Why do I see a shadow to the side of my vision after cataract surgery?
In our practice, we inform 100% of our patients that undergo cataract surgery that they will experience 4 common symptoms on the first day after their surgery:
- slightly blurred vision,
- a scratchy sensation like an eyelash is rubbing their eye,
- a flicker or quiver to their vision,
- a dark shadow out to the side.
This last symptom is also known as “Negative Dysphotopsia.”
Patients with negative dysphotopsia classically share the following history:
“I see a dark shadow or arc out to the side. It is curved like a semi-circle or crescent shape. And when I place my hand like this (out to the side), the shadow goes away.”
The typical evolution of the negative dysphotopsia is that it goes away within 1-2 months as the eye heals and the brain adapts to seeing through the new lens implant.
Rarely, however, some patients will have a persistent crescent or shadow that does not fully resolve and may persist indefinitely. Most of these patients however state that the shadow is so subtle that it does not bother them or affect their quality of life.
For less than one-half of one percent of patients – probably closer to one in 5000 patients – are severely bothered by the negative dysphotopsia that persists and does not go away.
What causes negative dysphotopsia?
First of all, ND typically occurs when the surgical procedure has been performed normally and the surgical result is normal without any complications whatsoever.
Some patients may ask, did something go wrong? The answer is “your surgery was routine and you are experiencing a normal unavoidable side effect that should go away with time…usually within one or two months.”
There are two factors associated with ND:
- the design of the edge of the intraocular lens
- the space between the lens and the iris
The best treatment is prevention. We have found that the lens that creates this side effect the least often in my experience is the Bausch and Lomb LI61AO lens. This is our standard basic monofocal lens used in basic cataract surgery in our practice. It is a 3 piece lens that due to its design simply does not cause much negative dysphotopsia.
To date, I have placed over 5000 Bausch and Lomb LI61AO lenses and have had 1 or 2 patients state that they have persistent negative dysphotopsia. Neither of these patients required additional treatment of their ND because their symptoms were relatively mild and tolerable.
Now, the most commonly used lens type used by most ophthalmologists is the “single-piece acrylic (SPA) lens.”
This lens design is used in the vast majority of basic, astigmatism-correcting or toric lenses, and premium presbyopia-correcting lenses.
So, all of our patients who receive a premium presbyopia-correcting lens or an astigmatism-correcting lens in our practice will receive a single-piece acrylic lens.
This lens design in my experience is associated with a higher rate of negative dysphotopsia than the LI61AO.
Let’s talk about the worst-case scenario: the patient has negative dysphotopsia, is very bothered by it, and the symptom – crescent/arc/shadow – is present all the time and is not getting better after waiting 3 months or more.
Then there are in my opinion 3 options:
- If the patient has a SPA, then remove the SPA and replace it with an LI61AO lens. In my experience, that treatment works almost every time.
- If the patient has a lens inside the bag, then we can place a lens between the bag and the iris into the ciliary sulcus – moving it closer to the front of the eye and decreasing the space between the lens and the iris.
- What if the patient however has a premium single-piece acrylic IOL that is correcting both presbyopia and astigmatism and is only designed to be placed in the capsular bag?
- Piggyback IOL in the sulcus
- Reverse optic capture.
So, let me present this case to you of a patient who had persistent very bothersome negative dysphotopsia.
This is a 49-year-old gentleman who had lens replacement surgery on 11/11/19 with a Panoptix toric lens.
His UCVA and MR on 11/2/19 were:
MR: -0.25+2.00×105 20/20
The original surgery was routine and uncomplicated. 4 months postoperatively he reported the classic symptoms of ND including that he could “constantly see the edge of the lens.” He was very bothered. So, we performed reverse optic capture on 4/29/2020.
His UCVA and refraction on the day of his IOL reposition:
UCVA 20/30 J2
The patient on POD1 was amazed by his vision. The ND and edge of the lens effect were completely gone and his vision was improved as well.
UCVA 20/20 J1+
MR: -0.25+0.75×115 20/20
This case illustrates the technique to perform reverse optic capture for the treatment of negative dysphotopsia in a patient with a Panoptix toric lens.
Thank you for your time and attention and have a wonderful day.