What are cataracts?
Cataracts are one of the most common causes of a loss of vision and are due to a loss of transparency of the crystalline lens, the eye's natural lens.
Naturally and due to ageing, the crystalline lens loses its transparency which translates into reduced visual acuity. Although the majority are related to age, there are other types like congenital cataracts (present from birth), secondary to certain diseases (uveitis, diabetes), medication (corticosteriod) and eye trauma.
Catracts normally develop slowly, which is why the symptoms appear gradually:
Blurred or cloudy vision in short-sighted individuals.
- Glare from sunlight, lights or car headlamps at night.
In some cases, cataracts cause short-sightedness, which is why they may improve long-sightedness.
A consultant can assess whether a patient is experiencing cataract onset, which is why it is good to have regular check-ups, whether you do or do not use glasses or contact lenses.
Types of cataract
Cataracts can be classified according to their cause or the area of opacity in the crystalline lens.
- Senile cataracts are the most common and they are age-related.
- Metabolic cataracts are associated with metabolic illnesses. The most common is diabetes mellitus.
- Congenital cataracts exist from birth or develop over the first few months of life. They may be associated with genetic conditions or a disease suffered by the mother during pregnancy like rubella or toxoplasmosis.
- Traumatic cataracts occur after experiencing eye trauma.
- Toxic cataracts are associated with chronic use or abuse of some drugs or toxic substances, corticoids being the most common causal element.
Furthermore, depending on the area affected by the opacified crystalline lens, we can distinguish between:
- Nuclear cataracts, in which the nucleus or centre of the crystalline lens in particular becomes opaque. A nuclear cataract usually evolves slowly and affects farsight more than nearsight. They are the most common and are usually associated with age.
- Cortical cataracts are cataracts where the cortex or lens cover becomes opacified. They are less common than nuclear cataracts and affect nearsightedness.
- Posterior subcapsule cataracts, which develop in the outermost layer of the crystalline lens: the posterior lens capsule. This type usually progresses quite quickly and a common symptom is glare.
Careful observation and description of cataracts in a slit-lamp exam is key in drawing up an ophthalmic clinical history for each patient. On one hand, it enables the progression of the cataract from one visit to the next to be evaluated. On the other hand, the type and grade of the cataract determine the most appropriate choice of surgical technique used to remove it, and warn of the possible intraoperative risks inherent to each type.
The definitive treatment is still surgery.
Cataract surgery is currently a quick and pain-free process. It is highly effective and carries few risks. The operation involves aspirating the content of the opacified crystalline lens and replacing it with an intraocular lens.
Intraocular lenses are under constant technological evolution, both in terms of their design as well as the material used to make them. There are currently different types of intraocular lenses:
Monofocal intraocular lenses
They correct distance vision, but the patient needs glasses to see up close.
Multifocal intraocular lenses
They provide vision at different distances: near, medium and far depending on the lens model.
Postoperative recovery is quick and normal vision is restored.
The femtosecond laser can be used in cataract surgery.
The surgeon will decide on the best option after assessing each case individually, depending on the expectations and anatomical and functional condition of each individual.
Professionals who treat this pathology
How do I know if I have cataracts?
At first, when the cataract is not so dense, cloudy vision is noted. Furthermore, lights can cause more glare than normal. As the cataract develops, the eyesight becomes more blurred, which gradually makes daily activities more difficult.
Once I've had my cataract surgery, will I still have the same prescription?
In theory, the prescription of the intraocular lens that we place in the eye after the cataract is removed is usually there for life because no changes are experienced. In fact, these changes are almost always due to the crystalline lens itself becoming a cataract, therefore this lens will be worn for life.
Will I need glasses after cataract surgery?
The intraocular lens we place inside the eye will determine whether or not the patient needs to wear glasses. Currently, there are intraocular lenses that can correct all kinds of vision impairments, hypermetropia, myopia and astigmatism with a toric lens, and even presbyopia or tired eyes with a multifocal lens, which can be bifocal or trifocal.
How is the crystalline lens removed from the eye when it has opacified?
Cataracts are currently removed by making a 2mm incision. A high-frequency ultrasound device that breaks up and aspirates the cataracts is used.
Do only the elderly get cataracts?
Cataracts usually occur in older people, although there are 60 year olds who should not be considered as elderly yet they already have cataracts. In addition, children may suffer congenital cataracts because of inheritance as one of their parents had them, or because of a deformity in the embryonic development of the crystalline lens.
I've been diagnosed with cataracts and I've heard that a laser is used in the operation. How does it work? Is it better than conventional surgery?
Femtosecond laser-assisted cataract surgery brings a new level of precision and safety to the delicate steps of cataract surgery. In the second part of the operation, ultrasound devices continue to be used to aspirate the cataract. This is a conventional technique. The use of a femtosecond laser is not indicated for all cataracts, therefore your ophthalmologist will recommend the most suitable technique in your case.
Can intraocular lenses (IOL) get dirty in the eye and cause blurred vision?
Although it is very common to hear that intraocular lenses "get dirty", what really happens, and relatively frequently too, is that the posterior lens capsule opacifies. It is very rare that the lens itself gets damaged or becomes dirty.
Cataract surgery involves fragmentation and aspiration of the opacified lens or cataract, and the subsequent implantation of a lens inside the capsule, a thin membrane that surrounds the lens. The posterior part of the capsule remains intact since it is normally transparent at the time of surgery. Posterior capsule opacification may appear months or years after the cataract operation and its consequence is gradually failing eyesight. It makes you feel like you are seeing things through a foggy or dirty window.
At present, the most effective treatment for capsule opacification is undergoing a laser capsulotomy. It involves opening a tiny window in the centre of the posterior capsule. It's a simple and pain-free technique that does not require surgery or hospitalisation. Recovery is fast. The patient regains the eyesight they had before opacification occurred.