Although the ophthalmologist cannot remove or cure the RP, he or she may sometimes be able to help. RP can be accompanied by other disorders which require regular checking of the eyes. As the eyes are more vulnerable than ‘healthy’ eyes because of RP, there is an increased chance of:
- Short-sightedness (myopy): this type of refraction deviation regularly occurs and can be checked by an ophthalmologist or optician. If the visual acuity becomes too low, prescribing loupes or other aids can be useful.
- Cateract: Cateract often occurs with RP. Cateract can be remedied by cateract surgery. This may improve visual acuity, but the field of vision will not be widened. As the retina is functioning less well, the result of cateract surgery can be limited. RP patients do not have a higher risk with respect to surgery than ‘normal’ cateract patients, but the choice of having surgery or not can be difficult. To what extent are the complaints caused by cateract and to what extent is de RP responsible for the deterioration of the eyesight? This makes the result of the surgery hard to predict. In general, RP patients undergo cateract surgery at an earlier age (on average between 45 and 65 years) than ‘healthy’ patients (70-75 years). Although with most patients the visual acuity does increase after surgery, this unfortunately does not hold for a part of the RP patients (10-50% of the patients). Despite the fact that the visual acuity does not always increase, there often is a functional improvement with respect to the visual problems. The result depends on the initial situation: the prognosis is better for patients with a less severe form of RP (based on the level of drop-out of the central field of vision and deviations in the OCT scan). The risk of cateract surgery itself is not higher for RP patients than it is for non-RP patients. However, after surgery the risk of posterior cateract is larger (60-80%), but this can be solved with a posterior cateract treatment (laser). A new artificial lens can be provided with a UV filter. Of course, the own lens also has a UV filter, but this is only minimal. Apart from this, a UV filter only protects the lens and not the retina.
- Malcula oedema: with about 10% of the RP patients the visual acuity decreases as a result of accumulation of fluid in the yellow spot. The ophthalmologist can prescribe a kind of diuretic (Diamox). This medicine has quite some side effects and does not always help.
- Glaucoma: a very small percentage of RP patients suffers from ocular hypertension. As this can usually be treated relatively easily (with eye drops), the checking of the ocular tension is important to prevent (unnecessary) damage.
Prof Dr C.B. Hoyng (Radboud UMC): “RP makes the eyes extra vulnerable. The above-mentioned risk factors, such as malcula oedema and cateract, are not symptoms of RP. Everyone can develop these complaints. However, people with RP do have a higher risk, as their eyes already are in a worse condition. It is very easy for an ophthalmologist to also check the malcula and to measure the ocular tension during a visit to the clinic for a check. I advise to have the ophthalmologist check the eyes every two years.”