Multiple Ocular and Systemic Disorders in Association with Bilateral Duane's Retraction Syndrome.

Duane's retraction syndrome (DRS) is characterized by limitations in horizontal eye movements, globe retraction, and palpebral fissure narrowing on attempted adduction. This disorder is caused by a disturbance in innervation originating in the brain stem and represents <1% of all cases of strabismus. It is postulated that this syndrome is due to an insult during the early weeks (8-10 weeks) of pregnancy and is 10-20 times more frequently associated with other systemic congenital anomalies. This case report of bilateral DRS included bilateral iris-retinal coloboma and congenital heart disease, sensory hearing loss, and inguinal hernia.

INTRODUCTION

Duane's retraction syndrome (DRS) is characterized by limitations in horizontal eye movements, globe retraction, and palpebral fissure narrowing on attempted adduction.1 This disorder is caused by an innervational disturbance originating in the brain stem origin and represents <1% of all presentations of strabismus.2 Although the pathogenesis is debatable, the most widely accepted theory is the innervational disturbance of brain stem origin in which the lateral rectus is partially controlled by the oculomotor nerve.

Numerous concomitant ocular and systemic anomalies have been reported with DRS. Some ophthalmic manifestations include iris dysplasia, ptosis, keratoconus, nystagmus, optic disc anomalies, colobomata, congenital cataracts, microphthalmia, and Marcus-Gunn jaw winking syndrome.34 Systemic anomalies include Goldenhar's syndrome, Klippel–Feil syndrome, Noonan's syndrome, Rubinstein–Taybi syndrome, spinal and rib malformations, sensory hearing loss, facial nerve palsy, genitourinary dysfunction, malformations of the limbs, and facial deformities.34 We report a case of bilateral DRS and multiple concomitant ocular and systemic abnormalities.

CASE REPORT

A 10-year-old female was referred to our clinic with a chief complaint of abnormal eye movements bilaterally. She was a product of full-term normal delivery without any history of prenatal and perinatal conditions, born out of a non consanguineous marriage with no family history of strabismus.

The best-corrected visual acuity was 7/10 in the right eye and 9/10 in the left eye. The refraction in the right eye was −0.5–0.25 × 40° and −0.75 sphere in the left eye. Bilateral inferonasal iris coloboma was present on slit lamp examination [Figure 1]. Bilateral macular sparing retinal coloboma was present on fundus examination [Figure 2]. There was no compensatory face turn. On the alternate cover test, the eyes were orthotropic in the primary position, but the ocular motility examination revealed the moderate limitation of abduction and mild limitation of adduction [Figure 3]. Slight palpebral fissure narrowing with retraction on attempted adduction was observed in bilaterally. Elevation and depression were intact. She had normal IQ with good functional status.

Figure 1

Orthotropia in primary position and bilateral iris coloboma

Figure 2

Macular sparing retinal coloboma

Figure 3

(a and b) Moderate limitation of abduction and mild limitation of adduction

The patient had multiple systemic problems. She had undergone open heart surgery for tetralogy of Fallot (TF) and repair of total anomalous pulmonary vein connections (TAPVC) when she was 3.5 years old and then underwent implantation of a pacemaker 3 weeks later for complete heart blockage. One year after pace implantation, she underwent surgery for bilateral inguinal hernia. She also suffered from hearing problems and audiometry showed left sensory hearing impairment. There was no indication for strabismus due to the orthotropia in the primary position, the absence of upshoot or downshoot, and lack of an anomalous head posture.

DISCUSSION

The nuclei for the 3rd, 4th, and 6th cranial nerves develop by the 4th or 5th week of gestation and their neural connection with corresponding muscles is complete by the 8th week. During the same period, extraocular muscles differentiate from primitive mesodermal tissue. Hence, anomalous incorporation of fibers from the oculomotor nuclei into the lateral rectus muscles in abducens hypoplasia is plausible.5

Yamaguchi and Honma examined brain sections obtained from preterm infants aged 20–43 postmenstrual weeks and found that the abducens nucleus was identified as a mass of cells as early as 20 weeks.6

It is postulated that DRS is due to an insult during the early weeks (8–10 weeks) of pregnancy.7 In addition, it is associated 10–20 times more frequently with other systemic congenital anomalies.8 Recently, Xia et al.9 investigated the innervation pattern of extraocular muscles in 11 DRS patients using magnetic resonance imaging. They found abnormalities however the abducens nerve was absent in six patients.9

Several ocular abnormalities have been described in association with DRS. Kim et al.10 reported bilateral DRS with bilateral tilted disc syndrome. The tilted disc is a form of coloboma which develops around 5 weeks of gestation. Garnica-Hayashi et al.11 presented a 15-year-old girl with a left-sided DRS in combination with ipsilateral retinal coloboma and contralateral microphthalmia.

Ocular coloboma is a congenital, common, and heterogeneous malformation which includes a spectrum of anomalies ranging from iris coloboma to clinical anophthalmos. The estimated prevalence of coloboma is 1 in 10,000 worldwide.12

Our case represents the first reported association of DRS and TF. TF occurs in 3 of every 10,000 live births. Associated chromosomal anomalies can include trisomies 21, 18, and 13, but recent experience indicates a greater association with microdeletions in chromosome 22.13

Our case had bilateral iris-retinal coloboma and congenital heart disease (TF and repair of TAPVC), sensory hearing loss, and inguinal hernia. One patient with coexisting cardiac anomaly but not TF and Duane syndrome has been described earlier. Cogulu et al., in 2007, presented a 20-month-old female with vertebral and rib anomalies, dextroposition of heart with Duane anomaly.14

Ocular coloboma develops around 5 weeks of gestation.4 Therefore, bilateral DRS with bilateral TDS presented in this case may be due to developmental anomalies that originated in the 2nd month of pregnancy. Hence, patients with Duane syndrome should undergo a comprehensive physical examination at regular intervals

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.