Acquired central fusional disruption with spontaneous recovery

Reversal of severe vergence anomaly associated with convergence insufficiency

Central disruption of fusion refers to a subject's inability to fuse images, resulting in constant diplopia. Severely reduced vergences, or vergence anomalies, producing markedly decreased fusional amplitudes resembling fusional disruption have not been reported previously with convergence insufficiency. We report 3 patients with severe vergence anomalies in the setting of convergence insufficiency.

Diplopia as the Complication of Cataract Surgery

The authors present systematic review of aetiology and treatment of diplopia related to cataract surgery. The problem is set in the modern perspective of changing cataract surgery. Actual incidence is discussed as well as various modalities of therapeutic options. The authors provide the guidance for the contemporary cataract surgeon, when to expect potential problem in ocular motility after cataract surgery.

Perceptual Relearning of Binocular Fusion and Stereoacuity After Brain Injury

Background. Brain lesions may disturb binocular fusion and stereopsis, leading to blurred vision, diplopia, and reduced binocular depth perception for which no evaluated treatment is currently available. Objective. The study evaluated the effects of a novel binocular vision treatment designed to improve convergent fusional amplitude and stereoacuity in patients with stroke or traumatic brain injury (TBI). Methods. Patients (20 in all: 11 with stroke, 9 with TBI) were tested in fusional convergence, stereoacuity, near/far visual acuity, accommodation, and subjective binocular reading time until diplopia emerged at 6 different time points. All participants were treated in a single subject baseline design, with 3 baseline assessments before treatment (pretherapy), an assessment immediately after a 6-week treatment period (posttherapy), and 2 follow-up tests 3 and 6 months after treatment. Patients received a novel fusion and dichoptic training using 3 different devices to slowly increase fusional and disparity angles. Results. At pretherapy, the stroke and TBI groups showed severe impairments in convergent fusional range, stereoacuity, subjective reading duration, and partially in accommodation (only TBI group). After treatment, both groups showed considerable improvements in all these variables as well as slightly increased near visual acuity. No significant changes were observed during the pretherapy and follow-up periods, ruling out spontaneous recovery and demonstrating long-term stability of binocular treatment effects. Conclusions. This proof-of-principle study indicates a substantial treatment-induced plasticity of the lesioned brain in the relearning of binocular fusion and stereovision, thus providing new, effective rehabilitation strategies to treat binocular vision deficits resulting from permanent visual cortical damage.

Dorsal midbrain syndrome with loss of motor fusion: a rare association

INTRODUCTION

Dorsal midbrain syndrome (DMS) is characterized by upgaze paralysis, convergence-retraction nystagmus, and eyelid retraction. Impaired downgaze and pupillary light-near dissociation may co-exist, while less common features including exotropia and convergence paralysis have also been described. However, loss of motor fusion is not a well recognised finding in DMS.

PURPOSE

To describe DMS associated with loss of motor fusion.

METHODS

Retrospective case series.

RESULTS

Five patients (age 21-80 years) presented with features of DMS due to severe head injury (n=1), brainstem stroke (n=3) and pinealoma (n=1). All five complained of constant diplopia with horizontal and vertical separation and had an exotropia (range 20Δ to 70Δ), absent convergence and motor fusion. Two underwent strabismus surgery and subsequently had a variable improvement in their motor fusion. The remaining three patients were managed with occlusion.

CONCLUSION

This case series illustrates the complexity of ocular motility findings associated with DMS and highlights the potential difficulties in the management of patients with loss of motor fusion.

The dragged-fovea diplopia syndrome: clinical characteristics, diagnosis, and treatment

PURPOSE

To identify the clinical characteristics of the dragged-fovea diplopia syndrome, to introduce a simple diagnostic test that aids in the evaluation of such patients, and to provide a simple treatment option to improve the diplopia in some of these patients.

DESIGN

Retrospective, observational case series.

PARTICIPANTS

Ninety-five affected eyes in 83 consecutive patients seen between January 1, 1993, and August 9, 2004, who were diagnosed with the dragged-fovea diplopia syndrome at one institution.

METHODS

We reviewed the records of 222 patients who have been seen in the Krieger Children's Eye Center at The Wilmer Institute since 1993 with a diagnosis of maculopathy, internal limiting membrane, or dragged fovea. We collected ocular findings and history for those patients who reported binocular diplopia that was not amenable to prism therapy and not secondary to acquired strabismus.

MAIN OUTCOME MEASURES

We recorded the presence of metamorphopsia on Amsler grid testing or other clinical evidence of macular wrinkling, response to prism trial, response to the small-field central fusion test (lights on-off test), and response to partial occlusion with Scotch Satin tape (3M Co., St. Paul, MN).

RESULTS

Ninety-five affected eyes in 83 patients met the criteria for inclusion in the study. All patients who were tested with the lights on-off test (n = 69) responded positively, demonstrating rapid central fusion with room lights off, and recurrence of central diplopia with peripheral fusion with room lights on. Forty-six patients (of 64 tested) were receptive to monocular occlusion with Scotch Satin tape.

CONCLUSIONS

The dragged-fovea diplopia syndrome consists of central diplopia in the presence of peripheral fusion, secondary to dragging of the fovea in one or both eyes by retinal disease. The central diplopia cannot be eliminated by prism therapy or eye muscle surgery. The lights on-off test has proved pathognomonic for this syndrome, and many patients have benefited from partial monocular occlusion with Scotch Satin tape.

Restoration of binocular single vision after long-term fusion disruption

BACKGROUND

One of the most difficult situations faced by orthoptists and pediatric ophthalmologists is attempting to restore binocular single vision to a patient who has experienced a long-term disruption of fusion. Initial poor results with standard treatment modalities, including prisms and strabismus surgery, may lead to a diagnosis of intractable diplopia.

METHODS

We examined, treated, and followed up 5 patients with strabismus after an extended period of monocular vision loss. All patients were diplopic after the restoration of visual acuity in the affected eye.

RESULTS

All 5 patients experienced a period of uncomfortable intermittent fusion with the initial prismatic correction. After many months of close follow-up with prism and orthoptic therapy, comfortable fusion was restored for 3 patients. Convergence amplitudes improved with the orthoptic exercises, and we were eventually able to eliminate most or all of the horizontal prism in the 3 patients who regained binocular single vision; however vertical fusion was less responsive and most often required permanent prismatic correction.

CONCLUSIONS

A combination of prism therapy, orthoptic treatment, and follow-up during a period of many months to years can restore fusion in some patients who have experienced a long-term disruption of fusion.

The role of vergence adaptation in recovery of binocular single vision (BSV) following sensory strabismus

Vergence adaptation is an important element of comfortable binocular single vision and probably contributes to the high incidence of orthophoria or small angles of heterophoria in the normal population. Where binocular single vision has been absent for a period of time, restoration of good visual acuity appears to enable the vergence adaptation mechanism to become active again. A case is presented in which a moderate to large angle of deviation rapidly 'disappeared' once good visual acuity was restored and the disparate images could be fused. Known factors concerning vergence adaptation are discussed in relation to such clinical cases.