A cataract is caused by a loss of transparency in the eye’s natural lens, the crystalline lens, which becomes thicker and less flexible. The patient notes a decrease in visual acuity which cannot be corrected with spectacles, only surgery.
WHEN IS CATARACT SURGERY NECESSARY?
Cataracts can develop very slowly. If you notice a deterioration in your vision which is progressing on a daily basis, it means that cataract surgery is needed. The exact timing of the surgery may vary depending on each patient, as there is no exact age for the operation, and the decision is subjective. In principle, it is best not to wait until the cataract has reached an advanced state, as the visual problems are usually very noticeable at this stage and there is a higher risk of complications during surgery. With cataract surgery, most refractive defects can be corrected in a single procedure, and for this reason many patients choose not to wait before making the decision and enjoying good vision without the need to use spectacles.
WHAT DO I NEED TO TAKE INTO ACCOUNT BEFORE THE SURGERY?
To avoid inflammation, it is recommended to carefully administer eye drops before the operation. Sometimes your surgeon or anaesthetist may advise you to obtain a prescription for these from your GP. It is important to pay special attention to this for the day of the operation.
Today, thanks to advanced technology, a local anaesthetic is all that is needed for performing cataract surgery. Despite this, an anaesthetist is always present for safety and monitoring purposes. If necessary, patients can be administered medication for sedation. The surgery is generally performed on patients in a fasting state (also in the case of local anaesthetic). The anaesthetist will inform you if you need to take medication on the day of the operation.
ON THE DAY OF THE OPERATION
Nowadays, a lens exchange is a quick and simple outpatient procedure. During the operation, surgical attire must be worn. If the patient has not dilated their pupil at home, they will receive drops in the operating room. Disinfection and application of the anaesthetic will also be performed.
After the operation, the doctor dresses the eye to protect it or uses a transparent patch. The operation takes approximately 15 to 20 minutes. After a short rest the patient may return home. Remember that driving is not permitted and you will need someone to help you travel.
The next day the operated eye must be checked. Your ophthalmologist will inform you of the necessary post-surgical medical treatment. You are recommended to:
- Not rub or put pressure on the operated eye
- Avoid physical exertion
- Until the doctor gives you permission, not go to a swimming pool or sauna
- Remember to attend medical checks and take the prescribed medication
TYPES OF ANAESTHESIA
Normally a local anaesthetic is all that is needed for cataract surgery. In some cases this is combined with a mild tranquillising injection. One alternative is a peribulbar anaesthetic to prevent pain and immobilise the eye. Another option may be a general anaesthetic (normally in children or restless, nervous adults).
Cataract surgery qualifies as a low risk procedure. Your ophthalmologist will inform you before surgery of the potential risks such as infection and haemorrhage. In any operation, it is impossible to fully exclude potential complications. Cataract surgery is highly successful and over 90% of patients can note an improvement after the surgery.
Vision starts to recover from the day after the operation, although full recovery can take several weeks. The end result depends on the condition of the rest of the visual system, such as the retina and the optic nerve.
Due to the fact that today cataract surgery takes into account correction of the patient’s refractive condition, in 90% of cases dependency on spectacles for distance is eliminated and they are only needed for high precision tasks. The degree of correction of presbyopia depends on the intraocular lens implanted. If the patient does not choose a multifocal lens they will need spectacles for near vision in all activities. If they do, they will be able to do without them or only need them for reading very small letters or performing very specific tasks.
The recovery time after cataract surgery is usually between one and two months, when the patient can be discharged and prescribed spectacles if necessary.
CATARACT SURGERY TECHNIQUE
The aim of cataract surgery is to replace the opaque crystalline lens with an artificial transparent lens. The procedure is as follows:
- The eyelids are held apart thanks to a palpebral separator known as a blepharostat.
- Incisions are made to be able to insert the instruments inside the eye. The incisions in well-equipped clinics with innovative technology are very small (between 1.5 and 2.8 mm), making the surgery less invasive.
- Viscoelastic is injected, a gelatinous material which helps to protect the corneal endothelium from the instruments used during surgery.
- Capsulorhexis is performed, in other words, the anterior lens capsule is opened manually using a very precise instrument, through which the opacified nucleus is extracted.
- A liquid is injected to irrigate and gently separate the crystalline lens from the capsule and the cortex. By separating the cortex from the capsule, the surgeon can manipulate the nucleus of the crystalline lens more easily by rotating it to facilitate its subsequent extraction.
- The nucleus is broken up and extracted using a procedure known as phacoemulsification. Thanks to the use of ultrasound, the crystalline lens is broken up and then, using the same instrument, these fragments are removed by suction.
- The intraocular lens is inserted using a special injector which allows for the lens to be folded. When it is inserted into the eye, it unfolds inside the capsular sac. Corneal stitches are not required if microincisions have been made. If the characteristics of the eye do not allow for a foldable lens to be injected, the incisions must be larger and this is when corneal stitches are performed.
Today there are many different possibilities when it comes to choosing the artificial lens, so it is important to be well informed of all the options available. The choice of lens type has a strong influence on the quality of vision after the surgery. Thanks to the latest technology such as Femto-Phaco, stitches are not needed thanks to the small incision made in the eye.