Historically the term 'congenital strabismus' was used to describe constant<unk> s with onset between birth and six months of age. However, this term was felt to be an inadequate classification as it covered a variety of<unk> s with different causes, features and prognoses. In 1988, American ophthalmologist Gunter K. Von Noorden discussed what he described as 'Essential<unk> '. He described the condition as: "early acquired, not... congenital ..., although congenital factors may favor its development between the ages of 3 and 6 months" and identified this squint sub-type as having the following features: # Onset between birth and six months of age. # Large size (greater than 30 dioptres) # Stable size # Not associated with abnormalities of the central nervous system. # Often associated with defective abduction (outward movement) and excessive adduction (inward movement) of the eyes. # Also associated with oblique muscle dysfunction and Dissociated Vertical Deviation. # Initial alternation of the squint present with crossed fixation, i.e. the affected individual uses the left eye to look right and the right eye to look left. # Limited potential for binocular vision. The same condition had also previously been described by other ophthalmologists, notably Cianca (1962) who named it Cianca's Syndrome and noted the presence of manifest latent nystagmus, and Lang (1968) who called it Congenital<unk>  Syndrome and noted the presence of abnormal head postures. In both cases, however, the essential characteristics were the same, but with emphasis placed on different elements of the condition. Helveston (1993) further clarified and expanded upon von Noorden's work, and incorporated the work of both Lang and Cianca into his summary of the characteristics of the condition: #<unk>  between 10 and 90 dioptres in size # Either alternation or fixation preference may be present (if the latter then amblyopia may result). # Neurologically normal. # Hyperopic correction does not eliminate or significantly reduce the squint size. # Frequent nystagmus (latent or manifest latent). # The patient may or may not have any or all of the following associated conditions: Oblique muscle dysfunction, vertical incomitance, dissociated vertical deviation, asymmetric optokinetic nystagmus, torticollis. # Presence will be 'confirmed' by six months. # Best treatment results in subnormal binocular vision. The expressions congenital<unk> ,<unk> , idiopathic<unk>  and essential<unk>  are often used interchangeably. Cross-fixation Cross-fixation congenital<unk> , also called Cianci's syndrome is a particular type of large-angle<unk>  associated with tight medius rectus muscles. With the tight muscles, which hinder adduction, there is a constant inward eye turn. The patient cross-fixates, that is, to fixate objects on the left, the patient looks across the nose with the right eye, and vice versa. The patient tends to adopt a head turn, turning the head to the right to better see objects in the left visual field and turning the head to the left to see those in the right visual field. Binasal occlusion can be used to discourage cross-fixation. However, the management of cross-fixation congenital<unk>  usually involves surgery.
Infantile esotropia
Dissociated vertical deviation
Ectopia cordis
Cerebral achromatopsia
Ametropic amblyopia
Nonsyndromic deafness
Lipoatrophia semicircularis
Cystic eyeball