Cataract is progressive blurring of vision resulting from clouding (Opacification) of natural lens of the eye.When this reduction of vision is problematic for the patient, cataract surgery can be done to remove cloudy lens & new artificial intraocular lens (IOL) is put inside the eye.
Technique of Surgery :Phacoemulsification is the latest technique of cataract surgery. In this procedure, small incision (usually less than 3mm) is given in the eye, Phacoemulsification probe inserted into the eye through this incision divides the natural lens into smaller pieces (using ultrasound waves) & then aspirates (emulsifies) these smaller pieces. Once the natural lens is out, new artificial lens (mostly foldable) is put into the eye.
Based on focusing power : Lenses are of two types
Unifocal :This lens has single focal length i.e. it focuses best at one point only (Which is usually aimed at far point). So patient mostly have clear vision for distance without glasses or with minimal power of glasses but need glasses for clearly seeing near objects. Contrast achieved with this lens is good.
Multifocal : It has two focal points (aimed at for point & near point).If power suitably adjusted then need for wearing spectacles is minimized.Not suitable for those having higher cylindrical power in the eye.
However, contrast achieved with this is lesser than unifocal and patient can have glare especially if driving at night.
Based on type of power :- Lenses can be of two types
Non-toric Lenses :Lenses having only spherical power.
Toric Lenses : Lenses having both spherical & cylindrical power. Very useful for those who have astigmatism (cylindrical power) in the eye.
Other modifications in Lenses
Spheric lenses are lenses in which surface of lens is uniformly curved while aspheric lenses have curvature flattening out towards the periphery. While aspheric lenses produce image with sharp contrast, but spheric lenses produce less contrast due to spheric aberration induced by them.
Alternatives Techniques :
MICS :- Phacoemulsification with incision size of < 2 - 2.2mm is called MICS (Microincision Cataract Surgery). It can have slight advantage over phacoemulsification with incision size of 2.8mm.
SICS (Small Incision Cataract Surgery) :- In this procedure, incision is much larger than phacoemulsification & whole natural lens is removed in toto through this incision manually without being broken into smaller pieces by phacoemulsification probe. Usually there is no need to put suture over the incision.
ECCE (Extracapsular Cataract Extraction) :- Again incision size is larger like that in SICS. In this technique wound has to be sutured.
Result of Cataract Surgery:
Result of cataract surgery are very good and it is considered relatively safe procedure but any surgical procedure do have some inherent associated possible risks/complications. So definitely no guarantee can be given for successful results.
Our Surgeon :Our Cataract specialist Dr Rajeev Gupta is highly experienced (experience of over 30,000 phaco surgeries) in latest technique of phaco emulsification. His results are comparable to the best in the field.
Modifications in Phacoemulsification:
Phacoemulsification :In this technique incision given is 2.8 mm & cataract (opaque natural lens) is removed with the help of phaco probe which divides the nucleus(cataract) into smaller pieces & then emulsifies & aspirates those pieces.
MICS :-It is same as phacoemulsification but the incision size is even smaller 1.8 to 2.2 mm.
Femto Laser Cataract Surgery
In this surgery incision & few other steps are performed by laser but actual removal (i.e. emulsification & Aspiration) of cataract is performed by phaco probe only like in phacoemulsification. Laser in this technique can have some advantage over phacoemulsification/MICS but have disadvantages also.Opinion of eye surgeons is divided if laser cataract surgery is better than phacoemulsification/mics or vice versa.
Our surgeon Dr. Rajeev Gupta feels if he has to undergo cataract surgery on his eye today, he will go by phacoemulsification/mics not by laser cataract surgery. May be with advancement in technique in future, his opinion changes in favour of laser cataract surgery. As of now phacoemulsification/mics is more safer ,reliable,time tested & reproducible in his views.
Which Lens to Choose:
There is no simple answer to this question. It depends on patients personality, work profile, lifestyle, condition of the eye & affordability.
But if we try to Simplify.
Hydrophobic is preferred over hydrophilic
Aspheric surface is better
Square edge preferred
Make of lens i.e of which brand (company). Rate can very a lot between different brands, patient can take his own decision regarding the brand depending upon affordability. It may not be an easy task to differentiate between different brands & opinion of various surgeons is likely to differ.
This is especially good for those who want to see both distance and near objects clear without glasses & less than perfect quality of vision is acceptable to them. Perfect quality of vision is more likely to be obtained when glasses are used (as required) with monofocal lens.
Moreover, those who have to drive in the night, can have glare with multifocal lens, so they also need to consider if they would like multifocal lens or not.