Under normal circumstances the lens is transparent. Cataract is a clouding of the eye lens. When the eye lens is clouded, the light beams are blocked and this will result in an unclear image on the retina. Usually the clouding of the lens happens really slowly. Complaints that may exist are:
- unclear view as if looking through frosted glass.
- change of colours, the surroundings look more grey and less colourful. This effect is only noticeable after one eye has been treated.
- seeing double or with shadows with one eye. This is caused by irregular refraction of the light in the clouded lens
- bothered by blinding/glare. Backlight and sunlight are then really unpleasant because of the blinding effect. This is caused by spreading of light in the clouded lens.
- fluctuating or ever changing prescription of glasses.
- trouble with seeing in the dark.
Many of these complaints are also a result of RP. A physician specialised in RP will be able to assess this.
The only remedy for cataract is cataract surgery. This surgery is daily done with many people and usually this will not lead to complications with people having a good eyesight. With people suffering from RP adverse effects may occur because of the messing up of a retina that is already weak.
The ophthalmologist can see with the slit lamp whether the eye lens is clouded and if so, to what level the cataract has been developed. The surgery usually takes place in day care under a local anaesthetic (by means of an injection or drops) and sometimes under general anaesthesia. The ophthalmologist will almost always treat only one eye at a time. During the surgery, the ophthalmologist will remove the lens from the eye and replace this by a clear, plastic implant lens. This lens will in principle last for the rest of your life.
Some time after cataract surgery, new clouding may develop of the capsule the artificial lens has been placed in (not of the artificial lens itself). It seems as if the cataract has come back again. This is called posterior cataract and usually develops itself some time after the cataract surgery. Posterior cataract can be treated with the YAG laser. Here an opening is made in the posterior cataract. This treatment is painless. Usually you will not feel anything and you will only hear a ticking sound and see small light flashes.
Generally, after cataract surgery they will try to make you minimally dependent on glasses. Therefore the lens is measured prior to the surgery. This measurement is required for calculating the strength to be chosen for the implant lens, ensuring a minimum residual strength for glasses after surgery. However, the ophthalmologist can never guarantee for 100% that the eye will be able to see clearly without glasses, even if the surgery was done perfectly. Reading glasses will usually remain necessary. In some situations it can be arranged, in consultation with the ophthalmologist, for you to read well without glasses. Glasses for seeing in the distance will then be necessary, though. This choice will depend on the strength of the glasses prior to surgery.
There are special implant lenses aimed at making people even less dependent on glasses after cataract surgery. There are four types of implant lenses:
- Monofocal lens (standard artificial lens): a lens that makes you see clearly at one distance. Usually in the distance. Often reading glasses are necessary after cataract surgery.
- Monofocal toric lens: a lens that corrects the cylinder deviation. Additional payment will be required for this lens when having cataract surgery.
- Multifocal lens: a lens that makes you see clearly both nearby and in the distance. You will not need reading glasses any longer. Additional payment will be required for this lens when having cataract surgery.
- Multifocal toric artificial lens: a multifocal lens, as described above, that also corrects a cylinder deviation.
The multifocal lens types are often advised against for people suffering from RP/Usher Syndrome because of their weak retina and their small field of vision.
Sometimes it is possible to opt for giving one eye a lens strength for seeing nearby and the other eye for seeing in the distance. In order to be able to see and read in a relaxed way, glasses will still be necessary, but not for reading the labels in the supermarket or a short walk.
Which hospital or which clinic will be suitable for you? The Oogvereniging has made an assistant in making a choice in cooperation with ZorgkaartNederland. This assistant in making a choice asks you a few questions and after this you will receive a list of three healthcare institutions that best suit your requirements. You can compare these institutions right away. (Unfortunately only available in Dutch)
The ‘consult card’ can help you weighing the pros and cons for having cataract surgery or waiting a bit longer. Besides, all kinds of questions are asked the answers of which are important for the treatment. You can go through this consult card step by step. The consult card was set up by the Oogvereniging in cooperation with ophthalmologists. (Unfortunately only available in Dutch)
In the episode of the podcast of the Oogvereniging ‘Een en al oog’ (All eyes), ophthalmologist Jolien de Jager (Oogziekenhuis Zonnestraal) and two experts by experience tell about cataract, the cataract surgery and choosing an artificial lens. (Unfortunately only available in Dutch)
It is always possible to ask an RP specialist for a second opinion. This requires a referral from a general practitioner or another physician. The section ‘NETWORK’ contains a number of RP specialists.