What is Ocular Torticollis?
The word “Torticollis” has a Latin origin, from the word “torti,” which means twisted, and “collis” means neck. Torticollis is also known as wryneck. Alfred Herbert Tubby, an orthopaedic surgeon, was the first to define, in 1912, Torticollis as a deformity, either congenital or acquired, which involved tilting of the head, facial asymmetry, and neck twisting. Torticollis refers to the twisted neck or persistent tipping or tilting of the head. The head is usually tilted towards the contracted muscle, whereas the chin is tilted in the opposite direction. Torticollis itself is not a disease but a clinical sign and symptom of a disease. A series of conditions can cause wrynecks.
The aetiology of Torticollis can be neurological, orthopaedic, and ocular. The Torticollis can give rise to multiple secondary problems like scoliosis, plagiocephaly, impaired balance, and cognitive development. It can occur at all ages, even to newborns. It can be acquired or congenital. The differential diagnosis in newborns or infants is quite different than in children or adults. The cause of Torticollis can be either ocular or non-ocular, i.e., musculoskeletal. The Non-Ocular Torticollis can either be Congenital Muscular Torticollis or Acquired Torticollis. The Ocular Torticollis is the tilting of the head due to ocular reasons. In the Ocular Torticollis, the individual tilts his head to either improve visual acuity or to optimize the binocularity.
Ocular Torticollis Symptoms
There are numerous symptoms associated with the Ocular Torticollis. There is a limited range of motion in the head and neck. The head tilt in the Ocular Torticollis causes drowsiness, vomiting, and irritability. It also causes musculoskeletal problems and head and facial asymmetry. Other symptoms of Ocular Torticollis include severe pain in the back, shoulder, and neck, decreased ability to move the head and neck, persistent headache, occasional mass formation, unequal shoulders, cramps, and spasms of neck muscles, muscle tightness and tenderness, burning sensation, and myalgia.
Ocular Torticollis Causes
The causes of Ocular Torticollis include:
· Congenital Nystagmus
· Incomitance (Strabismus or Paresis)
· Dissociated vertical deviation
· Brown Syndrome
· Refractive errors
· Combination of multiple etiologies
Ocular Torticollis Test
The diagnosis of the Ocular Torticollis is mainly based on the history and the physical examination. Various evaluations are done for the diagnosis. The abnormal head position is measured, and the extraocular motility and position concerning gaze are assessed. In the case of blepharoptosis and nystagmus, a physical examination is needed. Various tests such as slit lamp and dilated fundus examination are done in case of nystagmus and torsional misalignment, skiascopy for the assessment of refractive properties of the eye and Hess-Lancaster test to diagnose the ocular motility disorder. But the most common test that is performed for the Ocular Torticollis is the Bielschowsky test.
This test is also known as Park-Bielschowsky three-step test, Park’s three-step test, and Bielschowsky head tilt test. The purpose of the test is to determine the impairment of the extraocular muscle. The test determines the impairment in primary gaze, in the left and right gaze, and the left and right tilt. There are a total of eight cyclovertical extraocular muscles in both eyes that is 4 in each. Two of these are depressors, Inferior Rectus Muscle and Superior Oblique Muscle, and two elevators, Superior Rectus Muscle and Inferior Oblique Muscle. The test is based on three steps. The first involves determining which eye is higher than the other (hypertropia).
The second step determines whether hypertropia is worse in the left or right gaze. The third step determines whether hypertropia is worse in the left or right head tilt. The test particularly focuses on determining the impairment of Superior Oblique Muscle and the Cranial Nerve IV (also known as Trochlear Nerve).
Ocular Torticollis Treatment
The treatment and management depend upon the cause of the Ocular Wryneck. It is essential to get an early diagnosis to avoid any musculoskeletal condition or damage like the asymmetry of the head and face. When the cause of Ocular Torticollis is the Nystagmus, a condition in which an eye makes involuntary and uncontrolled movements. It is essential to first determine the eye with the Nystagmus. Then determine the null zone of that eye.
The purpose of the surgery is to move one or more eye muscle to adjust its position, that is, to move the null zone to its primary position. If there is any Strabismus, induced or residual, is also relocated in the other eye. When the cause is the Strabismus, that is the misalignment of eyes. The surgery is performed to correct the misalignment of the eyes by bringing it to its primary position, which causes restoration of binocular fusion, expansion of the binocular visual field, and improves abnormal head tilting.