The natural lens:
The natural lens like the cornea makes sure that the light rays which enter the eye are properly focused on to the retina. This results in a sharp image on the retina. The natural lens is transparent and clear which enables light to pass through it easily.
Clouding or opacification of the natural lens is cataract. Most commonly cataract is caused by old age or other reasons affects the clarity and the visual acuity. The lens starts loosing its transparency and becomes transluscent and then opaque. Cataract is the most common cause of vision impairment and blindness in the world.
Symptoms of Cataract:
• Blurred vision
• Double vision
• Sensitivity to light
• The need for more light when reading
• Diminished night vision
• Changed prescription power for glasses
Senile cataract is by far the most common type of cataract. Due to an aging population, this type of cataract is on the increase.
Ideal Time For Cataract Surgery:
Personal variation noted for the ideal time for cataract surgery. The need of emergency cataract surgery depends upon the grade of maturity of cataract and cataract associated with complication, quality of life, occupational need, personal health are some factors which are to be considered.
Indication For Cataract Surgery:
• Visual improvement : Most common indication.
• Medical indications: Phacolytic glaucoma, Phacomorphic glaucoma, for improvement of clarity of ocular media required in the context of fundal pathology.
• Cosmetic indication: Rare like mature cataract.
Preoperative evaluation for management of age related cataract:
1. Visual acuity     2. Cover test     3. Pupillary responses     4. Ocular adnexa     5. Cornea
6. Anterior segment     7. Lens     8. Fundus     9. Biometry and IOL power calculation.
Treatment of cataract:
The only option available for cataract is cataract surgery which includes removal of the opacified, opaque lens and replaced with intraocular lens which will remain in the eye permanently. When IOL is placed it is called pseudophakia. When IOL not placed it is called surgical aphakia, in that case patient have to wear plus numbers which are thick glasses which is cosmetically and practically cumbersome for patient.
Anaesthesia for cataract surgery:
Mostly performed under local anaesthesia sometime requires general anaesthesia like in children. Now a days cataract surgery is possible with topical eye drops in the eyes and patient may go home wearing dark goggles directly from operation theatre.
Types of cataract surgery:
Apart from conventional cataract surgery, now a days globally accepted advanced technology is phacoemulsification.
Advantages of phacoemulsification:
• Smaller incision size
• Little induced post operative astigmatism
• Early stabilization of refraction
• Post operative wound related problems eliminated
Is cataract surgery safe? Risks in cataract surgery?
Rarely there may be risks in cataract surgery, although potential risk with cataract surgery includes vitreous haemorrhage, secondary glaucoma, retinal detachment, posterior capsular tear, CME.
Instructions after cataract surgery:
Do not head bath for seven days
• Do not rub eyes
• Do not bend forward, Do not lift heavy weight
• Dark goggles for protection
• Regular medication
• Regular post op visits
• Follow up:
At Sunder Netralaya all the do’s and dont’s are written on the in patient file in details. The patient and attending relative should go through the matter in details.
What next after cataract surgery:
As per protocol at Sunder Netralaya oral medication for five days. If surgery is done under topical drops then dark goggles immediately after operation and topical drops started. If surgery done after peribulbar block then eye patch for 8-10 hours then dark goggles and topical drops.
Glasses after cataract surgery:
The patient have to wear glasses after cataract surgery exception is multifocal/multifocal toric IOL implementation, in special situation when it is possible. In unifocal IOL Implementation glasses are prescribed if needed for distance and all the way for near work.
Cataract surgery in special cases:
Some situation are complicated for performing cataract surgery as: Paediatric cataract surgery: Performed under general anesthesia.The child is not given any food 6-7 hours before surgery. After the surgery the child regains consciousness within few hours then liquid diet is started. Post operative care instructions are given to the parent. Vision rehabilitation therapy is explained to the parents. Regular follow ups are essential.
Trauma may not only cause cataract but also damage to cornea, iris, retina. B-scan ultrasonography plays a major role in such cases.
Post Lasik/PRK cataract surgery: As refractive surgery leads to a change in cornea, IOL power calculations at Sunder Netralaya we take special attention to this by using IOL master which is in corporated with special formulae.
Investigations for cataract surgery:
• IOL for power calculation: We use IOL master for the same.
• B-Scan: If needed in traumatic/mature cataract cases.
• Anterior Segment OCT: If needed like post lasik, PRK cases.
• Indirect Ophthalmoscopy/Direct Ophthalmoscopy
• Non Contact/Applanation tonometry
• Sac Syringing
• Xylocaine Test
• Systemic Examination
IOL(Lens) Options At Sunder Netralaya:
• Toric/Multifocal Toric
Extra Efforts for better vision:
Limbal relaxing incisions (LRI) when patient has astigmatism (Cylinder power) the cornea is not perfectely round.LRI is procedure performed on the surface of the cornea to modify its shape to treat astigmatism.
It is a refractive cataract procedure in which treatment of cataract and astigmatism in a single surgical procedure can be done. The patient who are having pre-existing astigmatism when underwent toric IOL surgery experiences spectacle free vision for distance.
Distance, intermediate distance and near distance along with astigmatism correction can be done with these lenses. Patient experiences total spectacle free vision.
In these lenses patient experiences spectacle free vision for distance and near. Suggested that both eyes to be operated for multifocal IOL’s.
When any patient is operated previously and IOL is not put then secondary IOL can be done for betterment of vision.