The retina is a tissue located in the back of the eye that contains neural structures that actually makes vision happen – it converts light into sight. Retinal photography allows your eye doctor to take an image of the retina; including the macula, optic nerve and major blood vessels of the retina. More specifically, retinal photography allows your eye doctor to take a picture of PART of your retina. Retinal photography has significant limitations and is not diagnostic, which is why it is often referred to as a 'screening retinal photo'.
Unfortunately, there are several misconceptions surrounding retinal photography that can make it difficult for you, as the patient, to understand when and why you would want a retinal photograph performed. So let's talk about how retinal photography fits into your eye care routine as well as the value and limitations of this technology.
If you have ever heard 'pictures are worth a thousand words' then you know the real value of a retinal photograph. Including a retinal photograph as part of your medical chart at the eye doctor provides a higher level of detail regarding our eye health. Retinal photographs from previous examinations can be referenced if a new and significant finding is detected by your doctor at a future exam. The same is true for progressive conditions; the doctor can compare photographs from one visit to the next to detect subtle changes in eye health.
So when are retinal photographs especially helpful?
BASELINE PHOTOGRAPH: Whether you are going in for your first eye exam with a new doctor or considering a retinal photograph for the first time, there is value in having a baseline photo. Should anything change in the future, you will always have 'day 1' to compare to.
IRREGULAR BUT BENIGN FINDINGS: Not every noteworthy finding in your retina is associated with an active disease process. Think of it as 'normal for you'. Any time you have a unique feature in your eye (whether it be the size of your optic nerve or the appearance of your blood vessels), it is beneficial to have a retinal photograph.
DIABETES OR HYPERTENSION: Certain systemic conditions affect the health of the eyes at high rates. Diabetes and high blood pressure affect the fine blood vessels and other structures of the retina, which can lead to vision loss. If you have been diagnosed with these conditions (or pre-diabetes), it is helpful to include retinal photography as part of your eye care routine. NOTE: Retinal photography does not replace the need for routine dilation. Diabetics should be dilated on an annual basis, or more frequently if medically necessary. Additional imaging might be required based on diabetic changes to the eye.
While retinal photography has value, it does come with limitations. It is important to keep in mind that retinal photography adds to your eye care routine but it does not replace another aspect of your eye care, such as a dilated exam or fundus evaluation by your doctor. A few of the major limitations of a retinal photograph include:
LIMITED VIEW: No retinal photograph available on the market today can adequately view the entire retina. This means that if you rely on a retinal photograph to 'assess eye health', you are gambling that any eye disease is within the view of the camera. You may hear a doctor or a company advertise that they have a 'wide angle camera' or a photo with a wider view. What they don't tell you is that even this wider view falls short of assessing your retinal health, does not image the entire retina and does not replace the need for a dilated exam by your doctor. The other 'oh by the way' is that the reported field of view is based on the perfect situation – perfect patient, perfect pupil size, perfect technician. Often times these wide angle photographs will have a significantly restricted view to the doctor. Your pupil size, your eye shape, and the skill of the technician can result in a lovely picture of your eyelid that obstructs the view of the retina. You end up with a poor photograph that is of minimal value to the doctor. So yes a photograph can see the central structures in the retina, such as the macula and optic nerve (which are very important), but they miss the peripheral retina. What can exist in the peripheral retina? Retinal detachments and tumors are just a couple things.
POOR IMAGE QUALITY: Many screening retinal photographs, or wide angle photographs, produce a low quality image. In addition to clarity, retinal photos (such as Optos), have the potential to distort the image of the back of the eye. We often receive images from offices that are so distorted and blurry that the only thing we can see is the patient's eyelid at the edge of the photograph. While there are high quality digital retinal cameras available, they are not always used for the screening retinal photograph at the time of your eye exam. Fortunately there is an alternative to this grainy, distorted picture of the back of your eye. It is your eye doctor; who has diagnostic lenses and a microscope with multiple magnification powers that can provide an extremely clear view of the retina. Your doctor looks directly at the back of your eye so that he or she can evaluate the health of your eye and view areas of suspicion under differing light conditions, from different angles and with a sense of depth (things that some retinal photographs cannot do).
LACK OF DEPTH AND VARIABLE VIEWS: Screening retinal photographs taken at your eye exam are usually a two dimensional image with inadequate brightness/lighting. Many conditions that affect the retina are better evaluated with a perception of depth and under differing lighting conditions – which can be achieved by your doctor directly viewing your eyes at your examination.
So what is the reality of many retinal photographs? You may think you are paying extra for superior technology, but you may be getting a distorted, blurry, limited view of your retina.
Why You Still Need To Be Dilated
Dilation (or 'the drops' as many patients call it) is a necessary part of anyone's eye care routine. Some people need to be dilated multiple times per year while others need to be dilated every few years. The specific schedule necessary for you depends on several factors and is ultimately determined by your eye doctor.
WHAT DOES DILATION DO?
The dilation drops enlarge the pupil (the black part in the middle of your iris, or colored part of your eye). By enlarging the pupil, the doctor is better-able to view the structures of the back of your eye. Without dilation, the doctor (or the camera) is only able to see limited areas in your eye. Think of an undilated exam as looking through a peep hole in your front door. You can see some things but not everything. The dilating drops are like 'opening the front door'. You get a much better view and can see substantially more. Without dilation, your doctor will not be able to evaluate the full extent of your retinal health
WHAT IS THE VALUE OF A DILATION?
The value of a dilation is that it allows your doctor to get a better view of the back of your eye and evaluate the full extent of your retinal health. What types of things can be hidden beyond the view of the camera? They include retinal detachments, ocular tumors and diabetic eye disease. So dilating your eyes may make your vision blurry and the sun seem a bit brighter for a couple hours, but that is a minimal price to pay for identifying sight and life threatening conditions.
DILATION IS STANDARD OF CARE
If you see an eye doctor who tells you to have a retinal photograph because it replaces dilation, it is time to find a new eye doctor. As discussed earlier in the blog, retinal photography is great if it is added to your comprehensive dilated eye exam routine. Retinal photographs do not replace dilation and they do not meet standard of care. If a doctor tells you that a retinal photograph replaces dilation they are either unaware, unable, or unwilling to provide you quality eye care.
If your eye doctor asks you if you want to have a photo instead of being dilated, there are a few questions you should ask in return:
Why do you practice in a way that does not meet standard of care?
Why are you willing to sacrifice my eye health and vision and actually charge me extra to do so?
Can you release my insurance authorization so that I may receive a comprehensive eye exam elsewhere?
How To Incorporate Retinal Photography Into Your Eye Care Routine
The best way to incorporate retinal photography into your eye care routine is to think of it as an added data point, or as an additional measure for your doctor to monitor. Screening retinal photographs are simply that – a screening device. They are not a replacement for comprehensive care from your eye doctor and cannot diagnose eye conditions – such as glaucoma. Retinal photographs should be added to your annual trip to the eye doctor and the schedule of periodic dilated eye exams outlined by your eye doctor. Retinal photography does not replace the need for a dilated eye exam and does not replace your doctor looking directly at your eye health using diagnostic lenses and the microscope (slit lamp).
So yes, retinal photography is a valuable part of your eye care routine. It does not replace the need to have dilated eye exams or work with a doctor who knows how to deliver quality eye care. If you decide to include retinal photography as part of your annual exam you are definitely adding another layer to your quality eye care. If you are unsure whether or not to include retinal photography you can always ask the doctor. If you do not wish to include it in your annual eye exam routine, keep in mind that you are seeing an eye doctor who is able to evaluate your eye health without the use of a camera. If an image is deemed to be medically necessary, your doctor can always discuss this with you and schedule you back for a medical office visit.