I’m off to Manila in the Phillipines as guest speaker for the tenth anniversary of the Asian Eye Hospital.  It’s always nice to be asked to these events.

The topic is Advanced Technology Intraocular Lenses.

Whenever I take out a cataract I have to put in an intraocular lens because a cataract is a cloudiness in the patient’s natural lens.  If you don’t replace it, everything is out of focus.

Fifteen years ago there was one type and style of lens and now there are a multitude of choices; multifocals, accommodative, toric, combinations of toric and multifocal, aspheric and others, and the list goes on.  How does an ophthalmologist decide and is this just too bewildering for a patient? It comes down to three things;

1.  Surgeons need to be familiar with what lenses are available and be confident about how to measure the eye to get the best results for the lenses and how to safely and efficiently place the lens inside the eye.  You would think ophthalmologists would do all this naturally, but it is not easy.  What is easy is to continue doing what you did last year.  It’s difficult to embrace change and eye surgeons are no different to anybody else.
2.  You have to assess the patient’s anatomy.  The anatomy will dictate the choice of lens because some eyes are unsuitable for example for a multifocal lens.  A patient who has loose attachments around their natural lens, some with retinal disease that would preclude good quality vision – these people probably should not have a multifocal lens as they would not be able to be placed with certainty in the correct position, nor would they get the visual results that go with the multifocal lens.  The surgeon has to work out which lens is suitable for that particular patient’s anatomy.
3.  The surgeon and patient need a conversation.  If the patient’s anatomy would allow any available lens to be placed, it comes down to what matters most to the patient.  If what matters is true independence from glasses for all activities then this will require an aspheric multifocal lens in both eyes.  The good reading that comes with this lens means that the patients will have some halos when driving at night, but these diminish with time, and this lens requires adaptation on the patient’s part, so patience is required.  If a person is driving a taxi cab on the night shift, it is not the sort of lens that would be ideal as they would be faced with halos constantly in their work environment.

For a person more interested in excellent quality distance vision with no fuss, no halos, quick adaptation and who doesn’t mind reading glasses, you would use an aspheric lens with or without astigmatism correction.

Sometimes there are subtleties between these two options, such as a form of blended vision aiming for slightly better intermediate vision with less than perfect distance, or using an accommodative lens for good distance vision and reasonable intermediate, but accepting the need for reading glasses. The conversation is essential to work out what best to do.

The accompanying slides show the range of lenses that I put in at present; from phakic intraocular lenses in people with high myopia, multifocal intraocular lenses which make up just over 50%, aspheric lenses, toric lenses and accommodative lenses.  These are choices for both patients and surgeons and it is a time consuming but beneficial process to get it right.

 Dr Michael Lawless