Persistent tunica vasculosa lentis or immature blood vessels growing over the lens which also restrict the dilatation of the pupils.Vitreous haze and anterior chamber haze.This reflects the increase of blood flow through the retina. Significant level of vascular dilation and tortuosity observed at the posterior retinal arterioles.
#Aion database tissue item plus#
Plus disease can be present as a major complicating factor at any stage.
Stage 4 is sub-total retinal detachment. 
Stage 3 is extraretinal fibrovascular tissue. The Stages describe the ophthalmoscopic findings at the junction between the vascularized and avascular retina. (The extent is a bit less important since the treatment indications from the Early Treatment for ROP.) The circumferential extent of the disease is described in segments as if the top of the eye were 12 on the face of an analog clock, e.g. Zone III is the residual temporal crescent of the retina. Zone II is an annulus with the inner border defined by zone I and the outer border defined by the radius defined as the distance from the optic nerve to the nasal ora serrata. Zone I is the posterior zone of the retina, defined as the circle with a radius extending from the optic nerve to double the distance to the macula. The zones are centered on the optic nerve. This classification was used for the major clinical trials. Each aspect of the classification has a technical definition. They are location (zone) of the disease, the circumferential extent of the disease based on the clock hours, the severity (stage) of the disease and the presence or absence of "Plus Disease". ICROP uses a number of parameters to describe the disease. The system used for describing the findings of active ROP is entitled The International Classification of Retinopathy of Prematurity (ICROP). In older patients, the appearance of the disease is less well described but includes the residua of the ICROP stages as well as secondary retinal responses. The stages of ROP disease have been defined by the International Classification of Retinopathy of Prematurity (ICROP). Patients with ROP, particularly those who have developed severe disease needing treatment are at greater risk for strabismus, glaucoma, cataracts and shortsightedness ( myopia) later in life and should be examined yearly to help prevent or detect and treat these conditions. Restricting supplemental oxygen use reduces the rate of ROP, but may raise the risk of other hypoxia-related systemic complications, including death. Supplemental oxygen exposure, while a risk factor, is not the main risk factor for development of this disease. Multiple factors can determine whether the disease progresses, including overall health, birth weight, the stage of ROP at initial diagnosis, and the presence or absence of "plus disease". Associated with the growth of these new vessels is fibrous tissue (scar tissue) that may contract to cause retinal detachment. 
This is growth of abnormal new vessels this may regress, but frequently progresses. The key disease element in ROP is fibrovascular proliferation. When the excess oxygen environment is removed, the blood vessels rapidly begin forming again and grow into the vitreous humor of the eye from the retina. If excess oxygen is given, normal blood vessels degrade and cease to develop. The normal growth of the blood vessels is directed to relatively low-oxygen areas of the retina, but the vessels remain in the plane of the retina and do not grow into the vitreous humor. Normally, maturation of the retina proceeds in utero, and at term, the medial portion (Nasal retina) of the retina is fully vascularized, while the lateral portion (Temporal retina) is only incompletely vascularized. When the blood and abnormal vessels are reabsorbed, it may give rise to multiple band like membranes which can pull up the retina, causing detachment of the retina and eventually blindness before 6 months. These abnormal blood vessels may grow up from the plane of the retina and may bleed inside the eye. If the vessels grow and branch abnormally the baby develops ROP.
If blood vessels grow normally, ROP does not occur. However, in premature babies it is incomplete. This process is completed a few weeks before the normal time of delivery. They are:ĭuring development, blood vessels grow from the central part of the retina outwards. Various risk factors contribute to the development of ROP. In rare cases ROP has been found in some patients with a mutation in the NDP gene, which is normally associated with the more damaging Norrie disease. Such formation of blood vessels appears to be very sensitive to the amount of oxygen supplied, either naturally or artificially. By the fourth month of pregnancy, the fetal retina has begun to develop vascularization.
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