The less developed a premature infant is, the higher the risk for ROP, even when there is no oxygen administered to the newborn.  The development of ROP is especially likely if the child is born before the 32^nd week of pregnancy and weighs less than 1,800 grams. According to American studies, 65.8% of 4009 neonates who have a birth weight of under 1,251 grams develop retinopathy of prematurity. About 20% of extremely prematurely born babies (with a birth weight of between 500-800 grams) normally develop ROP and around ¼ of these babies become blind later as a consequence of this disease. A higher risk for progressive ROP has been determined in multiple births.

In order to make an exact judgment of the patient’s visual health, an ophthalmoscopic examination of the back of the eye (ocular fundus), including the retina and optic nerve, is standardly conducted, with a dilated pupil and under complete anaesthesia. A lack of blood vessels on the temporal side of the retina as well as narrow vessels show up in the framework of this so-called funduscopy. The vascularised or blood vessel-rich zone is divided off from the greyish nonvascularised or blood vessel-free area by a line of demarcation (see picture). In advanced stages, a diseased excrescence, or growth, of the newly formed vessels can occur; the vessels grow forward towards the vitreous and can lead to bleeding. Damage to the retina (e.g. detachment) can occur in advanced progression of the illness. At the end stage, this illness is recognisable by a retina that looks like a shrunken disc in which the connective tissue and vessels are melded together with the detached retina (so-called retrolental fibroplasia). From the outside, this disc looks like a white pupil (leukocoria). ROP can, depending on diagnosis criteria, be divided into 4 stages; and it can be divided into 3 zones, depending on the location of the line of demarcation between vascularised and non-vascularised retinal areas. The average visual acuity of the affected patient lies at about 10% in the beginning stage of retinal detachment, whereas the central visual acuity remains intact relatively long, provided that the macula is spared.

What is the prognosis for retinopathy of prematurity?

In the beginning stages of the illness and as long as the retina is not detached, the blood vessels will usually be rebuilt. At later ages, a relict is sometimes seen-- a distortion of the retinal vessels and macula on the temporal side. The displacement of the sharpest point of vision (macula) can lead to pseudo-strabismus. Additionally most of those affected are nearsighted. In adult ages, the demand on the retina can cause holes in the retina or even a detachment of it. Later consequences such as the early development of cataracts with a clouded lens, glaucoma with a chronic increase of inner eye pressure, or retrolental fibroplasia-- a scarred shrinkage of the whole eye with complete blindness on the side affected, can further complicate the disease.

What is the “Plus Disease”?

In this disease, in addition to the typical signs of ROP, further eye diseases are present, signalling a rapid advancement of ROP. Diagnosis criteria for a plus disease are for example, a diseased progression and coiling of the retinal vessels in the central ocular fundus, vitreous clouding as well as a higher than normal blood circulation in the iris as well as its stiff movement, caused by the unnaturally developed blood flow in the affected eye.

In order to diagnose ROP as soon as possible, it is advisable to examine prematurely born babies with a birth weight of under 1,500-2,000 gr., or those born before the 28^th week of pregnancy, in a screening conducted during the first 4-6 weeks of life for eventual signs of retinal disease. Prematurely born babies at higher risk should have their ocular fundus checked weekly. The most important thing in treating premature babies is a close-meshed and above all timely check-up by an eye specialist, with an exact appraisal of the ocular fundus. In order to curb diseased vessel formation in the nonvascular areas as well as to curb further diseased growth in the still healthy part of the retina, in most cases it is necessary to obliterate or seal off these vessels with cold applications or laser treatments. If the retina is detached, removal of the vitreous and reattachment of the affected retina is the treatment of choice. Self help groups and early intervention groups provide great support and help in dealing with illness and learning practical skills for the patient him/herself as well as for parents and immediate family members of the ROP patient.

Modern intensive care of premature infants and retinopathy of prematurity: Is ROP continually increasing?

The latest technological and medical knowledge level of today makes it possible to optimally care for and coddle even extremely prematurely born babies.  Therefore it would be a logical conclusion that the appearance of ROP, due to the continual and successful development of intensive care for premature infants, will become more numerous in the future. Several scientific studies, however have not been able to support this prediction. Even with the increasingly improving technology of respirators and the optimised medical care of prematurely born children, as well as the newest therapeutic approaches, it has not been possible to prove a proportional rise of ROP in connection with the further development of the intensive care of extremely prematurely born children.