Advanced Diagnostic Equipment

The Retina Group of New York utilizes state-of-the-art diagnostic equipment including OCT (Ocular Coherence Tomography), Fluorescein and ICG Angiography, Automated Visual Field testing, Digital Color Photography, ultrasound, Farnsworth-Monsell and Anomaloscopic Color Vision Testing, Dark Adaptometry, EOG (Electro-oculography), Multifocal (mfERG) and Ganzfeld ERG. We are capable of diagnosing all types of retinal conditions. Dr. Maisel represented the Foundation to Prevent Blindness helping to develop the ANSI standards for the ophthalmic industry for diagnostic testing for visual acuity, tonometers, and intraocular lens implants.

Advanced Diagnostic Equipment.

Comprehensive Retinal Diagnostic Solutions To Meet Your Needs

Click on the Diagnostic Tests in the menu below to learn more about them.

Electroretinography (ERG)

  • What is electroretinography (ERG)?

    Electroretinography (ERG) is an eye test measuring the electrical response to light flashes, similar to the way the electrical signals from the heart are recorded with an EKG. It is used to detect abnormal functions of the retina, the light-detecting portion of the eye. Specifically, in this test, the light-sensitive cells of the eye, the rods and cones, and their connecting ganglion cells in the retina are examined. An ERG is useful in evaluating both inherited (hereditary) and acquired disorders of the retina. An ERG can also be useful in determining if retinal surgery or other types of ocular surgery, such as cataract extraction, might be useful.

  • How is an ERG done?

    The eyes are dilated with standard dilating eye drops. Anesthetic drops are then placed in the eyes, and eyelids are gently propped open with a speculum. A thread-like sensor is placed under the lower eyelid to measure the electrical responses to light. An additional electrode is placed on the skin to provide a ground for the very faint electrical signals produced by the retina.
    During an ERG, the patient watches a standardized light stimulus of flashes, called a flash ERG, and reversing checkerboard patterns, known as a pattern ERG. Readings are performed after adapting to the dark for 20 minutes, and readings are again taken with white light on. The faint electrical signal is measured for amplitude (voltage) and time course and the patterns analyzed to confirm diagnoses or monitor for safety and health.

  • What diseases is my doctor looking for with an ERG?

    There are a number of conditions, mostly ocular in nature, in which the ERG may provide useful information. The diagnoses most commonly suspected when ordering an ERG are predominantly conditions of the retina, including:● Retinitis Pigmentosa.● Retinitis Punctata Albescens.● Retinitis Pigmentosa Sine Pigmento.● Related Hereditary Retinal Degenerations.● Disorders That Mimic Retinitis Pigmentosa.● Leber's Congenital Amaurosis.● Choroideremia.● Gyrate Atrophy Of The Choroid.● Gyrate Atrophy Of The Retina.● Goldman-favre Syndrome.● Congenital Stationary Night Blindness.● X-linked Juvenile Retinoschisis.● Achromatopsia.● Cone Dystrophies.● Usher Syndrome.

Electroretinography (ERG) in New York.

ERG testing measures faint electrical signals from the eye in response to light flash stimuli.

Fluorescein and ICG angiography

Fluorescein and indocyanine green (ICG) angiography are eye tests that use special dyes that are excreted in your urine and an imaging system with a low-power safe laser to look at blood flow in the retina and choroid. These are the two layers in the back of the eye.

The Retina Group of New York utilizes state-of-the-art diagnostic laser scanning ophthalmoscopes to image the retina and choroidal circulation. Following an intravenous injection of a fraction of a teaspoon of a green dye in your arm vein, a low-power invisible laser is used to scan the retina and capture high-resolution digital images of the retina lining the back wall of the eye. As the dye fills the blood vessels of the two circulatory systems of the eye, the images immediately appear, showing abnormal blood vessels or patterns characteristic of many ocular conditions such as macular degeneration, central serous retinopathy, and macroaneurysms. The low-powered infrared laser can often see through cataracts and blood that fluorescein angiography cannot visualize and confirm suspected pathology. All images are displayed on large monitors and explained so that patients can readily see the progress of their treatments.

A teaspoon of Fluorescein dye IV injection is injected in the arm.

A teaspoon of Fluorescein dye IV injection is injected in the arm.

ICG image.

ICG image.

  • How the Test is Performed

    You will be given eye drops that make your pupil dilate. You will be asked to place your chin on a chin rest and your forehead against a support bar to keep your head still during the test. The nurse or photographer will take pictures of the inside of your eye. After the first group of pictures is taken, a dye called fluorescein is injected into a vein. Most often it is injected at the inside of your elbow. A camera-like device takes pictures as the dye moves through the blood vessels in the back of your eye.

  • How to Prepare for the Test

    You will need someone to drive you home. Your vision may be blurry for up to 12 hours after the test. You may be told to stop taking medicines that could affect the test results. Tell your healthcare provider about any allergies, particularly reactions to iodine.
    You may be asked to sign an informed consent form. You must remove contact lenses before the test. Tell the provider if you may be pregnant.

  • How the Test will Feel

    When the needle is inserted, some people feel slight pain. Others feel only a prick or sting. Afterward, there may be some throbbing. When the dye is injected, you may have mild nausea and a warm feeling in your body. These symptoms go away quickly most of the time. The dye will cause your urine to be darker. It may be orange in color for a day or two after the test.

  • Why the Test is Performed

    This test is done to see if there is proper blood flow in the blood vessels in the two layers in the back of your eye (the retina and choroid). It can also be used to diagnose problems in the eye or to determine how well certain eye treatments are working.

  • Normal Results

    A normal result means the vessels appear a normal size, there are no new abnormal vessels, and there are no blockages or leakages.

  • What Abnormal Results Mean

    If blockage or leakage is present, the pictures will map the location for possible treatment. An abnormal value on a fluorescein or ICG angiography may be due to:● Blood flow (circulatory) problems, such as blockage of the arteries or veins.● Cancer.● Diabetic or other retinopathy.● High blood pressure.● Inflammation or edema.● Macular degeneration.● Microaneurysms - enlargement of capillaries in the retina.● Tumors.● Swelling of the optic disc.● Retinal detachment.● Retinitis pigmentosa.

  • Risks

    There is a slight chance of infection any time the skin is broken. If your arm becomes red, swollen or tender after the test, notify us immediately. The dye may leak outside of the vein and cause discomfort. This is treated with ice pack and Tylenol and will dissipate within a day or two. Rarely, a person is overly sensitive to the dye and may experience:
    ● Dizziness or faintness.● Dry mouth or increased salivation.● Hives.● Increased heart rate.● Metallic taste in mouth.● Nausea and vomiting.● Sneezing.● Difficulty breathing or wheezing.
    Serious allergic reactions are rare occurring in about 1/250,000.

Ocular Coherence Tomography (OCT)

The Retina Group of New York utilizes state-of-the-art diagnostic Spectral Domain Heidelberg Ocular Coherence Tomography (OCT) to obtain high-resolution images of the retina and underlying layers using low-power, safe, multicolor laser light through the pupil. High resolution images are obtained in seconds that are helpful in diagnosing and managing many conditions such as diabetic retinopathy, macular degeneration, retinal vein occlusions, cystoid macular edema and central serous retinopathy. All images are displayed on large monitors and explained so that patients can readily see the progress of their treatments.

Ocular Coherence Tomography (OCT) in New York.

Heidelberg Spectralis OCT

  • Preparation

    At the start, you will be seated directly in front of the instrument. During the entire test, you will keep your head still with your chin resting on the chin rest and your head firmly against the instrument’s head band. The examiner will sit opposite from you on the other side of the instrument. You always look directly into the instrument, staring at a fixation point or at the point indicated by the eyecare professional. You can blink normally. The examination takes just a short time.

  • Examination

    When the examination begins, a blue dot will appear on the instrument. You will be asked to stare at the blue dot during the entire examination. The examiner will move the instrument toward your eye without touching you. At a safe distance from the eye, the examiner is able to produce a good image of your retina or optic nerve head. A safe light beam scans the most important structures.

  • After Examination

    The examination is completely painless for you and is done without touching your eye. After the examination, your vision will not be impaired. If your eyecare professional has not dilated your pupil to conduct the OCT test or another examination, you can drive as usual.

Plaquenil Toxicity Screening

Plaquenil Toxicity Screening Hydroxychloroquine Sulphate (Plaquenil) medication has been effectively used for many years for a variety of infectious and autoimmune conditions, including rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE). On rare occasions, and usually after many years, Plaquenil can damage the central portion of the retina and the macula and affect the central, fine visual acuity used for reading. There are many other macula problems, so patients using Plaquenil should have a baseline examination and testing to ascertain the health of the macula at the initiation of therapy and allow periodic monitoring for early signs of macular toxicity to lessen the risk of visual loss.

  • Symptoms

    Over time, Plaquenil can accumulate in the retina and cause permanent irreversible damage to the center of vision. The classic retinal changes appear as a “bull’s eye” area of discoloration of the central part of the retina. Symptoms of Plaquenil toxicity are similar to other macular problems and may include:
    ● Decreased fine vision or difficulty reading.● Changes in Color vision.● Missing Spots or shadows near the center of the vision.

  • Monitoring for Toxicity

    The American Academy of Ophthalmology has published guidelines for monitoring patients for Plaquenil toxicity. Some cases are difficult to detect, especially if other eye problems are present. Current testing for Plaquenil toxicity may include:
    ● Visual field testing to evaluate for missing spots near the center of the vision.● Farnsworth-Munsell 100 hue color test.● Color photographs of the macula.● Fluorescein angiography (FA).● Optical coherence tomography (OCT).● Fundus autofluorescence.● Multifocal electroretinograms (mf ERG).● Early detection of any maculopathy is critical to prevent central visual loss. The Retina Group of New York provides all of these testing modalities and is the only center on Long Island with mf ERG.

  • Treatment

    The treatment for early toxicity usually requires stopping Plaquenil. Patients taking Plaquenil should have an early baseline assessment of visual acuity, macular appearance and central field sensitivity. The macular appearance and function should be checked at intervals of 6 to 12 months. Factors such as renal or liver impairment must be considered in the dosing of this medication. Taking no more than 400 mg. daily total dose or under 5 mg./kg body weight is recommended.

  • Monitoring

    Patients can monitor themselves for possible toxicity at home in between visits. Paracentral scotoma (a small blind spot next to the center of vision) is often one of the first signs of Hydroxychloroquine toxicity. This can be picked up by the patient using an Amsler Grid (graph paper with a fixation spot in the center) at home, with reading glasses on. One eye is covered. The uncovered eye looks at the spot in the center of the graph paper and the patient takes note if any portions or parts of the graph lines appear missing. The other eye is then done in the same way. This should be performed once a week. With periodic monitoring, Plaquenil is a safe and effective medication for systemic problems and can usually be taken for decades with little risk to the vision.

Amsler Grid Testing

The Retina Group of New York recommends that patients monitor their central vision with an Amsler grid and report any abnormalities or changes promptly. Abnormalities such as missing spots, distortion or blotchy vision may indicate one of 50 macular problems.

You can easily test your macular function with this self-administered test.

● Wear your reading glasses and look at the grid at the normal reading distance (approx. 16-18 inches).● Cover one eye.● Focus on the black dot in the center of the grid and do not move your eye.● Check whether all lines of the grid are straight or whether they are distorted, blurred, or missing in any areas of the grid. Repeat the process with the other eye.

The test should be repeated at regular intervals (daily or at least every week).

Amsler Grid Testing.

©Retina Group of New York

The Amsler Grid test allows early detection of diseases affecting the macula.

Digital Color Photography

Color photographs of the eye help us document and follow many retinal problems.
● Diabetic Retinopathy.● Macular Degeneration.● Branch And Central Retinal Vein Occlusions.● Glacoma Optic Nerve Cupping.● Optic Atrophy.● Choroidal Melanoma.● Macular Hole.● Macular Pucker.● Retinal Detachment.

Automated Visual Field Testing

We look to see if defects or scotomas appear in the peripheral or central vision and how these change over time. The patterns may indicate macular disease, retinal vascular disease, retinal detachment, glaucoma or neurologic conditions. Patients may have 20/20 acuity but cannot read because of blind spots next to the center of vision. The test just takes approximately 5 minutes and each eye is tested separately to see if a brief visual stimulus is present in the center or peripheral visual field while the patient responds by clicking a button.

Ophthalmic Ultrasound

Ophthalmic ultrasound is helpful in identifying and following certain types of eye conditions. It is commonly used for:
● Retinal detachment.● Retinal evaluation with media opacities such as corneal opacities and cataracts.● Vitreous hemorrhage.● Ocular tumors.● Dislocated cataracts and IOLs.● Retinoschisis.● Choroidal detachments.● Foreign bodies.

Ophthalmic Ultrasound.

Ophthalmic Ultrasound showing malignant choroidal melanoma.

Color Vision Testing

The human eye is a remarkable evolutionary achievement, and humans are one of the few animals capable of color vision that we can test and quantify with several instruments. Farnsworth-Monsell color test objects are arranged in chromatic order by patients under standardized lighting conditions. Anomaloscopic testing compares the ability to discriminate and match colors and Ishihara color dot testing is well known to all elementary students. While the total inability to perceive colors, or color blindness, is quite rare, about 10% of males have abnormal perceptions of color, usually inherited from their mothers. Certain eye conditions and medications can also alter our color perception. Knowing you have a color perception problem may alter your career choice or has been known to influence the style of artists who see less blue as they develop cataracts.

Color Vision Testing.

An Ishihara color vision test plate may not show the number 5 if you have a certain type of color deficiency.

Color vision may be abnormal from birth (congenital) or become abnormal (acquired) due to conditions such as:
● Chronic illnesses: Alzheimer’s disease, diabetes mellitus, glaucoma, leukemia, liver disease, chronic alcoholism, macular degeneration, multiple sclerosis, Parkinson’s disease, sickle cell anemia and retinitis pigmentosa.● Trauma and accidents or strokes that damage the retina or affect particular areas of the brain or eye.● Medications such as antibiotics, barbiturates, anti-tuberculosis drugs, high blood pressure medications and several medications to treat nervous disorders.●  Industrial or environmental chemicals such as carbon monoxide, carbon disulfide and some containing lead.● Age: people over 60 years of age

Dark Adaptometry

We are able to see in both bright light and dim light with dark adaptation. We can measure the rate at which the eye adjusts to detect dimming light over 20 minutes. This gives us a normal dark adaptation curve or can identify hereditary or acquired causes of abnormal night vision or nyctalopia. If you can't see the people around you in the movie theater after 20 minutes, you may have a problem.

Common Causes of true Nyctalopia include:● Retinitis pigmentosa.● Retinal detachment.● Phenothiazines.● Oguchi disease.● Pathological myopia.● Dense Cataracts.● Sorsby's retinal dystrophy.● Vitamin A deficiency.● Choroideremia.

Dark Adaptometry.
Dark Adaptometry Graph.

Whole-field scotopic sensitivity (threshold) testing provides clinically beneficial information in a wide variety of ophthalmic conditions. Dark adaptometry is useful in the diagnosis and management of retinal degeneration, senile miosis, high myopia, vitamin A deficiency, and other night-blinding conditions. It has also been shown to be useful in the early detection of glaucoma.


Eyes generate electrical signals in response to light and these can be captured using thin hairlike electrodes the way we capture the electrocardiogram or EKG. We utilize different patterns and frequencies of flashes or flickers of light of different intensities to separate out isolated areas of the retina, such as the central macula or daytime vision, from the cones or the night-time vision generated by the rods. We can look at different layers of the retina altered by conditions or isolate the response of the optic nerve or the whole eye signals with different tests. Some tests are very precise, and the most sensitive indicators of early drug toxicity, such as Plaquenil allow us to use these medications safely. Others indicate rare hereditary diseases that can run in families. The tests are often repeated so we can estimate the rate of change or the effect of treatment. These include:


Pattern Visual Evoked Response (PVEP).

  • Multifocal (mfERG)

    The mfERG has been well documented to aid in the diagnosis and monitoring of retinal disorders, hereditary diseases and drug toxicity.● Clinical Applications.● Retinotoxic Drug Screening: mfERG is the preferred functional test for plaquenil screening and has been shown to detect toxicity before other methods.● Age-related Macular Degeneration: Physicians can now visualize functional degradation that has been shown to predict drusen progression.● Diabetic Retinopathy: Functional delays seen with mfERG testing can precede structural damage, allowing physicians to intervene in patient care before permanent damage occurs.

  • EOG (Electro-oculography)

    Retinal diseases producing an abnormal EOG will usually have an abnormal ERG, too, which is the better test for analysis of scotopic and photopic measures. However, a particularly good use for the EOG is in following the effects of high dosage treatment with antimalarials such as chloroquine and Plaquenil before the vision is severely affected and the ERG is abnormal. There is considerable variation in the fundus appearance in Best’s disease, which has an abnormal EOG.
    ● Best Vitelliform Macular Dystrophy.● Stargart Macular Dystrophy.● Pattern Dystrophies.● Membranoproliferative Glomeronephritis.● Ectodermal Dysplasia, Ectrodactyly, And Macular Dystrophy, Eem Syndrome.● Retinitis Pigmentosa.● Rod-cone Dystrophies.● Acquired Cone And Cone-rod Dystrophies.● Oguchi Disease.● Fundus Albipunctatus.● Choroideremia.● Gyrate Atrophy.● Diffuse Choroidal Atrophy.● Diffuse Chronic Chorioretinal Inflammation.● Hypertensive Retinopathy.● Retinal Detachment.● Silicone Oil.● Chloroquine and Hydroxychloroquine Toxicity.● Didanosine.● Desferrioxamine.● Diabetes.● Retained Intraocular Iron Foreign Bodies (Siderosis Bulbi).● Progressive High Myopia.● Choroidal Malignant Melanoma.

  • Pattern Visual Evoked Potential (PVEP)

    The VEP can be helpful for evaluating and following many ocular conditions including:
    ● Optic neuropathy.● Optic neuritis.● Ocular hypertension.● Glaucoma.● Diabetes.● Toxic amblyopia.● Leber hereditary optic neuropathy.● Aluminum neurotoxicity.● Manganese intoxication.● Retrobulbar neuritis.● Ischemic optic neuropathy.● Multiple Sclerois (MS).● Tumors compressing the optic nerve such as optic nerve gliomas, meningiomas, craniopharyngiomas, giant aneurysms, and pituitary tumors.