VISION CORRECTION REFRACTIVE SURGERY
LASIK laser vision Correction
Dr. Rushmika singhla is now using the latest Nidek EC5000 Cx3 "Quest" Custom-LASIK machine for the most accurate results and safety. The Nidek Cx3 system incorporates the latest IRIS REGISTRATION software to detect smallest error in eye rotation (the torsion movement) during laser vision correction for more accurate correction of astigmatism. The Cx3 is a wavefront guided laser delivery system for CUSTOM LASIK. The LASIK (Laser-in-situ Keratimilleusis ) corrects all types of refractive errors (Spectacle powers) like Myopia (minus) Hyperopia (plus) and Astigmatism (cylinder ). It can correct mixed powers also (Cross compound )
LASIK is the most popular laser vision correction procedure in the world today. LASIK is a two stage procedure. The first step is creation of a flap of 90 – 130 micron thickness. The flap is then reflected and the exposed corneal stroma is called "THE BED".
The second step is to modify the curvature of the cornea by laser shots – "ABLATION" on the bed according to the predetermined corneal profile made by computer suitable for the particular eye. The flap is the replaced on the bed to produce an un-interrupted surface . The flap sticks to the bed quickly in two minutes and there is no need of any stitch or bandage. The vision is good just after the procedure and gets better with time and in nearly all the cases becomes perfect in one day.
WAVEFRONT GUIDEDC – LASIK
Wavefront is measurement of reflected light rays coming out of eye. This will measure the distortion of rays by aberrations in the eye. Wavefront guided C-Lasik corrects the corneal aberrations thereby offering a possibility of a super-vision which could be better than vision correction by glasses or contact lenses. Nidek NAVEX SYSTEM has 3 steps to a most accurate laser vision correction.
The aberrometer "OPD Scan" measures 1440 points (Maximum in the industry – 80 to 200 in other machines) on the cornea and FINAL FIT software calculates the final profile and the laser shots to achieve that profile. This shot data is loaded into a USB pen drive and transferred to the EC5000Cx3 "Quest" Excimer laser machine which then corrects the error in the eye according to the pre-planned shape to achieve the best result.
Chandigarh Eye Care is a recognized LASIK training center imparting training to doctors from Asia and India . Dr. Rushmika singhla is the first and only International Clinical Investigator in the field of LASIK and is Instructor in LASIK.
Dr. Rushmika singhla her a passion for incorporating the latest technology as quickly as it comes and has the first EPI-LASIK system in the country.
Epi-LASIK is a new innovative technique where a thin epithelial flap of 50 micron is raised with Epi-Keratome instead of a 90 - 130 micron flap in LASIK thus making Epi-LASIK a safer procedure for correction of higher myopia of over 10 dioptres. Epi-LASIK saves atleast 60 microns of corneal tissue and thus allows a safer corneal profile after laser vision correction.
This is a variant of Epi-LASIK where the epithelial flap is created with the help of alcohol. It avoids the keratome induced short time (1-2 minutes) increase in pressure of the eye. This procedure is helpful in conditions where eye pressure can not be raised e.g. after cataract , glaucoma and retina surgery.
Lepto (Thin) lasik is best for eyes where a THIN FLAP LASIK is safer. In high powers the thin flap spares more corneal thickness allowing more residual thickness after laser ablation. The new generation microkeratomes have special heads for thin flap lepto-lasik making a thin flap of uniform thickness.
PRESBYOPIC LASIK is another new procedure where laser vision correction is done for correction of both far and near vision. Presbyopia ( Need of near glasses ) starts after the age of 40 years. A unique corneal remodeling is done with Presby-LASIK and 3 zones are created – The central zone is for far vision and the outer zone is for near vision thus providing independence from both distance and near glasses for person over 40 years of age.
LASIK with TED (Iris Registration)
The Nidek Cx3 system incorporates the latest IRIS REGISTRATION software to detect smallest error in eye rotation (the torsion movement) during laser vision correction for more accurate correction of astigmatism.
LASIK What to expect
Lasik is a painless procedure that takes about 5 minutes. The eye is made numb with eye drops. There may be slight watering or irritation after the effect of these eye drops go away but that does not last for over one day normally.
Lasik is a 2 stage procedure where a 90 – 130 micron flap is first made with a microkeratome and reflected. The exposed surface "BED" is the treated with laser shots "ABLATION" to modify the curvature to the desired shape to achieve refractive correction.
The minimum requirement is
- Age above 18 years
- Stable refraction (Spectacle power) for one year)
LASIK Post-op Care
After LASIK a normal life routine is possible after 2 days. There are no restrictions on food, watching TV or reading and these activities can be performed to the level of comfort. Washing face and taking bath is allowed with eyes closed with care so that water does not enter the eye. There is no restriction on room lighting.
After LASIK the person can perform all the tasks as before without dependence on glasses or contact lenses. The aim is to achieve a post lasik spectacle power of within +/- 0.50 D. Any residual power above this range may be corrected by enhancement after a minimum period of 3 months.
Lasik is basically a safe procedure and rate of complications is very low. Complications such as under or over correction can be managed by enhancement in majority of cases. The other complications are flap related and though are serious and vision threatening in nature , are becoming rarer with advances in microkeratomes and the present generation of microkeratomes are safer. Now the bladeless femtosecond laser keratome promises to be safer.
PHAKIC INTRA-OCULAR LENSES
Phakic Intraocular lenses or Refractive IOLs are new age foldable IOLs which can be inserted through a small incision of 2.8 – 3.2 mm. These lenses are fixed between Iris and Natural lens of the eye without touching the natural lens and crowding the angle of the eye.
This avoids complications like cataract and glaucoma. The other advantage of these lenses are that they can be removed any time.
INTRA-CORNEAL INLAYS (INTACS)
Intacs is a non-laser procedure with FDA approval for use in patients with low amounts of myopia (-1.00 to -3.00 diopters of myopia with up to +1.00 diopters of astigmatism). The commercially available segments in the U.S. are intended to correct low amounts of nearsightedness but not astigmatism. The procedure involves the placement of two plastic segments within the non-seeing periphery of the cornea.
These segments flatten the central cornea without removing tissue to better focus light. The segments are made of the same material that's been implanted in human eyes after cataract surgery for nearly 50 years, called PMMA (polymethylmethacrylate). Intacs have the advantage of removability or exchangeability for different sized segments, and maintaining a more natural corneal shape.
REFRACTIVE LENS EXCHANGE
For person with a very high refractive error, the preferable choice is removal of clear natural lens and implanting:
- IOL IMPLANTS
- CAPSULAR TENSION RINGS (Endocapsular Rings)
IOL of appropriate power will reduce the spectacle power to a remarkable extent and in some cases where monovision is aimed ( One eye for distant vision, the other eye for near vision) this provides a spectacle free life is also possible.
The Endo capsular rings or Capsular tension rings keep the posterior capsule taut and thus reduce turbulence in the eye. This reduces the risk to the retina in such cases because retinal degenerations are more common in myopes and there is higher risk of retinal detachment in these eyes.
The new Multifocal intraocular lenses provide excellent distant and near vision and are now increasingly becoming the first choice for treatment of Presbyopia. Here a clear lens is removed and a multifocal IOL is implanted which thus provides good vision for near, far and middle distance.
The old technique of "Diamond Cuts" on the cornea is still relevant in some cases. A high intolerable astigmatism after cataract surgery or a small residual power after lasik when the enhancement with lasik is not possible due to thin residual corneal thickness can very efficiently and accurately treated with keratotomy.
AUTOMATED LAMELLAR KERATOMILLEUSIS (ALK)
Lamellar keratomilleusis was procedure of choice little more than a decade ago when lasik was either not available or prohibitively expensive. A small disc of corneal tissue was removed by an automated keratome mechanically after making a flap just like in lasik. This procedure is now completely overtaken by lasik because of accuracy and versatility of lasik.