Eye abnormalities can occur at any age. Ophthalmic examination can detect a variety of congenital abnormalities, including Progressive Retinal Atrophy (PRA) and Collie eye anomaly (CEA), which also occurs in Shelties. The merling gene may make it difficult to detect mild cases of CEA by ophthalmic examination because merling is normally associated with less pigmentation of the eyegrounds (back of the eye). Also, the CEA lesions (chorioretinal hypoplasia) in some mildly affected dogs may be partially masked as the eye matures so may be missed at 8-10 weeks of age or later. Thus examination at an early age, about 5-8 weeks of age, is recommended. Because the onset of other eye diseases (such as cataracts and retinal degeneration) can occur at any age, dogs should be reexamined periodically. Ideally, each dog should be examined within the preceding 12 mos. of being bred. According to the link above, the likelihood of a genetic problem showing up after age 9 years is low. The test is an eye examination performed by a board certified veterinary ophthalmologist. Results are automatically included in the OFA database with no extra charge. See https://www.ofa.org/diseases/eye-certification for more information.
OFA Eye Registry Report
Descriptions of ocular disorders in Shetland Sheepdogs and statistics can be found at https://www.ofa.org/diseases/eye-certification/blue-book . All abnormal findings are listed, and no dog names are included in these reports. Dogs receiving more than one examination in a given year are not listed more than once. The report summarizes eye examination findings from 1991 through the end of the most current complete year.