All You Need To Know About Cataract And Its Treatment

What is a cataract?

Cataracts are a common eye condition that causes the natural lens of the eye to become gradually cloudy, leading to impaired vision. This condition affects people of all genders, races, and ages, but is more commonly associated with the natural ageing process. Cataracts typically develop in both eyes, but the severity may vary between the two, resulting in a difference in vision. As a leading cause of treatable blindness worldwide, it is essential to seek professional medical attention as soon as possible. With timely diagnosis and treatment, individuals can regain clear and focused vision.  

What causes cataracts?

Cataracts are a prevalent eye condition that often develops due to the natural ageing process. However, various factors can lead to the early onset of cataracts. Exposure to excessive sunlight, injury, toxic chemicals, and changes in the body's metabolism can all contribute to the formation of cataracts. Certain drugs, such as steroids, can also increase the risk of cataracts. Additionally, cataracts can occur as a secondary condition to other eye diseases, such as glaucoma and inflammation. Furthermore, hereditary predisposition can make an individual more susceptible to developing cataracts. As a result, it is crucial to take preventative measures, such as wearing protective eyewear and scheduling regular eye exams, to minimize the risk of developing cataracts. 

 

How do I know if I have a cataract?

The early symptoms of cataracts can significantly impact your vision and daily activities. Cloudy, blurred, or dim vision is often the first sign of this common eye condition. Additionally, individuals with cataracts may experience a need for frequent changes in their eyeglasses or a temporary improvement in near vision, leading to a reduced need for reading glasses. The fading and yellowing of sight can also make it challenging to perform everyday tasks, such as reading or driving. Sensitivity to light and glare, especially while driving at night, can be another common and early symptom of cataracts. You may also notice halos around lights or experience double vision, caused by irregular light distribution passing through the cataractous lens. 

Are there different kinds of cataracts?

Cataracts come in several different types, each with its unique effects. 

Nuclear cataracts, the most common type, form in the centre of the lens and can cause the lens to become yellow or brown, making it difficult to distinguish between colour shades. 

Posterior subcapsular cataracts can cause glare and halos around lights, particularly at night, and often occur in people with diabetes or high myopia. 

Cortical cataracts, on the other hand, form in the outer part of the lens, causing it to become opaque and affecting vision more severely. 

A polar cataract is a specific type of cataract that can appear either in the centre of the front or back of the lens, with the posterior polar cataract being the more common form. During surgery to remove this type of cataract, there is a risk of the lens capsule tearing, which may require a specialized type of intraocular lens to be implanted. 

Congenital cataracts, which occur at birth or during childhood, can be caused by genetic factors or infections and require prompt treatment if they impair vision. 

Traumatic cataracts, caused by ocular trauma, can also lead to vision problems and often cause lens swelling.

What is the treatment for cataracts?

Cataract surgery is the only effective treatment for cataracts, and there are no medications currently available that can prevent or treat the condition. The good news is that modern cataract surgery techniques have advanced significantly in recent years, making the surgery quick, painless, and highly effective. In fact, the average cataract surgery takes less than 15 minutes to complete. Today, cataract surgery is often performed as an outpatient procedure under topical anaesthesia, using anaesthetic eye drops. This means that patients can return home the same day as their surgery, making the procedure more convenient and accessible than ever before.

When is the right time to get my eye operated on for the cataract?

Cataracts progress through different stages, each with its own set of symptoms and treatment options. In the early stage, cataracts are relatively unnoticeable and mostly asymptomatic. However, as they progress into the immature stage, symptoms become more noticeable, such as mild blurring of vision, increased sensitivity to light and glare, and changes in prescription. At this stage, updating the glasses prescription can help improve vision.

In the mature stage, cataracts become denser, and symptoms become more severe, affecting one's quality of life. Reading small prints becomes challenging, and updating glasses prescription does not significantly improve vision. The hypermature stage is the final stage of cataract, where the entire lens is cloudy, leading to a significant reduction in vision and visual impairment. 

Determining the right time to undergo cataract surgery is a joint decision made by you and your eye doctor. Your doctor will assess the degree to which your vision is affected by the cataract and how it impacts your daily activities and quality of life. Based on this evaluation, you and your doctor can discuss the optimal timing for surgery. It is important to note that cataract surgery is a safe and effective procedure, and delaying surgery may result in further vision loss and decreased quality of life.

Are there different types of cataract surgeries?

The majority of present-day cataract surgeries are sutureless. The most common types of sutureless cataract surgeries are Phacoemulsification and Femto Laser Assisted cataract surgeries. 

What is phacoemulsification?

Phacoemulsification is an advanced surgical technique used to treat cataracts. During the procedure, an ultrasound probe is used to fragment the clouded lens into small pieces, which are then removed through a tiny incision using a suction device. This approach eliminates the need for sutures as the incision is self-sealing. In recent years, Micro Incision Cataract Surgery (MICS) has become increasingly popular due to its minimally invasive nature. Here, the surgical opening is less than 2.0 mm, resulting in faster recovery and improved outcomes.

What are the advantages of phacoemulsification?

Phacoemulsification offers several advantages as a cataract surgery procedure. Firstly, it is a painless and bloodless surgery that results in a fast postoperative recovery with minimal discomfort and restrictions. The surgery usually takes only between 5 to 10 minutes, depending on the surgeon's skill and the equipment used. Additionally, the small incision made during phacoemulsification leads to less induced corneal astigmatism, making it an ideal option for those concerned about wearing glasses after surgery.

What is LASER cataract surgery?

Laser cataract surgery is an innovative method for treating cataracts that uses a femtosecond laser, guided by high-resolution imaging, to fragment the clouded lens into small pieces. Unlike traditional surgery, laser cataract surgery does not require any blades as the laser is used to make the incision and opening on the lens capsule. After the laser has fragmented the cataract, it is easily removed with suction and replaced with an artificial lens. This cutting-edge technology offers unmatched precision and safety, resulting in faster healing time and reduced post-operative discomfort. 

A screengrab illustration of how cataract surgery happens with the Catalys Precision Laser System is this shown below. If you are interested to watch a comparison of phacoemulsification and Laser cataract surgery, click here - video

What are the advantages of Laser cataract surgery over phacoemulsification?

Laser cataract surgery offers several advantages over phacoemulsification. It is a less invasive and safer option, with a faster recovery time. Unlike phacoemulsification, laser cataract surgery is less dependent on the surgeon's skill and precision. Research studies have shown that there is practically no induced astigmatism in the postoperative period. Additionally, laser surgery is the preferred type of surgery for advanced IOL designs, where precise centration of the lens is critical to achieving the expected visual outcomes.

What is corneal astigmatism?

To understand corneal astigmatism, one should know what a spherical cornea is. In a spherical cornea, its surface has a uniform round curvature like the shape of a basketball and light rays passing through it bend evenly to focus on one spot.

Sometimes, the corneal surface is curved more like a Rugby ball, which is less curved on one side and more curved on the other side. In such a case, vision becomes distorted. This common irregularity is called corneal astigmatism and causes blurred or distorted vision because light rays are not focused on one spot.

What is an Intra-Ocular lens?

An intraocular lens (IOL) is an artificial lens that is surgically implanted inside the eye to replace the focusing power of the natural lens. When a cataractous lens is removed, a significant portion of the eye's focusing ability is lost. To restore vision, an IOL implant is usually inserted. The type of IOL implanted depends on various factors such as the patient's visual requirements and the surgeon's recommendation, which is usually determined after careful consultation with the patient and a patient education counsellor.

What are IOLs made of?

IOLs are made from biocompatible synthetic materials. Based on material, they can be classified as follows

PMMA (Polymethyl Methacrylate) IOL 

This is the oldest type of IOL that has been in use since the mid-1940s. It is a hard, rigid, and clear plastic material. They are still used today due to their affordable cost.

Silicone IOLs 

These are soft, flexible, and easy to fold, which makes them ideal for small incision surgeries. They were introduced as foldable IOLs in the 1970s.

Acrylic IOLs 

These came into existence in the 1990s and are composed of hydrophilic or hydrophobic acrylic materials. Even though hydrophilic acrylic IOLs are softer and more flexible than hydrophobic acrylic IOLs, hydrophobic ones are more prevalent today due to their capability to resist capsular opacification and ease of implantation. These lenses are engineered to repel liquids such as water, reducing inflammation and enhancing visual outcomes.

What are the common IOL types based on their functions?

In terms of their functions, IOLs can provide good vision at a specific distance and may also have additional features to enhance visual outcomes. Based on their optical designs, there are several common types of IOLs used by eye surgeons today.

MONOFOCAL IOLs

Monofocal IOLs provide clear vision at a fixed distance. They can have additional features like UV filters and reduced glistening properties. Basic options include PMMA, Hydrophilic, and Hydrophobic IOLs, but they lack advanced optical properties and have a higher chance of capsular opacification, which is less frequent in hydrophobic IOLs.

ASPHERIC SINGLE-PIECE IOL 

This is a type of monofocal IOL that mimics the natural shape of the human lens and eliminates spherical aberration, providing excellent vision quality similar to that of a person in their 20s and 30s. Capsular opacification is extremely rare with this type of IOL.

TORIC MONOFOCAL IOL

When a person has corneal astigmatism before cataract surgery and if a standard IOL is implanted, the patient may still experience distorted vision due to uncorrected astigmatism. However, a Toric IOL can correct corneal astigmatism and improve distance vision. These lenses are customized to each individual eye, based on preoperative measurements, and can improve distance vision. Patients will still require corrective lenses for near tasks like reading and writing. 

As all toric lenses are customized to each individual eye and preordered based on the preoperative measurements, an early confirmation from the patient is usually needed to avail of the benefits of this customized IOL Surgery.

MONOFOCAL IOL WITH SLIGHTLY EXPANDED DEPTH OF FOCUS

These IOLs are made with a unique refractive surface design that has a continuous increase in power from the periphery to the centre of the lens. This design helps patients undergoing eye surgery to experience high-quality vision at midrange and far distances, allowing them to achieve significantly improved midrange vision compared with a standard aspheric monofocal IOL, especially in low-illumination settings. Patients with this lens can comfortably engage in various personal interests, such as cooking, and hobbies specific to intermediate-distance viewing, thereby improving their overall quality of life. However, patients will still require near-vision glasses for prolonged reading. 

PRESBYOPIA CORRECTION IOLs

Presbyopia correction intraocular lenses (IOLs) are the latest advancement in lens technology. These lenses have multiple regions with varying powers that allow people to see at different distances. However, they may not be suitable for everyone, and a thorough preoperative assessment is necessary to understand the patient's visual expectations, lifestyle, and affordability. Some types may cause more glare than monofocal or toric monofocal lenses and may still require glasses for certain tasks.

MULTIFOCAL IOL (BIFOCAL)

Multifocal IOLs are intraocular lenses designed to provide clear vision at both near and far distances, reducing dependency on glasses or contact lenses. These lenses have multiple regions with varying power, enabling the patient to focus on objects at both near and far distances. The primary advantage of multifocal IOLs is that they provide patients with greater visual independence, allowing them to perform daily activities without the need for corrective eyewear. However, the limitation of this type of IOL is that some patients may experience halos, glare, and reduced contrast sensitivity under certain lighting conditions, especially at night, and some may have reduced clarity in the intermediate distance.

TRIFOCAL IOL     

There is no intraocular lens that exactly mimics a young eye. But trifocal lenses offer the latest advances in vision technology. They are designed to enhance your lifestyle by providing clear vision at near, intermediate and far distances. When there is a pre-existing corneal astigmatism a customized trifocal toric IOL is indicated.

CONTINUOUS RANGE OF VISION (CRV) IOL  

CRV IOL is the latest generation IOL that has the most advanced optics. CRV IOL delivers continuous high-contrast vision for patients with cataracts from far through near, even in low-light conditions. It eliminates the visual gaps present in trifocal and other multifocal technology, offering patients the freedom to focus within the range. Studies have shown that it demonstrates a reduction in halo intensity for tasks like night driving. When there is a pre-existing corneal astigmatism a customized CRV toric IOL is indicated.

EDOF (EXTENDED DEPTH OF FOCUS) IOL

EDOF IOL is a type of intraocular lens that can provide clear vision for distance, intermediate, and near activities. It works by extending the range of focus for patients, allowing them to see clearly at various distances without the need for glasses. The EDOF IOL is designed to reduce glare and halo effects while providing a continuous range of vision. This makes it an excellent option for patients who want to maintain a more active and independent lifestyle after cataract surgery and works especially as a great alternative to traditional multifocal or trifocal lenses, with fewer side effects and better overall visual outcomes. When there is a pre-existing corneal astigmatism a customized EDOF toric IOL is indicated.

How will I know which IOL will be the best for me?

To determine the best type of IOL for an individual, several factors must be considered. A good starting point is to assess the activities that one typically engages in and would like to continue doing after the surgery, with or without glasses. The below table can help identify the tasks that most people perform at specific distances. Note that there may be additional activities that are not included in the table and should also be considered when deciding on the type of IOL.

The next fact that needs to be considered is your eye condition and parameters. Your eye care professional will order certain tests like A Scan, Corneal Topography, Specular Microscopy, Macular Ocular Coherence Tomography (OCT)/ B Scan, and certain lab tests and present you with various options. 

What are my IOL options based on my visual demands?

Below is a table that outlines different types of IOLs and their dependency on glasses for near, mid-range, and distance vision, as well as their ability to correct astigmatism and provide a continuous range of vision. 

The '✔' symbol indicates that the IOL provides vision correction for the items listed in the respective column, while the 'x' symbol denotes the inability of the IOL to provide correction for the items mentioned in the respective column. The glasses symbol indicates that glasses will still be required to perform activities at the distances mentioned in the respective columns. 

Is it possible to replace the IOL after implantation?

Intraocular lenses (IOLs) are designed to last a lifetime, but there are circumstances where they may need to be removed and replaced. The process, however, is not straightforward, and potential complications may arise, leading to vision problems or loss of support for the replaced lens. Hence, careful consideration of the type of IOL to be implanted is crucial prior to surgery.

Despite meticulous pre-operative calculations, there are instances where unexpected outcomes occur after cataract surgery. In such cases, the implanted IOL may not provide adequate vision or may cause other vision problems. To rectify this, the IOL may need to be removed and replaced with one of a different type or corrected power. In rare cases, the IOL may shift from its position, necessitating repositioning or replacement by taking the patient back to the operating theatre. Generally, this procedure is performed within a few weeks of the initial surgery.

What are the common misconceptions about cataract surgery?

What should I do next?

If you suspect that you have cataracts based on the symptoms you are experiencing, it is recommended that you schedule an appointment with your eye care consultant. After an examination, it's important to discuss with your eye surgeon about the timing of the surgery and the different types of surgeries and IOL options available to you. This will help determine the best course of action based on your specific situation and needs. 

Disclaimer: This blog article is intended for educational and informational purposes only. It is not intended to be used as professional advice or as a substitute for consultation with a qualified healthcare professional. While every effort has been made to ensure the accuracy and completeness of the information contained in this article, the author assumes no responsibility for errors or omissions, or for any consequences arising from the use of the information. The author of this article does not receive any financial benefits, compensation, or incentives for recommending or promoting any products, services, or companies mentioned in this article. Please consult with your eye care provider before making any decisions regarding your eye surgery. This article does not guarantee any final benefits and is not intended to be a substitute for any medical treatment.