Cornea is the outermost transparent portion of the eye.
Keratoconus Infections Dystrophies Degenerations Corneal scars
Not all corneal pathologies need surgery. A number of pathologies can be treated medically. However, for treatment of corneal pathologies that are not treatable with medicines, a surgery may be required. Most common corneal surgery is penetrating keratoplasty (corneal transplant).
Cornea transplant is a procedure where the diseased cornea is removed and is replaced with a donor cornea that is collected from a healthy donor after death.
A patient who requires corneal transplantation needs to register in the eye bank for cornea. When a suitable cornea is available for the patient, eye bank and the hospital will coordinate for the transplantation to be performed. The surgery is done usually under local anesthesia. For children general anesthesia is preferred. For full thickness corneal transplant- a round trephine is made in the cornea and similar round full thickness donor cornea is sutured to the host For partial thickness transplant- DSEK The donor cornea is dissected either using an automated machine called microkeratome or manually. The donor lenticule is inserted in the eye of the patient and is attached to the host using air. This procedure does not require sutures to attach the graft. Deep anterior lamellar keratplasty- In this only the anterior layers of the cornea are replaced by donor cornea. Keratoprosthesis-Here a special device called keratoprosthesis is placed in the eye. This has a central cylinder that passes through the centre of the donor cornea.
After corneal transplant patient needs to be kept on drops for along time. These include antibiotics for a few days, steroids in tapering doses for a few months and lubricating drops.
For people who do intend to wear glasses and contact lenses and have a refractive error, we have options in the form of refractive surgery. Refractive surgery aims at making people spectacle free. This is done by means of performing surgeries such as LASIK, PRK or ICL LASIK (Laser assisted in situ keratomileusis) is a procedure where the cornea is reshaped to correct the refractive error. A flap of the cornea is lifted using a blade (microkeratome) or bladeless (femtosecond). After the flap is raised, the cornea is reshaped using eximer laser. Repositing the flap back follows this. PRK (Photorefractive keratectomy) is performed using the same laser. However, we do not life a flap of the cornea for this procedure. ICL (Implantable collamer lens)- This consists of placing a lens above the normal crystalline lens
Not every one is suitable for LASIK. Before planning a LASIK, patients have to undergo certain tests to evaluate if they are suitable for LASIK. LASIK is performed for patients with myopia of up to -10 diopters, Hyperopia of up to 6 D and Astigmatism of up to 4 D. However, it is not just the refractive error that decides the suitability for LASIK. A through evaluation of the cornea on slit lamp to rule out any clinical signs of keratoconus, corneal scars or infiltrates is done. A corneal pachymetry of more than 490 microns is required for LASIK. A corneal topography is done to rule out any signs of sub clinical keratoconus. If any of the above criteria are not fulfilled, patients cannot undergo LASIK
Yes. In cases of thinner cornea with low to moderate refractive errors, we can perform PRK.
Yes. For those who are not suitable for LASIK/ PRK can now undergo a surgery called ICL. In this procedure, we place an intraocular lens above the normal crystalline lens. It simply means placing a permanent contact lens in the eye.
LASIK surgery intends to make a person spectacle free. At the time of surgery, we feed the target refraction in the machine as Zero. However, sometimes there may be a residual error of 0.25 to 0.5D, especially in cases of higher refractive error that does not require to be corrected with glasses.
Prior to LASIK, the patient should stop wearing contact lenses atleast for 1 week before the surgery. This will facilitate an accurate refraction, pachymetry and topography so that we do not have any refractive surprises after the surgery. Patient should preferably have a hair bath a night prior to the surgery itself (patients will be advised to avoid hair bath for 2 weeks after the surgery) On the day of the surgery, patients should avoid wearing any perfume, deodorant and any eye makeup. After the surgery, the patients will be prescribed dark glasses to be worn for a couple of days. The patient will be also given a couple of drops that have continued for a month after the surgery. The patient can resume the routine activities in two days.
One can resume the normal activities after two days. What are the complications of LASIK? LASIK is relatively a safe surgery. During the early postoperative period, patients may experience halos and glare. However, these will disappear in a month.
Cataract refers to opacification of the lens
Most common cause of cataract is age related. Other causes of cataract include Congenital – since birth Developmental – in childhood Diabetic Uveitic Traumatic
Cataract is not preventable. Since most common cause is senile/ age related, if only we could stop aging, cataracts could have been preventable.
No. No drops can avoid or treat cataract. Only treatment for cataract is surgery
Cataract surgery is usually a simple procedure that lasts for few minutes. There is no need for any admission to the hospital prior to the surgery and also patient can go home after the surgery in a few minutes. It is called a day care surgery. The surgery is done under topical anesthesia i.e. using some drops to decrease the pain at the time of surgery. There is no need to give any injection to the eye. The surgery is done by making a small incision on the cornea that is around 1.8 to 2.2 mm in size. The incision does not require any sutures to be put. The patients start putting drops from same day. Patients can start their routine activity in a couple of days.
Before inserting the intraocular lens, the power of the lens is to be calculated. Performing a few tests that measure the axial length of the eye using A-scan ultrasound and keratometer does this. Patient can choose the lens from the various packages that we offer.
At the time of the cataract surgery, we aim at leaving zero refractive error for the patient. This translates into an excellent distant vision. The patients would not require glasses for distance. However, they would need to wear glasses for near. Can I not get rid of glasses totally, for both distance and near? The patients who chose not to wear any glasses for distance and near, we have options like Multifocal intraocular lenses. These help in correction of both distance and near vision. A second option is called monovision. In this one eye is corrected for distance and other eye is corrected for near.
Cataract surgery is usually a safe surgery. However, rarely there may complications such as posterior capsular rent, in which case the lens is implanted in the sulcus. Other rare complications include infection. At our center, we observe strict criteria for asepsis and hence the chances of infections are very rare.