Magical Diamond Ring: Retinal Detachment II

If you don't know what the Magical Diamond Ring is, please refer to the previous post about a shadow appears in my peripheral vision after RD surgery. The shadow consists of a big ring encircling the whole peripheral vision plus a dot at 6 o'clock that looks like a diamond ring.

Unknown root cause but some guesses

People have some guesses about the root cause of this shadow and my estimation of probability in parenthesis:

(1) My doctor believes it is vision field blockage due to the buckle indentation, most people cannot see this but me because I had cataract surgery long time ago without IOL (intraocular lens) implantation. So this refractive phenomenon happens. (60%)

(2) The retina needs sometime to accommodate the pressure from the buckle and to recover its function. (35%)

(3) The pressure of the buckle malfunctions the retina. (~5%)

(4) Stroke of optical nerve. (0.01%)

The probability of (3) and (4) are slim as the dark spot can adapt to ambient lighting, i.e., the spot becomes brighter when I move to brighter environment and it becomes darker in dimmer places. This means the retina in the dark spot area should still have function. I can't eliminate (2) but I can find a sound explanation after detailing the phenomenon with an optical diagram, keep on reading for the description.

Here comes the explanation.

Scleral buckle is a silicone band encircling the eyeball to make an indentation to help squeezing the subretinal fluid out and help your retina flatten and reattached to the choroid.

My doctor used a higher buckle in my case which is more preferable when the tears are many and big. I appreciate his doing but this produces a deeper indentation as well.

Shape and size of some buckles can be found here: buckle catalog and more buckle catalog

What is the problem of higher buckle or deeper indentation?

Let me draw an optical diagram to explain this. Remember I had my IOL removed without implantation so the refractive error could only be corrected using exterior lens, i.e. spectacle or contact lens.

If you look into the diagram carefully, it is pretty self-explanatory. The bold blue line represents the deeper indentation caused by the higher buckle. When normal glasses is used, part of the object is blocked by the buckle indentation (blue color) which creates a blind spot on the retina. If I change to use contact lens (red color), I could see the same object smaller as well as seeing a wider vision field (grey color). This agrees with my experience when I wore contact lens before the buckling surgery. If we look into the effect of closer lens (contact lens in this diagram) against buckle indentation, we could see the closer lens may reduce the blind spot area, about half in this diagram.

This explains the possible visual field improvement using contact lens (better) or IOL implantation (best), and it is the counter proof of why the patient with IOL removed would be more susceptible to see the blockage of higher buckle.

I hope this expensive diamond ring disappears soon with contact lens or IOL implantation.

While for the scar development progress, I may have more update after revisiting my doctor next week, stay tuned!