Hyperopia

Hyperopia (or hypermetropia) is called longsightedness in lay terms but this terminology is confusing. This is a condition where there is not enough focussing power in the eye to see in the distance without using the accommodative mechanism that is usually used just for seeing up close.

Presbyopia

Presbyopia is the name for losing the ability to see up close as you get older. This occurs as the lens inside the eye that does the changing in focussing (accommodation) stiffens with age and cannot change its shape so easily. For people who are not myopic or hyperopic this usually happens in late 40’s or early 50’s.

Presbyopia happens at an earlier age for hyperopic people as they are already using up some of their focussing power just to see in the distance. They will typically go through years of having to use glasses more and more for near work and then they will need them for seeing further away and then eventually many will need them for distance vision as well and end up wearing multifocal glasses all of the time. They can generally see better further away, though, than they can up close.

Presbyopia Treatment 

The only ways around presbyopia are compromises of one sort or another. There is no one treatment yet that will restore full focussing ability at all distances for both eyes.

Most people compromise just by wearing glasses for near work or multifocal glasses if they need them for distance as well. Multifocals are a compromise in that they are not as good optically as single vision glasses for any given distance but only one pair is required instead of multiple.

Some people can manage with multifocal contact lenses. Some wear a stronger contact lens in one eye to make it myopic (short-sighted) so that one eye is used for distance vision and the other for near vision. This is called a monovision correction. Not everybody is comfortable with this but many people manage very well.

Hyperopia Treatment 

Refractive surgery for hyperopia requires adding focussing power into the eye. This can be done in limited ways:

Hyperopic laser refractive surgery (LASIK or PRK) can be done if the cornea and ocular surface is healthy and there is no sign of cataract developing. The range of hyperopia that can be corrected is much lower than for myopia and there are many factors to be taken into account with this. Young people with moderate to high levels of hyperopia are not good candidates for laser refractive surgery. Typically, those people seeking refractive surgery for hyperopia are going to be older than myopes. Generally, we see people in their 50’s. At this age there are often early changes in the lens inside the eye that are leading towards cataract formation. There is often no cataract present as such but these changes can alter the focus. That means that if we do laser refractive surgery the benefit may only be short term as the changes in the lens progress. It does not take much of a change for people to then be aware that their vision is not so good without glasses and then something else will need to be done, typically then clear lens extraction or cataract surgery. In addition, the younger that hyperopic laser surgery is done, the more likely that the effect will slip back over time as the accommodative range of the eye is reduced with age.

Hyperopic laser surgery is not a good option for those with dry eye problems as it can make that issue significantly worse. That can affect vision as well as being uncomfortable.

Phakic intraocular lens (IOL) implantation can be done to place an artificial lens inside the eye to add the extra focussing power. Unfortunately, most hyperopes have small eyes and there is not enough room in the front of the eye to fit these in safely.

Clear lens extraction involves removing the lens inside the eye in the same manner as for cataract surgery but when there is no cataract present. An artificial lens is then placed inside the eye and any power of lens can be used to add in the extra power required. There are many different sorts of intraocular lenses available and they have various advantages and disadvantages.They are not perfect and will not make vision perfect in all circumstances.

Intraocular lenses (IOL’s) may be monofocal or multifocal. Monofocal lenses may be used to focus the eye for distance, or for near if a monovision correction is planned. Multifocal, bifocal or trifocal lenses have a distance and near focus but have different limitations to bifocal or multifocal glasses. Multifocal IOL’s split up the light coming into the eye so that there is a distance and a near focus. This means that not all of the light is used for each and vision may not be as good in some circumstances. This probably does not bother most younger people who have excellent retinal function but as people age and get some macular degeneration they will need all of the light they can get for reading. In that case the only thing that could be done to improve vision will be to change the IOL for a monofocal one and that operation entails more risk than the original procedure. In addition, these lenses have rings or zones of differing focussing power and some people are aware of rings or areas of ghosting around lights at night on a permanent basis. Some people are not happy with the quality of vision with multifocal intraocular lenses in any situation and they have to have them removed and replaced with monofocal lenses. There is also a greater chance of needing a YAG laser posterior capsulotomy for posterior capsule opacification some time after the surgery as a smaller amount of this has a more significant effect with multifocal IOL’s.

Having a clear lens extraction means that you are taking on all of the potential risks of cataract surgery when you do not have a cataract just so that you are not wearing glasses or contact lenses. You need to be aware of the difference in the balance of risks and benefits in this situation. For those people who already do have cataract then their vision is deteriorating even with their glasses and there is no other way to improve it. In that case it is easier to make a decision to have the surgery.

There are several ways of dealing with this issue and what suits one person does not necessarily suit another. All those people who have thrown away their glasses are accepting a compromise of one sort or another as far as their vision is concerned, whether they are aware of it or not. Having said that, having the surgery makes a huge difference to quality of life for many people.