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What Is Cystinosis?

Cystinosis is a rare disease that mostly affects children. It causes a substance called cystine to build up in different organs of the body, including the kidneys and the eyes.1

Nephropathic cystinosis is the most common and the most severe form of the disease. It can lead to renal tubular Fanconi syndrome, a serious condition that makes the kidneys unable to reabsorb nutrients and minerals that are lost in the urine.1,2 Other complications of cystinosis may include1,3:

  • Weakening of the muscles
  • Diabetes
  • Hypothyroidism (the thyroid gland does not make enough thyroid hormone)
  • Difficulty swallowing
  • Rickets
  • Corneal cystine crystals

CYSTARAN is indicated only for the treatment of corneal cystine crystal accumulation in patients with cystinosis.

When patients with nephropathic cystinosis have cystine buildup in their corneas, it can cause photophobia and other eye problems. In a rare type of cystinosis, only the eyes are affected.

Intermediate cystinosis has the same symptoms as nephropathic cystinosis, but develops more slowly. For example, kidney and eye symptoms typically begin during the teenage years or early adulthood. In nonnephropathic cystinosis, the kidney remains normal, however, cystine builds up and forms crystals within the corneas of the eyes .1,3

Typical patient age at time of diagnosis
  Infant Teenager/young adult Adult
Preferred term3 Nephropathic cystinosis Intermediate cystinosis Nonnephropathic cystinosis
Additional terms1,3 Infantile cystinosis, early onset cystinosis Adolescent cystinosis, late-onset cystinosis, juvenile cystinosis Adult cystinosis, benign cystinosis, ocular cystinosis

It is believed that cystinosis affects about 500 people in the United States and 2000 worldwide. It is hard to know the exact number, because people don’t always know they have it, and sometimes it is misdiagnosed.1,2,4

Genetic tests can also be done to see if the child or parents carry the gene for cystinosis.3

References: 1. Cystinosis Research Network Web site. Cystinosis symptoms & treatment. Available at: Accessed March 13, 2013. 2. Cystinosis Research Foundation Web site. About cystinosis. Available at: Accessed March 13, 2013. 3. Nesterova G, Gahl WA. Cystinosis. In: Pagon RA, Bird TC, Dolan CR, Stephen K, eds. GeneReviews [Internet]. Seattle, WA: University of Washington, Seattle; 1993-2001. Available at: Accessed March 13, 2013. 4. The Scripps Research Institute Web site. Rare genetic disease successfully reversed using stem cell transplantation [press release]. La Jolla, CA: The Scripps Research Institute; September 17, 2009. Available at: Accessed March 13, 2013.


CYSTARAN (CYSTEAMINE OPHTHALMIC SOLUTION) 0.44% STERILE is a cystine-depleting agent indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis.

Important Safety Information:

To minimize contaminating the dropper tip and solution, care should be taken not to touch the eyelids or surrounding areas with the dropper tip of the bottle. Keep bottle tightly closed when not in use.

There have been reports of benign intracranial hypertension (or pseudotumor cerebri) associated with oral cysteamine treatment that has resolved with the addition of diuretic therapy. There have also been reports associated with ophthalmic use of cysteamine; however, all of these patients were on concurrent oral cysteamine.

CYSTARAN contains benzalkonium chloride, which may be absorbed by soft contact lenses. Contact lenses should be removed prior to application of solution and may be reinserted 15 minutes following its administration.

CYSTARAN is for topical ophthalmic use only.

The most frequently reported ocular adverse reactions occurring in ≥ 10% of patients were sensitivity to light, redness, and eye pain/irritation, headache and visual field defects.