Ocular Neuromyotonia: Clinical Features, Diagnosis, and Outcomes.

PURPOSE: The purpose of this study was to describe the clinical features, management, outcomes, and diagnostic pitfalls in a large series of patients with ocular neuromyotonia. DESIGN: Retrospective cohort. METHODS: Patients diagnosed with ocular neuromyotonia from January 1, 2004, through January 1, 2023, seen at one of the 3 Mayo Clinic sites in Rochester, MN, Scottsdale, AZ, and Jacksonville, FL, comprised the study population. We ascertained patients with ocular neuromyotonia through a search using the medical records database. Only patients with an observed episode of ocular neuromyotonia were included and the medical records were reviewed. The main outcome measures were clinical features and outcomes of patients with ocular neuromyotonia. RESULTS: Forty-two patients who were diagnosed with ocular neuromyotonia were included. The median age was 58 years (range, 16-80 years). A history of cranial radiation therapy was present in 39 patients (93%). The sixth cranial nerve was involved in 31 patients (74%). Bilateral disease was found in 2 patients (5%). The median time from onset of diplopia to diagnosis was 8 months (range, 1 month-25 years), with a high rate of initial misdiagnosis in 52%. Twenty of 42 patients (48%) were treated with oral medication, of whom 95% had significant improvement or resolution of symptoms. CONCLUSION: Prior cranial irradiation is the most common cause for ocular neuromyotonia, affecting the sixth cranial nerve most often. Although delayed and initial misdiagnosis is common, most patients show improved symptoms on medical treatment.

Characteristics of childhood intermittent exotropia with and without DVD.

Purpose: Although dissociated vertical deviation (DVD) is reported to occur rarely in children with intermittent exotropia (IXT), little is known regarding the clinical features of these children. The purpose of this study was to compare the demographic and clinical characteristics of children with intermittent exotropia and DVD to those without DVD. Methods: The medical records of all children diagnosed with intermittent exotropia at our institution from 1 January 2002, through 31 December 2018, who had 2 or more exams with 3 or more assessments of control, were retrospectively reviewed. Exotropic children with DVD were compared to those without DVD. Results: During the 17-year study period, 115 children met the inclusion criteria, of which 25 (21.7%) had DVD. Compared to the 90 exotropic children without DVD, children with IXT and DVD were more likely to have a motility disorder (p = .021), a worse mean distance control score (2.8 vs 2.4; p = .09), a larger mean angle of deviation (27.8 prism diopters [PD] vs 25.1 PD; p = .04), and a lower median stereopsis (200 secs vs 100 secs; p = .08). The children with DVD were more likely to have undergone surgery (p = .17) although there was no difference in the mean age at initial surgery between the two groups. Conclusions: The presence of dissociated vertical deviation in children with intermittent exotropia is associated with more motility disorders and worse binocular function compared to those without DVD. These children will likely require closer observation and earlier intervention.

Stereopsis in children with intermittent exotropia and dissociated vertical deviation.

Dissociated vertical deviation (DVD) is generally associated with early-onset esotropic strabismus and poor stereopsis. It is infrequently observed among patients with intermittent exotropia. In this cohort of 242 consecutive children with intermittent exotropia examined over a 17-year period, 25 (10.3%) were found to have DVD, 13 (52%) of whom had normal stereopsis. In the children with both intermittent exotropia and DVD, disease severity appears to depend more on the quality of stereopsis than on the presence of DVD.

Comparison of Methods for Measuring Cyclodeviation.

PURPOSE: To compare the double-Maddox rod test with other methods of measuring cyclodeviation DESIGN: Retrospective cohort study. METHODS: We retrospectively identified 153 adults in a clinical practice with cyclodeviation assessed using double-Maddox rods, of whom 105 were also assessed using fusible synoptophore targets, 73 using nonfusible synoptophore targets, 118 using single-Maddox rod, and 43 using fundus photography. Relationships between double-Maddox rod and other tests were evaluated by calculating mean differences with 95% confidence intervals (CI), intraclass correlation coefficients (ICC), and Bland-Altman plots with linear regression. RESULTS: Synoptophore cross-in-circle targets and the largest (of right or left) single-Maddox rod values were similar to double-Maddox values (mean differences: -1.2° and 0.1°, respectively; ICC: 0.79 and 0.82, respectively). Synoptophore house targets measured less excyclodeviation (mean difference: -2.7°; ICC: 0.71). Mean summed single-Maddox rod values were somewhat similar to double-Maddox values (mean difference: 1.5°; ICC: 0.85), but differences increased with greater cyclodeviation (r2 = 0.2678; P < .001). Fundus photographs showed large, uncorrelated differences compared with double-Maddox rod test, when summing right and left eyes and when using the largest of right or left (mean differences: 12.2° and 6.2°; ICC: -0.02 and 0.21, respectively), and differences increased with greater cyclodeviation (r2 = 0.4094; P < .001 and r2 = .1143; P= .03, respectively). CONCLUSIONS: There was good agreement between double-Maddox and the largest single- Maddox test values and synoptophore cross-in-circle targets but poorer agreement with other tests. Further study is needed to understand which measurements best reflect true cyclodeviation and relationships with symptoms.

Treatment for Central-Peripheral Rivalry-Type Diplopia ("Dragged-Fovea Diplopia Syndrome").

PURPOSE: To report the effectiveness of treatments for central-peripheral rivalry (CPR)-type diplopia due to retinal misregistration. DESIGN: Retrospective, interventional case series. METHODS: Fifty adults with retinal misregistration and CPR-type diplopia (minimum frequency of "sometimes" at distance and/or for reading) caused by epiretinal membrane (n = 44) or other retinal disorders (n = 6) were enrolled in this study, conducted at adult strabismus clinics, Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, a tertiary medical center. Treatments included Bangerter filter, adhesive tape, Fresnel prism, clear prism (incorporated into glasses or loose prism in the office), iseikonic manipulation (using iseikonic lenses or contact lenses), a MIN lens, or epiretinal membrane (ERM) peeling (alone or in any combination). Not all patients underwent all of these treatments. RESULTS: Main outcome measurements were diplopia frequency, evaluated using the Diplopia Questionnaire. Success was defined as "never" or "rarely" diplopic for distance and reading, using the Diplopia Questionnaire, at an outcome examination as close as possible to 6 months. Overall, 17 of 50 patients (34%; 95% confidence interval [CI], 21%-49%) were classified as successful. Fresnel prism was successful in 4 of 7 patients (57%; 95% CI, 18%-90%); Bangerter filter in 4 of 28 patients (14%; 95% CI, 4%-33%); ERM peeling in 8 of 18 patients (44%; 95% CI, 22%-69%); and iseikonic manipulation in 1 of 23 patients (using a contact lens; 4%; 95% CI, 0%-22%). CONCLUSIONS: CPR-type diplopia may be relieved in some patients using nonsurgical treatment options consisting of Fresnel prism or Bangerter filter. ERM peeling was surprisingly successful and should be considered.

Role of a Standardized Prism Under Cover Test in the Assessment of Dissociated Vertical Deviation.

BACKGROUND: Dissociated vertical deviation (DVD) is commonly measured using a prism and alternate cover test (PACT), but some providers use a prism under cover test (PUCT). The aim of this study was to compare a standardized PUCT measurement with a PACT measurement, for assessing the magnitude of DVD. METHODS: Thirty-six patients with a clinical diagnosis of DVD underwent measurement of the angle of deviation with the PACT, fixing with the habitually fixing eye, and with PUCT, fixing both right and left eyes. The PUCT was standardized, using a 10-second cover for each prism magnitude, until the deviation was neutralized. The magnitude of hyperdeviation by PACT and PUCT was compared for the non-fixing eye, using paired non-parametric tests. The frequency of discrepancies more than 4 prism diopters (PD) between PACT and PUCT was calculated. RESULTS: The magnitude of hyperdeviation was greater when measured with PUCT (range 8PD hypodeviation to 20PD hyperdeviation) vs. PACT (18PD hypodeviation to 25PD hyperdeviation) with a median difference of 4.5PD (range -5PD to 21PD); P < 0.0001. Eighteen (50%) of 36 measurements elicited >4PD hyperdeviation (or >4PD less hypodeviation) by PUCT than by PACT. CONCLUSIONS: A standardized 10-second PUCT yields greater values than a prism and alternate cover test in the majority of patients with DVD, providing better quantification of the severity of DVD, which may be important for management decisions.

Relative roles of luminance and fixation in inducing dissociated vertical divergence.

PURPOSE: We evaluated the roles of luminance and fixation in the pathophysiology of dissociated vertical divergence (DVD). METHODS: Vertical eye position was measured in 6 subjects with DVD (ages 11-47 years, 5 females) and 6 controls (ages 16-40 years, 5 females) using video-oculography (VOG) under conditions of change in fixation and luminance. RESULTS: Subjects with DVD showed the following VOG responses. When fixation was precluded with a translucent filter and bright light was shone into one eye to produce a marked binocular luminance disparity, we found some subjects had a small induced vertical divergence causing the illuminated eye to be lower than the nonilluminated eye (mean -1.6° ± 1.5°, P = 0.06 compared to no vertical divergence using the signed rank test). When fixation was precluded with a translucent filter, while alternate occlusion produced a mild binocular luminance disparity, we found a smaller vertical divergence of the eyes that was not statistically significant (1.2° ± 2.1°, P = 0.3). When alternate occlusion produced reversal of monocular fixation in the dark (with essentially no change in peripheral luminance disparity), there was a significant vertical divergence movement causing the covered eye to be relatively higher than the uncovered eye (7.2° ± 3.1°, P = 0.03). The amplitude of this vertical divergence was similar to that measured under conditions of alternate occlusion in a lighted room (where there also was a significant average relative upward movement of the covered eye of 8.1° ± 2.9°, P = 0.03). Control subjects showed no vertical divergence under any testing conditions. CONCLUSIONS: Dissociated vertical divergence is mediated primarily by changes in fixation and only to a minor degree by binocular luminance disparity.

Congenital ocular motor apraxia with wheel-rolling ocular torsion-a neurodiagnostic phenotype of Joubert syndrome.

Joubert syndrome is a multisystem disorder that is associated with a constellation of cyclic ocular motor disturbances. We describe 2 children with congenital ocular motor apraxia who displayed wheel-rolling torsional eye movements and tonic alternating cyclodeviations of the eyes on retinal examination as a neurodiagnostic phenotype of Joubert syndrome.