Face Turn Research Articles

To be or not to be: Surgery for exotropia with homonymous hemianopia

Background/PurposeIn patients with early-onset homonymous hemianopia, ipsilateral exotropia and face turn could be a functional adaptation/compensation to expand the visual field. This case series study analyzed early-onset exotropia with homonymous hemianopia. MethodsMedical records of eight consecutive patients with early-onset exotropia and homonymous hemianopia were reviewed. ResultsThe five females and three males in this study (age range, 6–48 years) were followed up for an average of 28.3 months. In all patients, the fixating eye was contralateral to the side of the (major) visual field defect except in one patient (case 6) with maculopathy in the contralateral eye. Of the four patients who received strabismus surgery, one had troublesome diplopia after the surgery while the other three were free of complications. ConclusionsSome patients with homonymous hemianopia and exotropia, particularly young and/or female patients, may conclude that the cosmetic and psychosocial gains achieved by strabismus surgery outweigh the potential surgical complications such as decreased visual field or diplopia. However, these patients require consultation and thorough education in the potential outcomes of the procedure.

A phenotypic study of congenital stationary night blindness (CSNB) associated with mutations in the GRM6 gene

To describe the clinical phenotype and the molecular pathology in a group of patients with congenital stationary night blindness due to mutations in GRM6, a gene encoding the ON bipolar metabotropic glutamate receptor 6 (mGluR6). Nine patients from seven families (age range, 7-75; median, 10 years) with a clinical diagnosis of autosomal recessive complete congenital stationary night blindness were ascertained. Clinical examination, imaging and electrophysiological assessment were performed. The coding region and intron-exon boundaries of GRM6 were sequenced. The median visual acuity for the cohort was 0.2 logMAR (range 0-3). Most patients had myopic astigmatism with the median spherical equivalent being -5.375 dioptres (-0.125 to -18.75). Fundoscopy was within normal limits in 15 eyes; there was severe myopic maculopathy in three eyes. Other secondary complications included face turn because of nystagmus and strabismic amblyopia. All patients had electronegative dark-adapted bright white flash electroretinograms (ERGs) consistent with dysfunction occurring postphototransduction. In the two oldest subjects (aged 75 and 58 years), there was additional photoreceptor dysfunction in keeping with myopic degeneration. ON-OFF ERGs showed generalized cone ON bipolar system dysfunction in all five patients tested. Pattern ERG P50 was normal (Ν = 1), subnormal (N = 2) or undetectable (N = 2). Nine mutations in GRM6 were detected in all seven families; six of these changes were novel. The phenotype associated with GRM6 mutation is variable in terms of presentation, refractive error, visual acuity and macular function. ERGs are electronegative and suggest ON-pathway dysfunction.

Secondary or New Compensatory Head Posture after Anderson-Kestenbaum Surgery

To report clinical findings and surgical management of 4 patients with congenital nystagmus who presented with a new or reversal of their original horizontal compensatory head posture (CHP) after Anderson-Kestenbaum (A-K) surgery. Retrospective chart review. All 4 patients demonstrated a 40°-45° horizontal face turn at the time of their initial surgery and 3 underwent 20% and one 30% augmented A-K surgery to correct the CHP. The new CHP or reversal of the original CHP was observed at a mean of 4 years (range 1-9 years) after the initial surgery. The reversed CHPs measured 20°, 40°, 20°, and 20°, respectively. These new or residual CHPs were surgically managed in 3 patients and an acceptable head position was achieved in all patients. This series of patients points out the occurrence of secondary null points and reversed CHP after surgical correction of initial CHP.

Clinical Manifestations of Foveal Hypoplasia

Purpose: To estimate the baseline demographic/ocular characteristics and associated findings of patients with foveal hypoplasia. Methods: The medical records of 42 patients (84 eyes) who were clinically diagnosed with foveal hypoplasia were retro- spectively reviewed. Results: There were 28 males and 14 females with mode age at diagnosis of 1 (range, 0-60 years) year and a mean fol- low-up period of 9.7 ± 5.4 years. At the first office visit, the most common complaints were ocular oscillation and face turn. There were 75 eyes (91.5%) with best corrected visual acuity worse than 0.3 at the first visit, but that number decreased to 55 eyes (67.1%) at the last follow-up (age range, 7-60 years). The absolute spherical equivalent of refractive errors was 2.89 ± 2.96 diopters (D), and 71 eyes had astigmatism with a mean astigmatism of 2.1 ± 1.1 D. Forty-two patients had as- sociated diseases: 15 (35.7%) with aniridia, 16 (38.1%) with ocular albinism and 11 (26.2%) with oculocutaneous albinism. In addition, strabismus was found in 24 patients (57.1%). Conclusions: Diseases associated with foveal hypoplasia include aniridia, ocular albinism and oculocutaneous albinism. Since foveal hypoplasia is often associated with high refractive errors and poor vision, an early prescription of eyeglasses is mandatory for management of refractive amblyopia to ensure the development of the best corrected visual acuity. J Korean Ophthalmol Soc 2011;52(12):1496-1500

Duane Retraksiyon Sendromu Olan Vakalarda Farklı Bakış Pozisyonlarında Korneal Topografi Değişiklikleri

Objective: To evaluate the corneal topographic changes in patients with Duane retraction syndrome in different gaze positions and to investigate the effect of eyelids on corneal topography. Material and Methods: Thirty-three cases with Duane retraction syndrome and 19 control patients were included in the study. Corneal topographies of the cases with Duane retraction syndrome were first measured during their preferred gaze and then during primary gaze position. Topographies of the cases in control group were measured in their right eye during primary gaze position and when the eye was on adduction. Results: Mean horizontal sim K value of the cases with Duane retraction syndrome with preferred gaze position was 41.4 ± 2.3 D, while vertical sim K value was 42.7 ± 1.9 D, and with their primary gaze position, mean horizontal sim K value was 40.5 ± 1.8 D, and vertical sim K value was 42.7 ± 1.8 D. Statistically significant horizontal flattening was noted in primary gaze position (p= 0.009). No statistically significant difference was found between the measurements of horizontal and vertical sim K values of control patients in different gaze positions. Conclusion: Duane retraction syndrome is a rare congenital ocular motility disorder. Although the pathogenesis is not clear, abnormal innervation of the extraocular muscles is mostly blamed. Most of the patients with Duane retraction syndrome develope a face turn position to achieve binocular vision. In our study, we concluded that eyelid position and the changes in corneal topography might affect the development of face turn position.

Proposal of Coaching Points for Introduction of Wheel Gymnastics

The aim of this study was to propose coaching points for the introduction of wheel gymnastics. Toward this aim, beginners' particularities were investigated, especially those which appeared in side rotation. The examinees were 26 university students (3 males and 23 females) who had no previous experience in wheel gymnastics. Skill observations and questionnaires were conducted to analyze the participants' characteristics.Of the examinees, 54% tended to dorsiflex their necks during side rotation. This kind of feature may lead to a sway of the wheel and prevent smooth rotation. A tendency to dorsiflex ankles was also observed in 85% of the examinees. That means that many examinees could not fix their feet on the foot boards with the bindings. Some of them were unconscious of the positioning of their feet. Of the examinees, 77% examinees could not finish the side rotation, because they could not begin it or because the wheel stopped on the way. The wheel gymnastics program was thoroughly interesting for all, but at the same time, a fearful experience for about half of the examinees.From the results and considerations, the coaching points for introduction of this sport were derived mainly as follows.: 1) Visible target needs to be used to make the face turn toward the front.: 2) Assistant is to be arranged to help the beginner to fix the feet on the boards, to prevent the sway of the wheel, and to push it in case of stopping.:3) Timing of coaching the foot skill for fixing them on the boards needs to be considered. Players' emotional and technical capacity should be taken into account.: 4) Programs should be presented to accustom players to the wheel, and analogical movements should be utilized for emotional apprehension, which will help in developing the correct skills.

Residual torticollis in patients after strabismus surgery for congenital superior oblique palsy

Aim:To study postoperative residual vertical deviation and abnormal head posture (AHP) after surgical treatment for congenital superior oblique palsy (SOP).Method:Children with both SOP and AHP who underwent extraocular muscle surgery...

Vertical Rectus Muscle Transposition for Correcting Abduction Deficiency in Duane's Syndrome Type 1 and Sixth Nerve Palsy

To report the clinical outcome and complications of the Scott Foster procedure for treating abduction deficiency in patients with Duane's syndrome type 1 and sixth nerve palsy. A retrospective, interventional case series included 62 consecutive patients (62 eyes: 38 eyes with Duane's syndrome and 24 eyes with sixth nerve palsy) who underwent the Scott Foster procedure for treatment of abduction deficiency. The main outcome measures were deviation, face turn, and abduction deficiency. In patients with sixth nerve palsy, mean distance deviation improved from 44.7+/-7.2 prism diopters (PD) before surgery to 12.5+/-4.0 PD after surgery (P<.05), and in patients with Duane's syndrome type 1, mean distance deviation improved from 31.5+/-4.3 PD preoperatively to 9.2+/-3.1 PD. Mean near deviation improved from 27.1+/-4.5 PD to 6.2+/-2.5 PD in patients with Duane's syndrome and from 40.3+/-6.2 PD to 13.7+/-3.4 PD in patients with sixth nerve palsy. Mean abduction deficiency improved from -4 to -2 (P<.05) in both groups. Face turn improved significantly after surgery. No patient had an overcorrection. No recurrence was detected. The Scott Foster procedure is effective for improving deviation, abduction deficiency, and face turn in patients with Duane's syndrome type 1 and especially in those with sixth nerve palsy.

Abnormal Head Posture due to Ocular Problems- A Review

An abnormal head posture (AHP), or torticollis, is a common condition in children, with an estimated incidence of 1.3%. This condition is encountered commonly by primary care family pediatricians. AHP can be congenital or ac- quired. The cause of the AHP can be ocular, orthopedic and neurologic. The orthopedic causes of AHP include congenital muscular torticollis due to tightness of the sternocleidomastoid muscle, Klippel- Feil anomaly and brachial plexus injury. Neurologic causes of AHP are mainly related to brain tumors, postinflammatory central nervous system conditions, psy- chomotor delay and focal dystonia. Other less common reasons for AHP are: Sandifer syndrome (hiatal hernia associated with gastro- esophageal reflux) and unilateral hearing loss. Numerous conditions can cause AHP or ocular torticollis. Among them: superior oblique muscle palsy, lateral rectus muscle palsy, nystagmus, vertically incomitant horizontal strabismus (A or V patterns), Brown's syndrome, Duane's syndrome, refractive errors and DVD. The AHP can take the form of head tilt, face turn, chin up, chin down or combined, depending on the specific etiology. However, there are many variations and the type of the head posture cannot reliably predict the underlying cause. Since the etiology is not always obvious, these patients must be carefully evaluated, and sometimes a multidisciplinary approach is needed, including examinations by ophthalmologist, neurologist and orthopedist. Ocular AHP is usually an attempt to improve visual acuity or binocularity. Some patients adopt the head posture to avoid diplopia caused by incomitant strabismus, those with nystagmus adopt a head position that brings the eyes to the null point (where the oscillations dampen or markedly diminish). Ocular AHP is usually a binocular phenomenon. Rarely, ab- normal head position can be acquired following visual loss in one eye. The majority of these conditions require eye muscle surgery. Different etiologies of AHP require different surgical strategy, for this reason careful etiological diagnosis is important. The purpose of this article is to review the conditions that cause AHP, their relative frequency, indication for sur- gery and the appropriate surgical treatment.

Surgical Results in Duane Retraction Syndrome

Purpose: To report the clinical characteristics and the results of a series of patients treated with various strabismus surgery techniques for Duane retraction syndrome (DRS). Methods: Thirty-eight patients with DRS undergoing surgical treatment were retrospectively reviewed. In all patients, ocular alignment, abnormal head posture and ocular motility disturbance were assessed both preoperatively and postoperatively. The patients were treated with appropriate horizontal muscle recession, Y-splitting combined with horizontal muscle recession, medial rectus recession and lateral rectus resection. Results: The incidence of DRS was greater in females and in the left eye. Type 1 was the most common, and esodeviation was seen most frequently in the primary position. The esotropic patients with DRS turned their faces toward the affected eyes, while the exotropic patients with DRS turned away from the affected eyes. The deviation in the primary position was reduced from an average of 15.0 prism diopters (PD) to 1.5PD. The face turn was reduced from an average of 17.5 degrees to 1.2 degrees. Conclusions: The primary deviation and abnormal head posture found in DRS can be improved by proper preoperative evaluation and adequate choice of surgical methods.

The Clinical Characteristics of Superior Oblique Palsy Associated With Intermittent Exotropia

Purpose: The goal of this study was to determine the clinical characteristics of patients with intermittent exotropia (IXT) associated with hypertropia. Methods: This study recruited 268 hospital patients with IXT associated with hypertropia. After taking history, measuring the angle of deviation, conducting an ocular motor examination, performing a Bielschowsky head tilt test and taking a fundus photograph, the clinical characteristics of 23 patients diagnosed with superior oblique palsy (SOP) were investigated. Results: Twenty-three patients (8.6%) of the 268 subjects with IXT associated with hypertropia were diagnosed with SOP. The average angle of exodeviation was 17.13.8PD and the angle of hypertropia at primary position was 12.95.9PD. Excyclotorsion of an eyeball was observed in 19 patients (82.6%), the Bielschowsky head tilt test was positive in all patients, and head tilt or face turn was found in 12 (52.2%) patients. All subjects had inferior oblique overaction, and 20 (86.9%) had superior oblique underaction. Operations to weaken the inferior oblique muscle of the paralytic eye and for horizontal muscles were conducted at the same time. The angle of exodeviation and the angle of hypertropia were, on average, 1.83.6PD and 2.42.2PD, respectively, 6 months after the operation. Conclusions: When patients with intermittent exotropia have hypertropia, the possibility of SOP should be considered. SOP can be detected by determining a history of head tilt and conducting a Bielschowsky head tilt test. Surgical treatment for SOP is advised.

Night of the Red Mood

Our mother thought that the take-home pay would see us through for a good two weeks. As for our father, he was out of the loop; he had no idea about anything anymore. Three times eight equals twenty-four, came from our kid brother who'd been doing his multiplication tables. So the three of us ended up going. Ebram, the oldest, was strong and had done day labor ever since our chickens died and there were no more eggs for our mother to sell. Ebram could go on working all day and night. But and I, we were another story. We hadn't passed the test yet. But our mother said, Nabi and Naser are old enough now. Just then saw Nabi's lips tremble and his face turn red with anticipation, right, I'm coming too, he said quickly, I want to work. Even if our mother really thought that an eleven year old kid couldn't handle that kind of work, she didn't let on. Truth was, we weren't going to get another chance like this and it was all right if it got tough on a little. It was just this one time. Us three boys would put in a night's work and make enough money to last the family two whole weeks. Our father, like said, didn't know anything about anything. So we went. And as soon as we started, began imitating Ebram's walk. The kid was out to prove he was old enough for the job. He kept running up the hills, losing himself among those other boys from the Naftun and Bibiyan neighborhoods. Whoever wants to work, be at the oil well in the afternoon or in the morning. That's what they'd said to us. They needed laborers and their foremen had come around town letting us know about it. The well they'd dug hadn't hit oil and now they had to fill it back up. Every one of the school kids headed straight for the hills.

Pontine Gaze Deviation and Face Turn Relieved by Eye Muscle Surgery

A 34-year-old woman developed a bilateral horizontal gaze palsy, left gaze deviation, and right face turn consequent to a pontine hemorrhage. A bilateral horizontal recession and resection of extraocular muscles in both eyes (Parks procedure) eliminated the gaze deviation and face turn. This is the first reported case in which this procedure was used to correct a face turn in a patient with bilateral horizontal gaze palsy but without ocular misalignment.

A Case of Congenital Inferior Oblique Palsy

Purpose: Paresis of the inferior oblique is the least likely to result in paralysis. We report a patient without a history of trauma successfully treated using contralateral IO recession and SR recession. Case summary: A 25-year-old male patient presented to us with an extended history of abnormal head posture, manifested by a marked habitual left head tilt with a face turn to the right. A cover test in the primary position demonstrated 15 prism diopter right hypertropia, which increased to 25 prism diopter right hypertropia in right gaze and 20 prism diopter right hypertropia in right head tilt. The patient was diagnosed with IO palsy, and a right IO recession was performed. Results: Following the IO recession, head tilt was completely resolved and face turn to the right was slightly resolved. Cover test in the primary position demonstrated 12 prism diopter right hypertropia, which increased to 20 prism diopter right hypertropia in right gaze. A head tilt test demonstrated a symmetrical 12 prism diopter right hypertropia. We performed a right SR recession to decrease face turn and hypertropia in the primary position. Conclusions: We report a patient manifesting abnormal head posture diagnosed with IO palsy, which was successfully treated using contralateral IO recession and SR recession.

Periosteal Fixation in Bilateral Total Third Nerve Palsy

Purpose: We present a new technique of anchoring the eyeball to the nasal periosteum with supramaximal recession of the lateral rectus muscle in one eye for exotropia management in bilateral total third nerve palsy combined with trochlear nerve palsy. Case summary: A 38-year-old man presented with drooping of both upper lids and exodeviation of the left eye with a history of intraventricular hemorrhage 9 months previously. We noted bilateral ptosis, dilated pupils, right fixing eye, left face turn, and left exotropia over 100 prism diopters (PD) in the primary position with an inability to move both eyes together except abduction. He was diagnosed with bilateral total third nerve palsy and trochlear nerve palsy. We fixated the left globe (sclera anterior to the insertion of the medial rectus muscle) to the nasal periosteum including the medial palpebral ligament using a nonabsorbable suture. A large recession of the left lateral rectus muscle (14 mm) was also performed. Ocular alignment in the primary position was exotropia of 25PD and cosmetically satisfactory after 6 months of follow-up. Conclusion: Supramaximal recession of the lateral rectus muscle and periosteal fixation using nonabsorbable suture is an effective technique for the management of exotropia secondary to total third nerve palsy.

Exotropia and Face Turn in Children With Homonymous Hemianopia

Four children developed homonymous hemianopia, exotropia with the deviating eye pointing in the direction of the field defect, and a face turn toward the side of the defect following complete third cranial nerve palsy after brain tumor resection, an in utero middle cerebral artery infarction, nonaccidental head trauma, and a hemispherectomy for an intractable seizure disorder. We present evidence that the exotropia and face turn are part of an adaptive mechanism to increase the useful visual field.

What Winning Looks Like: Critical Environmental Justice Studies and the Future of a Movement

In the wake of Hurricane Katrina, the environment is becoming an ever more present concern. Al Gore's An Inconvenient Truth and Leonardo DiCaprio's The 11th Hour both foreground images of melting glaciers, dying coral, and people in the Lower Ninth Ward of New Orleans stranded on their roofs as evidence that we have reached a pivotal moment in human history. DiCaprio quotes United Nations estimates, which predict that ignoring the threats presented by global warming could result in more than 150 million refugees and a rapidly increasing extinction rate by the middle of this century. The subtitle of DiCaprio s documentary presents the audience with a choice: face catastrophe or Turn Mankind's Darkest Hour into Its Finest. The film features leaders from environmental and social justice fields (who even ten years ago may not have imagined working closely together) discussing how to turn crisis into possibility. These experts talk about their own research and innovations and refer to the hundreds of thousands of people around the world who are working to build carbon-neutral cities and create zero emissions transportation. They acknowledge, however, that it will take more than technology to make a difference; it will take leadership and it will take ideas that emerge from a deep encounter between our values, our experience, and the monumental social challenges we face.

A Prospective Clinical Evaluation of Augmented Anderson Procedure for Idiopathic Infantile Nystagmus

To evaluate the efficacy of the augmented Anderson procedure in idiopathic infantile nystagmus (IIN). Twelve consecutive patients older than 5 years having IIN with eccentric null position and anomalous head position were enrolled in an institution-based study. Best-corrected visual acuity (uniocular and binocular and in both null position and primary position), slit-lamp examination, fundus examination, ocular motility examination, and stereopsis using TNO were recorded. In all cases the augmented Anderson procedure, that is, recession of the yoke muscles (9-mm medial rectus and 12-mm lateral rectus), was performed. Eye movements were recorded before and 3 months after surgery in the primary position, right gaze 15 and 30 degrees, and left gaze 15 and 30 degrees. All patients had improvement in their anomalous head posture after surgery (p = 0.0001). The nystagmus intensity in the primary position decreased from 22.0 +/- 15.9 degrees cycles/s preoperatively to 10.6 +/- 10.2 degrees cycles/s at 3 months postoperatively. The change was statistically significant (p = 0.006). After surgery, binocular visual acuity using the Early Treatment Diabetic Retinopathy Study chart improved in primary position (p = 0.007). No patient developed more than mild limitation of horizontal movements after surgery. The augmented Anderson procedure is successful in correcting face turn in patients having IIN with eccentric null position, resulting in an increase in visual acuity and a decrease in nystagmus intensity in primary position. Further studies with a longer follow-up are required to assess the long-term efficacy of this procedure.

Extraocular Muscle Surgery for Nystagmus

&lt;h4&gt;EXCERPT&lt;/h4&gt; &lt;p&gt;&lt;b&gt;Wagner:&lt;/b&gt; A 9-year-old boy with tyrosinase-positive oculocutaneous albinism presents with best spectacle-corrected visual acuity of 20/80 in both eyes and a +2, -250 at 180° refraction that is symmetric in both eyes. He has a horizontal pendular nystagmus typical of oculocutaneous albinism, with no face turn or demonstrable null point or null zone. The parents want to know whether anything can be done surgically to reduce the nystagmus, and if so, whether it will improve his visual acuity. They have been told that he will never be able to drive, and they are hoping there may be a possible solution for this problem with surgery. Dr. Del Monte, how would you handle talking to the parents about this, and what can you offer the family?&lt;/p&gt; &lt;p&gt;&lt;b&gt;Del Monte:&lt;/b&gt; Certainly, you have to maximize the potential with standard means first. You have to make sure they have the correct refraction and double-check it with a repeat cycloplegic if you need to. Just because he has a poor macular formation and abnormal innervation of the optic nerve does not mean that he cannot have maximal potential, so you want to maximize that.&lt;/p&gt; &lt;p&gt;Assuming that you have done that, then of course you look for head positions. You mentioned there are not any, and that is another thing that is easy to work on and fix. Anyone older than 4 or 5 years is certainly a good candidate for those kinds of procedures, but this particular patient does fall into a group. I am not a big advocate of the large four-muscle recessions, and I have had no experience with the tenotomies. However, patients who have visual acuity near the driving vision range, from 20/70 to 20/100, are potentially candidates for large muscle recessions, and I have done it in a few of these patients.&lt;/p&gt; &lt;p&gt;Typically, the literature supports that you do not get more than a line or so of vision improvement. You do get cosmetic improvement in the amplitude of the nystagmus, so they do appreciate that, but you get only a line or so of improvement. A patient who has a 20/80 visual acuity potentially is one who could improve to 20/70 or 20/60 and get a driver’s license. That to me is one of the indications for that procedure, so I certainly would discuss that with the patient. However, there is a significant risk with that procedure of creating a strabismus, and I would have to warn them about that as well.&lt;/p&gt;

Vertical Rectus Muscle Transposition for Bilateral Duane Syndrome

Augmented transposition of the superior and inferior rectus muscles to the lateral rectus muscle is effective surgical treatment for esotropia in unilateral Duane syndrome. Medial rectus muscle recession in bilateral Duane syndrome may increase the risk of consecutive exotropia and cause limitation to adduction postoperatively. Vertical rectus muscle transposition may be useful in bilateral Duane syndrome with esotropia. We undertook a retrospective review of 11 patients with bilateral Duane syndrome and esotropia in primary position. All patients had vertical rectus muscle transpositions. Six patients had unilateral vertical rectus transpositions (2 eyes with and 4 without suture augmentation). Twelve eyes from 7 children (2 unilateral and 5 bilateral) had transpositions augmented with posterior fixation sutures. Posterior fixation suture were added to large deviations in patients without prior medial rectus recessions. The preoperative esotropia at distance was 22.8 +/- 6.3 prism diopters (PD). It reduced to 2.0 +/- 6.7 PD postoperatively. (P < 0.001) Esotropia at near changed from 21.0 +/- 5.8 PD preoperatively to 1.2 +/- 8.1 PD postoperatively. (P < 0.001) One patient with a 10-degree face turn had complete resolution postoperatively. One patient had a small undercorrection and developed a vertical deviation requiring additional surgery. All patients had improvement in abduction. Nine of 11 patients did not develop any limitation to adduction. One patient developed a -1 adduction deficit 5 years later. Three patients achieved fusion with a mean stereovision of 67 seconds of arc (range, 80-40 seconds.). Follow-up averaged 22.2 months (range, 1-100 months). Vertical rectus muscle transposition in patients with bilateral Duane syndrome and esotropia is an effective procedure to improve ocular alignment and motility while preserving adduction.