Prism Diopters Of Esotropia Research Articles

Risk Factors Predicting the Need for Additional Surgery in Consecutive Esotropia

To evaluate the risk factors predicting surgical treatment in consecutive esotropia occurring after surgery for intermittent exotropia. The clinical records of 52 patients with consecutive esotropia who underwent exotropia surgery were retrospectively reviewed. All patients demonstrated consecutive esotropia with diplopia or suppression for more than 1 month after surgery for exotropia. Patients were divided into two groups (the surgical group and nonsurgical group) depending on whether surgery was required for consecutive esotropia. Surgery for esotropia was performed only in patients with more than 10 prism diopters (PD) esodeviation that persisted for a minimum of 6 months, those who had suppression in 1 eye or diplopia, and those who could not achieve fine stereopsis. The nonsurgical treatment up to 6 months postoperatively was part-time patching and prism therapy in both groups. Patient characteristics were evaluated in the two groups. The surgical group was composed of 17 patients and the nonsurgical group was composed of 35 patients. Age, gender, refractive error, best-corrected visual acuity, and postoperative overcorrection at 1 day were not significantly different in the two groups (P > .05). However, the distance strabismic angle at 1 month postoperatively was 2.5 ± 3.8 PD esodeviation (range: 14 PD esotropia to 4 PD exotropia) in the nonsurgical group and 5.4 ± 5.1 PD esodeviation (range: 20 PD esotropia to orthotropia) in the surgical group; these values were statistically significant (P < .05). The clinically significant risk factor affecting the surgical decision for consecutive esotropia was a large esotropic angle at 1 month postoperatively in this study.

Surgical outcomes of symmetric and asymmetric surgery for intermittent exotropia with postoperative large early overcorrection

To compare surgical outcomes between bilateral lateral rectus recession (BLR) and unilateral lateral rectus recession-medial rectus resection (RR) for intermittent exotropia with overcorrection of 20 prism diopter (PD) or more on postoperative day 1. A retrospective chart review identified 319 patients who underwent either BLR or RR for primary surgical treatment of intermittent exotropia between July 2008 and June 2011. The patients with basic type intermittent exotropia and overcorrection of 20 PD or more, at either near or distance, on postoperative day 1 and had more than 6 months of follow-up were included. Patients with simultaneous vertical and/or oblique muscle surgery and those with paralytic or restrictive strabismus were excluded. The pre- and post-operative deviation, visual acuity, and near stereoacuity were analyzed. Twenty-four patients were included. The mean postoperative day 1 alignment was 21.5 ± 6.2 PD esotropia at distance, and 13.8 ± 8.0 PD at near. Fourteen patients underwent BLR and 10 underwent RR. Three patients were wearing the base out prism below 15 PD at the last follow-up. The mean duration from the surgery to esotropia below 10 PD was 2.9 ± 1.1 weeks and 8.0 ± 7.1 weeks in the BLR and RR groups, respectively (p = 0.030). All three recurrent patients underwent RR. None of the patients completely lost stereoacuity, postoperatively. In basic type intermittent exotropia with overcorrection of 20 PD or more on postoperative day 1, the overcorrection resolved faster and recurrence rates were lower in BLR group than in the RR group. Consecutive esotropia over 15 PD did not occur in both groups.

Analysis of Risk Factors for Consecutive Exotropia and Review of the Literature

To evaluate the possible risk factors in patients with consecutive exotropia following esotropia surgery. Medical records of patients who had comitant esotropia surgery between June 1999 and April 2011 were reviewed. Those who developed consecutive exotropia composed the exotropia group; patients matched for age and duration of follow-up who did not develop consecutive exotropia composed the no exotropia group. The charts of the patients were reviewed and possible risk factors for development of consecutive exotropia were investigated. The average ages of 47 patients in the exotropia group and 54 patients in the no exotropia group were 10.8 ± 8.7 years (range: 1 to 41 years) and 8.5 ± 6.3 years (range: 1 to 30 years), respectively (P = .292). Amblyopia was detected in 31 (66%) and 12 (22.2%) patients in the exotropia and no exotropia groups, respectively (P = .004). Anisometropia was observed in 20 patients (42.6%) in the exotropia group and 5 patients (9.3%) in the no exotropia group (P = .003). Preoperative average esodeviation values were 42.5 ± 8.3 prism diopters (PD) (range: 25 to 60 PD) in the exotropia group and 42 ± 9.4 PD (range: 20 to 65 PD) in the no exotropia group (P = .673). Postoperative deviations were 32.8 ± 23 PD exotropia (range: 10 to 90 PD exotropia) in the exotropia group and 4.4 ± 4.2 PD esotropia (range: 0 to 10 PD esotropia) in the no exotropia group (P = .000). Asymmetric surgery had been performed in 61.7% of the exotropia group (n = 29) and 9.3% of the no exotropia group (n = 5) (P = .000). Limitation of adduction was detected in 14 patients (29.8%) in the exotropia group; none was noted in the no exotropia group (P = .000). The mean interval between the initial surgery and the onset of consecutive exotropia was 11.1 ± 15.1 months (range: 0 to 126 months). Anisometropia, amblyopia, asymmetric surgery, and postoperative adduction deficit were associated with the development of consecutive exotropia. Long-term follow-up should be considered because consecutive exotropia can develop after months or years.

Trigemino-Abducens Synkinesis After Lateral Orbitotomy

A 30-year-old man underwent lateral orbitotomy with removal of dermoid cyst in the right orbit. One month after operation, the patient started to experience double vision. He had 25 prism diopters of esotropia in primary gaze with marked limitation of abduction in the right eye. Seven months after the operation, he developed synkinetic movement of the eye when clenching his teeth. He could abduct his right eye while gritting his teeth. This is the fourth reported case of trigemino-abducens synkinesis and the first reported case without brain trauma.

Bupivacaine Injection to Lateral Rectus in Abducens Nerve Palsy

A 49-year-old female presented with bilateral abducens nerve palsies. She had 75 prism diopter esotropia. The extraocular movement of the lateral rectus was -1 limitation for the right eye and -4 limitations for the left. After performing orbital magnetic resonance imaging (MRI), 2 mL of bupivacain (5 mg/mL) was injected into the left lateral rectus (LR). One month after injection, a further orbital MRI was performed. Subsequently, recession of both medial rectus (6 mm) and resection of the left LR (9 mm) were performed. After one month, bupivacaine had no hypertrophic effects. There was little change in angle of deviation. The orbital MRI scan showed a 1.91% increase in volume compared to the muscle prior to the injection. Histological findings showed no muscle fibers of the left LR muscle, only the fiber nucleus and the collagen that replaced the fibers. We report on the changes in stiffness and muscle volume and on the histology of the muscle one month after injecting bupivacaine into the paralyzed left LR muscle combined with standard surgical treatment.

Prognostic factors for recurrence after bilateral rectus recession procedure in patients with intermittent exotropia

The purpose of this study is to evaluate prognostic factors, specifically age, at the time of surgery, for recurrence after bilateral lateral rectus recession (BLR) in patients with intermittent exotropia. Medical records of 511 subjects who underwent BLR procedures between the ages of 3 and 10 years with more than 12 months of follow-up were retrospectively reviewed. Patients' surgical outcomes with a deviation of less than 10 prism diopters (PD) exotropia and less than 5 PD esotropia were defined as a success. Outcomes with more than 11 PD exotropia were designated as recurrences, and those with esotropia of more than 5 PD after 3 months of surgery were noted as overcorrection. Prognostic factors for recurrence were analyzed by multivariate logistic regression test. Of the 511 subjects, 371 had successful surgical outcomes and 129 had recurrences, whereas 11 were found to be overcorrected. Age at surgery and immediate postoperative alignment proved to be significant factors influencing a favorable outcome by multivariate logistic regression analysis (P<0.05). However, gender, photophobia, age at onset, spherical equivalent (SE) refractive error, astigmatism, SE anisometropia, and preoperative deviation size were not significantly predictive of success (P>0.05). In BLR procedures, increasing patient age at surgery was associated with lower recurrence rates.

Medial Rectus Recession After Vertical Rectus Transposition in Patients With Esotropic Duane Syndrome

To describe preoperative characteristics and postoperative results among patients with esotropic Duane syndrome who underwent vertical rectus transposition with vs without subsequent medial rectus recession (MRR). Clinical records were compared of patients with esotropic Duane syndrome who underwent vertical rectus transposition with (study group) vs without (control group) subsequent MRR. Twenty-three study group members and 26 control group members were identified. Preoperative characteristics that differed between groups were the mean (SD) primary position deviation (20 [7] prism diopters of esotropia [ΔET] for the study group vs 15 [9] ΔET for the control group, P = .002) and the mean (SD) adduction deviation (1.4 [4.0] ΔET for the study group vs 2.5 [4.0] Δ exotropia for the control group, P = .04). Forced duction testing (FDT) revealed greater restriction to abduction (17 [7]° for the study group vs 23 [6]° for the control group, P = .002). After vertical rectus transposition, study group members had significantly greater mean (SD) ET (16 [7] ΔET vs 0.4 [0.6] ΔET for the control group, P < .001) and torticollis (10 [4]° vs 1 [5]° for the control group, P < .001) and significantly less mean (SD) abduction (-3.0 [-0.6] vs -2.0 [-0.7] for the control group, P = .20). After MRR, no significant difference was observed between groups in primary position deviation, but the study group had significantly less mean (SD) adduction (-1.0 [-0.8] vs -0.4 [-0.6] for the control group, P < .003). Risk factors for requiring MRR after vertical rectus transposition include greater ET in the primary position and in the adducting field of gaze, as well as greater restriction to abduction on intraoperative FDT. Postoperative results of patients who required MRR were similar to those of patients who did not require MRR.

Prognostic factors for recurrence with unilateral recess-resect procedure in patients with intermittent exotropia

To evaluate the prognostic factors, particularly age at the time of surgery, for recurrence after unilateral medial rectus resection and lateral rectus recession (R&R) procedures in patients with intermittent exotropia, or X(T). Medical records of 489 subjects who received unilateral R&R procedures with more than 12 months of follow-up were reviewed. The patients' surgical outcomes with a deviation of less than 10 prism diopters (PD) of exotropia and less than 5 PD of esotropia were defined as a success. Outcomes with more than 11 PD of exotropia were designated as recurrences, and those with esotropia of more than 5 PD after 3 months of operation were noted as overcorrection. The prognostic factors for recurrence were analyzed by the multivariate logistic regression test. Of the 489 subjects, 209 had successful surgical outcomes and 280 had recurrences, whereas overcorrection was not found. Mean age at operation was 8.9 ± 6.5 years, mean preoperative distant X(T) size was 32.9 ± 6.0 PD, and mean follow-up period was 27.5 ± 17.9 months. On the basis of the survival analysis in which survival represented time of recurrence, the mean duration was 31.2 ± 1.7 months. Age at onset, age at surgery, and immediate postoperative alignment proved to be significant factors influencing a favorable outcome by multivariate logistic regression analysis (P<0.05). However, gender, family history, and preoperative deviation size were not significantly predictive of success (P>0.05). In unilateral R&R procedures, increasing patient age at the time of surgery was associated with lower recurrence rates. Recurrence rates also increased with the immediate postoperative angle and with the postoperative angle of deviation at 1, 3, 6, and 12 months.

Superior Oblique Tucks for Apparent Inferior Oblique Overaction and V-pattern Strabismus Associated with Craniosynostosis

Introduction: Apparent inferior oblique overaction and apparent superior oblique underaction are common in strabismus associated with craniosynostosis, and in many cases are likely due to excyclotorsion of the globes, with the rectus muscles acting with oblique vectors. We present a patient with craniosynostosis who underwent bilateral superior oblique tucks to specifically address the excyclotorsion of the globes.Methods: A 16-year-old male with Saethre-Chotzen syndrome presented with apparent bilateral inferior oblique overaction and apparent bilateral superior oblique underaction. He had 30 prism diopter (PD) esotropia and 5 PD left hypertropia by simultaneous prism and cover test (SPCT) at distance and near fixation. Fundus exam revealed marked excyclotorsion of both globes. The superior oblique tendons were tucked 10 mm bilaterally, using a 6-0 mersilene suture and the medial rectus muscles were recessed 5.5 mm on an adjustable suture with a 10-mm inferior displacement. Surgical results were reviewed at 6 weeks and 2 years postoperatively.Results: At 6 weeks and 2 years postoperatively, apparent inferior oblique overaction, apparent superior oblique underaction, and V-pattern esotropia were markedly improved. At 2 years, SPCT measurements were 8 PD esotropia in primary position at distance and 4 PD esotropia and 3 PD left dissociated vertical deviation at near.Conclusions: Bilateral superior oblique tucks are useful in addressing the excyclotorsion that leads to apparent inferior oblique overaction and V-pattern strabismus associated with craniosynostosis.

An Unexpected Outcome of Blunt Ocular Trauma: Rupture of Three Muscles

Introduction: Traumatic strabismus due to isolated extraocular muscle rupture is uncommon. Treatment usually depends on the severity of both the subjective and objective findings. Methods: We report a male patient with restricted abduction and supraduction in the right eye follow ing a blunt ocular trauma. The exploration revealed the rupture of superior rectus, superior oblique, and lateral rectus muscles. Only lateral rectus muscle could be sutured to the proximal segment. Superior rectus and superior oblique muscles were severed brutally, so that repairing was not possible.Results: On the day after exploration and primary suturation, there was 25 prism diopters (PD) hypotropia and 15 PD esotropia in his right eye with severe limited supraduction and abduction. His major complaint was a large vertical diplopia which resolved partially with the prismatic glasses prescribed. After 6 months follow-up, medial rectus and inferior rectus recession was performed in the right eye. The patient had a limited but improved abduction after the operation. He was orthotropic and had a single binocular vision in the primary position.Discussion: In suspected extraocular muscle ruptures, orbital imaging methods and surgical exploration should be considered promptly. MRI may be mandatory to demonstrate the severed muscles in cases with persistent diplopia and normal CT. Prognosis is usually better in patients having partial extraocular muscle damage and treatment options should be evaluated on patient basis.

A Child With Muscle-eye-brain Disease

Purpose: To describe a child with muscle-eye-brain disease as the first case report in Korea. Case Summary: A 35-month-old girl presented with esotropia and nystagmus since birth. She was born with a birth weight of 3.45 Kg at the gestational age of 39 weeks. She had a history of developmental delay and developmental dislocation of the hip. Her elder sister also had generalized weakness and mental retardation. The patient's creatinine kinase and lactate dehydrogenase serum levels were high. Cycloplegic refraction showed a significant myopic astigmatism in both eyes. She showed nystagmus and 20 prism diopters of esotropia in the primary position with the alternative prism cover test. Slit lamp examination revealed a mild posterior subcapsular cataract and lower lid epiblepharon in both eyes. Funduscopic examination showed diffuse retinal degeneration with remnant hyaloids membranes in both eyes. Both optic nerves were dysplastic with abnormal vascular branching pattern. Flash visual evoked potential was normal and standard electroretinography showed decreased amplitude in both eyes. Brain magnetic resonance imaging (MRI) revealed diffuse T2 high signal lesions of the cerebral white matter, diffuse pachygyria of the cerebral cortices, pontine hypoplasia, and multiple small cerebellar cysts. Conclusions: When a child with developmental delay has ophthalmologic problems including severe myopia, cataract, strabismus and retinal degeneration, the systemic condition should be examined. In this case, in addition to the ophthalmologic findings, blood test and brain MRI were helpful for the diagnosis of muscle-eye-brain disease.

Age-Related Distance Esotropia

To describe a form of acquired esotropia occurring in older adults, which here is termed age-related distance esotropia. A retrospective consecutive case series of 26 patients with this condition was reviewed. The patients ranged in age from 62 to 91 years old with a median age of 77 years. The distance deviation varied from 4 prism diopters (PD) ET (esotropia) to 20 PD ET, with a median angle of 9 PD ET. At near fixation, the measurements ranged from 9 PD ET' to 10 PD X' (exophoria), with a median deviation of 3 PD ET'. Ductions and versions were full, with no evidence of lateral rectus paresis. None of these patients had an obvious underlying neurologic disorder, such as tumor or stroke. Treatment consisted of prescribing the minimum prismatic correction that eliminated distance diplopia, which was then incorporated into the patients' current spectacles. This treatment successfully eliminated the symptoms in all patients. No patient in this study required surgery. A distinctive form of strabismus occurs in older adults that is characterized by esotropia greater at distance than near fixation. The etiology of this disorder is unknown, but it is likely secondary to anatomical changes in the orbit and/or muscles associated with aging. Most patients are readily corrected by prisms but, surgical correction might be required in some cases.

Clinical features of V patterns strabismus and its long-term effect of surgical treatment

To investigate the features and treatment of V patterns strabismus. Pre- and post-operative deviation and oblique muscle action as well as binocular visual function were evaluated in sixty-three V pattern patients. The difference between upgaze and downgaze of deviation were recorded before and after operation. Sixty-two patients (98.4%) with binocular or unilateral inferior oblique overaction + 2 to + 3 were treated with inferior oblique weakening procedure and horizontal rectus recession-resection procedure. 1 patient with binocular inferior oblique overaction + 1 treated with horizontal recti recession-resection procedure. The difference between upgaze and downgaze is 25.6 prism diopters (PD) preoperatively and 4.5 PD postoperatively. The primary-position exotropia preoperatively of 48 V pattern exotropia is 37.2 PD, after surgery, the average deviation is 3.4 PD of esotropia [38 cases (79.2%) with deviation within +/- 10 PD]. 15 cases of V pattern esotropia had deviation 50.6 PD preoperatively, after surgery, the average deviation is 2.4 PD of esotropia [11 cases (73.3%) with deviation within 10 PD]. 21 patients (33.3%) obtained stereo visual function after surgery. V patterns always had inferior oblique over action and could be treated with the inferior oblique weakening procedure. The primary-position deviation should be treated by traditional horizontal rectus recession-resection procedure. The stereoscopic function had a good prognosis with surgery.

Three-Muscle Surgery for Infantile Esotropia in Children Younger Than Age 2 Years

To review the long-term outcome of infants undergoing three-muscle surgery for infantile esotropia. Surgical records of 10 patients with esotropia > or = 55 prism diopters (PD) who underwent three-muscle surgery for large-angle infantile esotropia were reviewed. Outcome measures included over- or undercorrection, need for additional surgery, and amount of deviation at last follow-up. Mean age at initial surgery was 13 months. Mean preoperative deviation was 62.5 PD of esotropia. A single surgery was associated with satisfactory horizontal alignment in only three (30%) patients at last follow-up (mean, 37.1 months; range, 8-70 months). Esotropia was undercorrected in one (10%) and overcorrected in six (60%) patients, all of whom required additional surgery. One patient with satisfactory horizontal alignment required an additional procedure to correct a right hypertropia causing a left face turn. In contrast to older children and adults, three-muscle surgery may be inappropriate for infants with large-angle esotropia due to a large overcorrection rate. This controversy may benefit from a prospective study.

‘Largest angle to target’ in surgery for intermittent exotropia

To evaluate the safety of the approach based on the notion that the surgical dose for intermittent exotropia should be based on the largest angle ever measured. Prospective case series of 33 patients. A total of 33 patients with intermittent exotropia, in whom angles of misalignment at distance or near showed a difference of 15 prism diopters (PD) or more among visits, were included. All the patients were treated by bilateral lateral rectus recession by the same surgeon (JMH), and all were followed up for a minimum of 6 months postoperatively. Short- and long-term surgical results after the initial procedure for intermittent exotropia were analysed. The short-term average result at a postoperative 1 week was 9.3 PD esotropia at distance (range 30 esotropia-16 exotropia). The long-term average results postoperative 6 or 9 months were 4.8 PD exotropia at distance (range 12 esotropia-30 exotropia). At the last follow-up, no overcorrection over 2 PD esophoria at distance was found, and 9 PD of intermittent esotropia and esophoria at near was observed in two patients, respectively. The strategy of surgical dose for intermittent exotropia based on the largest angle ever measured did not result in overcorrections and is believed to be safe.

The Gradient AC/A Ratio: What's Really Normal?

The two most commonly used methods for determining the AC/A ratio are the Gradient Method and the Clinical Method. Though both methods are simple, practical, and often used interchangeably, they are really quite different. The Gradient AC/A measures the amount of convergence generated by a diopter of accommodative effort, while the Clinical Method detects the presence of a distance-near disparity of 10 or more prism diopters of esotropia. The purpose of this prospective study was to compare the Gradient and Clinical AC/A in 69 consecutive patients presenting with acquired nonparalytic esotropia. In addition, two methods of calculating the Gradient AC/A were compared: “minus” AC/A in which accommodation (and therefore accommodative convergence) is stimulated, and “plus” AC/A in which accommodation (and accommodative convergence) is relaxed. Mean Gradient AC/A for patients with a normal Clinical AC/A was 2:1, below the range traditionally thought of as normal. Mean Gradient AC/A for patients with a high Clinical AC/A was 5:1. Forty-four percent of those with a high Clinical AC/A had a normal or low Gradient AC/A, suggestive of nonaccommodative convergence excess. Mean Gradient AC/A with plus lenses was statistically identical to the AC/A with the minus lens method.

Intact sensory fusion in a child with divergence paresis caused by a pontine glioma

PURPOSE: To describe a child with divergence paresis esotropia caused by a brain tumor with intact sensory and motor fusion. METHOD: Case report. RESULTS: A 9-year-old boy who had one episode of double vision was initially seen with a small, variably present esophoria at near vision, an intermittent 10 prism diopter esotropia at distance, and stereopsis of 80 arc seconds. A magnetic resonance imaging examination disclosed a 4.0 × 4.5-cm pontine glioma. CONCLUSIONS: Ophthalmologists should recognize that the presence of intact sensory and motor fusion in a child with acute, comitant esotropia of the divergence paresis type does not preclude intracranial abnormality. If immediate neuroimaging is deferred, repeated thorough ocular motility examinations are warranted to detect progression.

Adjustable vertical rectus muscle transposition surgery.

Transposition of the vertical rectus muscle to the insertion of a paralytic or aberrantly innervated lateral rectus muscle is useful in treating esotropia associated with abducens palsy and Duane syndrome. However, this procedure may cause a manifest vertical deviation, requiring either prismatic or additional surgical correction. In an attempt to reduce the incidence of this surgical complication, we performed vertical rectus muscle transposition surgery, using an adjustable suture technique on each muscle, in 10 consecutive patients with abnormal lateral rectus function. Preoperative diagnoses included abducens palsy (70%) and Duane syndrome (30%). Preoperative deviations ranged from 14 to 85 prism diopters esotropia (mean, 39 delta) in the primary position. No vertical deviation was present preoperatively. Following transposition surgery, 8 of 10 patients were esotropic, 1 of 10 patients was exotropic, and 4 of 10 patients had a manifest vertical deviation. At the time of adjustment, all vertical deviations were corrected by "recessing" the appropriate vertical rectus muscle. Additionally, exotropia was lessened by "recessing" both vertical muscles in one patient.

Prism Treatment of Acute Esotropia following Interruption of Fusion

The authors report a 13 year old boy who suffered temporary occlusion of one eye following a minor ocular injury. The patient developed a comitant 35 prism diopter esotropia with diplopia. There wa...

Ocular Alignment Under General Anesthesia in Congenital Esotropia

Ocular alignment is usually more divergent in strabismus patients under general anesthesia than in the awake state. Although clinical and anesthetized alignments have been reported to be correlated through the equation A = 0.8P + 30, significant differences in the amount of divergence under anesthesia have been reported between esotropes and exotropes. We found differences in response to general anesthesia in a group of 83 congenital esotropes. The averaged anesthetized alignment pertained to the whole group of 6.2 prism diopters of esotropia, which correlated poorly with the preoperative deviation. Mean anesthetized alignments were similar for any amount of preoperative deviation. Recommendations of intraoperative adjustment of surgery based on the anesthetized position should, in our opinion, be reconsidered and recalculated when treating congenital esotropes. A prediction of surgical results following these recommendations suggested an increase of the undercorrection rate, probably linked to an incorrect identification of normal and anomalous cases to the Apt-Romano test.