Cataract Surgery Procedure

Cataract surgery (synonym cataract surgery; cataract surgery) is a surgical procedure in ophthalmology (ophthalmology) to remove an existing cataract so that an improvement in vision can be achieved. As corrective measures for an existing cataract, there are various surgical methods. Cataract is a clouding of the lens of the eye, which is clear under physiological conditions, usually occurs due to age and significantly reduces visual performance. As treatment measures of cataract, cataract surgery is the gold standard (procedure of choice). The various methods of correcting an existing cataract are usually performed as an outpatient procedure, so there is no need for a prolonged recovery period. Cataract surgery is now one of the most commonly performed surgical procedures because the procedure is characterized by a high success rate and complications occur only in very rare cases at all.

Indications (areas of application)

Cataract

  • In contrast to earlier surgical methods for the correction of cataract, today the surgical procedures are used already in the case of a subjective influence on the visual performance, which is based on a clouding of the lens.
  • In the case of an advanced cataract, surgery should be performed because, if necessary, difficult-to-correct sequelae can be prevented by timely therapeutic intervention.

Contraindications

  • Uveitis (inflammation of the middle skin of the eye (uvea), which consists of the choroid (choroid), ray body (corpus ciliare), and iris; the vitreous may also be involved) – uveitis is a contraindication because the inflammatory reaction present could be flared up by cataract surgery.
  • Alpha-adrenoreceptor blockers (alpha-1 antagonists) – shortly before or during surgery, alpha-blockers must not be used to lower blood pressure during cataract surgery, otherwise intraoperative floppy iris syndrome (IFIS) (symptom complex associated with an increased risk of intraoperative complications of cataract surgery. The cause is probably the effect of the selective alpha-adrenoceptor antagonist (tamsulosin), which is used in the treatment of benign prostatic hyperplasia (BPH). Drugs of this group cause iris relaxation at the eye and miosis due to alpha-adrenoceptor blockade of the dilatator pupillae muscle) is threatening. In the presence of the syndrome, follow-up surgery is necessary.
  • In the presence of other diseases such as diabetes mellitus, greater caution is required during surgery. However, this is usually not an absolute contraindication.

Before surgery

  • Measuring the eye – in order to perform surgery on the eye, the exact length or volume measurements must be known so that optimal correction can be ensured.
  • Medication history – anticoagulants (“blood thinning” substances) such as Marcumar or acetylsalicylic acid (ASA) must not be taken before the procedure. The presence of a pathological coagulation disorder should also prompt the surgeon either to cancel the planned procedure or to take additional measures to stabilize coagulation. With the help of blood tests, it is possible to check the blood clotting characteristics and allow the patient to undergo the procedure.
  • Allergy – allergic reactions can represent not only a subjective influence on well-being, but also significantly reduce the probability of success of the procedure in the case of an exaggerated reaction to a surgical material.
  • Anesthesia – anesthesia is necessary before the start of the surgical procedure. However, since it is a minor surgical procedure, it is possible to use either local anesthesia (local anesthesia) or general anesthesia. As a rule, local anesthesia is chosen because both application by injection and in the form of eye drops are gentler on the organism. Furthermore, it must be decided whether the procedure should be performed as an inpatient or outpatient procedure. This decision is mainly dependent on individual risk factors.

The surgical procedures

Intracapsular cataract extraction (ICCE).

  • This surgical procedure is now used exclusively in exceptional cases, since it is based on the removal of the lens including its capsule and, furthermore, there is no use of an artificial lens. To remove the lens, it is connected to a cold probe and pulled out of the eye. This procedure is also known as cryoextraction.
  • Without the use of an artificial lens, the use of “cataract glasses” or contact lenses is necessary. The use of the procedure is now indicated only in the presence of weakness of the zonular fibers.

Extracapsular cataract extraction (ECCE).

This surgical option represents the currently almost exclusively used method for the correction of cataract, in which the posterior lens capsule is preserved in a physiological state, so that the artificial lens can be fixed in it. The cloudy lens content is eliminated from the capsular bag. Different extracapsular extraction variants are distinguished:

  • Phacoemulsification – this method involves ECCE with lens nucleus liquefaction using ultrasound waves. During the procedure, the anterior chamber is opened at the junction of the cornea (cornea) and the sclera (sclera). A corneal tunnel incision is usually used for this purpose. After the anterior lens capsule has been opened using special micro forceps, the lens nucleus can then be liquefied using ultrasound waves. After liquefaction of the nucleus, it is now possible to aspirate it. The remaining thin cortical layer in the capsular bag is then aspirated with a suction rinsing device. Of crucial importance is the preservation of the posterior capsule, so that one can apply a posterior chamber lens instead of the missing lens.
  • Expression of the nucleus – unlike phacoemulsification, the removal of the lens nucleus is not done via crushing, but instead as a whole component. For better removal, the nucleus is flushed out with a liquid. The procedure is of particular benefit in the case of a massively opacified and hard lens.

The refractive power of the eye after surgery is close to the target fraction: more than 90% of patients show refractive results after surgery that are no more than 1 diopter (+/-) from the zíel fraction.

After surgery

  • After the surgery, the patient receives a bandage. Care should be taken by the patient to prevent any manipulation of the operated eye.
  • The following day, the surgeon performs a control examination of the eye, during which the bandage is removed. Furthermore, the patient is informed how often and when the application of eye drops is necessary and useful.
  • Prophylactically, antibiotic eye drops are prescribed for 7-14 days, if necessary in combination with steroid drops.
  • In the first two weeks after the procedure, the patient should be particularly careful when showering, for example, as no irritating substances such as soap or shampoo should enter the eye. Furthermore, there should be no physical exertion beyond normal housework.
  • After one, two and three months after the procedure, further check-ups are performed by the attending physician.

Possible complications

Acute complications

  • Inflammation – inflammatory reactions may occur as a result of cataract surgery. In clinical studies, these have been demonstrated by increases in inflammatory mediators (messenger substances).
  • Rupture of the posterior capsule of the lens – rupture of the posterior capsule is a relatively rare complication, but may occur more frequently in diabetics, for example.
  • Retinal detachment (retinal detachment) – a very rare complication is detachment of the retina. When detachment occurs, retinal surgery is inevitable.
  • Intraoperative floppy iris syndrome (IFIS) – complication occurring during surgery; characterized by the triad of an “undulating” iris (undulating movement of the iris of the eye), iris prolapse, and intraoperative progressive miosis (progressive pupil constriction); association with the selective alpha-1A receptor antagonist tamsulosin has been described. Incidence: approximately 1.2%.Conclusion:Tamsulosin should be discontinued as early as possible before cataract surgery.

Chronic complications

  • Aftercataract – this complication is based on opacification of the posterior capsule, which can be due to various causes.A possible cause of development is increased regeneration of the remaining epithelium.