Primary angle closure/closed angle glaucoma Primary Angle Closure Glaucoma (PACG)/Primary Closed Angle Glaucoma (PCAG) is significantly associated with defective development of the drainage angle which is termed goniodysgenesis (gonio = angle, dysgenesis = defective development), also known as Pectinate Ligament Dysplasia (PLD) or Pectinate Ligament Abnormality (PLA).
Goniodysgenesis is inherited in complex fashion in several breeds and is tested for using a technique called gonioscopy. It was originally believed that the degree of goniodysgenesis did not progress after birth and so a ‘one-off’ test before breeding was advised for dogs of certified breeds. However, recent research has provided evidence of progression of goniodysgenesis with age in several breeds, including the Dandie Dinmont Terrier. In consequence, the advice on gonioscopy has been updated for all breeds in which gonioscopy is performed.
It is advised that for Schedule A breeds gonioscopy should be carried out every 3 years, unless any evidence to the contrary emerges. The first test can be performed in dogs from 6 months of age onwards and current advice is that gonioscopy is performed at approximately 1, 4 and 7-8 years of age. Repeat testing should provide much needed longitudinal information about the risk of developing glaucoma in later life and, in conjunction with Breed Health Coordinators and assistance from the Kennel Club Health Team, will enable breed-specific recommendations to be developed.
Please note that the Southern Dandie Club recommends eye testing every two years for breeding stock.
How do I go about having my dogs examined?
Performing gonioscopy requires certain expertise and specialised equipment and it is for these reasons that gonioscopic examinations are not a routine part of the eye scheme and are not available from every member of the BVA/KC/ISDS Eye Panel. See attached ISDS Eye Scheme – Panel of Examiners at September 2018. However, when telephoning a panellist to book an appointment, owners who wish to have gonioscopy performed should check whether this is available.