What is squint (strabismus)?

Strabismus is the medical word used for squint. It defines a condition in which one eye of the patient does not move in coordination with the other, but moves in a different direction than the other.

One eye may turn inward, outward, upward or downward as the other may look forward toward.

Symptoms

One eye that does not look straight ahead but faces inward, outward, upward or downward is the most visible indication of a squint. Minor squints are even less noticeable.

Squints may cause blurred vision or double vision, but the issue may not be understood by babies and young children.

Causes of squint

Congenital squints:

It is not always clear what causes a squint. Often squints run in families, and a baby with the condition can be born. This is known as congenital squinting.

Often squints are also the result of childhood diseases, or other sight-related problems, such as refractive errors.

Refractive errors:

Squints are commonly caused by the inability of the eye to focus on the light that passes through the lens. That is considered a refractive defect. These include:

  • – An issue impacting the ability to see things from afar
  • – A sight problem which affects the ability to see objects close-up
  • – Where the cornea is unevenly curved at the front of the eye causing blurred vision

Other causes:

They are:

Treatments for squints

Treatment outcome for squints depends on how fast the assessment has been done and treatment initiated.

Alternatives include:

For a lazy eye, an eye-patch over the impaired eye is advised. In the majority of the patients only regular monitoring of the condition is required.

The benefits of surgery for squint are:

·         Improved appearance (often)

·         Increased peripheral (side) vision (often)

·         Improved depth perception (sometimes)

·         Occasionally, it is done to improve the abnormal position of the head

Squint surgery usually involves squeezing or rotating one or more of the muscles of the outside eye that shift the other to adjust its position. Beneath the conjunctiva, the transparent surface layer, these muscles are attached very close to the front. In surgery the eye is never taken out of the socket. Stitches are used to fasten the muscles in the new positions.

Squint surgery is almost always a day-case operation. 

There are two types of surgeries:

·         Adjustable

·         Non-adjustable

Adjustable is done in older children and adults, in the wake state these stitches can be maneuvered immediately post surgery.

There are chances of regression of this condition in later years.

Preoperative tests for strabismus surgery

A sensorimotor examination is conducted to determine the alignment of the eyes and to assess the muscles which are playing a role in causing strabismus. The identification of muscles is done which needs to be altered. The degree of strabismus is assessed by the use of prisms. Surgical planning is done on the basis of this examination. 

In most of the cases, both the eyes are operated even though only one eye is found to be not aligned properly. Reoperations are planned based on the initial surgery.

Preparing for squint surgery

Before surgery:

What happens during squint surgery:

This surgery is performed under general anesthesia and surgical time is less than 1 hour. 

The eye is held by lid speculum and then the surgeon cuts the muscle connected to it and these muscles are placed at a new location and sutured with dissolvable stitches and these stitches are not visible as they are hidden behind.

In few of the cases, additional adjustments are done after the patient wakes up from anesthesia after the initial surgery.

After squint surgery

After the surgery, a pad is put on the treated eye to protect it. Generally, it is removed the following day or while the patient is being discharged home. Analgesics are prescribed for pain and eyedrops for healing.

Risk factors for squint

1. Risks of the surgery

Serious adverse reactions are very rare, but some of the following adverse effects can be experienced, which include:

2. Returning to normal activities

Normally, the patient returns to normal activities in many weeks. Reading and watching television can be done as per the patient’s assessment. Driving is not allowed for at least 2 to 3 days or till the time the patient has double vision. Swimming is disallowed for at least 7 days. They need to be protected from dust, shampoo, face paints, etc. 

Ongoing spectacles need to be worn, but use of contact lenses should be done after getting the approval from the surgeon.

Follow-up care

The patient needs to make regular follow-up visits as advised by the surgeon. In case of any adverse event the patient should make a visit to the surgeon.