Download Fernandes, N - American Academy of Optometry

Title : Treatment options for Cyclic Esotropia
Author(s): Noelda Fernandes, O.D. (Pediatric Optometry Resident, SUNY) and Elsa Sheerer O.D
(Pediatric Optometry Resident)
Abstract
A four year old female presents to the University Eye Center for a second opinion on options for treating cyclic
strabismus. Cyclic esotropia and treatment options will be explored.
I. Case History
Patient demographics: 4 year old half Asian half Caucasian female presents to the University Eye Center.
Chief complaint: Right eye turn in.
Ocular History:
-Mother noticed patient’s right eye turn in frequently. First occurrence was 14 months ago and most often occurs in
the morning time. Mother further states that eyes are straight at times as well. Patient has been diagnosed with
cyclic strabismus by an OMD, who recommended the patient undergo strabismus surgery. Therefore, mother is
seeking a second opinion, as she has concerns about the surgery.
-Patient is currently undergoing home therapy 2x/day for 15-20 minutes. Activities the patient carries out include
reading a chart with red letters on a white background with R/G glasses. Pt was also given a pair of bifocals with a
plano prescription at the top and an add at the bottom. Mother reports patient does not wear glasses often due to
complaints of blurry vision. No glasses were worn at the office visit.
Medical History: Heart murmur.
Medications: None
Other salient information: Receiving speech, occupational and physical therapy. Use of forceps during delivery.
Posterior segment revealed a myelinated nerve fiber layer, OD.
II. Pertinent findings
Clinical
VA 20/25 with Snellen Acuity OD/OS/OU
Entrance testing
CVF: OD had poor responses, OS was full to toy
EOMs: full range of motion with an A pattern deviation and an over acting IO OS.
Pupils: PERRL (-) APD
CT: 30 pd CRET at distance
30 pd CRET at near (variable)
Stereo: 200 seconds of arc (Animals)
Color Vision: HRR 6/6 OD/OS/OU
Dry Retinoscopy findings
OD: +0.50-0.75x180
OS: +0.75-0.75x180
Hand held slit lamp Biomicroscopy findings
Adnexa OD: microcornea 9.0mm
OS: microcornea 9.5 mm,
Lids OD: lids and lashes normal
OS: lids and lashes normal
Sclera/conj OD: white and quiet
OS: white and quiet
Cornea OD: anterior displaced Schwalbe's line temporally
OS: anterior displaced Schwalbe's line temporally
Anterior Chamber OD: d+q
OS: d+q
Iris OD: flat and intact
OS: flat and intact
Lens OD : cl
OS: cl
Angle OD: 4x4 VH
OS: 4X4 VH
IOP pressures: Non contact Tonometer 17mmHg OD 19 mmHg OS
Vitreous OD: cl
OS: cl
Disc OD 0.35, myelinated nerve fiber surrounding ONH
OS: 0.35 pink, distinct and healthy rim margins
Macula OD: (+)FR, cl
OS: (+) FR, cl
Vessels OD: 2/3 normal course and caliber
OS: 2/3 normal course and caliber
Posterior Pole Undilated with Direct O’scope. Fundus Photos were taken which showed a myelinated nerve fiber
layer OD.
III. Differential diagnosis
•
Cyclic Esotropia- Primary Diagnosis.
•
Accomodative Esotropia
•
Acute acquired comitant esotropia
•
Intermittent Esotropia
IV. Diagnosis and discussion
Cyclic esotropia is a condition that presents itself one day and is absent the next (Verman and Yen 2010). It is a
recurrent condition where a large esotropic posture alternates with normal eye alignment in a rhythmic pattern
(Verman and Yen 2010). To date, the most commonly reported pattern is a 48 hour cycle, but 24, 72, 96 and 120
hour cycles are also noted. During the esotropic state, sensory anomalies are observed where one’s fusional
amplitudes through the synoptophore are found to be either defective or absent (Cole et al. 1988). However,
normal binocular vision and stereo acuity are observed on days when the eyes are aligned. Cyclic esotropia is not
related to visual acuity, fatigue or accommodation (Turan et al. 2014). Although this deviation manifests
spontaneously, some factors that may precipitate this condition include ocular trauma, orbital surgery, excision of
intracranial tumors and associations with CNS lesions or epilepsy (Reinhardt et al. 2028). While the etiology of
cyclic esotropia is unknown, one leading theory suggests this condition results from an aberration in the 24 hour
biological clock (Cole et al. 1988). Other theories include pathologies of the hypothalamic-hypophyseal axis, the
oculomotor nuclei, the superior colliculi or cyclic sixth nerve palsy (Reinhardt et al. 2008).
Expound on unique features
Cyclic esotropia is a rare disorder of ocular motility that is reported to be 1 in 3000-5000 cases of strabismus
(Verman and Yen, 2010). It often presents in childhood between 2-6 years of age which explains the mild
hyperopic refractive error also observed within this condition (Verman and Yen, 2010). The cyclic nature of cyclic
esotropia is eventually broken down over time to a constant esotrope (Tapeiro et al. 1995). Other characteristics
include the presence of a bilateral over-elevation in adduction and V-pattern (Turan et al, 2014). Potts and
colleagues (2004) report how Ohm postulated that the over-elevation in adduction is due to the abnormal
innervation of the vestibular system. One of the functions of the oblique muscle includes the control of eye
movements during body movements in lateral eyed animals. When fusion is lost, these primitive ocular motor
reflexes manifest itself in humans (Brodsky and Donahue 2001). Other characteristics include no diplopia when
strabismic, mild amblyopia, moderate to large deviation and a high AC/C ratio (Metz and Jampolsky 1979).
Our patient presented to clinic with findings that correlate with characteristics apparent in cyclic esotropia. When
the patient presented to clinic, a 30 pd constant right esotrope was found. According to the mother, the deviation
first manifested itself in the morning. Other times during the day, the mom reports the patients eyes are aligned. A
hypermetropic prescription was found at this visit that once again correlates well with this condition (Lai and
Fredrick 2005). This patient was able to appreciate 200 seconds of arc of animals on the Randot Stereo Test.
However, the responses attained by the patient could be confounded by the presence of monocular cues present in
Randot stereo test. Fawcett and Birch (2003) suggest that when using either the Titmus or Randot tests in patients
with binocular vision disorders, when results state 160 seconds or arc or better caution should be used as
monocular cues may invalidate the results.
It is important to note, the mother did not give permission to cyclopledge the patient at this visit due to prior
cycloplegic exam a few months earlier by OMD. Thus, a follow up appointment with an OMD was scheduled to rule
out the differential diagnosis of accommodative component, intermittent esotropia and acquired comitant
esotropia. In addition, since the patient presented with bilateral anterior displaced Schwalbe's line, a referral to the
OMD was also done to rule out any of the pathological anomalies associated with this finding.
Treatment, management
Treatment and response to treatment
A successful treatment for cyclic esotropia is defined as being able to prevent the loss of stereoscopic vision and
good binocular vision potential. To date, the most successful therapy for cyclic esotropia is surgical correction for
the total esodeviation when the eye is observed to manifest the squint. The surgical procedure includes having
either bilateral medial rectus recession or a unilateral medial rectus recession with lateral rectus resection
completed. Individuals who have undergone this form of treatment have reported successful outcomes.
Postoperatively, the patients showed orthophoric alignment, with a positive stereoscopic vision, the V pattern
deviation resolved and the patients had good fusional amplitudes (Pott et al 2004). At this time no specific age
requirement for conducting surgery has been noted. Strabismus surgery have been carried out on individuals as
young as 2-3 year old and as old as 37 years old who developed cyclic esotropia following a scleral buckle surgery
for retinal detachment (Pott et al, 20004; Di Meo et al 2013).
Other modes of therapy that have been attempted include occlusion therapy which is not reported to be used
often. As reported by Verman and Yen (2010) occlusion therapy converts a cyclic strabismus to a constant one.
Due to the association of cyclic esotropia with hypermetropia, treatment with lenses have reported variable
outcomes. Verman and Yen (2010) discuss how Windson and Berg after fully correcting the hyperopia converted a
24 hour cycle to a 48 hour cycle. On the other hand, Halveston (1973), was able to obtain fusion with glasses for 3
out of 14 patients.
The use of botulinum toxin is a novel treatment approach that has been reported to have temporary effects
producing good ocular alignment and elimination of the cyclic deviation (Jones & Jain; 2014). A 3 year old female
who was treated with botulinum toxin to both medial rectus muscles broke down the cyclic esotropia to a constant
esophoric posture for 1 year (Jones & Jain; 2014)
Another mode of treatment where not much data is available that could possibly be an option for individuals who
do not want to undergo surgery could be the use of vision therapy. The goal of these session would be slowly build
both fusional vergences and amplitudes of the patient by starting therapy on the patient when they are normally
aligned and continuing to slowly build the patients ranges when the patient manifests the deviation.
According to Verman and Yen (2010) the most important aspect in the optometric management of these patients is
repeated case histories and follow-ups to help aid in proper diagnosis and treatment.
Conclusions
Cyclic strabismus results in defective stereopsis and fusion (Dawson et al, 2009). Thus early intervention is
necessary to prevent the loss of stereoscopic vision and good binocular vision amplitudes. Although to date surgery
has been noted to have the most successful rate, other non-invasive techniques need to be explored.
Bibliography
1) Verman K, Yen KG. A Toddler with Periodic Strabismus. Medscape Ophthalmology. 2010 Accessed 20 August
2015.
http://www.medscape.com/viewarticle/727787_2
2) Cole MD, Hay A., Eagling EM. Cyclic esotropia in a patient with unilateral traumatic aphasia: case report. British
Journal of Ophthalmology 1988; 72:4:305-308.
3) Turan KE, Sekeroglu HT, Sanac AS. Constant Deviation in a Child after Surgery for Cyclic Esotropia. Journal of
Clinical Case Reports 2014;4:467.
4) Reinhardt K, Naxer S, Weise D, Gärtner J, Schittkowski M. Cyclic Esotropia – A rare differenzial diagnosis in nonparalytic strabismus in childhood. Neuropediatrics 2008; 39 - VI8.
5) Tapiero B, Pedespan JM, Rougier MB, Huslin V, Massicault B, Le Rebeller MJ. Cyclic strabismus. Presentation of
two new cases and critical review of the literature. Journal français d'ophtalmologie 1995; 18(6-7):411-20.
6) Brodsky MC, Donahue SP. Primary oblique muscle overaction: the brain throws a wild pitch. Archives of
Ophthalmology 2001;119:9:1307-14.
7) Metz HS, Jampolsky A. Alternate day esotropia. Journal of pediatric ophthalmology and strabismus 1979;
16:1:40-2.
8) Lai YH, Fredrick DR. Alteration of cyclic frequency by botulinum toxin injection in adult onset cyclic esotropia.
British Journal of Ophthalmology 2005 Nov; 89:11:1540-1.
9) Fawcett SL, Birch EE. Validity of the Titmus and Randot circles tasks in children with known binocular vision
disorders. Journal of American Association for Pediatric Ophthalmology and Strabismus 2003 Oct; 7:5:333-8.
10) Pott JW, Godts D, Kerkhof DB, de Faber JT. Cyclic esotropia and the treatment of over-elevation in adduction
and V-pattern. British Journal of Ophthalmology 2004; 88:66-68.
11) Di Meo A, Costagliola C, Della Corte M, Romano A, Foria C, et al. Adult-onset cyclic esotropia: a case report .
Optometry and Vision Science 2013; 90: e95-98.
12) Helveston EM. Cyclic strabismus. The American Orthoptic Jounral 1973; 23:48-51.
13) Jones A, Jain S. Botulinum toxin: a novel treatment for pediatric cyclic esotropia. Journal of American
Association for Pediatric Ophthalmology and Strabismus 2014; 18:6:614-5.