Why choosing a premium lens starts long before surgery

The decision to implant a multifocal (so-called premium) lens during cataract surgery or lens exchange is one of the most important decisions about your vision for the decades to come. The lens will stay in your eye for the rest of your life. That is why it should never be chosen “by eye” or according to a single, one-size-fits-all scheme.

At OKUMED we treat qualification for a premium lens as a separate, fully fledged stage of treatment — just as important as the operation itself. Below we explain why.

Not every eye is suitable for a multifocal lens

Trifocal and EDOF lenses are an outstanding achievement of modern ophthalmology — they allow you to see well at distance, at computer range and up close, often freeing you from glasses. But they are precise optical instruments that only work when matched to the individual structure of your eye.

The cornea — the front “lens” of the eye — is of key importance. Every cornea is different and has its own set of subtle optical imperfections known as higher-order aberrations. The most important are:

• spherical aberration — affects how sharply we see in dim light and whether light effects appear around lamps,
• coma — an asymmetric distortion that can “smear” the image in a way a multifocal lens cannot compensate for,
• angle kappa — the offset between the centre of the pupil and the optical axis.

If these parameters exceed certain values, a trifocal lens will not give a good result even with a perfectly performed operation. The patient may be disappointed with the quality of vision despite flawless surgery — because the problem lies in the mismatch between the lens and the anatomy of the eye, not in the operation itself.

This cannot be assessed without the right equipment

And here we come to the heart of the matter. Measuring corneal aberrations, corneal topography (a precise map of its shape) and accurate biometry requires specialised diagnostic equipment:

• a corneal topographer/tomographer — creating a three-dimensional map of the front and back surfaces of the cornea,
• an aberrometer — measuring the optical imperfections of the visual system,
• a modern optical biometer — precisely measuring the dimensions of the eye and allowing the right lens power to be chosen.

This is expensive equipment which — unfortunately — many centres do not have. And yet premium lenses are implanted there anyway, without a full assessment of whether the eye qualifies for them at all. The patient pays for advanced technology but does not receive the diagnostics that are a precondition for its effectiveness.

It is a bit like tailoring a suit without taking measurements first. The fabric may be the best in the world — but if it does not fit, the result will disappoint.

What thorough qualification at OKUMED looks like

Before we propose a specific lens, we perform a complete set of examinations that answer the question: which lens will give this particular eye the best possible result?

Among other things we analyse:

• corneal aberrations and topography,
• angle kappa and pupil size,
• the dimensions of the eye and the predicted position of the lens,
• the condition of the macula and retina (OCT scan) — because even the best lens will not help if the problem lies in the retina.

Only on this basis do we choose the lens — sometimes a trifocal, sometimes an EDOF, and sometimes we recommend a monofocal lens with reading glasses, if that will be the safest and most satisfying choice for you. Honest qualification also means being able to say when a premium lens is not the best solution.

What to ask before surgery — at any clinic

Wherever you decide to have your operation, you have the right to ask a few questions:

• Before qualifying me for a premium lens, will you perform topography and aberration measurements of my cornea?
• Do you perform a macular OCT scan before surgery?
• On what basis will the specific lens for my eye be chosen?

If the answer is full, specific diagnostics — that is a good sign. If a premium lens is proposed without these tests, it is worth asking for an explanation.

Summary

The success of surgery with a premium lens depends less on the day of the operation itself and more on what happens before it: on thorough diagnostics and a conscious, individual choice of lens. This is a stage that cannot be skipped or replaced by a universal scheme.

At OKUMED we believe your eyesight deserves a decision based on complete data — not on the assumption that “any premium lens will be good for any eye”.

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Do you have questions about lens selection, or would you like to book a qualification visit? Please get in touch with OKUMED.

This article is educational in nature and does not replace an individual medical consultation.