Cataract | National University Hospital (NUH), Singapore's Leading University Hospital

What is Cataract

Cataract refers to the clouding of the native lens of the human eye. While it usually occurs with ageing, certain individuals, such as those with diabetes and those on long-term steroid use, may experience its onset earlier.

Cataract Occurs Here

Symptoms and Causes

What Are The Symptoms?

Patients most commonly experience a gradual and painless blurring of vision, with one eye potentially being more affected than the other.

Common signs of cataract include:

Cloudy, blurry or foggy vision
Dimming of vision
Increased glare
Loss of colour vibrancy

Cataract Vision

What Causes Cataract?

Ageing is the most common cause of cataract, with most forms developing in adulthood. As we age, the protein in our lens undergoes gradual changes, causing it to clump together to cloud the lens. This results in increased thickness, reduced transparency and a yellowish tint.

Other Risk Factors include:

Diabetes
Excessive exposure to ultraviolet (UV) radiation
Genetic disorders
Smoking
Prolonged use of drugs
Previous eye injury or trauma

What Can I Do To Prevent Cataract?

Currently, there is no established method for preventing cataracts. However, adopting standard precautions such as minimising sunlight exposure (ultraviolet rays) may slow down its progression.

Treatment Options

What Treatment Is Available For Cataract?

Early cataract is managed conservatively, and patients are usually prescribed glasses to aid their vision. When cataract affects one’s vision significantly, or in some individuals who may have other eye problems, cataract is managed by the surgical removal of the lens (cataract extraction surgery).

When Do I Have To Remove My Cataract(s)?

Cataract surgery is recommended when visual impairment affects daily activities such as dressing, navigating, cooking, showering, etc., or when the severity of cataract becomes more severe. There is no absolute cut-off age for cataract surgery.

What Happens If I Leave My Cataract(s) Untreated?

If left untreated, cataract(s) lead to progressive loss of vision and eventually reversible blindness. In rare circumstances, it may cause acute angle closure.

What Are The Types Of Cataract Surgery?

The most common form of cataract surgery is phacoemulsification, a 20-minute procedure often performed under local anaesthesia as a day surgery.

Patients with more advanced cataract may undergo a more traditional surgery known as extracapsular cataract extraction (ECCE). This surgery, lasting about 30 minutes, requires a larger incision and visual rehabilitation will take longer. Sutures may need to be removed one to two months after surgery.

Cataract surgery involves the removal of the existing lens, replacing it with an intraocular lens with refractive power correction. Typically, a monofocal lens, correcting vision for distance only, is used in the process.

Cataract Surgery

What Are Some Important Pre-operative Information Required?

You MUST inform your surgeon if you have undergone laser refractive surgery performed (e.g. LASIK, PRK, epi-LASIK, SMILE) previously. Please bring along records of your previous treatment as the information is important in ensuring accurate IOL calculation.
You will need to stop wearing contact lens (at least one week for soft lens and at least two weeks for hard lens) prior to undergoing intraocular lens (IOL) calculation for surgical planning.

What Happens After Cataract Surgery?

Cataract surgery is done as a day surgery procedure, and patients are usually discharged a few hours after the surgery. Post-surgery, a follow-up schedule is established, with clinic appointments schedule one day, one week and one month after the operation. Patients who undergo ECCE may require suture removal one to two months after the surgery.

After the procedure, patients are given an eye shield for use during sleep. It is advised that patients refrain from rubbing their eyes and maintain cleanliness and dryness of the operated eye.

Will I Benefit From Femtosecond Laser Surgery

What is laser-assisted cataract surgery

What Is Laser-Assisted Cataract Surgery?

Femtosecond laser-assisted cataract surgery (FLACS) is the latest type of cataract extraction surgery, wherein a precise laser is used to replace certain steps of standard phacoemulsification. A laser creates an opening in the anterior lens capsule and softening the lens nucleus. It aims to reduce damage to the inner surface of the cornea while increasing precision of intraocular lens placement.

The laser procedure is first performed on a separate machine before the patient is transferred to the surgical bed for completion of the cataract surgery. The surgeon evaluate an individual's suitability for this procedure.

Will I benefit from femtosecond laser surgery

Would I See Better After FLACS Compared To Phacoemulsification?

There are many factors affecting the visual outcome after cataract surgery, such as the extent of spectacle power correction, inflammation degree and the wound healing process. It is advisable to discuss this with your eye doctor.

What Are The Additional Risks Of FLACS?

The complications associated with FLACS are similar to those of standard phacoemulsification, as evidenced by major clinical trials (Abell et al, 2014; Daya et al, 2014). The risks include anterior capsule tear and tags, increasing the likelihood of posterior capsule rupture. After the surgery, there may be swelling of the back of the eye (macula oedema) or elevated intraoperative pressure.

Who Should Consider FLACS?

FLACS may be beneficial for patients with less healthy corneas; however, it is not currently recommended as a standard procedure for all cataract surgeries (Day AC et al, 2016). The decision for FLACS should be discussed with your eye doctor.

References

Chen X, Xiao W, Ye S, et al. Efficacy and safety of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification for cataract: a meta-analysis of randomized controlled trials. Sci Rep. 2015 Aug;13;5:13123.

Conrad-Hengerer I, Al Juburi M, Schultz T, et al. Corneal endothelial cell loss and corneal thickness in conventional compared with femtosecond laser-assisted cataract surgery: three-month follow-up. J Cataract Refract Surg. 2013 Sep;39(9):1307-13.

What Intraocular Lenses Are Suitable For Me

What Are Intraocular Lenses?

Intraocular lens (IOL) focuses light beams onto the retina, enabling distant objects to appear sharp without the need for glasses. The lens is placed into the capsular bag at the end of cataract surgery.

What are intraocular lens

What Are The Different Types Of Intraocular Lenses?

Monofocal IOL

Standard monofocal lens corrects for distance vision; however, reading glasses will still be required for near vision.

Monovision is a form of presbyopic correction whereby one eye is corrected for distance and the fellow eye is corrected for near vision. This allows for spectacle independence in selected patients. However, fine depth perception may be compromised.

Multifocal IOL

Multifocal IOL reduces spectacle dependence by correcting for both distance and near vision in both eyes. However, these IOLs may be associated with increased glare and haloes, and a reduction in contrast. In rare instances, a second procedure may be necessary to refine refractive correction. Multifocal IOLs are generally not recommended for individuals who have undergone previous refractive surgery.

Toric IOL

Some patients may have high corneal astigmatism that requires correction. Standard IOLs do not correct for astigmatism. Residual astigmatism can be corrected with the use of glasses post-operatively, corneal incisions or with toric IOL. Toric IOL aims to reduce residual astigmatism, but in some rare instances, repeat surgery may be required to adjust the IOL rotation.

What Are Some Questions To Consider In Deciding My Preferred Choice Of IOL?

Do you mind wearing glasses (for distance and/or near)?
Do you hope to be spectacle-free?
Are you very sensitive to glare and haloes?
Do you do a lot of reading or computer work?
Would I be suitable for monovision?
What are my hobbies?

To Find Out More Information:

Book an appointment with NUH Eye Surgery Centre for a comprehensive eye check-up and recommendations for your individualised treatment plan.

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