Category: Education

What is the Retina?

The retina is the light sensitive tissue that translates light into electrical signals for the brain. That’s how we see.

The retina is a highly specialized layer of tissue that lines the inside of the eye. As part of the central nervous system, it serves as a crucial component of the visual system. Its primary function is to convert light into electrical signals that can be translated to “vision” by our brain.

It consists of several layers of cells, each with a specific role in the process of vision. The outermost layer contains the photoreceptor cells, known as rods and cones. Rods are responsible for vision in low-light conditions and are highly sensitive to light, while cones are responsible for color vision and visual acuity in brighter light conditions. Cones are further classified into three types: red, green, and blue cones, allowing us to perceive a wide range of colors.

Converts Light to Electrical Signals

When light enters the eye, it passes through the cornea and lens, which help focus the light onto the retina. The rods and cones in the retina absorb the light and convert it into electrical signals. This process involves the activation of light-sensitive pigments within the photoreceptor cells, triggering a cascade of chemical reactions that generate electrical signals.

The electrical signals produced by the rods and cones are then processed by several layers of cells within the retina. Bipolar cells receive the signals from the photoreceptor cells and transmit them to ganglion cells, which are the final layer of cells in the retina. The ganglion cells collect the signals and their axons form the optic nerve, which carries the visual information from the retina to the brain.

Highly Specialized Cells Sharpen Vision

Within the retina, there are also other types of cells, such as horizontal cells and amacrine cells, which help refine and modulate the visual signals. These cells play a role in enhancing contrast, adjusting sensitivity to light, and facilitating communication between different parts of the retina.

The central region of the retina is known as the macula, which contains a high concentration of cones. At the center of the macula is a small depression called the fovea, where visual acuity is highest. The fovea contains a high density of cones, allowing for detailed and sharp central vision.

For us to see, all layers of the retina must be healthy, maintain normal blood supply and remain attached.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

What are Eye Floaters?

Vitreous floaters, eye floaters or just floaters can be annoying or a dangerous threat to your vision.

Eye floaters, or vitreous opacities, are common but not always benign. They also affect us all differently, from a mere annoyance to visually impressive.

Floaters are the common name for dark specks or spots which move to and fro in your vision.  They move with eye movement in your field of vision.  They may or may not be associated with clumps or strands of protein floating in your vitreous. These clumps or strands may represent “cob-webs” also seen in your vision.

There are many causes of floaters.

What is the Vitreous?

The vitreous is the substance that fills the vitreous cavity.  The vitreous cavity, or posterior chamber, is the largest compartment of the eye and is located between the lens and the retina.  The retina is the inside lining of the eye. 

Normally, the vitreous is optically clear, color-less and has the consistency of a gel.  The vitreous is composed mostly of water, but has about 5% protein. 

The vitreous is essential for normal embryologic development of the eye.  Once we are born, we are not sure of any true functions of the vitreous although many believe it is essential in oxygenation of the tissues of eye, such as the lens.

The vitreous may absorb energy.  For instance when you are engaged in sports, running, or suffer a head injury, the vitreous may be absorbing shock waves.  This is unproven.

What are floaters?

The vitreous is never regenerated.  While the fluid component does renew (aqueous humor), the proteins do not.  With time and normal aging, the proteins can denature or breakdown and the vitreous becomes more water-like.  

The thinner, more fluid, vitreous means that the vitreous changes from a thicker gel to a more watery substance.  The proteins can more easily coalesce and clump together casting shadows on the retina…more commonly known as floaters. 

Floaters can also be a result of retinal disease, blood or inflammation.  Floaters from any cause are indistinguishable from one another (i.e. you can’t tell the difference between floaters due to blood vs. inflammation).  Only your eye doctor can tell the difference after a thorough dilated examination of your eye.

It is recommended that you alert your eye care professional should you ever experience a sudden increase in floaters.  New floaters could be a sign of a potentially blinding condition. 

Treatment of Floaters

In general, the best treatment for floaters is to treat the underlying disease.  Persistent floaters can be bothersome.  Removal via vitrectomy may be the only solution for clearing the floaters from your vision.

Some doctors may offer Nd:Yag laser for the treatment of floaters.  There are limitations to this type of treatment and not all retina specialists view this treatment equally. 

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Face Mask May Increase Eye Infections

Here’s another reason to be careful about wearing a mask.

Wearing a face mask is important for patients from the moment they walk into a clinic to protect themselves and others from SARS-CoV-2 infection. But additional safety measures should be used when the patient is wearing a face mask and receiving intravitreal injections to prevent contamination that could occur when exhaled breath is blown toward their eyes.

A study to investigate the air that escapes from the top of face masks used a thermal camera and found that air jets originating from the top edges of face masks and radiating toward the eye were detected in 81% of cases.

3 Face Masks

Three face masks were tested. A regular face mask with four tying strips, one with elastic ear loops, and the 220 N95 tuberculosis particulate face mask.

Exhaled breath that is normally blown forward is blocked by face masks and that air is redirected toward the eye. People who wear glasses and face masks are aware of this issue. It causes their glasses to fog up.

Anti-VEGF injections have a very low risk of endophthalmitis. Several large studies have estimated the risk at approximately 0.05% or 5 in 10,000 for any individual patient receiving monthly injections. Having face masks blowing air into the eye could increase that risk slightly and for that reason extra precautions are recommended.  

Study Recommendations

The additional precaution can be done in one of two ways—a surgical drape can be used to isolate the eye or medical adhesive tape can be applied on the upper border of the face mask to block air passage. The study also recommends using an eyelid speculum to keep the eye open and prevent the eyelid from coming into contact with the needle.

The study’s author, Amir Hadayer, MD, says, “Protocols for preparing patients for intravitreal injections vary and not all specialists use draping and a speculum in normal times, but under the current circumstances, these extra precautions are recommended.”

What is Endophthalmitis?

Endophthalmitis is an infection that causes severe inflammation of the tissues inside the eye. The infection is typically caused by bacteria for fungi.

Symptoms of Endophthalmitis

  • Decreased vision
  • Pain
  • Redness or swelling of the eye

These symptoms don’t always mean you have endophthalmitis, but if you experience one or more of these symptoms, contact your ophthalmologist.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Causes of Distorted Vision

What’s the difference between blurry and distorted vision? Here are some causes.

Distorted vision is not the same as blurry vision. Visual distortion causes the straight edges of things and straight lines on paper to appear wavy and it causes objects to appear bent or misshapen.

Visual distortion can be caused by eye diseases, injury to the eye, eye infection, or inflammation. It could be caused by abnormal blood vessels that are leaking under the retina and affecting the macula—the part of the retina at the back of the eye that has a very high concentration of photoreceptor cells and that is responsible for our central vision.

In diabetics, increased blood sugar can cause the lenses of the eyes to swell with fluid and cause visual distortion. In people with age-related macular degeneration, it could signal that dry macular degeneration has become “wet” macular degeneration.

Because it could signal serious eye conditions, always see an eye care professional when you experience visual distortions. 

Common Diagnostic Exams

The exact cause of distorted vision must be diagnosed so the proper treatment can be started. A dilated eye exam along with specialized medical imaging techniques are used to diagnose the cause of visual distortion.

Dilated eye exam. Dilating the pupil allows the doctor to closely examine the condition of the macula and detect the presence of blood vessel leakage or cysts.

Optical coherence tomography. This type of imaging captures detailed microscopic views of the cell layers inside the retina. It detects the thickness of the retina, making it useful in determining the amount of swelling in the macula.

Fluorescein angiogram. In this test, a special dye is injected into your arm and a camera takes photos of the retina as the dye travels through the blood vessels. This test helps your ophthalmologist identify the leaking blood vessels and the amount of damage they have done to the macula.

Monitoring Your Vision at Home

The Amsler Grid. The Amsler Grid is a good way to test the functioning of your macula by detecting visual distortions. If you have a pre-existing condition that can affect your vision, using an Amsler Grid daily can help you detect the first signs of visual distortion that signal eye involvement. 

AMSLER GRID

INSTRUCTIONS FOR HOME USE:  Wear glasses if you need them and look at the Amsler Grid from about 14 inches away. Test both eyes, one at a time, to see if any parts of the grid look distorted, missing, or dark. Mark the areas of the chart that you’re not seeing properly and bring it with you to your eye exam.

Treatments

There is no single treatment for the various causes of distortion. The exact cause will dictate possible therapeutic options.

If you are experiencing distortion, especially if it of recent onset, please contact your eye doctor.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Diabetes: You Can Take Charge

November is Diabetes Awareness. Newly diagnosed with diabetes or know someone? Share this article.

Diabetes is a serious life-long condition, but there’s a lot you can do to protect your health. If you have been newly diagnosed with type 2 diabetes or prediabetes, this article offers you tips for managing your diabetes.

Overtime complications of diabetes caused by uncontrolled blood sugar can develop in the eyes (diabetic retinopathy), the kidneys (diabetic nephropathy), and the feet (diabetic neuropathy). Those three areas all receive their blood supply from tiny blood vessels called microvasculature that are susceptible to damage from high blood sugar levels.  

However, when blood sugar is well controlled the rate of complications falls. A 1% decrease in the A1c test that is maintained decreases your risk of microvascular complications by about 37%.

Taking care of your diabetes or prediabetes right after diagnosis will pay off in your long-term health.

Managing Your Type 2 Diabetes

The following steps will help keep your blood sugar levels closer to normal and maintaining close-to-normal blood sugar levels can delay or prevent diabetic complications:

  • Weight loss and maintenance of the weight loss
  • Healthy diet
  • Regular exercise
  • Blood sugar monitoring
  • Using diabetes medications as prescribed

Watch your diet

There is no “diabetes diet”, but making efforts each day to take the following steps will help put you on the right track for lowering your blood sugar levels:

  • Eat more fruits and vegetables
  • Eat more foods high in fiber
  • Eat fewer refined carbohydrates, such as white bread, white rice, pastries, pancakes, and crackers
  • Eat fewer saturated fats, such as fatty cuts of beef, pork, and lamb, processed meats, butter and full-fat dairy
  • Eat fewer overall calories

You don’t have to entirely cut out foods high in saturated fats, but you should limit your consumption. Check labels and choose foods that have more unsaturated than saturated fats. 

Fatty fish such as salmon, tuna, sardines, mackerel, herring, and trout are good sources of long-chain omega-3 fatty acids and are a healthy addition to your diet.   

Get Moving

Fitness is an important aspect of managing type 2 diabetes. It can be walking, bike riding, or swimming laps, but the key is to find activities you enjoy and will keep doing. 

Just 30 minutes a day of exercise will, in time, decrease your blood sugar levels, increase your cardiovascular fitness, strengthen your bones, reduce excess body fat, and boost muscle power. Walking will also improve your mood especially if you walk in an area with some greenery or water.

Monitor Your Glucose         

Frequently check your blood sugar levels. Doing so can help you see which foods or activities trigger blood sugar highs or lows. Keep your food and activity consistent and test your blood sugar and look for patterns over 2 to 3 days. The goal is to find the insulin dose that keeps your blood sugar levels stable without causing a low.

Have regular A1c tests that will assess your average blood sugar level for the past 2-to-3 months.

Your blood sugar monitoring schedule is individual to you and should be set according to your needs and under the supervision of your doctor.

Connect with a Diabetes Care and Education Specialist

Diabetes care and education specialists are certified healthcare professionals with specialized knowledge in diabetes self-management and care. They will help you chart and then monitor the best diabetes healthcare course for your situation.

Visits to accredited diabetes education specialists are covered by most insurance plans and by Medicare Part B. You can locate an accredited diabetes education program by clicking here.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Saving Your Vision: Diabetic Retinopathy

November is National Diabetes Awareness month.

If you have diabetes, take a few minutes to learn about diabetic retinopathy and how you can take steps to help keep your eyes healthy.

Diabetic retinopathy is the most common cause of vision impairment and blindness among working-age adults in the U.S. It occurs when high blood glucose levels damage the blood vessels at the back of the eye causing them to become weak and leaky and damage the retina.

If not found and treated early, diabetic retinopathy can cause permanent vision loss. That’s why it is important to manage your diabetes and stay alert to the early signs and symptoms of diabetic retinopathy.

Types of Diabetic Retinopathy

There are two main types of diabetic retinopathy—NPDR (non-proliferative diabetic retinopathy) and PDR (proliferative diabetic retinopathy). The “proliferative” refers to new blood vessel growth, so in non-proliferative, there is not yet new blood vessel growth.   

NPDR is the early stage of diabetic retinopathy. At this stage, high glucose levels have weakened the blood vessels and, in time, may cause bulges in the weakened vessels (microaneurysms) that may leak fluid into the retina and the leakage may swell the macula or some blood vessels may begin to close. So this is an ongoing disease cycle that can be slowed or stopped if caught early.

PDR is the more advanced stage of diabetic retinopathy. The NPDR has weakened the blood vessels or closed them, so new blood vessels have grown in an attempt to supply oxygen to the retina, but these new vessels are fragile, and they leak and damage the retina. 

PDR can lead to vitreous hemorrhage, traction retinal detachment, or neovascular glaucoma.

Stay Alert

Anyone with type 1 or type 2 diabetes, or women who have gestational diabetes during pregnancy, can develop diabetic retinopathy. The risk increases when blood sugar, blood pressure, and cholesterol levels are not under control.

In the early stages diabetic retinopathy may not have symptoms, so it’s important to have a comprehensive dilated eye exam once a year. That way diabetic retinopathy can be diagnosed and treated before symptoms appear.   

Symptoms that indicate diabetic retinopathy has progressed are:

  • Blurry vision
  • Vision that goes from blurry to clear
  • Increased number of floaters
  • Poor night vision
  • Spots or blank areas in your central vision
  • Colors appear faded

Diabetic Retinopathy Treatment

The best treatment happens before you develop symptoms. Strict control of your blood sugar will significantly reduce your risk of vision loss from diabetic retinopathy. If you have high blood pressure and kidney problems, make sure those are kept under control too.

Injections in the eye of anti-VEGF medication can stop the growth of new blood vessels. VEGF stands for vascular endothelial growth factor, and it is a signal protein your body produces that stimulates new blood vessel formation, but the new vessels are weak and leaking vessels that damage your eyes, and anti-VEGF injections will stop that abnormal blood vessel growth.

Laser surgery and vitrectomy are other treatments for advanced PDR. But the most important thing to remember if you have diabetes, is that control of your blood sugar and early diagnosis and treatment of diabetic retinopathy are the best protections against vision loss.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Diabetes Awareness: A Look Back And Ahead

November is diabetes awareness month. Read this article to raise your own diabetes aware and share it with others.

November is Diabetes Awareness Month and World Diabetes Day is November 14, the birthday of the man credited with the discovery of insulin—Frederick Banting.

Diabetes is a chronic, metabolic disease which can lead, over time, to serious damage to the heart, blood vessels, eyes, kidneys, and nerves. Diabetes awareness aims to improve understanding of this disease within your family and your community.

An estimated 34.3 million Americans, 10.5%, have diabetes according to the CDC’s National Diabetes Statistics Report, 2020 and 88 million adults, approximately 1 in 3, have prediabetes. New diagnosed cases for both type 1 and type 2 diabetes are on the rise for U.S. youths.  

Diabetic retinopathy, the disease that affects the eyes, is a leading cause of blindness, yet vision loss can be prevented.

A Look Back

Fredrick Banting was a Canadian orthopedic surgeon who was fascinated with the published research into the role of the pancreas in diabetes. In 1901 it was discovered that the pancreas produces insulin from a collection of cells known as the Islets of Langerhans, which are  irregularly shaped patches of endocrine tissue located within the pancreas.  

The problem Banting wanted to solve was extracting the insulin from the pancreas. Many attempts had been made, but all of them had failed.

Banting had an idea but had no research experience and needed help. He convinced the head of the University of Toronto to give him a laboratory and a research assistant.  Banting and his research assistant, Charles Best, started work on May 17, 1921. James Collip, an experienced Canadian biochemist, was asked to join Banting and Best in December 1921 to purify their insulin extract.  

On January 23, 1922, a 14-year-old boy, Lenard Thompson, became the first person to receive an insulin injection as treatment for diabetes. By 1923 insulin was widely available and a diagnosis of diabetes was no longer an immediate death sentence.

Insulin from cattle and pigs was used for many years, but it could cause allergic reactions in some patients. In 1978 recombinant DNA technology made it possible to insert a human gene into a common bacterium so it will produce the protein (insulin) encoded by the human gene. The insulin is extracted from the bacteria and purified.

Today and a Look Ahead

Diabetes is now a manageable disease and the technology for managing it is constantly evolving.  The American Diabetes Association (ADA) has a Device Technology section on its website that describes and explains continuous glucose monitoring devices, glucose meters, and insulin pumps.

On the ADA website you also can find a Diabetes Education Program. These programs are located throughout the U.S. and the educators in the programs work with diabetics to give them the information, skills, and resources they need to successfully manage their diabetes. Medicare and most insurance plans cover these diabetes education programs.

On September 28, 2016 the FDA approved the first artificial pancreas device system. It works by inserting a very tiny sensor under the skin, usually on the stomach or arm, that measures the glucose fluid in the fluid between cells every few minutes and sends this information to an insulin pump attached to the body that, when needed, delivers the right amount of insulin. In this way insulin is released throughout the day as a natural pancreas would.

Islet cell transplants are in the experimental phase and being done in 17 centers around the country that are participating in islet cell research programs. The challenges the researcher face are methods for collecting enough islet cells for a transplant and preventing rejection of the transplant.

What Can You Do?

Improve your own diabetes awareness.

Living with diabetes is now easier than ever before. Share this information with your friends and family to raise their level of knowledge and understanding of this disease.

No matter what, every patient with diabetes needs to have their eyes examined yearly. Severe vision loss and blindness can be prevented, but only with timely and regular examination.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Board Certified Eye Doctor

What does board certified really mean…and what’s a retina specialist?

I am both a board certified ophthalmologist (eye doctor) and a retina specialist. Board certification requires periodic testing of knowledge.

To become a retina specialist required additional training following my completion of ophthalmology residency.

The test to become a board certified certified ophthalmologist had nothing to do with my decision to become a retina specialist. Board certification is required to obtain hospital privileges, state licensure and, perhaps, participate in many health insurance plans.

Ophthalmology Residency

After completion of medical school, all graduates are technically an “M.D.”

Internship: In most cases, the first year after graduating from medical school is spent as an intern where we gain practical experience in various core fields of medicine such as internal medicine, general surgery or some combination of the other specialties. We do not focus on ophthalmology.

Residency: Ophthalmology residency begins after the internship. Most residency programs are 3 years long and for this period, we learn nothing but ophthalmology. Residents are essentially apprentices to the craft of ophthalmology learning from practicing ophthalmology attending physicians.

At the end of residency, many of my colleagues chose to start private practice in general ophthalmology. A general ophthalmologist usually performs cataract surgery, treats various diseases such as glaucoma, diabetic retinopathy, etc.

Fellowship Trained Retina Specialist

The period of training following residency is dedicated to sub-specialty training and is called a fellowship. To become a retina specialist, I completed an additional 2 years of training after completion of residency.

In other words, after I was qualified to become a general ophthalmologist, I took on optional training to allow me to become a retina specialist.

There are about eight or recognized sub-specialties within ophthalmology. Diseases of the retina is one of the these sub-specialty areas.

The sub-specialties in ophthalmology are:

  • Cornea/Refractive
  • Glaucoma
  • Neuro-ophthalmology
  • Ocular pathology
  • Oculoplastics
  • Pediatrics
  • Oncology
  • Uveitis
  • Retina Specialist

Most fellowship trained doctors eventually practice only their sub-specialty, that is, as a retina specialist, I only take care of patients with problems with the retina.

While I am qualified to perform cataract surgery and diagnose glaucoma, I choose not to.

Board Certified

What does this mean?

Board certification, at least in ophthalmology, is a test or certification of competency in general ophthalmology. It has nothing to do with my being a retina specialist. At this time, there is no sub-specialty board certification.

Though I am a retina specialist, my board certification reflects that I am fluent and knowledgeable in all the various areas of ophthalmology. This is true of all ophthalmologists who practice a sub-specialty.

“Board certified” simply means I know a lot about general ophthalmology.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Jon Doe