Squint also clinically known as Strabismus is a condition where both eyeballs are not straight aligned to each other, looks like cross eye because they are not parallel. One eye focus to a particular object where other eye bends inwards, upwards, downwards or outwards.
Physiologically we have 6 extra ocular eye muscles which help in eye movements, so when squint present these muscles are not working together or sometimes any muscles paralysis or may brain disorder happens with it.
We can define it generally by two types:-
Phoria:- is a hidden type squint, a condition in which the eye has a tendency to bend one side while looking distance or near but not all the time. Types are esophoria deviate inward, exophoria deviate outward these both are common, hyperphoria deviate upward, hypophoria deviate downward very rare, cyclophoria deviation is cyclic order.
Tropia:- is a squint which is constant deviation of eyes, you can see the deviation is present all time. Types are- esotropia(convergent), exotropia(divergent) these are very common.
Causes:-
- Uncorrected refractive errors likes hypermetropia very frequent, myopia or astigmatism.
- Hereditary or may come by family.
- Due to tumour in brain or nerve.
- Sometimes by birth without any cause.
Assessments:-
- Correction of eye power or sometimes perform with cycloplegic means after putting atropine, homide eye drops.
- Cover test- We can cover one by one eye then examiner can see the affected eye will bend under the cover, if remove the cover eye will suddenly fix the object while another eye remains fixed that object.
- Ocular movements check- Eyeball is moving in all the direction without any restriction.
- Corneal reflex test- Grossly estimation of angle of squint, the patient is instructed to fix a point light which is present 40cm in front, we have to observe the corneal reflex from centre of pupil in squinting eye.
Treatment:-
- Full refractive error correction it will improve vision and may correct squint partially or sometimes totally, another option is Prism may add in glass prescription.
- In early age not for adult, patching or occlude one eye after correcting refractive error the better eye will close and the squinting eye should use more and more.
- Muscles exercise is very effective by Synaoptophore machine to stimulate retina and muscles.
- Surgical treatment to correct extraocular muscles.