Pupillary membrane is a fetal structure, which covers the pupil prior to Birth. Shortly after birth it resolves. Sometimes part or all of it persists, therefore, it is called persistent pupillary membrane (PPM). This disorder is hereditary but the way of inherence is unknown.

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. [1]

Persistent pupillary membranes (PPMs) are embryonic residues of neural-crest origin. During the embryonic life, the pupillary mem-branes have the role of feeding the developing lens but they lose this function when the aqueous humour is produced. Normally, few weeks after birth, the pupillary membranes undergo atrophy.

Persistent Pupillary Membrane (PPM) in dogs and cats causes visual impairments; there will be a tiny strands in pupil space, corneal opacities, cloudiness eyes, abnormal iris movement in controlling the light that entering the eye.

Persistent pupillary membranes (PPMs) are remnants of the embryonic pupil. Shortly after birth these membranes usually break down. Those that don’t are termed Persistent pupillary membranes and the remnants of these membraned sometimes stick to the back of the cornea, producing localised, or more generalised, opacity where they are attached.

Persistent pupillary membrane (PPM) is a frequently encountered congenital anomaly. It represents remnants of anterior tunica vasculosa lentis and appears as strands of connective tissue bridging the pupillary area. They are usually asymptomatic and …

If some of these fine strands of tissue remain they are described as persistent pupillary membranes (PPM). It is not unusual to see such strands in 6-to-8 week old puppies or kittens; however, if they persist much beyond this age they are considered a defect.

2020年1月23日 · Background: Pupillary membrane persistence (PMP) is a congenital abnormality, which is not usually reported in felines. It is characterized by remnants of the fetal membrane...

2018年8月1日 · Persistent pupillary membrane (PPM) is a defect in mesodermal development, which occurs due to incomplete resorption of embryonic vasculature and mesenchymal tissue....

Persistent pupillary membranes, cat Iris-to-cornea PPM originating from the iris collarette region and adhering to the central posterior cornea in a cat. Courtesy of K. Gelatt.