Question: It seems from the relatively small population of distance cyclists I know that there are a disproportionate number of people who have experienced detached retinas. I wonder if there has been any correlation research or conclusions? I experienced a detachment in 2003 which prevented me from traveling to France for PBP that year, and have heard of 2-3 other Randonneurs who have had similar experiences. — Tom K.
Peter Gordon, MD, Replies: There is no current evidence that long-distance cycling increases the likelihood of a retinal detachment, Tom. However, the factors that underlie the condition are found in a fairly sizable portion of the population, so it’s no surprise that cyclists — of all types — suffer retinal detachment from time to time.
Let’s look at the factors that predispose to retinal tears and retinal detachment. Lattice degeneration is a thinning of the peripheral retinal secondary to abnormal vitreoretinal interface. The vitreous is the gel inside the eye behind the human lens. It fills the inside of the back of the eye and adheres to the retina. The retina is the lining of the back of the eye composed of photoreceptors and other supporting layers.
The retina is where the image is formed that is converted from a light image to a photochemical and subsequent neuronal response that is transmitted to the visual cortex of the brain, where we “see” an image. If there is further thinning and hole formation in areas of lattice degeneration, then a retinal tear and subsequent retinal detachment can occur.
Lattice degeneration occurs in 6-10% of the general population. That is indeed a large number of people. In other words, lattice degeneration is not an uncommon finding during an eye exam. It is more common in nearsighted individuals. Most frequently, young patients with nearsightedness (myopia) wear contact lenses to cycle or have frequently had Lasik in order to ride without contact lenses or prescription glasses.
Neither Lasik nor contact lenses predispose to retinal detachment; however, the increased frequency of lattice degeneration in these nearsighted individuals increases the likelihood that one will find a higher rate of retinal tears and subsequent retinal detachment in nearsighted people. Blunt trauma (a serious bicycle crash) can increase the possibility of violent shifting of the vitreous gel inside the eye with traction — pulling or tearing — of the retina and retinal detachment.
The most important take-away message regarding retinal tears or detachments is that they do have important symptoms. Tears in the retina, whether spontaneously or from blunt trauma, produce “flashes and floaters.” Flashes are like lightning and are seen most easily in a darkened room. Floaters are like “1,000 black dots or coffee grounds” swimming around inside the eye. These are not subtle signs or symptoms. And they require a prompt phone call to an ophthalmologist to carry out a dilated eye exam with careful examination of the retina.
So, Tom, there is no evidence that long-distance cycling causes retinal detachment. However, you and some of your fellow Randonneurs may have had nearsightedness with lattice degeneration or have experienced significant trauma. Finally, it should be noted that family history of retinal detachment is yet another risk factor.
Peter Gordon, MD, is a practicing, board-certified ophthalmologist specializing in Intralase bladeless Lasik, cataract surgery, and comprehensive ophthalmology in the Atlanta, Georgia, suburb of Decatur. He can be reached at [email protected].