What is microphthalmia?

Affected dogs have prominent third eyelids and small eyes which appear recessed in the eye socket (enophthalmos). A defect early in development results in the smaller than normal eye (microphthalmia).This is often associated with other eye abnormalities, including defects of the cornea, anterior chamber, lens and/or retina. Microphthalmia is also seen with coloboma – a cleft in a portion of the eye, particularly the iris.

Microphthalmia with multiple defects (ocular dysgenesis) is often seen in dogs with a merle hair coat with excessive amounts of white. The eyes are commonly different colours. Partial deafness may also be part of this syndrome. These dogs are frequently blind.

Cataracts (opacity of the lens) often occur with microphthalmia, causing some degree of visual impairment.

What breeds are affected by microphthalmia?

microphthalmia (with or without other ocular defects): Cavalier King Charles spaniel, all collie breeds, Doberman pinscher, miniature schnauzer, old English sheepdog, poodle (miniature, toy, and standard), Portuguese water dog, Saint Bernard, soft-coated Wheaten terrier