It is not only children that get squint, but adults can also develop a squint (strabismus). In adults, a squint can occur because of a nerve palsy or because they have got thyroid eye disease or merely because they used to have a squint in childhood, which was then corrected, and as they have got older one eye is lazy and has drifted outwards. That is called consecutive exotropia.
At Clinica London, I see a lot of adult patients who have an outward turning eye, which is called wall-eyed or exotropia. Unfortunately, by the time they are an adult, their lazy eye cannot be improved. In other words, I cannot give them better vision. However, I can help them have straighter looking eyes so that people they are talking to and interacting with will know which eye to look at and which eye is looking at them. It can be very disconcerting to someone when they have to talk with another person and yet that other person does not know, which eye to look at, and they think it is rude because one eye is looking outwards and they wonder why they are not concentrating on talking to them. Therefore, surgically correcting a wall-eyed adult with exotropia can help them in their life and work.
Adult patients with squint who come to see me at Clinica London have to see the orthoptist as well to do measurements. I like to have full measurements of the squint so that I have an idea of whether it is just one eye, or whether the eyes alternate.
Most importantly, I want to make sure that there is no risk that I could give them a double vision by realigning the two eyes into the straight position. Therefore the orthoptist does assessments of their binocular vision to see how much they can use the two eyes together, or whether they are at risk of getting double vision if I fully correct their squint. This is called the postoperative diplopia testing.
Adult squint surgery is done under general anaesthetic at the Harley Street Clinic or the Weymouth Clinic as a day case. I often use adjustable sutures, which means that I put one of the little muscle stitches on to a particular loop so that if I have to adjust their position minutely the day after surgery, I can still do that under local anaesthetic, but very often this is not required. I usually have to operate on one eye namely the eye that is turning outwards, by moving the inner muscle forwards called a medial rectus resection or advancement, and moving the outer muscle backwards, which is known as a lateral rectus recession. However, if they had previous surgery as a child for their squint when they possibly had an in-turning eye at that age, then I have to first find the muscles surgically and then work out how many millimetres to move them and in which direction. Squint surgery can be defined as the minute movement of the eye muscles by between 4 to 6 mm each in order to correct the alignment of the eyes.