Squint or Crosses Eyes: What does it mean? by DR ALOKA HEDAU
- December 19, 2018
- Win Vision
Squint / Crossed Eyes
Squint means misalignment of both eyes which visualising an object.
One eye focusses on the object and the other focusses elsewhere. When both eyes do not work in sync it is called Squint or Crossed eyes or “Mela Kannu” in Telugu.
Types of squint
Outer deviation of the eyes. If the eye is deviated away from the nose it is called exotropia
Inner deviation of the eyes. If the eye is deviated towards the nose it is called esotropia
If the eye is deviated upwards it is called hypertropia
If the eye is deviated downwards it is called hypotropia
DVD/ Dissociated Vertical Deviation:
If the eye drift upwards and outwards dissociated from the other eye it is called DVD.
Latent or hidden deviation of the eyes inside is called Esophoria
Latent or hidden deviation of the eyes outwards is called Exophoria
Etiology or causes for squints:
It is a multifactorial disease, which means that there are multiple causes of squinting. Birth traumas, or infections during birth, birth asphyxias can cause squinting.
Twin or Triplet pregnancy also poses risk on the child to get squint.
Refractive Error or glass powers can give squint.
It can also be familial where previous generations may have had squint. It can also be genetic, where in even if no one in the family has had squint a new mutation can occur and cause squinting.
Some squints are called acquired squints. This can occur due to paralysis of a muscle or acquired tightness of a muscle like in condition of Thyroid diseases.
Side Effects or Dangers of Squinting
Squint causes loss of Binocularity. Binocularity is the ability to use both eyes together to see an object, which then further forms image in the brain which helps to see in 3D format and Depth Perception. This helps us understand height, depth, texture of things. When only one eye sees, 2D images are made and so finness of vision is lost. The Binocularity and Depth Perception can be regained if restored within the critical period of vision development which is scientifically till 6-8 years of age. After this even if the squint is surgically corrected, the binocularity cannot be regained.
Also, the eye that squints has the danger of going into Lazy eye. A Lazy eye means poor vision inspite of best glasses or normal eyes. That means the eye is fine but the brain and eye do not coordinate any more and so have got used to seeing blurry images. This requires therapy to improve lazy eye and many children may permanently also suffer from poor vision in the squinting eye all throughout life.
Another side effect is often understated and not talked about by the people suffering from it. Children or Adults with Squint suffer from a lower self esteem, bullying or poor professional or personal relationships due to the obvious squint. Unable to make eye contact and develop rapport has often been cited by the patients suffering from squint.
Squint can also be a sign of any other dangerous eye issues. High glass number in the eye, corneal opacity, cataract, retinal detachment or macular dystrophies have been found in the eye with squint. So squint may be only an external feature but internal eye may be suffering from a grave eye problem.
Also Another problem with squint is if left unattended the angle of squinting may go on increasing. This would in turn cause tightening of the other muscles of the eyeball and will finally make the surgery later slightly complicated. So early rectified the better.
There are many treatment options.
Non Surgical Options:
1. Eye Exercises:
Some simple exercises like cat card fusion or dot card exercises may help treat certain kind of squints.
Glasses play a very important role in treating squints. Many squints are of the variety that they can be completely treated with glasses. Special glasses called Executive Bifocal glasses can also be tried.
In acquired squints or small angle squints, prisms can be given an a treatment or exercise option for the squints. These can be incorporated into your glasses or is available as a temporary stick on prism also.
4. Patching exercises:
Many squints respond very well to patching. Occlusion therapy is the gold standard in the treatment of lazy eye and squint. It can help reduce the angle of the squint and also prevents suppression from developing. There are many protocols for patching which will be shared by your clinician in details.
Small angle squints and squints of acquired variety respond to Botox injection, injected into the muscle belly. This works as a relaxant and can prevent development of amblyopia and suppression in the patients eye.
Squint Surgeries are surgeries which require recession and resection of muscles. Recession means weakening and Resection means strengthening of the muscle.
This is done on the basis of type of squint, angle of squint and visual acuity.
All surgeries are cosmetically appealing and do not leave any permanent scars or signs of surgery visible. This are done with absorbable, fine suture material.
The surgery can be done under general anaesthesia or local anaesthesia.
General Anesthesia is given with the safest child friendly gases and is risk free.
Good pain coverage is given to all patients after the surgery.
The recovery from squint surgery is quick.
Adjustment of the muscle behind the site of origin is called Recession
Shortening the length of the muscle and attaching it at the origin is called Resection
Double folding the muscle and attaching it at the origin is called Plication
Adjustable Squint Surgery:
For Certain types of squints, the outcome of the surgery would depend on the type of muscle tightness. These type of squints are dealt with a technique called Adjustable Suture technique. The postoperative measurement can be taken and the muscle can be readjusted based on the outcome
For very large angle squints or squints in high myopia, the muscle is attached at the origin with a hangback material which keep the muscle hanging behind at a precalculated distance from the origin. This is done when it is inaccessible or unsafe to suture behind on the sclera.
These are done in special kind of paralytic squints where the muscle looses strength completely and so cannot be used in squint correction. In such squints, the remaining healthy muscles are taken into picture and transposed to give good squint correction
In large squints, that have already been operated earlier, the other muscles needs to be tranplanted from the patients own eyes to give maximum benefit.