range, 6-8.5 mm), and the mean dose-response for lateral rectus recession was 2.79Δ ± 0.64Δ/mm for near and 2.45Δ ± 0.67Δ/mm for distance. CONCLUSIONS: Simple lateral rectus recession (with or without Y-splitting), even in the presence of significant deviation (through 35Δ), seems to be a successful procedure for management of patients with unilateral exotropic DRS.

The effect of alternate occlusion on control of intermittent exotropia in children.

PURPOSE: The aim is to investigate the effect of alternate occlusion on control of intermittent exotropia in children 3 to 8 years old. METHODS: The ability of 28 children to control of the deviation at far and near was evaluated based on 3-point and 6-point control scales. Stereopsis and fusion were assessed using the Titmus and Worth 4-dot tests, respectively. Two-hour alternate daily occlusion was prescribed for children with no dominancy. For children with a dominant eye, 2-h occlusion of the dominant eye for 5 days and the non-dominant eye for 2 days. All measurements were repeated at 3, 6, and 9 months after the treatment. RESULTS: For all children with a mean age of 4.7 ± 1.56 years, deviation control at far improved significantly after 3, 6, and 9 months of treatment using both control scales when compared with baseline (p = 0.005 after 3 months and p = 0.008 after 6 and 9 months for the 3-point scale, and p < 0.001 after 3 and 6 months and p = 0.010 after 9 months for the 6-point scale). Control at near showed a significant improvement after 3, 6, and 9 months of treatment based on the 6-point scale (p = 0.007 for 3 months, p = 0.004 for 6 months, and p = 0.014 for 9 months). Near stereopsis improved significantly after 9 months of treatment (p = 0.043). CONCLUSION: Alternate occlusion is significantly effective on control of intermittent exotropia. As a result, it can be used as a useful method to postpone or even eliminate the need for surgery in intermittent exotropia.

Clinical findings and surgical outcomes of patients with traumatic isolated inferior rectus muscle paresis.

PURPOSE: To evaluate clinical findings and surgical outcomes of patients with traumatic isolated inferior rectus muscle paresis. METHODS: The medical records of patients with traumatic isolated inferior rectus paresis who underwent strabismus surgery at Farabi Eye Hospital between 2011 and 2018 were reviewed retrospectively. Clinical features, type of surgery, and surgical outcomes were extracted from the record for analysis. RESULTS: A total of 19 patients (14 males [74%]) were included. Mean patient age was 34.8 ± 14.6 years. Left eyes in 13 patients (68%) were involved. Thirteen cases (68%) underwent orbital reconstruction surgery for blow-out fracture. Preoperative limitation of duction in the gaze of the inferior rectus muscle was -2 to -3 in all cases. Four patients (21%) had a paradoxical contralateral compensatory head tilt. Inferior rectus muscle resection alone was the first surgical intervention in 12 patients (63%). At the final follow-up, 12 patients (63%) were orthotropic, without any deviation or diplopia in primary position and downgaze. Three patients (16%) had a residual hypertropia of 3Δ at distance and near without diplopia, and 4 patients (21%) required reoperation. CONCLUSIONS: In our patients with traumatic isolated inferior rectus paresis with persistent deviation at least 6 months after trauma, a stepwise approach based on size of the vertical deviation was employed, with good outcomes: inferior rectus resection alone for hypertropia of 6Δ-20Δ and inferior rectus resection and superior rectus recession for hypertropia of ≥20Δ or significant hypertropia in the field of the superior rectus muscle.

Clinical characteristics, histopathology, and treatment outcomes in adult and pediatric patients with nonspecific orbital inflammation.

PURPOSE: To evaluate the clinical characteristics, histopathology, and treatment outcomes in adult and pediatric patients with nonspecific orbital inflammation (NSOI). METHODS: This retrospective study evaluates 76 patients with NSOI. The patients were categorized in 9 groups according to the site of involvement and histopathology results. These groups included: anterior involvement, dacryoadenitis, myositis, perineural involvement, acute fat involvement, focal mass, orbital apex involvement, diffuse sclerosing form, and multiple tissue involvement. The course of the disease was categorized as acute, subacute, or chronic. The cases with symptom duration of less than 1 week were classified as acute, 1 week to 1 month as subacute, and more than 1 month as chronic. RESULTS: 36 (47.4%) patients were males. The mean age was 41.68 ± 17.62 (6-75) years. The most common signs and symptoms were periorbital pain, periorbital edema, decreased ocular movements or diplopia, and conjunctival injection. The most common group was dacryoadenitis in 29 (38.1%) cases. The most common form of disease was the acute involvement (50% of patients). Most of the patients were treated by oral corticosteroids. Duration of follow-up was 7.17 ± 6.26 months. Recurrence occurred in 9 (11.8%) of patients during the follow-up period. CONCLUSIONS: This study presents a new categorization in which multiple tissue involvements were separated. Some of the NSOI features differ between adults and children. In most patients, treatment especially with corticosteroids, resolves the clinical findings.

Ocular movement disorders following scleral buckling surgery: A case series study.

PURPOSE: To evaluate ocular movement disorders after scleral buckling surgery (SBS) for retinal detachment. METHODS: In this prospective, observational, case series, 206 patients (206 eyes) with rhegmatogenous retinal detachment who underwent SBS and investigated at the strabismus ward of Farabi Eye Hospital in Iran between November 2011 and November 2014 were assessed. Patients were followed from 6 to 36 months after SBS to evaluate for strabismus. Logistic regression analysis test and SPSS software version 20 were used for statistical analysis. RESULTS: From 206 patients, 56.8% were male, and 33.2% were female. For scleral buckle in 44.7% of patients, silicone band and tire (SBT) was used, and in 55.3%, a sponge. Among all patients, seven (3.39%) exhibited ocular movement disorder. There was no significant relation between type of buckle (P = 0.65) or the location of buckle (P = 0.56) and movement disorder. CONCLUSION: Ocular movement disorder is one of the main complications after SBS without specific association between the type and location of exoplanet.

Pseudo inferior oblique overaction, clinical findings, mechanism, and surgical outcomes.

PURPOSE: To investigate clinical findings of the pseudo inferior oblique overaction (IOOA) syndrome and the outcomes of strabismus surgery and to discuss the mechanisms proposed for this disease. METHODS: This syndrome is defined by Y pattern strabismus with exotropia in upgaze. There is marked abduction and hypertropia of the adducting eye when elevation is carried out in side gaze, but there is no hypertropia of the adducting eye in horizontal side gaze. Sixteen patients were included and surgery was performed in 14 patients. Success of the surgical intervention was defined as correction of the Y pattern, orthotropia in primary position, upgaze, and downgaze. RESULTS: Thirteen of the sixteen patients were female. The mean age was 9.6 ± 6.1 years. The mean follow-up time was 14.7 ± 16.9 months. Pre-operatively, 12 patients were orthophoric, and four patients were exophoric (4 to 8 PD) in primary position. In downgaze, all patients were orthophoric. Mean exotropic deviation in upgaze was 25.06 ± 5.9 (18 to 40 PD). Fourteen patients underwent surgery with 2-mm bilateral lateral rectus recession and full tendon supraplacement in seven cases, and 2/3 tendon supraplacement in the other seven patients. The success rate of surgery was 92.8% after the first operation, which reached 100% after a second surgical procedure was performed on one of the patients. CONCLUSIONS: Strabismus surgery is effective in correcting the Y pattern in patients with pseudo IOOA. A 2/3 tendon supraplacement combined with 2-mm recession of the lateral rectus muscles is the preferred treatment.

Surgical Outcome of Single Inferior Oblique Myectomy in Small and Large Hypertropia of Unilateral Superior Oblique Palsy.

PURPOSE: To determine the efficacy of isolated inferior oblique myectomy on hypertropia in primary position, side gazes, and tilts, and its effect on comitancy and abnormal head posture in unilateral superior oblique palsy. METHODS: Thirty-nine patients with unilateral superior oblique palsy who had inferior oblique overaction underwent inferior oblique myectomy. The hypertropia was measured in primary position, side gazes, and tilts preoperatively and postoperatively. Abnormal head posture was also assessed. Success was defined as primary position hypertropia of 5 prism diopters (PD) or less. RESULTS: The mean distance hypertropia was 15.7 ± 7.7 PD (range: 3 to 30 PD) preoperatively and 1.5 ± 3.3 PD (range: 0 to 16 PD) postoperatively (P < .001). The mean reduction of distance hypertropia postoperatively was 14.2 ± 7.8 PD (range: 3 to 30 PD). The contralateral gaze hypertropia decreased from 21.7 ± 9.0 PD (range: 5 to 45 PD) preoperatively to 3.6 ± 5.1 PD postoperatively (range: 0 to 20 PD) and ipsilateral head tilt hypertropia decreased from 21.9 ± 8.4 PD (range: 8 to 40 PD) preoperatively to 5.0 ± 5.9 PD (range: 0 to 24 PD) postoperatively (P < .000 for both). Incomitance (contralateralipsilateral gaze hypertropia) decreased from 15.0 ± 7.4 PD (range: 3 to 35 PD) preoperatively to 2.8 ± 4.1 PD (range: 0 to 16 PD) postoperatively (P < .001). The success rate between the two groups of patients who had hypertropia of 15 PD or less and greater than 15 PD in primary position was not statistically different (94.7% vs 85%). Two patients underwent a second operation for residual hypertropia. There was no overcorrection. Thirty-two patients had abnormal head posture, which resolved postoperatively in 29 cases. CONCLUSIONS: Isolated inferior oblique myectomy is an effective procedure in resolving hypertropia up to 30 PD due to unilateral superior oblique palsy, with a minimal risk of overcorrection and low risk of undercorrection. It decreases incomitancy, is a self-titrating procedure, and resolves abnormal head posture efficiently. [J Pediatr Ophthalmol Strabismus. 2019;56(1):23-27.].

Surgical outcome of a new modification to muscle belly union surgery in heavy eye syndrome.

OBJECTIVES: To report the clinical outcomes of a new modification to muscle belly union surgery in heavy eye syndrome. METHODS: Muscle belly union was performed in patients with large-angle esotropia and characteristic findings of heavy eye syndrome on orbital imaging. After isolation of superior and lateral rectus muscle and passing a single armed suture in each muscle belly, approximation was achieved via tying of both arms of separate sutures together. Medial rectus (MR) was also recessed considering the results of the intraoperative force duction test. RESULTS: Surgery was conducted in 24 eyes of 16 patients. The mean preoperative esotropia was 93.71 ± 23.1 prism diopters (PD), which improved significantly after the operation (final esotropia: 11.53 ± 15.59 PD, P value = 0.001). Six patients also exhibited mild hypotropia preoperatively (9.33 ± 6.88 PD), which resolved completely after surgery in all cases. Evaluation of preoperative abduction limitation (minus 3.1 ± 1.83) showed a significant improvement postoperatively (minus 0.95 ± 0.68, P value = 0.000). Additionally, mild limitation of adduction (minus 1) was seen in nine patients due to large MR recession. However, none of the patients reported postoperative diplopia. CONCLUSION: Our new approach in muscle belly union surgery resulted in favorable outcomes compared with previous studies. It seems that the two-suture technique presented in this study yields more convenient approximation of muscle bellies and acts as a safety suture upon spontaneous loosening of the first applied suture.

Clinical and Histopathologic Features of Consecutive Exotropia.

PURPOSE: The purpose of this study is to investigate clinical and histopathologic features of consecutive exotropia. METHODS: Thirty patients with consecutive exotropia and negative forced duction testing underwent unilateral medial rectus resection and advancement. Abnormal scleral attachment (appearance of stretched scar or slipped muscle) was documented and compared with histopathology results. The term "stretched scar" is used when tendon-like scar appears between muscle fibers and scleral attachment. The term "slipped muscle" is used when a thin capsule is attached to the sclera and the muscle fibers retracted posteriorly in the capsule. Histopathologic results of resected medial rectus muscles of 11 control patients were compared with cases of consecutive exotropia. Surgical success was defined as <10 PD deviation at both distance and near, 6 months after the surgery. Dose-response and risk factors for abnormal scleral attachment were also evaluated. RESULTS: Forty percent of the cases had abnormal scleral attachment. Nineteen patients (63%) showed successful results. The mean dose-responses were for near 4.7 and for distance 4.2 prism diopters per millimeters of resection plus advancement. Preoperative medial rectus underaction was a risk factor for abnormal scleral attachment. The mean muscle percentage in pathology was 10 ± 18.7 in patients with abnormal scleral attachment, 28.3 ± 27.9 in other consecutive exotropia patients, and 26.5 ± 30.6 in 11 control eyes. CONCLUSION: This study showed surgical success of 63% with one-muscle surgery in consecutive exotropia. Calculated dose-responses could be helpful in surgical planning. In the cases with preoperative medial rectus underaction, risk of abnormal scleral attachment is increased.

Augmented superior rectus transposition procedure in Duane retraction syndrome compared with sixth nerve palsy.

PURPOSE: Superior rectus transposition (SRT) with medial rectus recession has been used for the treatment of sixth nerve palsy and esotropic Duane retraction syndrome (DRS). The purpose of this study was to compare the results of augmented SRT (with scleral fixation) without medial rectus recession in DRS and sixth nerve palsy. METHODS: Patients with unilateral esotropic DRS (DRS group) and sixth nerve palsy were included in this prospective, comparative study and underwent SRT. Preoperative forced duction testing was negative or slightly positive in both groups. Prospective measurements were compared between the two groups. RESULTS: There were 11 patients in the DRS group and 11 patients in the sixth nerve palsy group. The mean preoperative esotropia decreased from 20.9 ± 6.0 prism diopter (PD) at far to 13.2 ± 5.8 PD in the DRS group (P = 0.003). The same measurement improved from 28.0 ± 8.5 PD to 8.4 ± 7.3 PD in the sixth nerve palsy group (P = 0.003). In the sixth nerve palsy group, the improvement in primary gaze esotropia and abnormal head posture was more than the DRS group (Both P < 0.001).The average dose effect for SRT was 7.8 ± 2.2 PD in the DRS group and 19.2 ± 4.6 PD in the sixth nerve palsy group. Although objective intorsion was significantly induced after SRT, subjective torsion was not significant after surgery in both groups. CONCLUSION: SRT appears to be more effective in improving primary gaze deviation and head posture in sixth nerve palsy compared with DRS. Subjective torsional and vertical diplopia were rare in both groups.

Surgical treatment of Duane retraction syndrome.

PURPOSE: Surgical treatment in Duane retraction syndrome (DRS) can be very challenging even for the strabismus specialists because of a wide spectrum of diversity in clinical manifestations. The purpose of this article is to review these different surgical treatments. METHODS: A comprehensive search was performed using PubMed database with the different keywords of "Duane retraction syndrome" and "surgery". Articles were selected from original English papers published since 2000. The full text of the selected articles was reviewed, and some articles were added based upon the references of the initial articles. We also provided selected case examples about some of these procedures. RESULTS: 125 articles were found in the initial search of which 37 articles were mostly related to the topic of this review. The number finally increased to 59 articles after considering the relative references of the initial articles. Different surgical methods performed on horizontal and vertical rectus muscles (recession, resection, transposition, Y splitting, periosteal fixation and posterior fixation suture) are reviewed. Careful selection of the surgical technique is important to achieve optimal results. CONCLUSION: With accurate diagnosis of patients with DRS and proper surgical management, several adverse situations associated with this syndrome (amblyopia, abnormal head posture, upshoot, downshoot, and muscle underaction) can be prevented.