Management of Esotropia

Management of Esotropia

HISTORY

 Ocular history

 Diplopia indicates a recent onset deviation, usually paretic. children relatively rarely complain of diplopia,

General history

 Information on pregnancy, perinatal history, and general development are obviously important

EXAMINATION

 Ophthalmic examination

Measurement of visual acuity is the first step. , but this remains the Achilles heel of paediatric ophthalmology. Even at the age of 3 and 1/2 years accurate measurement is often not possible using standard tests.17 Preferential looking based techniques are opening important new horizons in clinical vision assessment. Look for any facial, orbital, eyelid, or ocular asymmetry.

Assessment of the squint and ocular motility, including the cover test, is mandatory. Ocular movements must be tested in all positions of gaze. Hess chart  of overaction of the synergistic muscle of the other eye can be invaluable in suspected cases of paralytic squint.

No ophthalmic examination is complete without assessment of the pupillary reactions, visual fields (when indicated) and fundoscopy.

As many esotropias are associated with an abnormal refractive status, cycloplegic refraction is an essential part of the assessment(upto 6 years).Above 8 years usually cycloplegic refraction is not required.

Systemic examination

Most squints occur as an isolated anomaly; however, the possibility of coexistent or causal systemic pathology must not be forgotten, and a detailed paediatric assessment undertaken if indicated.

ADDITIONAL INVESTIGATIONS

 Having already indicated the range of conditions that can be associated with strabismus, the need for additional tests such as a Hess chart, tensilon test, muscle biopsy, or computed tomogram is dictated by the prevailing clinical conditions

Treatment:-

The aim of treatment is to restore binocular single vision and another indication is cosmetic. This single aim encompasses :a)  rectifying and refractive error,b)  the treatment of amblyopia, and c) finally correction of the ocular deviation.

Treatment of Amblyopia:-

The principle of all modalities of amblyopia treatment is to promote the use of the amblyopic eye by compromising the vision of the better eye. This is usually achieved by occlusion, but other commonly used methods include penalisation and the CAM stimulator. Treatment should commence at as early an age as possible, but a prerequisite to all amblyopia treatment is a clear retinal image, and consequently accurate optical correction is essential using either spectacles or contact lenses.

TREATMENT OF SQUINT:-

1)      Nonsurgical treatment:-

Refractive errors and squint are commonly associated, and for this reason every strabismic child should have a meticulous mydriatic refraction. Spectacles are prescribed for two distinct reasons: first to correct a visually important refractive error and to provide a clear retinal image-essential before embarking on amblyopia treatment. Second, to ensure reasonable balance between accommodation and convergence. In this latter situation spectacles are prescribed to rectify the ocular misalignment and not to correct a visual deficit. Certain deviations, such as fully accommodative esotropia, can be adequately controlled by spectacles, while for others the result is less satisfactory and surgery may then be indicated. The effect of refractive correction depends on the age of the patient and squint type, but even so is often difficult to predict and it is common practice to correct any 'significant' refractive error as an initial step before embarking on surgery. Prisms are rarely used in paediatric practice except perhaps temporarily to control diplopia in a paralytic squint.

2)      Surgical treatment:-

A)     Comitant Squint:-Surgery for infantile esotropia is generally undertaken between 6 months and 2 years of age as correction after this time achieves less in terms of binocular function. Surgery usually involves bilateral/ unilateral  medial rectus recessions. A muscle recession moves the muscle insertion closer to the muscle’s origin(it is a weakening procedure).

Resection(Strengthening procedure). of one or both lateral recti or

surgery to the other eye may also be required depending upon initial procedure.

B)      Paralytic squint-Whether the palsy is congenital or acquired, treatment is essentially surgical (having first corrected any amblyopia) aiming to correct either a compensatory head posture or diplopia. For an acquired palsy at least six months of recorded stability is mandatory before surgery is contemplated.