General / Routine Eye Check-up at Angel Eyes

The cornerstone of our responsibility towards the long term care of your vision is a comprehensive eye checkup at every visit. Regardless of your eye problems, we follow a strict protocol of eye-checking so as not to miss any other problem in the eye which you may not be even aware of.

The experienced optometrists at Angel Eyes value your vision as much as you do. The eye examinations performed by our professionally trained staff involve a complete vision analysis. Together the optometrists and then the specialist Consultant will perform a thorough eye examination and provide you with a diagnosis and treatment strategy to ensure an overall satisfactory outcome of your eye check up.

Each general eye exam entails the following services:

1. Complete review of your medical and ophthalmological history along with your family’s medical and ophthalmological history
2. Detection of ocular diseases
3. Examination of eye muscle coordination
4. Testing of colour vision
5. Neurological pupil evaluation
6. Preliminary screening for glaucoma
7. Refraction to determine an accurate eye glass prescription

The steps you will undergo for ascertaining all of the above are as follows:

Step 1: Complete history, symptoms, treatment history evaluation

Step 2: Auto refractometer analysis

Step 3: Intraocular pressure measurement by NCT

Step 4: RNFL screening by Zeiss GDx VCC

Step 5: Refraction by optometrist

Step 6: Pupil check

Step 7: Ocular movement check

Step 8: Slit lamp exam of the eyes

Step 9: Examination of the external structure of the eyes

Step 10: Examination of the internal structure of the eyes

Step 11: Repeat Refraction by Consultant (if required)

Step 12: Diagnosis and Treatment strategy finalized by Consultant

Step 13: Counselling and instructions issued by counsellors

• Please note that a patient needs to move from one examination chamber to another for completing the different steps.
• Dilating drops if required may be used after informing the patient
• Anaesthetizing drugs if required may be used after informing the patient
• Eye stain if required may be used after informing the patient
• It will normally require one to one and a half hours to complete the general examination of the eye followed by consultation and prescription

Diagnostic and Therapeutic Outdoor Procedures

• Refraction – Also known as Eye test or Vision test
  

(this pic is from my centre….will need to photoshop the background)

• The refraction test is an eye exam that measures a person’s prescription for eyeglasses or contact lenses.
• This test is performed by an ophthalmologist or optometrist.
• You sit in a chair that has a special device- refractometer attached to it. You look through the device and focus on an eye chart 20 feet away. The test is performed one eye at a time.
• If you wear contact lenses, ask the doctor if you need to remove them before the test and for how long.
• There is no discomfort.
• This test is done as part of a routine eye exam. The purpose is to determine whether you have a refractive error (a need for glasses or contact lenses). For people over age 40 who have normal distance vision but difficulty with near vision, a refraction test can determine the right power of reading glasses.

• Contact lens fitting : ‘Get the right lenses!’

The main objective is to ensure comfort and improve your vision

For those who wish to wear contacts, it’s important to remember that the standard prescription provided by eye care practitioners is generally only for eyeglasses. There are additional measurements that must be taken in order to get the right lenses for your needs. 

Every eye is different – your left is slightly different from your right, and your eyes are different from those of everyone else around you. Differences include the diameter and the curvature of your eye, not to mention the severity of any vision problems that you might have. This is why getting a precise contact lens fitting is so important. 

If you have problems with your vision and want to use contacts to correct the problem, or if you wish to get coloured contacts for cosmetic purposes, a contact lens fitting is something to consider before you start shopping….read more

• Schirmer’s Test:

• Also known as Tear test, Dry eye test, Basal secretion test
• Schirmer’s test determines whether the eye produces enough tears to keep it moist. This test is used when a person experiences very dry eyes or excessive watering of the eyes.
• You will be asked to remove your contact lenses before the test.
• Before the test, you will be given numbing eye drops to prevent your eyes from tearing due to irritation from the paper strips.
• The health care provider will place a special paper strip inside the lower eyelid of each eye, under the eyelid (usually the bottom one). Both eyes are tested at the same time.
• The exact procedure may vary somewhat. Most often, the eyes are closed for 5 minutes. Close your eyes gently. Closing the eyes tightly or rubbing the eyes during the test can cause abnormal test results.
• After 5 minutes, the doctor removes the paper and measures how moist it is.

• Applanation Tonometry

• Also known as Intraocular pressure (IOP) measurement; Glaucoma test
• Tonometry is a test to measure the pressure inside your eyes. The test is used to aid in screening and monitoring for
• This method measures the force needed to flatten a certain area of the cornea.
• The surface of the eye is numbed. A fine strip of paper stained with orange dye is touched to the side of the eye. The dye stains the front of the eye to help with the examination.
• Theslit-lamp is placed in front of you, and you rest your chin and forehead on a support that keeps your head steady. The lamp is moved forward until the tip of the tonometer just touches the cornea.
• The light is usually a blue circle. The health care provider looks through the eyepiece on the lamp and adjusts the tension on the tonometer. There is no discomfort with the test.
• Remove contact lenses before the examination. The dye can permanently stain contact lenses.
• Inform the health care provider if you havecorneal ulcers and infections, an eye infection, if you are taking any drugs, or if you have a history of glaucoma in your family.
• As numbing eye drops are used, you will not have any pain.
• Non Contact Tonometry
  
• This is a faster though slightly less accurate method of checking the intraocular pressure for monitoring or screening of Glaucoma.
• The method is the noncontact method (air puff). In this method, your chin rests on a padded stand.
• You stare straight into the examining device. The eye doctor shines a bright light into your eye to properly line up the instrument, and then delivers a brief puff of air at your eye.
• The machine measures eye pressure by looking at how the light reflections change as the air hits the eye.
• In the noncontact method, you may feel mild pressure on your eye.

• Fluorescein Eye Staining

• This is a test that uses orange dye (fluorescein) and a blue light to detect foreign bodies in the eye. This test can also detect damage to the cornea, the outer surface of the eye.
• This test is useful in identifying superficial scratches or other problems with the surface of the cornea. It can also help reveal foreign bodies on the eye surface. It can be used after contacts are prescribed to determine if there is irritation of the surface of the cornea.
• You will need to remove your contact lenses before the test.
• A piece of blotting paper containing the dye will be touched to the surface of your eye. You will be asked to blink. Blinking spreads the dye around and coats the “tear film” covering the surface of the cornea. (The tear film contains water, oil, and mucus to protect and lubricate the eye). A blue light is then directed at your eye. Any problems on the surface of the cornea will be stained by the dye and appear green under the blue light.
• The health care provider can determine the location and likely cause of the cornea problem depending on the size, location, and shape of the staining.
• If eyes are extremely dry, the blotting paper may be slightly scratchy. The dye may cause a mild and brief stinging sensation.
• If the test result is normal, the dye remains in the tear film on the surface of the eye and does not adhere to the eye itself.

Abnormal results will mean

• Abnormal tear production (dry eye)
• Corneal abrasion(a scratch on the surface of the cornea)
• Foreign bodies, such as eyelashes or dust (seeeye – foreign object in)
• Infection
• Injury or trauma
• Severe dry eye associated with arthritis (keratoconjunctivitis sicca)

• Punctal Plugs Insertion

• Punctal plugs are tiny, biocompatible devices inserted into tear ducts to block drainage. This increases the eye’s tear film and surface moisture to relievedry eyes.
• Also known as punctum plugs, lacrimal plugs or occluders, these devices often are no larger than a grain of rice.
• Punctal plugs usually are considered when non-prescription or prescriptioneye drops fail to relieve your dry eye condition.
• To prepare you for the procedure, some eye doctors use a local anesthetic before inserting the punctal plug. In many cases, no anesthetic is needed.
• Follow this link to read more about punctal plugs

• Corneal Topography –

Corneal topography, also known as photokeratoscopy or videokeratography, is a non-invasive medical imaging technique for mapping the surface curvature of the cornea, the outer structure of the eye. Since the cornea is normally responsible for some 70% of the eye’s refractive power,  its topography is of critical importance in determining the quality of vision.

The three-dimensional map is therefore a valuable aid to the examining ophthalmologist or optometrist and can assist in the diagnosis and treatment of a number of conditions; in planning refractive surgery such as LASIK and evaluation of its results; or in assessing the fit of contact lenses. A development of keratoscopy, corneal topography extends the measurement range from the four points a few millimeters apart that is offered by keratometry to a grid of thousands of points covering the entire cornea. The procedure is carried out in seconds and is completely painless.

SCHWIND SIRIUS Topogpraph

SCHWIND SIRIUS offers the perfect combined solution for refractive and therapeutic corneal surgery. The highly precise, multi-functional diagnostic device combines a rotating Scheimpflug camera with a Placido disc.

• The “2 in 1” systems provides a quick, three dimensional analysis of the whole cornea and the anterior segment in only one step.
• The extremely high resolution of only one micrometre and more than 100,000 analysis points  detect the smallest of irregularities.
• The contact-free measurement allows an analysis of the complete corneal wavefront, the topography of the anterior and posterior corneal surface (including the tangential and axial curvature) as well as the anteror chamber.
• Keratoconus Screening: The SCHWIND SIRIUS offers detailed descriptions of the morphology as well as the classification of the keratoconus.  
• The corneal pachymetric map of an eye can be generated by the SCHWIND SIRIUS for corneal transplants (Pachymetry Assisted Laser Keratoplasty).
• The integrated pupillometry captures the pupil diameter either dynamically or statically according to the defined lighting conditions.

Procedure

The patient is seated facing a rounded hood like structure containing an illuminated pattern, which is a series of concentric rings. The pattern is focused on the anterior surface of the patient’s cornea and reflected back to a digital camera at the centre of the bowl. The topology of the cornea is revealed by the shape taken by the reflected pattern. A computer provides the necessary analysis, typically determining the position and height of several thousand points across the cornea.

• Corneal Pachymetry (CCT)

• Corneal pachymetry is the measurement of corneal thickness. A pachymeter is a medical device used to measure the thickness of the eye’s cornea. With the emergence of refractive surgical techniques, corneal pachymetry is necessary to determine suitable candidates for ablation procedures. Furthermore, the identification of central corneal thickness (CCT) as an independent indicator of glaucoma risk has made corneal pachymetry a routine part of the ophthalmic evaluation.
• Corneal specialists and general ophthalmologists rely on accurate corneal pachymetry readings to manage patients with corneal ectasias (e.g., keratoglobus, pellucid degeneration, keratoconus), Fuchs’ endothelial dystrophy, bullous keratopathy, corneal rejection post – penetrating keratoplasty, and other causes of corneal edema.
• Several techniques are available to reliably and reproducibly measure corneal thickness. The methodologies used in these techniques are based on either ultrasonic or optical principles. While each of the methods have a peculiarity of their own, all have been described as reliable.
• The most commonly used equipment uses ultrasound technology and is the clinical standard. Traditional ultrasound pachymetry (10-20 MHz) offers the advantages of portability and relative ease of use. These dry contact systems are simple, portable, and cost-effective. Most of the clinical work studying the association between CCT and glaucoma has relied on ultrasound pachymetry. Ultrasound require contact with the cornea; the ophthalmologist delivers a drop of anesthetic to the eye and applies a sterile pachymeter tip gently onto the cornea. At Angel Eyes, we routinely use Tomey Pachymeter to measure the corneal thickness.
• Though the Ultrasounds continue to be popular, affordable and accurate, but a newer line of pachymeter that use optical low – coherence reflectometry technology may enhance accuracy and allow non – contact pachymetry. At Angel Eyes we use the Sirius Scheimpflug Camera, which is a noncontact technique that uses a rotating Scheimpflug camera to rapidly capture images of the anterior segment of the eye. This technique allows measurement of corneal thickness from limbus to limbus.

• Visual Fields

The visual field refers to the total area in which objects can be seen in the side (peripheral) vision while you focus your eyes on a central point.

The visual field is measured by perimetry. At Angel Eyes the perimeter used is the automated Humphrey Field Analyzer II.

Humphrey Field Analyzer II

Visual field testing is an important tool in the diagnosis and management of glaucoma. It is used to confirm that glaucoma has affected the visual function, to evaluate the severity and to monitor progression of the disease. The Humphrey Field Analyzer II is a wheelchair accessible, diagnostic tool used to examine a patient’s visual field. The Humphrey Field Analyzer II is the recognized standard of care for early diagnosis and management of ocular diseases resulting in visual field loss.

Why we’ve invested in the Humphrey Field Analyzer II

• Diagnostic Precision: the Humphrey Field Analyzer II has been shown to be extremely accurate.
• Early Glaucoma Detection: this technology has been shown to provide earlier detection of vision loss due to glaucoma.
• Quickness: the Humphrey Field Anazlyzer II measures visual fields in as little as two minutes.

How the Test is Performed

Automated perimetry: You sit in front of a concave dome and stare at an object in the middle. You press a button when you see small flashes of light in your peripheral vision. Your responses help determine if you have a defect in your visual field.

There is no discomfort with this test.

This eye exam will show whether you have a loss of vision anywhere in your visual field. The pattern of vision loss will help your doctor diagnose the cause.

Abnormal results may be due to diseases or central nervous system disorders, such as tumors that damage or press on (compress) the parts of the brain that deal with vision.

Other diseases that may affect the visual field of the eye include:

• Diabetes
• Glaucoma
• High blood pressure
• Macular degeneration
• Multiple sclerosis
• Optic glioma
• Overactive thyroid(hyperthyroidism)
• Pituitary gland disorders
• Retinal detachment
• Stroke
• Temporal arteritis

• Refractive Surgery work up

This work up is the first part of your vision correction procedure. Only after this procedure is completed, the specialist can decide whether to do a laser vision correction or a non-laser procedure. Also the type of laser procedure (custom aspheric/trans-PRK/wavefront guided/presby Max) will be decided after this work up is completed.

The work up will require at least half an hour to 45 minutes of your time. You will undergo the following tests to complete your refractive procedure work up:

• Complete general check up of the eyes
• Corneal Pachymetry
• Corneal Topography by Schwind Diagnostic System
• Detailed eye examination by the Consultant
• Counselling to discuss your results and choice of procedure
• Pre operative instructions given

Complete details of this work up can be found in section for refractive services

• Glaucoma work up

This work up is designed to screen for glaucoma as well as to monitor the progress of the disease in those already diagnosed with glaucoma. Since glaucoma causes irreversible blindness the importance of this work up cannot be overemphasized.  The time interval  between two consecutive work ups will be determined by the consultant and should be strictly adhered to. The following steps will comprise a complete glaucoma work up:

• Complete general check up of the eyes
• Applanation Tonometry
• Corneal Pachymetry
• Visual Fields – Automated Perimetry by Humphrey Field Analyzer
• Retinal Nerve Fibre Analysis by Zeiss GDx VCC

Complete details of this work up can be found in section for glaucoma services

• Examination under anaesthesia

Many circumstances like in children or patients in extreme pain or in a state of reduced cognition where they are not able to follow commands or are unable to co-operate, such patients require eye examination under anaesthesia. This examination comes in most handy especially in cases of retinitis pigmentosa in kids where a detailed fundus  examination is required and will be extremely difficult without the immobility provided by anaesthesia.

• Ultrasound A-scan
  
• A-scan ultrasound biometry, commonly referred to as anA-scan, is routine type of diagnostic test used in  The A-scan provides data on the length of the eye, which is a major determinant in common sight disorders. The most common use of the A-scan is to determine eye length for calculation of intraocular lens power. Briefly, the total refractive power of the emmetropic eye is approximately 60. Of this power, the cornea provides roughly 40 diopters, and the crystalline lens 20 diopters. When a cataract is removed, the lens is replaced by an artificial lens implant. By measuring both the length of the eye (A-scan) and the power of the cornea (keratometry), a simple formula can be used to calculate the power of the intraocular lens needed.
• The A-scan procedure is a painless, noninvasive technique usually performed in the doctor’s office. A topical anesthetic (numbing eye drop) is administered, and then the ultrasound probe is touched to the surface of the anesthetized eye. The probe emits sound waves that bounce back from various structures within the eye, producing the image on a video screen. The A-scan emits very high frequency radar-like waves that are reflected by ocular structures, converted into electrical impulses, and displayed on a screen as a series of echo spikes.
• The other major use of the A-scan is to determine the size and ultrasound characteristics of masses in the eye, in order to determine the type of mass. This is often termed quantitative A-scan. For instance, echoes produced from a malignant melanoma are different from those reflected from a benign or noncancerous hemangioma. This highly specialized exam requires special training.

• Nd YAG Laser – Capsulotomy
  

• Nd:YAG lasers or Laser posterior capsulotomy or YAG laser capsulotomy, is a noninvasive procedure performed on the eye to remove the opacification (cloudiness) that develops on the posterior capsule of the lens of the eye after extraction of a cataract. Laser posterior capsulotomy is performed with Nd:YAG laser, which uses a wavelength to disrupt the opacification on the posterior lens capsule. The energy emitted from the laser forms a hole in the lens capsule, removing a central area of the opacification.
• Laser capsulotomy is usually performed in an ophthalmologist’s office as an outpatient procedure. A weak dilating drop to enlarge the pupil is applied to the eye. The patient then puts the head in the chinrest of a slit lamp microscope, to which a laser is attached. It is important that the patient remain still as the doctor focuses on the posterior capsule. A head strap to help keep the patient’s head in place may be used. While focusing on the posterior capsule, the doctor, with repeated bursts from the Nd:Yag laser in a circular manner, disrupts the PCO. An opening forms on the posterior part of the lens capsule as part of the PCO falls off of the posterior capsule and into the vitreous. This is a brief procedure lasting only a few minutes and is not associated with pain.
• Complete details of this can be found in section for cataract services

• Nd YAG Laser – Synecholysis

This is done in cases where the iris has formed adhesions with the IOL seen sometimes after cataract surgery. This is also useful as an adjunct therapy where the adhesions of iris is causing pupillary blockage leading to an increase in eye pressure. The procedure is done on an outpatient basis.

• Nd YAG Sweeping

This is done to clean the deposits on the IOL. This may occur in some of the operated cataract patients more likely in those suffering from chronic eye disease like iritis, uveitis. The procedure is quite similar to the one above and can be done on an outpatient basis.

• Nd YAG Laser – Iridotomy

• Laser peripheral iridotomy (LPI) is the preferred procedure for treating angle-closure glaucoma caused by relative or absolute pupillary block. LPI eliminates pupillary block by allowing the aqueous to pass directly from the posterior chamber into the anterior chamber, bypassing the pupil. LPI is performed, with a neodymium:yttrium-aluminium-garnet (Nd:YAG) laser.
• Topical anesthesia with proparacaine 0.5% is usually adequate for performing LPI. The patient must be comfortable at the laser table, as when a patient is examined at the slit lamp.
• Monitoring and Follow-up: At 1 hour after completion of LPI, the intraocular pressure (IOP) is checked to make sure that it has not increased significantly (ie, that IOP has not increased by 8 mm Hg or more and that IOP does not exceed 30 mm Hg). Topical prednisolone acetate 1% is given 4 times a day for 5-7 days. At 1 week, the patient is seen to monitor IOP, to confirm the patency of the iridotomy site, and to check for any significant intraocular inflammation.

Follow this link to read more about Nd YAG Laser – Iridotomy

• Intraocular lens power calculation using Zeiss IOL Master 

The IOL Calculator is meant to serve as an adjunct tool to assist physicians in selecting the appropriate IOL for a particular patient. It is intended to be used in conjunction with a comprehensive ophthalmic examination and the appropriate diagnostic tests and measurements necessary for cataract surgery candidates with a history of prior refractive surgery. The equipment used at our eye centre is the ‘Zeiss IOL Master’.

The Zeiss IOL Master  was approved by the United States Food and Drug Administration in March of 2000. A non-contact optical device that measures the distance from the corneal vertex to the retinal pigment epithelium by partial coherence interferometry, the IOL Master is consistently accurate to within ±0.02 mm or better.

Considering the fact that axial length measurements by A-scan ultrasonography  have a typical resolution of 0.10 mm to 0.12 mm, axial length measurements by the IOL Master represent a fivefold increase in accuracy.

In cases where the cataract is fully mature, the IOL power calculation is not possible with IOL Master. In such cases we have to rely upon A Scan measurements for calculating the IOl power.

Intraocular lens (IOL) implantation after refractive surgery is challenging because standard IOL power formulae can lead to significant unintended postoperative refractive errors. The IOL Master used at our centre is equipped with special software to calculate the IOL power in cases with a history of refractive surgery. 

To read more about IOL Power calculation  (link to  Determining the Accurate Power of IOL in AELC Cataract Document)

• Retinal Nerve Fibre Layer Analysis  – RNFL

At Angel Eyes we perform Retinal Nerve Fibre Layer Analysis using the scanning laser polarimetry method.  Scanning laser polarimetry is the use of polarised light to measure the thickness of the retinal nerve fiber layer as part of a glaucoma workup. The equipment we use for this purpose is the GDx-VCC. The assessment of the thickness of the retinal nerve fiber layer is essential as this is the very first part of your eye that is damaged by glaucoma.

For overview, the first prototype of this instrument was developed about 10 years ago, and was first released commercially as the GDx Nerve fiber analyzer (Laser Diagnostic Technologies Inc). The second generation product was called the GDx Access. These prior versions of the machine provided a fixed compensation for the corneal birefringence that contributes to the retardation of the laser signal (fixed corneal compensation [FCC]). However, the corneal effect may differ significantly among individuals, change over time, and be substantially altered after ocular surgery, particularly LASIK. The updated device, GDx with variable corneal compensation (VCC), incorporates individualized compensation for the corneal component.

This test is completely objective and takes about 10 minutes to complete, though it makes the actual measurements in less than one second. It works best on undilated pupils and can work quite well through cataracts up to 20/60. A normative database compares the patient’s measurements to those of normal patients of the same age, sex, and race.

• Posterior Sub Tenon Injection

Posterior subtenon injection (PSTI) of triamcinolone acetonide (TA) is one of the delivery methods for the treatment of posterior uveitis, diabetic macular edema and cystoid macular edema secondary to retinal vein occlusions. Injection of corticosteroids into the posterior subtenon space is a well established and highly effective modality in the treatment of intermediate uveitis. The conventional technique of posterior subtenon injection involves the use of a sharp tipped 26-gauge, 5/8 inch needle that must be inserted up to its hub to obtain adequate placement of the drug into the posterior subtenon space. 

EYE HEALTH

Incorporate your eye health as part of your regular health check-ups. Having a comprehensive dilated eye exam is one of the best things you can do to make sure that you’re seeing the best you can and that you’re keeping your eyes healthy.

Millions of people have problems with their vision every year. Some of these problems can cause permanent vision loss and even blindness, while others are common problems that can be easily corrected with glasses or contact lenses.

SOME TIPS FOR KEEPING THE EYES HEALTHY

• Have a comprehensive dilated eye exam. A dilated eye exam is the only way to detect many common eye diseases such as glaucoma, diabetic eye disease and age-related macular degeneration in their early stages.
• Know your family’s eye health history. It’s important to know if anyone has been diagnosed with a disease or condition since many are hereditary. This will help to determine if you are at higher risk for developing an eye disease or condition.
• Eat right to protect your sight. Eating a diet rich in fruits and vegetables, particularly dark leafy greens such as spinach, kale, or collard greens is important for keeping your eyes healthy, too. Research has also shown there are eye health benefits from eating fish high in omega-3 fatty acids, such as salmon, tuna, and halibut.
• Maintain a healthy weight. Being overweight or obese increases your risk of developing diabetes and other systemic conditions, which can lead to vision loss, such as diabetic eye disease or glaucoma. If you are having trouble maintaining a healthy weight, talk to your doctor.