Possible strabismus/diplopia (double vision) after LASEK

[Terry]

Hi

I am hoping someone is able to help me: perhaps an expert in either amblyopia (lazy eye) or diplopia.

I had LASEK treatment 2 months ago to treat myopia in both eyes and astigmatism in the right eye. Procedure went well, with my sight after 10 days beings 20/15 in left eye, 20/20 in right. However, just after this i started experiencing double vision, whereby if i close one of my eyes the second image goes away. It is not so noticeable with near vision/objects, but it is exacerbated when looking at far away objects: i can feel my right eye turn in slightly. You can imagine it's problematic if im driving or watching tv even.

I went back to the surgeon who seems to think, because my left eye was always dominant eye prior to surgery, now the right eye has correct vision, the brain is re-learning how to process the image it gets from the right eye. He believes my brain will eventually learn to supress the second image.

However, it's nearly 2 months on now, and i still have this problem: i cannot find any literature of this side-effect on any lasek/lasik forums. Im afraid it is not a temporary problem, but im wondering whilst the problem is in it's infancy if some eye exercise can improve it.

I need help from a double vision expert here.
Thanks
Terryb

[LasikExpert]

Accommodation and convergence issues can arise during the early healing stages after vision correction surgery like Lasik.

When we look at an object, the dominant eye looks directly at the object and the non-dominant eye looks at the object at an angle. The farther the distance of the object, such as infinity, the closer the two eyes are at the same angle to the object. The closer the object is brought to the patient, the greater the angle the non-dominant eye is to the object, while the dominant eye stays straight-on. Close enough and the eyes cross. Additionally, as an object is brought closer, the pupils constrict, changing the area of the cornea through which light passes into the eye and is "seen".

It is possible that you had a small amount of misalignment before Lasik that was corrected with prisms in your eyeglasses, however you would have noticed the full alignment effect with contact lenses.

Your brain may be switching dominance because, for whatever reason, it likes the image from the other eye better. A switch in dominance most certainly could present the problems you describe.

An accommodation and convergence specialist would likely be able to shed some light on your situation. This is most likely going to be an optometrist, although ophthalmologists who specialize in strabismus surgery would undoubtedly be able to evaluate you. I recommend that you ask your Lasik doctor to refer you to an accommodation and convergence specialist for evaluation. This may indicate if your issue is directly Lasik related, peripherally related, is likely to resolve on its own, requires a treatment plan, is permanent, or is temporary.

All issues about convergence are predicated upon both corneas being regular and fully corrected across the entire through which light travels when the pupils are fully and naturally dilated. If there is an irregularity, such as astigmatism at the periphery of the cornea, changes in pupil size could cause the same effects you report. If the effect is different in bright light compared to lower light environments, then this could be something as straight-forward as residual or induced astigmatism.

My bet would be on a treatment plan of continuing to use both eyes normally and allowing the brain to learn how to best use your new vision, but only a comprehensive evaluation by the right specialist would know for sure.

[Terry]

Dear Glen,

THanks a lot for taking your time out to reply. I really do hope it is some type of accommodative issue as you mention, that my brain is learning to adapt to. I'm just a little concerned as i have been undergoing this effect for 2 months now - the lasek surgeon has assured me the surgery has corrected my astigmatism.

I have scheduled another appointment with him, as everyday living is becoming really uncomfortable: Esp. in an environment of open space such as looking ahead in a mall, or talking to someone on the other side of the room: the further away the object im looking at, the further the distance between the "doubled" image. to clarify more: If i look at an object, and then close my left (dominant) eye, i can see my right (non-dominant) eye is pointing markedly to the left of the intended of the object.

Just FYI: i never was told i had, or experiences misalignment issues prior. My eyeglasses were just corrective for short-sightedness and astigmatism. I never had alignment issues when i wore my contact lenses: in old pictures with contacts, my eyes look ok. If i take a picture of myself now trying to look at a distant object you can see the right turn-in slightly.

I shall take your advice and try to get referred to a specialist and keep the forum posted if there is any news.

Thanks again.

[Terry]

**UPDATE**

I went to see an orthoptist at Moorfields here in Dubai, to ask them about my alignment. He carried out several tests on me as he wasn't able to come up with immediate prognosis. He seemed to think that i must have had misalignment since childhood and that it had gone unnoticed as my brain had somehow compensated for it. He alluded towards something called Anomalous Retinal Correspondence, and that the laser surgery my have disrupted this system that i had unknowingly adopted.

In the end, they told me if within the next month there is no improvement, i will have to wear prism glasses, or have eye muscle surgery.

I also went for my regular follow-up with my lasek surgeon: he was a bit more open-minded, as it is not conclusive that my eyes are misaligned. He wanted to eliminate that i didn't have something called Accommodative Estotropia (similar to what you mentioned in your reply): because my eye is slightly over-corrected, that my brain tells the eye to turn-in slightly when looking at distant objects. He has told me to wear +1.00 reading glasses for a few days to see if this encourages the brain to stop sending signals to the eye so that it can relax.

I will let you know how i get on.
So far, i still have the double vision, but the turning-in seems to be less.

[LasikExpert]

It sounds like you are on the right track. Your surgeon is correct that being 1.00 diopter hyperopic after being myopic can cause convergence issues.

[Terry]

**ONE MONTH UPDATE**

After a few days of wearing reading glasses (+1.5) the doubling had significantly improved. certainly driving is not the problem it was before with seeing 2 sets of lane markings etc. I still have slight doubling with faraway objects, or if i have to focus on a small detail. Eg if i look at a registration plate of a car a few feet in front of me i would see the last digit, a space, and then the double image of the last digit, whereas before i would see 2 separate images of of the whole plate.

Since then i have been trying to wear the glasses less to see if i can manage without, and i can go most of the day without them. Having seen my surgeon for a follow-up this week he suggests still a couple of months or so for the brain to improve fusion.