Dr Verma Eye Hospital, Durg

Blurred vision can occur due to many reasons which can be temporary for short time & gets corrected by its own can occur due to dryness, watering, inability to open eyes in bright light, discharge, eye infection etc and associated with other symptoms like redness, grittiness, ocular pain, burning, stinging, stickiness or matted eye. Some abnormality seen in eyes like particles on its surface, white or yellow dots on black or white portion of eyes etc can also be present. Usually patients visit ophthalmologist and symptoms with vision gets corrected in 2-3 days with treatment. Persisting blurring can occur due to refractive errors which needs correction with suitable spectacles. If one do not get full vision even after spectacles and there is usually no other symptoms then it commonly indicates presence of cataract. Reduced vision can also occur due to other eye diseases and ocular effects of some systemic diseases, hereditary diseases, drugs trauma, amblyopia due to long standing uncorrected refractive errors and strabismus. Over maturation of cataract can cause pain due to very high intraocular pressure and untreatable visual loss following permanent damage to optic nerve therefore over waiting for cataract surgery may be dangerous.

Each eye has a clear transparent natural crystalline lens inside just behind its brown or coloured iris in central light ray path for making a high quality image of objects with good focus on retina for a good vision. It is little smaller than size of black of eye and 3-4 times thicker than one of your shirt button. It is made by flexible transparent lens protein & collagen fibres and has an aspheric round covering of transparent acellular material called it’s capsule and has some elasticity this capsule has all around 360* attachments near its equator (at its circumference and little anterior & posterior to it) of fine fibers called ‘Zonules” which at the other end are attached to humps of dark brown tissue inside coat of eye globe behind attachment of coloured iris called ciliary processes having ciliary muscles within them when one look at near objects ciliary process & iris constrict like a sphincter causing loosening of zonular fibers and natural crystalline lines as per it’s tendency swell to get thicker to focus more diverging light rays from near objects to retina to make clear image to read & see near objects. When seeing at distance iris & ciliary muscle relaxes causing larger diameter of ciliary processes lining attached to eyeball coat causing stretch on zonular fibers and natural crystalline lens gets pulled at periphery and slims and now focus parallel light rays on retina very well causing formation of very good image of far objects on retina. This crystalline lens gets denser with age due to uninterrupted growth & deposition of lens protein and naturally loose it’s elasticity enough by 40 years and people almost everyone needs reading glasses to see near objects or read fine prints it is called presbyopia. People wear halved glasses or moon segment glasses for it, the multi focal progressive spectacles are now being used for it from past few years since spectacle lens material now preferred is acrylic plastic in place of heavy & easily breakable glass, the progressive lenses are easy to make now and its cost has gone down compared to the past.

Further continuation of this aging process causes further condensation of lens protein and natural crystalline lens gets dense hard and opaque enough to block & disperse light rays to distort block or blur the image formed on retina therefore patients can not see clearly and this condition of eye and its natural lens is called cataract. This age related cataract is very common in old age. Cataract can occur if its outer watertight covering capsule is breached the fluid seep in and makes lens fiber white and opaque this occur in case of eye injuries. Harmful substances can deposit in lens like in diabetes iridocyclitis ets and can cause cataract. Glaucoma also can cause cataract. Cataract can be present since birth as a developmental anomaly is called congenital cataract. Harmful rays like infrared, ultraviolet (prolong sun exposure), radiation (radiotherapy) and some of the drugs (steroids in long uses) can cause cataract.

If cataract is not there rarely some other eye diseases like corneal problems affecting surface transparent coat of eye ball in round area of black of eyes, iridocyclitis the disease affecting inside brown tissues of eye may cause deformation of central jet black windows opening in center of the brown tissue from where light enters within eyes and we see, glaucoma where eye globe has higher fluid pressure within causing retinal nerve and optic nerve to get pinched and slowly die, hemorrhages or floating opacities within eyes to interfere image formations on retina, retinal diseases itself which fail to create good electrical impulse conversion of an image for transmission to brain by optic nerve tracts, faults in these optic nerve tracts or fault in brain which is in its back portion near its back tips which process visual information. Presence of high uncorrected refractive errors or cataract for longer period like for many years can cause settings up of amblyopia meaning non gaining of vision due to over neglected vision correction efforts, this may result from or cause eye deviations or squint.

So all these eye diseases can coexist with cataract and can cause not regaining good vision even after successful cataract surgery. Most of the eye diseases can be identified during eye examination before surgery by ophthalmologist and patient is told before hand, but some eye diseases can be still missed to be identified because as patient can not see the world out side similarly the eye surgeon can not see in detail the health of deeper eye structure due to presence of the cataract. In case of suspicion of any coexistant eye disease the ultrasonography can be done to rule out retinal detachments vitreous hemorrhages tumour etc, OCT test the macula & optic disc sometime is not accurate

There are older types of cataract surgeries which use to remove cataract only and patient needs to wear thick and heavy spectacles to regain vision but what he was able to see was 30% magnified with wrong distance appreciations that made patient to rely on hit & try method making him slow to walk slow to read & write slow to catch an object and slow to appreciate a currancy note like he may get confused between old one rupee note with new hundred rupees note and old two rupee note with new two thousand rupees note. Overall slowness and slow speed of work on average shorten his life post cataract surgery by two years with less visual experiences. Now a days this intracapsular cataract surgery are not done.

Intra ocular lens implantation is newer cataract surgery where an artificially manufactured light weight bio-inert material lens replaces the opaque natural lens of eye (cataract), this implant is now most widely used worldwide and most common among all body implants and being implanted inside most sensitive structure of body the eyes and proved very safe. Earlier technique of ECCE is still done for low cost but it is being replaced by SICS suture less or single suture surgery costing rupees 10000-20000/- depending on costly medicine & other devices used like viscoat, scleral fixation IOLs, fibrin glue, combined with trabeculectomy, pterygium etc

Phacoemulsification is now a modern technology being practiced widely is a bit difficult surgery needs costly instruments but now is affordable with single vision IOLs it varies between 18000/- to 35000/- due to different IOL specifications and make. Imported IOLs are of superior quality than economic Indian IOLs. Phacoemulsification with Toric IOL cost between 40000/- to 60000/- and Multifocal IOLs cost between 75000/- to 180000/-. Laser adjustable single vision IOLs are costing about 180000/-. Customized made imported IOLs are more costly.

Variety of multifocal IOLs providing vision depicted in graph with their optic design on the side, top most is Monofocal IOL providing distant vision only for comparision

Choice between non aspheric (Traditional) versus aspheric IOL

Fematosecond Laser Assisted Cataract Surgery (FLACKS) where no knifes are used every incision is finely produced by Laser followed by use of Phacoemulsification is new technologies available for approximately Rs 200000/- package

The intra ocular lenses implanted within the transparent membranous bag of the cataract after removing all opaque lens material. The peripheral softer material can be taken out by simple irrigation and aspiration only and the central hard nucleus needs to be catched by suction broken or cut in to pieces while held and bit by bit removed using ultrasound or laser energy to make its emulsion to suck it out from eye. If this strategy is not used than a larger 7-9 mm incision needed to take the coat button size double thick hard central nucleus of the cataract out of eyes in toto. Once cataract is cleaned the foldable IOLs loaded in carteridge with rolled like calander can be injected inside the eye by small 2.8mm incision if Phacoemulsification is used as a tachnique to remove cataract. With manual technique cataract is removed by atleast 7-9 mm incision and larger tunnel creation Which can cause astigmatism ( cylindrical power) a rigid intraocular lens is implanted as large size is incision is already available.

Multifocal & EDOF IOLs are used to provide distance & near or distance near and intermediate vision. Some haloes & glare will be there with decrease in contrast sensitivity. Phakic IOLs are implanted to remove spects over natural crystalline clear lens here cataract is not present it cost about 70000/- to 150000/- per eye depending upon cost of IOLs