About Diagnostic Testing
At Retina Consultants of Houston, our experienced and sub-specialized physician team uses advanced technology to help detect potential retinal problems and design precise, customized treatment plans to optimize care for each of our patients.
Depending on your condition, your physician may use one or more of the following imaging and testing technologies:
Anterior Hi-Res Ultrasound
Although ultrasound is more commonly used to evaluate the retina and optic nerve, it can also be used at higher frequencies to help evaluate some parts of the anterior or front part of the eye. Anterior high-resolution ultrasound (UBM) can be used to evaluate any abnormalities of the front of the eye, including the cornea, angle of the eye, iris, ciliary body, and lens.
Dark adaptometry is a test to see how well you see in the dark. It is a useful test for evaluating certain hereditary or genetic retinal diseases since night vision problems are a common complaint in many of these diseases.
In dark adaptometry, you will sit in a dark room for two minutes, and then you will be exposed to a bright light for several minutes. The bright light is then turned off, and you will be in total darkness once again. At this time, different intensities of dim light are introduced to you over a period of time, and the you let our technician know when you can see the light. The technician records the information as a curve on a graph and can compare it to a normal dark adaptation curve. Patients who have diseases that cause poor night vision (such as retinitis pigmentosa) are unable to see better in the dark over time.
Dark adaptometry can be used in addition to an electroretinogram/electrooculogram (ERG/EOG) in the evaluation of inherited retinal diseases.
ERG and EOG
ERG (electroretinography) and EOG (electrooculography) measure the electrical response of the different layers and components of the retina to light and dark stimuli. These tests can help us diagnosis hereditary conditions affecting the retina such as retinitis pigmentosa or Stargardt’s disease.
Fluorescein angiography (FA) is a photographic study of the blood supply to your retina. Fluorescein dye is injected into the vein of your arm, and this yellow dye passes through the blood vessels in your retina. A specialized camera is then used to take digital photographs of the blood vessels. This procedure is used to diagnose many different disorders affecting the retina and is generally very safe. The dye can be used in people who are allergic to shellfish or iodine and can also be used in patients who previously had reactions to contrast dye during radiologic procedures. However, in some rare instances, the dye may cause an allergic reaction, and this will be closely monitored during the procedure. Patients who undergo fluorescein angiography may also notice that their urine is yellow or green on the day of the procedure. This is normal and should stop within a day or two.
Fundus autofluorescence utilizes a blue-green wavelength light to visualize conditions that affect the pigment layer of the retina (retinal pigment epithelium). This simple, non-invasive, diagnostic test has greatly expanded our understanding and management of many different diseases affecting the macula, including dry age-related macular degeneration. Fundus autofluorescence takes only a few minutes and has no known adverse effects.
Hi-Res Anterior Segment OCT
Although optical coherence tomography (OCT) is more commonly used to evaluate the retina and optic nerve, it can also be used to visualize parts of the anterior or front part of the eye. High-resolution anterior segment OCT can help your retina physician evaluate any structures in the front of your eye, including the cornea, angle of the eye, iris, ciliary body, and lens.
Visual Field Tests
Certain eye diseases, such as glaucoma and retinitis pigmentosa, may cause loss of peripheral vision over time. This loss of peripheral vision can be documented and followed using visual field testing. Depending on your vision and the degree of the visual field loss, your retina doctor may recommend a Humphrey or a Goldmann visual field test.
During an automated Humphrey visual field test, you are asked to look at a target straight ahead and then press a button if and when you see a light that shows up in your peripheral visual field. The computer automatically generates and prints out a copy of your visual field test.
A Goldmann visual field test is less commonly performed. It is generally used in patients who have very poor vision or advanced visual field loss. In a Goldmann visual field test, an examiner manually moves a light target of differing sizes and intensities while you look straight ahead. You let the technician know as soon as you see the target. The examiner draws or maps out the visual field while performing the test.
Indocyanine Green Angiography
Indocyanine green angiography (ICG) is a photographic study of the blood supply to part of your retina. Indocyanine green dye is injected into a vein of your arm, and a specialized camera is used to take digital photographs of the blood vessels under the retina. This procedure can allow your doctor to study parts of your eye that are difficult to visualize with the more commonly used procedure of fluorescein angiography. It is especially useful in evaluating cases of central serous chorioretinopathy, certain forms of macular degeneration, and some inflammatory disorders. ICG is generally safe but has a slightly higher incidence of allergic reactions than fluorescein angiography. If you are allergic to shellfish or iodine, you should not undergo ICG testing.
Microperimetry allows us to measure the visual function of a specific part of the retina. Usually the test is used to measure macular function. Before the test begins, you stay in a dimly lit room for a few minutes. After this, you are asked to look straight at a target and are presented lights of varying intensity. You press a button every time a light stimulus is seen. The computer generates a map of the specific part of your retina that was tested, measuring the visual function. The microperimeter can be done along with optical coherence tomography (OCT) to objectively measure the visual function of a particular area of your retina over time.
Ocular and Orbital Ultrasound
We use ocular ultrasound to evaluate the eye in circumstances where we have difficulty seeing into the eye during a dilated exam because of eyelid swelling, poor pupil dilation, corneal scarring, an advanced cataract, or a hemorrhage in the eye.
Ultrasound can also be useful after a traumatic injury to the eye to evaluate a foreign body or retinal detachment. Some optic nerve findings, such as optic nerve drusen, can also be confirmed using ultrasound. Finally, ultrasound is used in the evaluation and treatment of tumors in the retina and choroid.
After anesthetic eye drops are placed in the eye, an ultrasound probe is gently positioned over it. The probe is used to transmit sound waves that travel through the eye. As these sound waves hit different parts of the eye, they are reflected back to the probe. The reflected sound waves are then transmitted into an electrical signal that is then turned into an image on a computer monitor. We can then study and even measure these images from the ultrasound.
Ultrasound is a very safe, non-invasive test that has no adverse effects and is available at all Retina Consultants of Houston offices.
Retinal photography (as well as ultra-widefield photography) utilizes a camera to take pictures of the retina in the back of the eye. The eye generally needs to be dilated to ensure we can obtain quality images. Retinal photography may be used in a variety of conditions to document findings and follow them over time. It is non-invasive, and there are no reported adverse effects.
Spectral Domain OCT Imaging
Optical Coherence Tomography (OCT) is an imaging technique that utilizes light wave interferometry to produce high-resolution, cross-sectional images of the retina, similar to a computed tomography (CT) scan. The images measure the thickness of the retina and are very useful in the diagnosis and follow-up of many diseases affecting the macula. The scan takes only a few minutes and is non-invasive with no adverse effects. High-resolution spectral domain OCT testing is available at all of our Retina Consultants of Houston offices.
Spectralis Multi-Color Imaging
Multi-color imaging is a new technology that enables your retina doctor to obtain higher quality photographs of the retina. This new system uses three separate laser colors, each scanning a different layer of the retina. The combined information obtained from each laser provides a sharper and clearer image than previously possible. An advantage of using this technique is that quality photographs can be obtained even in difficult-to-image patients such as those with advanced cataracts or eye movement disorders.
Classic retinal photography and angiography usually covers only about 45 degrees or roughly 20 percent of the retina at one time. Many abnormalities of the peripheral retina are difficult to image during fluorescein angiography (FA), and therefore, we are unable to thoroughly evaluate it. However, with ultra-widefield photography, we are able to view a much larger portion of the retina in one image.
Ultra-widefield imaging allows us to view almost 200 degrees or 80 percent of the retina at one time. Fluorescein angiography (FA) can also be done using ultra-widefield photography, and it provides superior visibility of the peripheral retina. Many abnormalities in the peripheral retina that were previously unable to be viewed on traditional angiography are demonstrated clearly on wide-field imaging. However, it is important to note that ultra-widefield photography, or any photography for that matter, does not take the place of a good, dilated eye exam by your ophthalmologist.
Most of our Retina Consultants of Houston offices are equipped with instruments that allow ultra-widefield photography and fluorescein angiography (FA).
"Mine was, more or less, an urgent situation, so I was very lucky to be able to see her. She had a staff who did the photos/preliminary exams and they were excellent. When I saw her, she had all the results. The news was good and she gave me all the info I needed. To me, time spent was not relevant, as she gave me all the time I needed to ask questions. Since the news was good, I had very few questions."- F.A. / Healthgrades / Oct 06, 2018
"Dr. Major and all the staff are amazing! Very caring, very comfortable atmosphere! Highly Recommend!"- B.C. / Facebook / Mar 12, 2019
"The entire staff has been very patient and caring. I'm thrilled to have Dr. Shah as my doctor! He's so gentle and caring."- B.S. / Facebook / Mar 07, 2019
"Dr Shefler and everyone else in the office were outstanding. I highly recommend Retina Consultants of Houston."- M.T. / Google / Feb 28, 2019
"I was told by my Optimologist that there was a concern with my retina and encouraged me not to delay in seeing a Dr at Retina Consultants. Fortunately, Retina Consultants allowed me to come right away to have my eyes examined. Dr. Kim and the staff was very professional and courteous. I felt that I was in the best place for my eye issues. I highly recommended Retina Consultants."- R.P. / Google / Feb 16, 2019
Your First Appointment
During your first visit to Retina Consultants of Houston, your board-certified retina specialist will gather your patient history, which will include your general and ocular health, medications, family medical history, allergies, and more. We will give you a vision test where you will read from a chart on the wall to test your vision function.
You can also expect your doctor to perform a tonometry to measure the pressure in your eyes. Your pupils will be dilated. Dilation makes your pupils open wide so the doctor can get a clear view of the inside. Dilation will make your eyes sensitive to light and typically lasts up to three hours. Many patients prefer to bring someone to drive them to and from appointments.
Please bring the following with you to the appointment:
- Photo identification and insurance card(s)
- List of all health conditions and allergies
- List of all your medications and supplements
- List of questions and concerns about your eyes
See the fees and insurance page to find out what insurances we accept. For your convenience, you can complete your patient forms online before your appointment.
What To Expect
The first visit is generally the longest visit as we set aside a few hours to complete a diagnostic testing session for new patients. All other follow-up appointments may be shorter depending on the amount and type of testing needed. Once your retina specialist has the necessary information to determine a diagnosis, you will discuss your medical options in detail to begin treatment. We will do our best to explain your results and give you plenty of opportunities to ask questions along the way.
Plan Your Procedure
Innovative Testing With RCH
At Retina Consultants of Houston, you are in control of your health. We just give you the right tools (testing) and retina specialists with decades of collective experience in the management of diseases of the retina, vitreous, and macula. We are the largest retina-only ophthalmology practice in southeast Texas and one of the most respected in the country. Our team at RCH is ready to advise you on your journey. Call for a consultation.