Articles on lasik

Here Is All You Want to Know About Lasik!

Dr. Sridevi Haldar, Ophthalmologist
Refractive Surgery/Laser Vision Correction With technological advancements happening at a rapid pace, the options for refractive vision correction have increased dramatically during the last few years. We at itek vision centre are keeping up with the latest technological trends to give youthe best possible treatments options available worldwide.Laser Vision Correction (Refractive Surgery) is a term given to surgical procedures designed to correct certain vision problems such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. These procedures use an excimer laser beam to help reshape the cornea. An excimer laser produces "cool" light beams, which are ideal for refractive surgery. These procedures are done on an outpatient basis. The two most common procedures performed with the excimer laser are laser in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).There are risks involved with laser vision correction just as there are with any other surgical procedure. Some risks are dryness to the eyes, and visual side effects such as hazy vision, glare, halos, and other night vision disturbances. An in-depth review of the various risks associated with refractive surgery is included in our surgical consent forms. The U.S. Food and Drug Administration (FDA) has approved the use of several excimer lasers, for the treatment of myopia, myopia with astigmatism, hyperopia, and hyperopia with astigmatism.Laser Vision Correction SurgeryThe procedures offered include:PRK(Photorefractive Keratotomy)LASIK (Laser Assisted In Situ Keratomileusis)PTK(Phototherapeutic Keratectomy)Phakic Intraocular Lenses(ICL/EyePCL)Refractive/Clear Lens ExchangePRK (Photorefractive Keratotomy)An Excimer laser beam that emits ultra violet light reshapes the cornea after removing the epithelial surface layers of the cornea. It is indicated in patients with thin cornea and who cannot undergo Lasik but are highly motivated to undergo vision correction procedure owing to their lifestyle and cosmetic needs.LASIK (Laser Assisted In-Situ Keratomileusis)LASIK can correct varying degrees of nearsightedness (myopia), farsightedness (hyperopia), and astigmatism and is generally the treatment of choice for patients with mild to modaerate degrees of myopia or hyperopia. In LASIK surgery, the underlying surface of the cornea is reshaped with the laser, allowing light to be refocused and vision improved. LASIK surgery generally results in little or no post-operative pain and rapid recovery of vision.detailed corneal profile(adequate thickness and appropriate curvature) must be evaluated to decide if you are eligible to undergo LASIK.Accurate refraction assessment and detailed corneal profile (i.e. thickness, curvature,etc..) is evaluated with the help of pentacam before choosing the type of refractive procedure for your eyes.FLAP CREATIONa)Depending on the thickness of your cornea a microkeratome(either Moria microkeratome, Hansatome or an SBK) is chosen to create a flap of differential thickness.b)Femtosecond Lasers, such as the FS200 or the Intralase®, are an all laser approach to vision correction; they create thin flaps in the eye using short laser pulses. The flaps are then lifted from the eye's surface, and the curvature of the eye is corrected. Its popularly known as the’ bladefree’ approach.TISSUE ABLATIONExcimer Lasers, such as the ALLEGRETTO WAVE® or VISX CustomVue™, are used to produce beams of invisible ultraviolet light energy, and remove microscopic amounts of tissue in the eye; this process reshapes the curvature of the eye.Various treatment algorithms are available that are customized according to individual patient profile.Eg.Standard LASIKc-LASIK (customvue LASIK)Topo guided LASIKAspheric LASIKLASIK improves the uncorrected vision -- one's visual capacity while not wearing corrective lenses -- in most patients who have the procedure Many patients can also expect to see better than 20/40 uncorrected.  However, there are no guarantees that you will have perfect vision, and patients with high myopia (more than -7D) and high hyperopia (more than +4D) should have lower expectations.The effects of LASIK are permanent and do not wear off over time therefore a stable prescription for over a period of 1 year is require before proceeding with this procedure.. Patients should also note that while results are stable long-term, a mild regression of the laser effect may occur during the first few post-operative months. This occurs in approximately 10% of patients and if noted, may require an enhancement procedure if your doctor feels it to be appropriate.PTK(Phototherapeutic Keratectomy)This procedure is used for removing minute irregularies and opacities in superficial layers of cornea as in certain corneal dystrophies.Phakic Intraocular LensesPhakic Intraocular Lenses are clear, implantable lenses that are surgically placed between the cornea and iris. The lenses allow light to focus on the retina, which causes clearer vision without glasses or contact lenses. The phakic intraocular lenses work from within the eye, unlike corrective lenses, which work from the surface of the eye.STAAR Visian ICL™ intraocular lenses are made to remain in the eye for a lifetime. Visian ICL™ lenses are able to treat patients with thin corneas, dry eyes, and patients with extreme refractive errors.Refractive/Clear Lens ExchangeRefractive/Clear Lens Exchange is typically performed on patients with high degrees of hyperopia (farsightedness). In this procedure, the eye's natural lens is replaced with an artificial, intraocular lens. This corrects refractive error and helps achieve sharper focus.Frequently Asked Lasik Questions1. How long does the surgery take?Lasik is performed as an in-office procedure in our laser center. Although the treatment takes approximately 10 minutes per eye, you should expect to be at the laser center about 2 to 3 hours for the total process2. Should I expect any pain after my Lasik procedure?The procedure itself is relatively painless. It is common, however, to have a foreign-body sensation or burning with tearing for 4 to 6 hours following the treatment.3. How soon can I return to work after Lasik?Often the next day, although it may be difficult to perform prolonged reading or computer tasks right away.4. How soon after the laser procedure can I bathe or take a shower?Typically, you can shower or bathe the following day, but you should avoid getting shampoo, soap, or water directly into your eyes.6. When can I wear eye makeup?Please do not wear mascara, eye shadow or eyeliner for 3 days prior to treatment. On the day of treatment, please refrain from wearing any makeup, after shave and lotion or moisturizer or a deodrant. You can start wearing eye makeup approximately 1 week after the procedure. Purchasing new makeup, especially mascara, is strongly recommended.7. How long before I can exercise?Strenuous exercise should be avoided for approximately 1 month. Sweat in the eye should be avoided for at least 2 weeks due to bacteria on the skin. Otherwise, non-contact sports can be resumed as soon as you feel comfortable. If you are involved in any kind of contact sports, remember to wear sports goggles for protection.8. How soon can I swim, sauna, or hot tub?Swimming, saunas, and hot tubs should be avoided for 2 weeks, minimum.9. When can I travel on an airplane?Unless it is an emergency, and we advise you to stay locally for approximately 1 week after your surgery in case of an emergency.TAKE HOME MESSAGEPeople who are most satisfied with the results of laser correction clearly understand the potential risks and complications of the surgery and possess realistic expectations of what their vision will be like following surgery.

High Myopia: If Not Lasik, Then What?

Dr. Vaibhev Mittal, Ophthalmologist
Question 1: What is the option in high myopia if LASIK is not possible?Answer :  Phakic intraocular lens/Implantable contact lens  (ICL) is a form of refractive surgery where specially designed lens is implanted into the eye to correct high myopia (nearsightedness) in patients who are not suitable candidate for LASIK.  Word “Phakia” means lens, so in this surgery natural lens present in eye is left untouched and new lens is implanted over the natural lens.Question 2: Who are suitable candidate for  ICL?Answer: Patients who are more than 21 years of age with stable refraction and without any preexisting eye disease such as uveitis etc. are suitable candidate for ICL surgeryQuestion 3: What are the advantages of ICL surgery?Answer: The biggest advantage of ICL surgery is that it can treat high myopic refractive errors that is not possible with LASIK surgery. An added advantage is that natural lens is preserved  and so natural accommodation is preserved. Moreover, it is reversible procedure.Question 4: Is this procedure safe? What are risks involved?Answer : ICL is a very safe procedure.There may be some minor side effects  like  glare and haloes which usually settle with time. Serious complication like  cataract, glaucoma etc. are less common  and can be managedQuestion 5: Is the lens visible to others? Answer:  As  ICL is positioned behind the iris (the colored part of the eye), so  it is not visible to anybody.LASIK Vs ICLICL and LASIK  both are good options to get rid of glasses. ICL is a boon to those patients who were rejected for LASIK due to their irregular shape or insufficient thickness of their cornea. Moreover patients with eye diseases like keratoconus or dry eyes who were not suitable for LASIK can now also enjoy good vision without glasses with the help of ICL.

Most Important Questions Regarding Spectacle Removal Surgery (Lasik)

Dr. Vishal Arora, Ophthalmologist
1. WHAT IS LASIK? HOW IS IT PERFORMED?LASIK or laser-assisted in situ keratomileusis is procedure commonly used for removal of spectacle number (Glasses) of the patient. The surgery is done on the cornea which is the outermost clear part of the eye. A flap is created as a part of the process followed by laser delivery on the cornea to remove the glass number. The flap is positioned back at the end of the procedure. 2. WHAT OCULAR CONDITIONS OR DISORDERS CAN BE EFFECTIVELY TREATED BY LASIK?LASIK is most commonly performed for Myopia (Negative spectacle power) and its variants like High Myopia, Myopic astigmatism (patients with cylindrical glass power), Anisometropia (difference in glass power of both eyes).LASIK can also be done for Hypermetropia (Positive spectacle power), Off  late it has been increasingly done for presbyopia(Age related positive power beyond 40 years of age.)3. HOW SAFE IS THIS PROCEDURE ? WHAT ARE THE SUCCESS RATES WITH LASIK TREATMENT FOR REFRACTIVE  ERRORS?LASIK is one of the most evolved procedures in ophthalmology today. It has been more than 20 years since first procedure was done. It’s SAFE and EFFECTIVE in patients who want to get rid of their glasses. (http://www.ncbi.nlm.nih.gov/pubmed/21946784)4. HOW DO YOU DECIDE WHETHER A PARTICULAR PATIENT IS FIT FOR LASIK OR LENS?I follow a very strict criteria for my patients undergoing LASIK (I reject 4 out of 10 cases)The criteria are Expectation: the expectations of the patient should be realisticStability: the glass number should be stable over a period of 6 months to 1 yearCorneal Thickness:the corneal thickness should be adequate so that the procedure can be done safely. The cornea should be disease free.Retina: Patients with retinal diseases need treatment for the same before proceeding for LASIKIn patients who don’t  have adequate corneal thickness a procedure called ICL is done in which a thin lens is implanted in front of the natural lens.5. WHAT SHOULD A PATIENT EXPECT BEFORE AND AFTER LASIK SURGERY?The expectation of the patient before the procedure should be realistic. Most patients who wish that their number should never come back should consider that it took 20 + years for the number to develop and expecting the doctor to predict that it will not come is unrealistic. But if the number has remained stable and all above mentioned criteria are met there is less than 1 % chance that it will come back.After LASIK one can resume normal activities from day 1. Eye rubbing and swimming should be avoided for at least one month.6. WHAT ARE THE POSSIBLE COMPLICATIONS OR RISKS ASSOCIATED WITH LASIK SURGERY?LASIK is one of the safest and most rewarding surgery. The patient starts seeing from day 1 post surgery. Dry eye is most common and can be controlled with eye drops. Other complications like Regression of number, Ectasia can also occur.

Correct Your Eyesight With Lasik

Dr. Vaibhev Mittal, Ophthalmologist
LASIK or laser in situ keratomileusis, is a form of corrective surgery that help patients who are suffering from near sightedness (Myopia), far sightedness (Hypermetropia) and even astigmatism (cylindrical power in glasses). This procedure aims at correcting the shape of the cornea, which is the transparent layer that lines the front of the eye. Through this procedure, the cornea is reshaped so that the retina receives a focused light.So what are the health tips for people going through a LASIK procedure? Here is our take:Advantages:The biggest advantage of LASIK is that it helps people to get rid of glasses and contact lenses, which sometimes are cosmetically unacceptable and in some cases are visually disabling.The best part of LASIK is that it is:Quick (total duration of surgery is hardly 5 minutes) and virtually painless.Has a high success rate ( success rate is 96%).Does not require bandages or stitches.Adjustments can be made years later to alter the vision as per growing impairment in the future and advancing years.Risks/Side Effects:Minor side effects like dryness, glare and halos, if appear, subside with time.Eligibility Criteria:Any person 18 yrs or older who fulfils the following criteria can undergo Lasik surgeryStable refractionCorneal thickness and topography should be in normal rangeDilated retinal examination should be normalAdequately wet eyesNote: One should abstain from wearing contact lens at least 2 weeks before the procedure.Precaution after the Procedure: Patient is likely to have some inflammation after the procedure and temporary dryness. Use medicines as prescribed by the doctor.Avoid any type of eye makeup for at least 1 month after surgeryAvoid swimming or water sports for at least 2- 3 weeks after surgeryGoing through a LASIK procedure is a matter of finding the right specialist and ensuring that you take all the precautions before the procedure. Also, it is important to look into your medical history and eyes in particular so as to avoid complications.

Cataract

Dr. Rajesh Babubhai Shah, Ophthalmologist
 Practice ManaCATARACTSWhat Are Cataracts?Cataract SymptomsWho Is at Risk for Cataracts?Cataract CausesCataract DiagnosisCataract TreatmentCataract SurgeryIOL Implants: Lens Replacement and Cataract SurgeryCataract Vision SimulatorCataract Pictures and Videos: What Do Cataracts Look Like?IOL Implants: Lens Replacement and Cataract SurgeryWritten by: Kierstan BoydReviewed by: Elizabeth Yeu MDMar. 01, 2016Before intraocular lenses (IOLs) were developed, people had to wear very thick eyeglasses or special contact lenses to be able to see after cataract surgery. Now, with cataract lens replacement, several types of IOL implants are available to help people enjoy improved vision. Discuss these options with your Eye M.D. to determine the IOL that best suits your vision needs and lifestyle.Cataract lens replacement: How IOLs workLike your eye's natural lens, an IOL focuses light that comes into your eye through the cornea and pupil onto the retina, the sensitive tissue at the back of the eye that relays images through the optic nerve to the brain. Most IOLs are made of a flexible, foldable material and are about one-third of the size of a dime. Like the lenses of prescription eyeglasses, your IOL will contain the appropriate prescription to give you the best vision possible. Read below to learn about how IOL types correct specific vision problems.Which lens option is right for you?Before surgery your eyes are measured to determine your IOL prescription, and you and your Eye M.D. will compare options to decide which IOL type is best for you, depending in part on how you feel about wearing glasses for reading and near vision.The type of IOL implanted will affect how you see when not wearing eyeglasses. Glasses may still be needed by some people for some activities.If you have astigmatism, your Eye M.D. will discuss toric IOLs and related treatment options with you.In certain cases, cost may be a deciding factor for you if you have the option of selecting special premium lOLs that may reduce your need for glasses.Intraocular lens (IOL) typesMonofocal lensThis common IOL type has been used for several decades.Monofocals are set to provide best corrected vision at near, intermediate or far distances.Most people who choose monofocals have their IOLs set for distance vision and use reading glasses for near activities. On the other hand, a person whose IOLs were set to correct near vision would need glasses to see distant objects clearly.Some who choose monofocals decide to have the IOL for one eye set for distance vision, and the other set for near vision, a strategy called "monovision." The brain adapts and synthesizes the information from both eyes to provide vision at intermediate distances. Often this reduces the need for reading glasses. People who regularly use computers, PDAs or other digital devices may find this especially useful. Individuals considering monovision may be able to try this technique with contact lenses first to see how well they can adapt to monovision. Those who require crisp, detailed vision may decide monovision is not for them. People with appropriate vision prescriptions may find that monovision allows them see well at most distances with little or no need for eyeglasses.Presbyopia is a condition that affects everyone at some point after age 40, when the eye's lens becomes less flexible and makes near vision more difficult, especially in low light. Since presbyopia makes it difficult to see near objects clearly, even people without cataracts need reading glasses or an equivalent form of vision correction.Multifocal or accommodative lensesThese newer IOL types reduce or eliminate the need for glasses or contact lenses.In the multifocal type, a series of focal zones or rings is designed into the IOL. Depending on where incoming light focuses through the zones, the person may be able to see both near and distant objects clearly.The design of the accommodative lens allows certain eye muscles to move the IOL forward and backward, changing the focus much as it would with a natural lens, allowing near and distance vision.The ability to read and perform other tasks without glasses varies from person to person but is generally best when multifocal or accommodative IOLs are placed in both eyes.It usually takes 6 to 12 weeks after surgery on the second eye for the brain to adapt and vision improvement to be complete with either of these IOL types.Considerations with multifocal or accommodative IOLsFor many people, these IOL types reduce but do not eliminate the need for glasses or contact lenses. For example, a person can read without glasses, but the words appear less clear than with glasses.Each person's success with these IOLs may depend on the size of his/her pupils and other eye health factors. People with astigmatism can ask their Eye M.D. about toric IOLs and related treatments.Side effects such as glare or halos around lights, or decreased sharpness of vision (contrast sensitivity) may occur, especially at night or in dim light. Most people adapt to and are not bothered by these effects, but those who frequently drive at night or need to focus on close-up work may be more satisfied with monofocal IOLs.Toric IOL for astigmatismThis is a monofocal IOL with astigmatism correction built into the lens.Astigmatism: This eye condition distorts or blurs the ability to see both near and distant objects. With astigmatism the cornea (the clear front window of the eye) is not round and smooth (like a basketball), but instead is curved like a football. People with significant degrees of astigmatism are usually most satisfied with toric IOLs.People who want to reduce (or possibly eliminate) the need for eyeglasses may opt for an additional treatment called limbal relaxing incisions, which may be done at the same time as cataract surgery or separately. These small incisions allow the cornea's shape to be rounder or more symmetrical.Protective IOL filtersIOLs include filters to protect the eye's retina from exposure to UV and other potentially damaging light radiation. The Eye M.D. selects the filters that will provide appropriate protection for the patient's specific needs.Other important cataract lens replacement considerationsIn some cases, after healing completely from the cataract lens surgery, some people may need further correction to achieve the best vision possible. Their ophthalmologist may recommend additional surgery to exchange an IOL for another type, implant an additional IOL, or make limbal relaxing incisions in the cornea. Other laser refractive surgery may be recommended in some cases.People who have had refractive surgery such as LASIK need to be carefully evaluated before getting IOLs because the ability to calculate the correct IOL prescription (PDF 650K) may be affected by the previous refractive surgery.Additional cataract information resourcesIf you're interested in learning more about cataract from the ophthalmologist's perspective, follow the link below to read American Academy of Ophthalmology practice guidelines for clinicians.American Academy of Ophthalmology Preferred Practice Pattern: Cataract in the Adult EyePreviousCataract SurgeryNextCataract Vision SimulatorRelated Ask an Ophthalmologist AnswersDid my six-month glutathione deficiency cause my cataracts?MAY 01, 2016Why has my near vision gotten worse since my cataract surgery two weeks ago?APR 26, 2016Are penicillin and clindamycin used in the antibiotic eye drops prescribed after cataract surgery?APR 21, 2016Which precautions should a diabetic patient take after cataract surgery?OCT 05, 2015Posterior Capsulotomy and TASSAUG 31, 2015Leer en Español:Reemplazo de Lente y La Cirugía de las CataratasSelect LanguageAfrikaansAlbanianAmharicArabicArmenianAzerbaijaniBasqueBelarusianBengaliBosnianBulgarianCatalanCebuanoChichewaChinese (Simplified)Chinese (Traditional)CorsicanCroatianCzechDanishDutchEsperantoEstonianFilipinoFinnishFrenchFrisianGalicianGeorgianGermanGreekGujaratiHaitian CreoleHausaHawaiianHebrewHindiHmongHungarianIcelandicIgboIndonesianIrishItalianJapaneseJavaneseKannadaKazakhKhmerKoreanKurdish (Kurmanji)KyrgyzLaoLatinLatvianLithuanianLuxembourgishMacedonianMalagasyMalayMalayalamMalteseMaoriMarathiMongolianMyanmar (Burmese)NepaliNorwegianPashtoPersianPolishPortuguesePunjabiRomanianRussianSamoanScots GaelicSerbianSesothoShonaSindhiSinhalaSlovakSlovenianSomaliSpanishSundaneseSwahiliSwedishTajikTamilTeluguThaiTurkishUkrainianUrduUzbekVietnameseWelshXhosaYiddishYorubaZuluPowered by TranslateFind an OphthalmologistAdvanced SearchAsk an OphthalmologistBrowse AnswersFREE NEWSLETTERGet ophthalmologist-reviewed tips and information about eye health and preserving your vision.Privacy PolicyRELATEDPet Fish Fitted with Fake Eye in Rare ProcedureJUN 30, 2016Firework Blinds Teenager, Severs HandJUN 29, 2016Ethnicity and Eye Disease: A Risk Reminder for Asian-, African- and Latino-AmericansAPR 26, 2016Vitamin See: Foods Rich in Vitamin C Help Curb CataractsMAR 28, 2016Los Alimentos Ricos en Vitamina C Ayudan a Controlar el Desarrollo de CataratasMAR 28, 2016Follow The Academy Professionals:        Public & Patients:   Contact UsAbout the AcademyJobs at the AcademyFinancial Relationships with IndustryMedical DisclaimerPrivacy PolicyTerms of ServiceFor AdvertisersFor MediaOphthalmology Job Center© American Academy of Ophthalmology 2016OUR SITESEyeWikiInternational Society of Refractive SurgeryMuseum of Vision

Common Eye Investigations Explained!

Dr. Quresh Maskati, Ophthalmologist
Pachymetry: Measurement of the thickness of the cornea – a test done to determine if your cornea is suitable for LASIK or collagen cross linkage procedure in patients with keratoconus or conical corneaKeratometry: Measurement of corneal curvature, usually done in the centre of the cornea. This measurement is handy to add to other measurements to calculate amount of LASIK laser required to bring your spectacle number to zero; also one of the measurements required to calculate the Intra-ocular lens power suitable for your eye in case you have a cataract.AS-OCT: Anterior Segment Optical Coherence Tomography. Something like a CT scan of the front portion of the eye. Comes in handy for a variety of diseases of the cornea and anterior segmentUBM – Ultra Biomicroscopy: This is an ophthalmic ultrasound using a special probe, to view in detail structures in the anterior segment, up to and including the crystalline lens of the eye and an inserted IOL. Also useful to examine the angle of the eye (UBM Gonioscopy) to find out if it is narrow, closed or open. This may influence decision making about glaucoma surgery in some cases.B-scan: An ultrasound test to examine structures in the back of the eye, especially if the view of the back of the eye is hampered due to opacities in the normally clear media, such as a cataract or haemorrhage in the posterior compartment(vitreous haemorrhage), so that ophthalmoscopy examination is not possible. Also useful in lesions of the extraocular muscles and any space occupying lesions in the orbit, outside the eye.A-scan: Also called A scan biometry. In this the examiner determines the front to back measurement of the eye using ultrasound. He then feeds in the keratometry reading obtained from the keratometer. An inbuilt computer in the A- scan biometry machine, using one of several complex formulae, then calculate the power of the intra-ocular lens implant required for your eyeOCT: Exactly like the AS-OCT talked about earlier; it gives you colour coded pictures of the back of the eye including individual layers of the retina. Therefore , if there is bleeding into the back of the eye or fluid collection in the retina, the OCT can tell you in which layer of the retina or whether it is just in front of or just behind the retina. It can also measure retinal thickness .This is helpful in planning treatment  in conditions like diabetic macular oedema or monitoring efficacy of intravitreal injections given for wet age related macular degeneration.Corneal Topography: This gives you several ‘maps’ of the cornea; an invaluable tool in assessing suitability of the cornea for LASIK and useful in detection of keratoconus and in fitting of contact lenses. It provides information on the curvature of the cornea at various points of the cornea, the ‘power’ of the cornea etc.Aberrometry: This is often used by the LASIK surgeon in patients unhappy after a successful LASIK – it detects minute flaws called “higher order aberrations” in your eye’s optical system which prevents you from enjoying ‘super’ vision after LASIK. Some LASIK machines which are “wave-front guided” routinely use data from aberrometers to fine tune the LASIK treatment to reduce these aberrations post LASIK surgery.Visual Field Analysis:  Mechanical devices that measured your field of vision were called perimeters. They have been largely replaced by Visual Field Analysers (VFA). These have inbuilt computers for storing and analysing your visual fields. They can compare fields done over a period and analyse whether the patient’s field is worsening or remaining the same. The routine test is a little cumbersome and requires your co-operation, lasting around 30-40 minutes, though for simple screening faster tests are available in the same machine. VFA is ordered in cases of glaucoma both for diagnosis and for judging efficacy of treatment. They are also invaluable in some neurological disorders causing drop in vision like in stroke etc.Fluorescein Fundus Angiography (FFA): In this test a dye, fluorescein Sodium is injected into the vein of your forearm. It takes around 10 seconds for the dye to spread into your retinal vasculature. This can be viewed by the observer using an ophthalmoscope, though more commonly, a digital camera called a fundus camera is used to take multiple photos of the retina shortly after dye injection.Depending on the areas of perfusion (dye seen) or non-perfusion (dye not seen) or leakage of dye from the vessels into the retina, decisions are made in cases of diabetic retinopathy, age-related macular degeneration etc. about whether to do laser or give some injections or treat with medications .HRT/GDX : These are fancy names for computer software in which images of the optic disc and retina are analysed. Accurate measurements are made of optic  nerve size, cup/disc ratio, retinal nerve fibre thickness. This is a useful adjunct to diagnose glaucoma and monitor its progression.Electro-retinography (ERG):  This test is used to find out the function of the retina. This comes in useful when the retina appears normal on ophthalmoscopy but patient has poor vision and also when the retina is not clearly seen due to media opacities. If the ERG is poor or absent, the eye surgeon may decide that the visual prognosis is poor and further surgery to clear the media opacities like a corneal transplant for corneal opacities or a cataract extraction for a mature cataract is not warranted.M-ERG or Multifocal ERG. This is the newest version of the ERG. In this a colour map is generated with the area of maximum cone function (macula) showing a steep elevation while the area with no cones (optic nerve ) showing up as flat and blue in colour. In diseases like macular degeneration, the central hill is considerably flattened, making diagnosis a ‘no-brainer’.Visual Evoked Potential (VEP):  In this test, either a very bright light (Flash VEP) or a checker board pattern is shone into the patient’s eye. The time taken for this to be perceived by the visual area of the brain (situated at the back of the head) and the intensity of the signal is recorded by sensitive electrodes placed at the back of the scalp. This measures the integrity of the visual pathway from the eye right up to the brain. In conditions like optic neuritis, where the optic nerve which carries signals from the eye to the brain is inflamed, the VEP will be reduced. On the other hand, a patient who is feigning blindness will have a normal VEP.Can a person who has undergone one or more of these tests donate their eyes?None of these tests is life threatening. However, it is proved that every patient who undergoes any of these tests will die some day, maybe months, years or decades later! If a patient were to die due to natural or accidental causes years after any of these tests were performed, the author does recommend donation of the eyes!

LASIK, Laser - You Can Avoid Spectacles or Contact Lenses!

Y Siva Kumar, Ophthalmologist
LASIK or Laser Vision Correction is a proven, highly successful procedure that can enable you to give up spectacles or contact lenses.Most types of eye sight problems, such as short sight (minus power) or long sight (plus power) can be corrected by these procedures.The benefits are clear:• First of all, It works! It corrects vision. Around 96% of patients will have their desired vision after LASIK. An enhancement, if at all needed, can further increase this number.• LASIK is associated with very little pain due to the numbing drops that are used. The discomfort experienced hardly lasts few seconds.• Vision is corrected nearly immediately or by the next day after LASIK.• No bandages or stitches are required after LASIK.• Adjustments can be made years after LASIK to further correct vision if vision changes while you age.• After having LASIK, most patients have a dramatic reduction in eyeglass or contact lens dependence and many patients no longer need them at all.The actual procedure:Basically, Lasik or Laser Vision Correction can be done in different ways. The most commonly done procedure needs a thin flap to be taken from the cornea ( the curved glass like structure which makes the front of our eyes ). This flap making can be done by an automated, very thin, rotating blade (microkeratome) or by a very advanced Laser, called Femtosecond. The femtosecond laser option is the best, but also the most expensive, may not be suitable for all eyes. After creating the flap, the next most important part is the application of excimer laser, which is a must for all Laser Vision Correction procedures.There are few side effects or complications, but most of them can be prevented by careful preoperative planning or can be overcome by treatment, or by using eye drops after the procedure.

Choose the Right Refractive Procedure for Your Eyes (And, Get Rid of Those Glasses!)

Dr. Manoj Rai Mehta, Ophthalmologist
It becomes confusing for a patient to select a "Refractive Procedure" that is safe for his or her eyes.  It is important to know that "LASIK" is not the only procedure  that is available to get rid of the glasses. There is a wide selection of procedures available with distinct advantages and disadvantages and it becomes imperative for a patient to weigh the pros and cons and then reach a conclusion.Procedures that are carried out on the "Cornea" of the eye, carry out correction by changing the curvature of the cornea and thus, change the refractive power.  Before the surgery inputs required are as follows:1) Cycloplegic Refraction, slit lamp examination of cornea, tear film function 2) Complete retinal check up; Indirect ophthalmoscopy and Central retinal evaluation by +90 D lens3) Corneal Topography (OCT/Orbscan/Pentacam) and Corneal Thickness graphs. Both front and back surface of the corneas need to be evaluated.4) Wave Front analysis for correction of aberrations   LASIK/LASEK/PRK/Lenticule removal can be carried out depending upon the parameters and patient safety. Profession, need to drive at night, age are taken into consideration and a discussion should happen between the doctor and the patient. Guardians of a patient are often a part of this discussion.Mechanical flap/ Femto Second flap/ Flap free procedures should be discussed for their merits and demerits and financial implications as well.  Minimum amount of tissue loss should take place during the procedure.  Safety measures during surgery especially tracker mechanisms should be discussed and elaborated upon.(Corrective lens over the existing natural lens) ICL/IPCL: In this a special lens is put over the existing lens behind the iris mostly for correction.  When the power is very high or the corneas relatively thin the procedure is indicated. A report on shape of the is required to find enough space for the lens. Clear lens removal with an IOL implant can also be carried out in certain situations. One procedure in one eye and another for the other can also be recommended if need be.    Select a safe procedure and be safe!  

Refractive Errors In Children

Dr. Brijinder Singh Rana, Ophthalmologist
Refractive error is the most common cause of visual impairment in children. Visual impairment can have a significant impact on a child’s life in terms of education and development. It is important that effective strategies be developed to eliminate this easily treated cause of visual impairment.Children with such errorsFind difficulty in reading, writing and have difficulty to see distanceEye strain while reading for long or shrink eyes to see at a distanceMay have squint (crossed eyes)May hold book close while readingIn addition to the above condition,Child may rub the eyes or blink frequentlyHeadache in forehead regionRecurrent swelling in the eyelidsCorrection using the spectacles is the best option available .Though children may initially refuse to accept glasses, They will become fond of them once they realize they can see better with them on. The power of glasses may change depending on the growth of eyeballs. An eye checkup and change of glasses if necessary, has to be done once six months for children less than 5 years of age and once a year thereafter.Making a child wear glasses regularly is the duty and responsibility of the parents. Failure to wear glasses in childhood will retard the development of vision in that eye. Children older than 15 years can use contact lenses, if they don’t want spectacles. Those over 18 years of age with stable power have option of going in for lasik.“HELP YOUR CHILD SEE THE WORLD BETTER.WEARING GLASSES IS NOT A STIGMA”

I Have a Dry Eye, Will I Lose My Sight?

Dr. Manoj Rai Mehta, Ophthalmologist
Dry Eye Disease is one of the commonest problems that is diagnosed in an Eye Clinic.  Ironically watering of eyes is one of the symptoms of a "Dry Eyes".  This brings us to the understanding that "Dry Eye"is essentially a problem of lubrication of the front surface of the eye, called cornea. Cornea is like transparent watch glass and is also the most powerful refractive component of a complex refractive system of human eye. Surface of cornea is made smooth and glistening by a thin layer of "Tear Film" that itself is made up of three important components. Mucous the innermost that bridges water repellent corneal surface with a watery middle layer full of nutrients and ions and an oily layer on top to reduce evaporation losses. When we blink the lids pull a small fraction of this fluid from a collection pouch in the lower with capillary action and paints it in uniform coat over the front surface of cornea (much like a paint brush).  The tear film breaks due to evaporation and blink reflex sets in making eyes blink and restore the tear film again.Dry Eye, therefore, can be due to mechanical problems of the corneal surface or lids, quality of special mucous produced by microscopic glands (post chemical/mechanical damage), lack of watery fluid or over production of oily secretions etc.  Mild inflammation sets in that produces destructive chemicals further worsening the condition.Reflex tears that are shed due to irritation/noxious fumes/emotional situations are produced by lachrymal glands and do not lubricate the eye surface, in fact they take away some of the precious mucous with their flow.     Dry Eye Disease is also associated with many auto immune- inflammatory systemic diseases,  that need to be ruled out as well.Management involves firstly a complete evaluation of the Tear Production and Flow system and tear film stability studies.  Systemic associations of Dry Eye must also be ruled out.  Stay in cool environment temperatures around 24 degree Celsius, Relative Humidity 62%.  Avoid direct flow of air on to the eyes.  Preserve tear film by using protective glasses and use shades out doors.  Cool polarised glass shades cut down glare significantly.  Outflow may be blocked with temporary plugs of varying time periods.  Tear substitutes and tear flow enhancing drops in conjunction with anti-inflammatory drops may be used as per the directives of your doctor.  Some time bandage contact lenses may be required to manage filamentary keratitis.Dry Eyes are prone to infection which can spread very fast therefore it is important to report immediately if the eyes turn red, develop a discharge or there is sudden aggravation of symptoms.  Formation of filaments can also cause worsening of symptoms.  You can preserve your sight by regular visits to your doctor and report immediately on worsening of symptoms.