Persistent pupillary membrane (PPM) is a condition of the eye involving remnants of a fetal membrane that persist as strands of tissue crossing the pupil. The pupillary membrane in mammals exists in the fetus as a source of blood supply for the lens. It normally atrophies from the time of birth to the age of four to eight weeks. PPM occurs when this atrophy is incomplete. It generally does not cause any symptoms. The strands can connect to the cornea or lens, but most commonly to other parts of the iris. Attachment to the cornea can cause small corneal opacities, while attachment to the lens can cause small cataracts. Using topical atropine to dilate the pupil may help break down PPMs. In dogs, PPM is inherited in the Basenji but can occur in other breeds such as the Pembroke Welsh Corgi, Chow Chow, Mastiff, and English Cocker Spaniel. It can also be observed in cats, horses, and cattle. References


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Baastrups sign is an orthopedic and radiographic disorder that often occurs in elderly humans. It is characterized by enlargement of the posterior spinous processes of the lumbar spine, with normal intervertebral disc height and neuroforamina. The reason it is referred to as kissing spine is because the posterior spinous processes kiss and touch one another as the individual goes into lumbar extension, for example when flat on their stomach. The condition has been seen in humans,  canines, particularly with boxer breeds, and certain breeds of horses. This disorder is named after Christian Ingerslev Baastrup. Diagnosis
The salient feature of the disorder is the exuberant osteophytosis that occurs at posterior lumbar spinous processes. Osteophytes are coarse calcifications at the edges of bone that form due to repetitive stress and trauma. There is also atrophy and fatty replacement of paraspinal musculature, which can be detected by CT or MRI. Treatment
The malpositioning seen on radiography may not cause any symptoms at all. If there are related symptoms, however, therapeutic options include chiropractic care, physical therapy and nerve block injections. As a last resort, decompressive laminectomy may be attempted to relieve pain symptoms and remove the abnormally enlarged portions of bone. References


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