Cataract
The eyeball is divided into two sections: the anterior and posterior segments. The transparent, watch glass-like corneais located at the front, while the lens is positioned further back, marking the boundaries of the anterior segment. The iris, which gives the eye its color, divides the anterior segment into two chambers: the anterior and posterior chambers. Behind the lens, the vitreous body, a gelatinous structure, fills the interior of the eyeball. The outer layer of the vitreous is surrounded by the retinal nerve layer and the optic nerve. The lens is held in place by ligaments attached to its surrounding capsule, securing it within the eye.
What is Cataract?
Light rays reflected from objects pass through the cornea and lens, refracting to focus on the retina. The retinal cells process these rays and transmit the information to the brain’s visual centers via the optic nerve, where the image is formed. For a clear image to be perceived, the lens must remain transparent. Cataract is the condition in which the lens loses its transparency, becoming cloudy and leading to progressive vision loss.
What Causes Cataract Formation?
Several factors contribute to cataract development, including:
- Genetic disorders
- Radiation exposure
- Inflammatory eye diseases
- Blunt and penetrating eye injuries
- Previous eye surgeries
- Certain muscular and skin diseases
- Ultraviolet (UV) exposure
- Aging (the most common cause)
Symptoms of Cataract
- Blurred vision
- Distorted or wavy vision
- Double vision in one eye
- Reduced night vision
- Increased sensitivity to light and glare
When Should Cataract Be Treated?
It is a common misconception that cataracts must fully mature before treatment. The timing of cataract surgery varies depending on the patient’s profession, daily activities, and the level of vision impairment. Surgery should be considered when the cataract significantly interferes with daily life and work-related tasks.
Cataract Surgery Techniques
Sutured Cataract Surgery
In this method:
- An opening is created in the capsule surrounding the lens.
- Pressurized fluid is used to separate the cataractous lens from the capsule.
- The cataract is removed through a 180-degree corneal incision.
- Any remaining lens fragments are aspirated and removed.
- A non-foldable artificial intraocular lens (IOL) is implanted through the same incision.
- The corneal incision is sutured closed.
Disadvantages:
- Longer healing time due to a larger incision
- Higher risk of astigmatism
- Delayed recovery of optimal visual acuity
Phacoemulsification (Phaco) Cataract Surgery
Phacoemulsification, commonly known as phaco surgery, is the preferred modern method:
- A small (approximately 3 mm) incision is made in the cornea.
- A phaco device is inserted to break up the cataract inside the lens capsule.
- Ultrasonic waves from the phaco device fragment the cataract, allowing aspiration.
- A foldable intraocular lens is implanted in place of the removed cataract.
- No stitches are required (sutureless surgery).
Advantages of Phaco Surgery:
- No need for sutures
- Less astigmatism after surgery
- Faster visual recovery
- Quicker return to daily activities
Phacoemulsification is the gold standard for cataract surgery today due to its minimally invasive nature and rapid post-operative recovery.
