WHAT IS A CATARACT?
Cataract is clouding of human crystalline eye lens which is normally clear & transparent. This blocks the light rays from passing through the lens & blurs the vision. The patient feels like as if he is looking through a frosted/fogged glass. As the cataractprogresses, the vision blurs further & eventually there is complete loss of vision
WHAT ARE THE SYMPTOMS OF CATARACT?
Slow, painless and progressive bluring of vision is the hallmark of a contract. Images are yellow, hazy and blurred. Sometimes it may cause double or multiple images. All these symptoms are not correctable by change in glasses. Also there may be increased glare, haloes at night time. Some people may notice an improvement in their near vision or a frequent change in their glasses prescription.
CAUSES OF CATARACT?
It is an ageing process. Everyone will experience a cataractin their lifetime. Only the age at which a cataractstrikes varies in individuals. It usually sets in around 60 years but in certain individuals it can happen early in life. Other causes of early cataractare Diabetes, infection or inflammation inside the eye. Cataract can sometimes be a congenital defect in children.
CATARACTSURGERY & RECOVERY ?
With all the advances in technology, cataract is removed through a tiny 2.2 mm microincision with ultrasonic energy. The eye recovers rapidly within 2-3 days and patient can resume his work schedule in quick time. The patient notices an improved vision almost immediately after the procedure.
IS CATARACT SURGERY SAFE ?
Cataract surgery is one of the safest surgeries performed the world over. However some minor complications like slight drooping of lid, lid swelling, corneal haze, glare, floaters(black spots) are temporary and recover with healing & medications, Chances of serious complications like infection, inflammation, retinal detachment & nucleus drop are negligible.
WHAT ARE THE OPTIONS FOR INTRAOCULAR LENSES ? (IOL)
- When cataract is removed during surgery, surgeon replaces the natural lens with an Intraoculars (IOL) A variety of IOL’s including Non-Foldable, Foldable & Premium lenses like Astheric, Toric, Multifocal, Extended range of vision & Microphaco Intraocular lenses are now available to improve quality of vision after Cataract Surgery.
- Foldable lenses are made up of Acrylic & can be injected through a micro incision. Because of the tiny incision size, no stitches are required. This helps in faster healing, less chances of infections & lesser chances of post-operative astigmatism (Cylindrical numbers) & all this translates into an enhanced quality of vision.
- Hydrophobic Acrylic IOL’s have an edge over Hydrophilic Acrylic IOL with respect to the lens material. This translates into superlative vision with lesser chances of capsular thickening.
ASPHERIC LENSES :
1. Conventional or non aspheric lenses impart images which are not as sharp as they could be, which means the patient will have vision of an order person rather than that of a healthy younger person.
2. Aspheric lenses or aberration free lenses are surface modified to improve image quality, brightness & overall contrast. Because of its wavefront design they provide excellent night vision & low light vision e.g walking in a fog or dining by candlelight. It also enables faster reaction time when driving at night.
3. Aspheric lenses which are negatively aberrated also improve depth perception.
In a healthy human eye, cornea is round is shape like a basketball. In eyes with atigmatism (Cylindrical numbers) the cornea is asymmetrical & shaped more like an egg. When light passes through a cornea with astigmatism the images does not focus sharply on the retina causing blurred vision. Toric lenses are designed to correct the astigmatism lenses after surgery.
- Monofocal lenses provide an individual with good distance vision bitt patient typically needs reading glasses to see up close.
- Multifocal lenses technologically designed to provide an individual with full range of vision from distance to intermediate to near (reading).
- However in Multifocal Lenses, patient notices rings (haloes) around light when driving at night. Also it may cause glare which is scattered light effect thet can appears around a source of light. As the eye adjust to the lens, over time, the visual impression of haloes & glare typically lesses. Also multifocal lenses decreases some amount of contrast which may affetct low light visibility e.g. dim lighting or fog. On the other hand it has an advantages of spectacles free vision for most distances.
These lenses use two advanced technologies of elongating the focus of the eye & correcting chromatic aberration (Color distortion). Hence these lenses provide sharp vision in all lighting conditions including low light. Also these lenses almost eliminate the problem of glare & haloes associated with multifocal lenses. But unlike multifocal lenses the patient may require the aid of small reading numbers to read extremely fine print. These lenses provide excellent distance & intermediate (computer) vision & functional near vision.
Other advances in lenses include microphone lenses that are injected through an extremely tiny 1.8 mm incision, Accomodative lenses that rely on patient’s own accommodation to import near vision, Trifocal lenses that provide excellent intermediate vision as compared to multifocal lenses, Heparin coated & Ozone modified lenses to overcome the posterior capsule opacity.
DOES THE CATARACT REOCCUR ?
No, but the patient can develop blur vision months or years after cataract surgery which gives a mistaken assumption that the cataract has grown again. This is not a cataractbut clouding or thickening of the thin capsular bag that helps keep the lens implant in place. This thickening is called PCO (Posterior Capsular Opacification) & it can be treated with YAG Laser on an outpatient basis & the vision improves soon after lase treatment.
WHAT IS THE BEST TIME TO TREAT CATARACT ?
- The old concept of operating the cataract only when it is mature or ripe has now become obsolete . With the advances in surgical techniques & with innovative lens implant now available, the quality of vision regained is similar to the youthful vision.
- Hence when a cataract starts interfering with the patient’s routine activities at work or leisure, it is recommended to consider cataract surgery & enjoy good quality vision.
WHAT HAPPENS IF THE SURGERY IS DEPLAYED / NOT DONE ?
- If the left untreated, the cataract will blur vision to an extend that the patient will not be able to perform any task at home at work.
- Also cataract may become overripe & burst causing increased intraocular pressure, redness & swelling of eye resulting in permanent visual loss.