Difference; Most of them are round or irregular flat melanin patches or the iris surface is slightly prominent, but its thickness is generally less than 65438 0 mm.
Some pigmented nevus have a wide range, which can extend from the periphery of iris to the edge of pupil. Pigmented nevus around the iris can also spread to the anterior chamber angle. Some pigmented nevus are surrounded by small lesions with "satellite focus" distribution. Most pigmented nevus of iris are relatively stable and have no obvious growth tendency. Clinical symptoms are mostly related to the location and volume of pigmented nevus and its influence on adjacent tissues. Pigmented nevus, which occurs in the middle of iris, is small in size and generally has no obvious symptoms. It is often found by accident during routine eye examination. However, pigmented nevus, which occurs at the root of iris or the edge of pupil, or has a large volume, usually has different clinical symptoms because of its influence on adjacent tissues. Pigmented nevus at the root of iris can spread to the anterior chamber angle tissue, causing increased intraocular pressure. Pigmented nevus near the pupil edge has pupil deformation or iris ectropion. Some pigmented nevus are accompanied by non-progressive and localized opacity adjacent to the lens. Very few of them show multiple pigmented nevus in both eyes, and most of them are accompanied by neurofibromatosis.