Nail-Patella syndrome (NPS) is a rare genetic disorder that causes abnormalities of bone, joints, fingernails and kidneys. NPS is commonly characterized by absent or under-developed kneecaps and thumbnails. It is estimated to occur in one in 50,000 newborns.
Researchers at the U-M Kellogg Eye Center have found strong evidence of a link between glaucoma and Nail-Patella syndrome. A research study was initiated after Paul Lichter, M.D., noticed a glaucoma patient had no thumbnails and recalled the patient's mother, whom he had treated years earlier, also lacked thumbnails. Both patients had NPS in addition to glaucoma. Other family members were subsequently examined, and some -- who previously were unaware of NPS --were diagnosed with the disorder.
Lichter's research team examined 24 people with Nail-Patella syndrome in two families and found that more than half of them suffered from glaucoma. "As a result of these findings, we recommend people with Nail-Patella syndrome have regular ophthalmologic exams so glaucoma can be diagnosed and treated as early as possible," said Lichter.
The gene which mutates to cause NPS is located on a portion of chromosome 9 called 9q34. The U-M study provides indirect evidence that glaucoma-related genetic material is located at that same chromosomal site. It's not clear, however, whether glaucoma results from the NPS mutation or from a separate but closely linked gene.
The research team's findings were reported in the October 1997 issue of the American Journal of Ophthalmology.
- Loss of peripheral (side) vision
- Blind spots
- Need for frequent changes in glasses
- Difficulty in adjusting to a dark room
- Blurred vision
- Sore, reddened eyes
- Appearance of halos or rainbows around lights
- Severe headaches, nausea and eye pain in rare cases
The symptoms described above may not necessarily mean that you have nps or glaucoma. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.
The treatment for nps and glaucoma depends upon the nature and severity of each case. As a rule, glaucoma cannot be cured, but it can be controlled. Eye drops, pills, laser procedures, and surgical operations are used to prevent or slow further damage from occurring. With any type of glaucoma, periodic examinations are very important to prevent vision loss. Because glaucoma can worsen without your being aware of it, your treatment may need to be changed over time.
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For more information, see the Glaucoma, Cataract, & Anterior Segment Disease Clinic and the complete Clinic Services listing of the U-M Kellogg Eye Center.