The Retina & Retinal Eye Exams

The light-sensitive tissue that lines the back of the inner eye is called the “retina”. Images that you look at are projected through the pupil and focused onto the retina. The rod and cone cells in the retina then convert that image into electric signals, which are then sent to the brain through the optic nerve. Understandably, the retina is vital to your visual system, and if damaged or diseased, can cause blindness or loss of vision.

There are 3 important structures in the retina:

  • Optic Nerve: The ‘wire’ that connects the eye to the brain. This nerve carries visual signals to the brain, much like the cables that connect a DVD player to your TV.
  • Macula: This is the area of the eye with the highest density of rods and cone cells. Much like more pixels in a digital photo give you a clearer higher resolution image… the higher density of rods and cone cells in the macula give you more detailed and higher resolution central vision.
  • Retinal Blood Vessels: These are the arteries and veins that feed the eye nutrients and oxygen and are responsible for removing waste materials. The retina needs a constant blood supply to function properly and provide good vision.

There are many diseases and disorders that can affect the retina. Systemic disorders such as high blood pressure, high cholesterol, diabetes, atherosclerosis, blood disorders, and many more can negatively affect retinal health. External factors such as accidents/injuries, UV light, lasers, smoking, occupational hazards, and medications can also cause damage to the retina and affect your vision. Some conditions like glaucoma, macular degeneration, retinal detachments/holes, can have some genetic inheritance ? but can also occur spontaneously in individuals with no family history of these issues.

Because there are so many known (and unknown) conditions that can cause problems for the retina, it is important to have the health of your retina assessed yearly at your comprehensive eye exam – even if you do not wear glasses or have perfect vision.

The latest technology that we have to screen central retinal health is the retinal camera. This camera uses a special set of focusing lenses to take a quick and painless digital image of your retina. Most of the time, good images can be taken without dilation eye drops, and there are no side effects (other than the temporary brightness from the camera flash). In addition, these photos can be used as a baseline to look for changes that can occur to your retina through the years. Although this instrument is not yet considered the standard of care, it is quickly becoming so. In our office, we offer digital retinal photography to all patients for a nominal fee, and are happy to email these photos to our patients at no charge.

A more comprehensive way to assess eye health is with the dilated eye exam. Without dilating the pupils, peripheral portions of the retina are not viewable. It is important to view these parts of the retina in order to properly assess eye health and screen for potentially vision threatening conditions. The dilation also allows for a much more thorough assessment of the central retina, as it increases the field of view for the doctor to see inside the eye – much like viewing the inside of a room is easier through a big open doorway vs. an old fashioned keyhole in the door. In order to dilate the eyes, the technician or doctor will put eye drops into the eyes, and when the pupil widens, the doctor will exam the retina using a special head-mounted scope. In my office, we offer the dilated eye exam free of charge within 30 days of your comprehensive eye exam. The main side effects of dilation include blurry vision, light sensitivity, and inability to focus for a few hours ? because of this; it is usually a good idea to have a driver take you home.

Ask your eye doctor for more information on how you can keep your retina healthy, and what tools they use to check your retinal health.

-Dr. Mika Fu

Grand Vision Optometry 151 S Las Posas Rd Ste 171, San Marcos CA 92078. Tel: (760) 510-3130