Gary Johnson, University of Missouri

I would like to take this opportunity to report on our Lens Luxation/Glaucoma research project that has been supported by the Dandie Dinmont Terrier Breed Club and several other breed clubs. We are studying these two diseases together because primary lens luxation can and usually does lead to glaucoma and primary glaucoma can result in lens luxation. In some breeds the nature of the primary disease is uncertain, perhaps because both conditions may exist in the same breed. There seems to be general agreement that among Dandie Dinmont Terriers the major problem is primary glaucoma.

Our project has six specific aims. The first is “to accumulate DNA from individual dogs with lens luxation and/or glaucoma and their close relatives.” So far we have received 27 blood samples from Dandie Dinmont Terriers, including ten from affected dogs. This would be a sufficient number if they were all from two or three litters, however, in your breed we have just a few samples from the unaffected parents and siblings of the affected dogs. Furthermore, many of the unaffected samples that we have received are only distantly related to affected dogs. In order to make progress we need to get blood samples from both affected dogs and from as many of their parents and siblings as possible.

Our second specific aim is “to examine individual dogs with lens luxation and/or glaucoma to define the phenotype as closely as possible.” There seems to be agreement among veterinary ophthalmologists that the glaucoma typically encountered in Dandie Dinmont Terriers should be characterized as a narrow angle glaucoma. For Dandie Dinmont Terriers, however, this diagnosis is poorly documented in the scientific literature. As part of our project, our veterinary ophthalmologists would like to do a careful clinical examination of one or two affected Dandie Dinmont Terriers. Up until now, we have not requested access to an affected Dandie Dinmont Terrier because Dr. Kristina Narfstrom, the veterinary ophthalmologist who is helping with the project, has been intensely involved in her own exciting research project on gene therapy and has been traveling and speaking around the world. In the next few weeks we will be joined by a second veterinary ophthalmologist, Dr Lawrence Galle, who is also planning to help with this project. So, if any of you would be willing to allow us to examine your affected Dandie Dinmont Terrier, please contact Ms Liz Hansen at the address below and we will make arrangements.

The third specific aim is “to add a limited canine glaucoma/lens luxation section to our canine epilepsy internet website”. Ms Liz Hansen has made substantial progress toward the development of a glaucoma/lens luxation page for our website and we expect to have the page ready for public viewing in a month or so. This page should help us recruit samples and enable you to keep track of our progress. Eventually, we expect the Lens Luxation! Glaucoma site to have its own internet address; however, initially it will become available at the www.canine-epilespy.net address. Please watch for it in about a month.

The last three specific aims are technical and deal with the development and testing of markers to help us find the genes responsible for lens luxation and glaucoma in dogs. We have made some progress along these lines but cannot apply this progress to Dandie Dinmont Terriers unless we receive the necessary samples from affected dogs and their close relatives. If you can help us with this, please contact Liz Hansen by phone (573-884-3712), email (HansenL@missouri.edu), or regular mail (321 Connaway Hall, University of Missouri, Columbia, MO 65211) or look under “Sample Submission” on our www canine-epilepsy.net website.

Your support is appreciated.

Sincerely,

Gary Johnson, DVM, PhD
GLAUCOMA PROJECT REPORT
October, 2002

Dr. Gary Johnson's glaucoma web site can be accessed at: www.CanineGeneticDiseases.net, then click "Glaucoma and Lens Luxation" button. The previously mentioned ophthalmologists have been replaced by Lawrence Galle, DVM, DACVO and Elizabeth Giuliano, DVM, MS, DACVO.