Rod-Cone Dystrophy is a genetically-based deterioration of vision caused by damage to the photoreceptors in the eye. Rods and cones are the photoreceptor cells in the retina that give us daytime and night time vision. Genes that provide the blueprint for manufacturing proteins crucial to the eye’s rods and cones are damaged. Without enough of these proteins, vision deteriorates and blindness may result.
Much of the current research into rod-cone dystrophy is focused on genetic research. Scientists are busy identifying the faulty genes and how they function. Stem cells or other genetic therapy offers hope for a treatment and possibly cure in the future. In the meantime, nutritional and lifestyle choices may slow the progression of rod-cone dystrophy.
The cones provide central vision and color vision. Iodpsin pigment in the cones helps protect them. Cone opsins (also known as “Photopsins”) are the photoreceptor proteins found in the cone cells of the retina that are the basis of color vision. In Cone Dystrophy, the genetic code that produces iodpsin pigment malfunctions. Cone Dystrophy can be stationary (stable, usually after appearing in childhood) or progressive (getting worse over time).
Rod-Cone Dystrophy involves both the rods and cones. Rod cells provide peripheral vision and night vision. In Rod Dystrophy, the genetic code for rhodopsin pigment is damaged. Rhodopsin (also known as visual purple) is a light-sensitive receptor protein that enables us to see in low light conditions.
How Rod-Cone Dystrophy Is Diagnosed
Dystrophy means it is a condition that a child is born with. Parents may notice these signs of rod-cone dystrophy in young children:
- Nystagmus – the eyes move quickly from one edge of the eyes to another
- Eyes move slowly, wandering around and not fixing or pausing on objects
- Touching eyes with fingers (eye poking)
In the case of cone dystrophy, bright light may cause vision to appear blurry and washed out. Stable Cone Dystrophy is also called “achromatopsia” because many patients cannot see color. Malfunctioning cone cells expose the rods to too much light, making vision in bright light difficult.
With cone dystrophy, central vision can be blurred, and colors not bright. Things that are not moving, color objects, fine details in daylight, printed words and faces may be difficult to recognize. Vision can be so poor that patients are considered legally blind, although they are rarely completely blind.
Patients with rod-cone dystrophy may have difficulty seeing in the dark and moving objects. They may have limited peripheral vision.
Any parent who suspects their child may not be seeing clearly should consult an eye doctor. The optometrist or ophthalmologist can screen and test for cone and rod-related diseases, as well as other possible causes. A number of eye diseases affect the photoreceptor cells, including Retinitis Pigmentosa (RP), Leber’s Hereditary Optic Neuropathy, Usher Syndrome and Batten’s Disease.
In some cases, the problems are not noticed or significant until later in life. If you notice any change in vision, go to the eye doctor to get evaluated.
Genetic diseases such as rod-cone dystrophy have two possible sources:
- Inheritance. One or both parents passed on genes that affect the child’s ability to produce proteins/pigments crucial for good vision.
- Mutation. Sometimes, genes mutate before birth. Mutation can be positive or negative. While mutation can be accelerated by exposure to radiation, many mutations take place with no known cause. Even identical twins have some mutations separating them genetically.
Rod-cone dystrophy can stabilize (stationary), or get worse over a lifetime (progressive).
There is currently no cure, nor any conventional treatments to hold off or halt the disease’s progression.
Professionals can teach vision-impaired people techniques for navigating everyday tasks. Devices and technology aimed at the visually impaired can improve quality of life and open up opportunities. Doctors may recommend tinted glasses.
Other Approaches to Cone-Rod Dystrophy Support
Although cone-rod dystrophy is genetic, there are many lifestyle choices that influence eye health. Targeted nutrition for the eyes is supported by a body of research. Avoiding harmful drugs, and using alternative health modalities such as acupuncture and microcurrent stimulation daily at home may also be helpful for these patients.
Nutrition aimed at supporting the photo receptors has been studied. They can be obtained through oral supplements as well as a healthy diet. The carotenoids lutein5 and zeaxanthin6, taurine7, vitamin C8 and Omega 3 fatty acids9 have properties that support the retina. Additionally, the antioxidant bilberry extract protects against photooxidization of the retinal cells and support night vision (rods). Vitamin A Palmitate10 may be helpful for some patients’ retinas, but is contraindicated for certain mutations. This vitamin can be over-dosed and may need to be taken with the bile salt TUDA, under the supervision of a health care provider.
Acupuncture is an ancient Chinese technique that stimulates meridians to improve the flows of energy in the body. Acupuncturists in the US are licensed by each state, and utilize disposable, hair-thin needles. They have protocols for addressing energy flow to the eyes. One protocol aimed at patients with another retinal disease, Retinitis Pigmentosa (another genetic based retinal disease), was used in a pilot study11. It found improvement for most subjects in several measurements.
Microcurrent Stimulation has been used by surgeons, orthopedists, anesthesiologists for several years to treat pain and promote healing. It is FDA approved for these uses. Microcurrent Stimulation (MCS) can be used for helping support overall retinal health by: supporting healthy circulation in the retina, increasing energy production (ATP) and helping the retina eliminate waste. There have been 5 studies12 done to date showing good results using MCS daily for a range of retinal conditions such as macular degeneration, retinitis pigmentosa and Stargardt Disease. This treatment method is listed as “off-label” use for the eyes by the FDA.
Men with Cone-Rod Dystrophy should avoid Viagra and similar drugs. It prevents the body from creating an enzyme essential to vision. While temporary vision problems are a known possible side-effect, one study found permanent damage13. Patients who already have a genetic strike against them should not take any chances.
Cone-rod dystrophy is a genetic disease, and signals a lifetime of vision challenges. Training and technology help the patient adapt; lifestyle choices may slow the disease’s progression and help preserve vision. As genetic research continues, a treatment may be available in the future.
Up Next: Explore our Photoretinal Support Page and learn more about Cone-Rod Dystrophy.
- Mol Vis. 2016 Feb 20;22:150-60. eCollection 2016. “Next-generation sequencing-based comprehensive molecular analysis of 43 Japanese patients with cone and cone-rod dystrophies.” Oishi M et. al. ↩
- Ophthalmic Genet. 2016 Feb 11:1-7. “A novel C8orf37 splice mutation and genotype-phenotype correlation for cone-rod dystrophy.” Rahner N et. al. ↩
- Exp Eye Res. 2016 Mar 15. pii: S0014-4835 “Molecular genetics of cone-rod dystrophy in Chinese patients: new data from 61 probands and mutation overview of 163 probands.” Huang L et. al. ↩
- Curr Opin Ophthalmol. 2016 Feb 6. “Cell therapy for retinal disease.” Ehmann D, Shahlaee A, Ho AC. ↩
- Bahrami H, et al. Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized double-masked placebo-controlled clinical trial, BMC Ophthalmology, June 2006 ↩
- S.R. Kim, Photooxidation of A2-PE, a photoreceptor outer segment fluorophore, and protection by lutein and zeaxanthin, Experimental Eye Research, May, 2006 ↩
- Mol Vis. 2012;18:2673-86. Epub 2012 Nov 12. Review: taurine: a “very essential” amino acid. Ripps H1, Shen W. ↩
- C. I. Calero, et al., Allosteric Modulation of Retinal GABA Receptors by Ascorbic Acid, Journal of Neuroscience, 2011 ↩
- PLoS One. 2015 Jun 4;10(6):e0128395. doi: 10.1371/journal.pone.0128395. eCollection 2015. Dietary supplement enriched in antioxidants and omega-3 protects from progressive light-induced retinal degeneration. Ramchani-Ben Othman et.al. ↩
- E.L. Berson, et al., Clinical Trial of Lutein in Patients With Retinitis Pigmentosa Receiving Vitamin A, Archives of Ophthalmology, 2010 ↩
- Ava K. Bittner, OD, PhD, Jeffrey M. Gould, MEd LAc, Andy Rosenfarb, ND LAc, et al., A pilot study of an acupuncture protocol to improve visual function in retinitis pigmentosa patients, Clinical and Experimental Optometry, May, 2014 ↩
- See a microcurrent stimulation research page on the Natural Eye Care website ↩
- L. Nivison-Smith, et al., Sildenafil alters retinal function in mouse carriers of retinitis pigmentosa, Experimental Eye Research, November, 2014 ↩