National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Cone dystrophy

Cone dystrophy is a general term for a group of rare eye disorders that affect the cone cells of the retina. Cone cells allow a person to see color and fine detail, and they work best in bright light. The cone dystrophies can cause a variety of symptoms such as decreased visual clarity when looking straight ahead, a reduced ability to see colors, and an increased sensitivity to light.[1] There are two main subtypes of cone dystrophy, called stationary cone dystrophy and progressive cone dystrophy. The age when symptoms begin, the type and severity of symptoms, and the progression of symptoms are all very different between individuals, even between people with the same type of cone dystrophy.[1] Mutations in many genes have been found to cause cone dystrophy, and the condition can be inherited in an autosomal dominant, autosomal recessive, or x-linked manner.[2]
Last updated: 7/1/2013

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal electroretinogram 0000512
Abnormality of retinal pigmentation 0007703
Color vision defect
Abnormal color vision
Abnormality of color vision
[ more ] 		0000551
Photophobia
Extreme sensitivity of the eyes to light
Light hypersensitivity
[ more ] 		0000613
Visual impairment
Impaired vision
Loss of eyesight
Poor vision
[ more ] 		0000505
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Last updated: 7/1/2020
The diagnosis of cone dystrophy is made based upon the presence of characteristic symptoms, a detailed family history, a thorough clinical evaluation and a number of supporting tests. While exams that measure visual acuity, perception of color, and field of vision are used to arrive at a proper diagnosis, an electroretinogram (ERG) is used to confirm the diagnosis.[3][4]

During an ERG, eye drops are used to numb the eye before a special contact lens recorder is placed on the eye. Then a series of flashes of light are used to stimulate the retina. Doctors can then measure the electrical response of the rods and cones to the light. The test is performed twice – once in  bright room and again in a dark room. A weak of absent signal of cone cells indicates cone dystrophy.[3][4] More details about the diagnosis of cone dystrophy can be accessed through the University of Michigan Kellogg Eye Center. 
Last updated: 9/2/2014

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • The National Organization of Rare Diseases (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Cone dystrophy. Click on the link to view a sample search on this topic.

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  1. Heckenlively J. Cone Dystrophy. NORD. 2010; https://rarediseases.org/rare-diseases/cone-dystrophy/.
  2. Simunovic, M.P., Moore, A.T. The cone dystrophies. Royal College of Ophthalmologists. 1998; http://www.nature.com/eye/journal/v12/n3b/pdf/eye1998145a.pdf. Accessed 6/19/2013.
  3. Heckenlively J. Cone Dystrophy. National Organization for Rare Disorders (NORD). 2010; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/847/viewAbstract. Accessed 9/2/2014.
  4. Openshaw A, Branham K, Heckenlively J. Understanding Cone Dystrophy. University of Michigan Kellogg Eye Center. February 2008; http://www.kellogg.umich.edu/patientcare/downloads/Understand-Cone-Dystrophy.pdf. Accessed 9/2/2014.