Cyclic strabismus in adults

Yokoyama procedure for cyclic strabismus with axial high myopia:a case report

BACKGROUND

It is a very rare form of ocular motility characterized by alternating strabismus and orthotropia. We report a patient with a 48-h cycle of esohypotropia associated with axial high myopia that resolved by Yokoyama procedure.

CASE PRESENTATION

A 43-year-old female patient who underwent left medial rectus muscle recession and lateral rectus muscle resection elsewhere due to highly myopic strabismus 2 years ago. The patient experienced a recurrence of left esohypotropia 12 months after undergoing surgery, exhibiting a 48-hour cycle. The cycle is one full day of esohypotropia and one day of orthotropia. The patient exhibited a case of high myopia in the left eye, characterized by a diopter measurement of -24.00DS and an eye axis measurement of 28.43 mm. Orbital CT showed supertemporal dislocation of the posterior portion of the elongated globe out from the muscle cone. Based on these observations, we performed Yokoyama procedure by uniting the muscle bellies of the superior rectus(SR) and lateral rectus (LR) muscles to restoring the dislocated globe back into the muscle cone.

CONCLUSIONS

When cyclic strabismus is combined with axial high myopia, the Yokoyama procedure was effective and cycles are successfully terminated without overcorrection on no squint days. The purpose of this procedure is to put the dislocated globe back into its muscle cone by uniting the muscle bellies of the superior rectus and lateral rectus.

Cyclic Esotropia Managed With Botulinum A Toxin Injections: A Report of Four Cases and Literature Review

Cyclic strabismus is a rare entity and is unique in that patients follow variable but reliable time cycles where they alternate between orthotropia or "straight" eyes and strabismus, most commonly in the form of esotropia. Despite many theories on the underlying etiology and unique features of this diagnosis, none have been proven and its pathophysiology remains unknown. Four cases of cyclic esotropia diagnosed by pediatric ophthalmologists have been included in this report. The ages of the patients ranged from 10 months to eight years. The time duration from the onset of deviation to presentation to an ophthalmologist ranged from 1-52 weeks with three of the four patients presenting in the cyclic phase and the fourth presenting with a constant esotropia after a clear history and photographically documented cyclic esotropia for the preceding two months. All four patients were followed for periods ranging from one to four months to confirm their diagnosis or obtain multiple readings of the maximal deviation on the strabismic days before any intervention. The angle of esotropia when present ranged from 25 to 35 prism diopters and the cycle duration was 48 hours for all four cases (24 hours of esotropia followed by 24 hours of orthotropia). All patients were treated with botulinum toxin A injections to both medial recti, which resulted in an end to their cyclic deviation with excellent alignment obtained during follow-up periods ranging from 12-36 months for all cases. Cyclic esotropia is an elusive diagnosis that can be easily overlooked. When identified, classical treatment is usually extraocular muscle surgery targeting the largest angle of deviation. Many non-surgical treatments have been tried to no avail. However, in recent times, botulinum toxin A has been seen as a viable alternative.

Retroequatorial myopexy in the management of adult-onset cyclic esotropia

A 65-year-old otherwise healthy female, with bilateral normal visual acuity, presented with a unique pattern of strabismus. She complained of esotropia and diplopia occurring after every 24 h. There was no history of previous injury or ocular surgery. Other differentials were ruled out and the patient was diagnosed as adult-onset cyclic esotropia. The patient underwent right eye medial rectus retroequatorial myopexy, which tackled both diplopia and strabismus, without causing exotropia on nonsquint days.

Role of Botulinum Toxin Type A in Cyclic Esotropia: A Long-Term Follow-up

PURPOSE

To describe two patients with childhood cyclic esotropia 8 and 9 years after they underwent botulinum toxin type A treatment to report its long-term outcome.

METHODS

Two patients with sudden onset cyclic esotropia aged 2 and 4 years were included. Botulinum toxin type A injections were performed on the appropriate muscles.

RESULTS

The first patient was a 2-year-old boy with left dominant alternating esotropia on a cyclic basis. His strabismus ranged from 25 to 45 prism diopters (PD) at near and distance. A botulinum toxin type A injection into the left medial rectus muscle revealed orthotropia at near and distance with a stereopsis of 60 seconds of arc (arcsec). During the 9 years of follow-up, he remained stable. The second patient was a 4-year-old girl who complained of double vision and strabismus. Her deviation was 40 PD at near and 35 PD at distance on a cyclic pattern. She became orthotropic with glasses after a bimedial botulinum toxin A injection. During the 8 years of follow-up, she remained stable with a stereo-acuity of 120 arcsec.

CONCLUSIONS

Considering the consecutive and recurrent deviations with surgical treatment in previous reports, botulinum toxin type A is an appropriate first-line option for the treatment of cyclic deviations, despite its limitations. The results suggest that botulinum toxin type A is an effective method to break the cycle in cyclic esotropia permanently. [J Pediatr Ophthalmol Strabismus. 2019;56(6):360-364.].

A Cluster of Cyclic Esotropia: White Matter Changes on MRI and Surgical Outcomes

PURPOSE

To report a series of patients with cyclic esotropia, their surgical outcomes, and incidental findings.

METHODS

The medical records of five patients with cyclic esotropia presenting over 17 months were reviewed. Age at onset, ocular and motility examinations, brain magnetic resonance imaging (MRI), acetylcholine receptor antibodies, thyroid hormone levels and antibodies, calendars documenting phases, surgical treatments, postoperative alignment, and fusion were documented.

RESULTS

Three boys and two girls presented at 3 to 4 years old in 2015-2016. Typical periodicity followed a 48-hour cycle. Duration of cycling varied from 1 to 9 weeks. Mean maximum deviation was 37 prism diopters (PD) of esotropia (range: 35 to 40 PD of esotropia). All patients had normal laboratory studies. MRIs showed an abnormal white matter signal in the frontal lobes in 2 patients and were normal in the others. Bilateral medial rectus recessions for the maximum angle were successful in 4 patients at a minimum follow-up of 13 months; the other patient required reoperation for a residual esotropia. Fusion was present in 4 patients preoperatively and all postoperatively. Stereopsis was stable or improved in all postoperatively.

CONCLUSIONS

This is the first report of frontal white matter changes occurring in the setting of cyclic esotropia. MRI with attention to frontal lobe white matter might be considered in the work-up of cyclic esotropia to determine if this is a common finding. Bilateral medial rectus recessions can restore fusion in these patients. [J Pediatr Ophthalmol Strabismus. 2019;56(3):178-182.].

Long-Term Follow-Up of Cyclic Esotropia

BACKGROUND AND PURPOSE

To describe the development and treatment of patients with cyclic esotropia.

PATIENTS AND METHODS

The clinical course of seven patients with cyclic esotropia were retrospectively reviewed and described. All patients underwent bilateral medial rectus recession based on the deviation manifested on the day they were esotropic. Additionally, one patient had previously undergone surgery for intermittent exotropia.

RESULTS

All patients developed excellent postoperative alignment. After strabismus surgery, normal eye alignment with some degree of binocularity was reached in five patients. Moreover, there was no recurrence of the cyclic deviation in any patient, and no patient experienced an overcorrection.

CONCLUSIONS

Strabismus surgery aimed to correct the horizontal esotropic angle present on the day the esotropia is manifested provides a good outcome that is stable long-term, with minimal risk of overcorrection. Possible explanations for the origin of cyclic esotropia are discussed.

Acquired Adult Onset Cyclic Esotropia in Patients With Myopic Strabismus Fixus and Intraocular Lens Implantation

PURPOSE/BACKGROUND

Cyclic esotropia is a rare condition that mostly occurs in children, characterized by patterns of straight and strabismic days with a regular cycle of 24 to 96 hours. In this report, 2 patients of cyclic esotropia in adults who showed a regular 48-hour cycle of mild deviation on 1 day followed by a more severe deviation on the second day are presented.

METHODS

Clinical reports, clinical features, imaging findings, and surgical outcomes are presented.

RESULTS

In patient 1, a 42-year-old male with high myopia was diagnosed with progressive esotropia for 2 years. A medial and lateral rectus (LR) recession/resection was performed 9 months before. On day 1 after this surgery, a relatively mild esotropia was present which developed into a severe esotropia on day 2. Being diagnosed as cyclic esotropia with myopic strabismus fixus, he underwent a 4 mm re-recession of the medial rectus combined with a half-Jensen procedure in his right eye. After the second surgery, the cyclic pattern was no longer present. In patient 2, a 39-year-old female with high myopia had concomitant esotropia for 20 years. At 6 months following bilateral intraocular lens implantation for her high myopia, she demonstrated a cyclic strabismus. On day 1, a 25 prism dioptres esotropia was present, which increased to a 45 prism diopters esotropia on day 2. A 4 mm recession of the medial rectus and 6 mm resection of the LR was performed in her left eye. After surgery, the cyclic pattern disappeared.

CONCLUSIONS

Cyclic esotropia can occur in adults with myopic strabismus fixus subjected to horizontal strabismus surgery and with concomitant strabismus following intraocular lens implantation for high myopia. Their cyclic strabismus consisted of a mild squint on day 1 which increased in severity on day 2. The extent of surgery required for correction was based upon the "severe esotropia" experienced on day 2 and resulted in an excellent therapeutic outcome.

Cyclic esotropia with development of a high accommodative convergence to accommodation ratio after surgery for intermittent exotropia

PURPOSE

To report a patient with cyclic esotropia with a high accommodative convergence to accommodation (AC/A) ratio after surgical correction of intermittent exotropia who was found to have bilateral anomalous medial rectus muscle insertion sites.

METHOD

A 5-year-old girl developed intermittent esotropia on alternating days after undergoing bilateral lateral rectus recessions for correction of intermittent exotropia. Alternate prism and cover measurement of ocular alignment and binocular function was assessed on consecutive days. Surgical correction was performed for the full amount measured on a "crossed" day.

RESULT

On "straight" days, her eyes were orthotropic with normal binocular vision. Examination on "crossed" days revealed a left esotropia of 75 prism diopters (PD) at near fixation and 40 PD at distance fixation in primary gaze without fusion or stereopsis. The patient underwent bilateral medial rectus recessions in conjunction with posterior fixation sutures (MRP). During surgery, the distance from the limbus to the medial rectus muscle insertion was 3.5 mm bilaterally. Postoperatively, the cycle was broken, and the esotropia disappeared with no recurrence at the latest follow-up at 12 months.

CONCLUSION

MRP is an effective procedure for correction of cyclic esotropia with a high AC/A ratio. Strabismus surgeons should design surgical strategies based on preoperative measurement of deviations at all distances and the anatomy of muscle insertions in patients with cyclic esotropia.