July 16, 2012 FIBRAE MEDULLARES
These are myelinated optic nerve fibers in the retina, where no normal myelination exists. They are located along the optical disk in the level of the surrounding retina, white in color and look like little flames that stretch from the edge of the disc. They do not affect vision.
TORTUOSITAS VASORUM RETINAE CONGENITA
Retinal blood vessels are curved in serpentine way, while the normal ones stretch in mild arches. Change does not affect vision.
Retinopathy of prematurity
The development of blood vessels within the retina ends after birth. Immature retina of premature infants sometimes responds to elevated CO2 partial pressure by vasoconstriction and obliteration of blood vessels at the periphery of the retina. In the further course, on the border of ischemic retina neovascularized membranes develop which grow into vitreous and cause the ablation of the retina. Sometimes these membranes are thicker and more abundant so that they pervade the entire vitreous all the way behind the lens – hence the old name of this disease, retrolental fibroplasia. If the disease is not detected on time and left untreated, the consequences can be tragic for the vision.
Risk factors for the occurrence of premature retinopathy:
As birth weight and gestational age of the child are lower, the risk is higher. Much as 90% of children with birth weight less than 700 g have some degree of retrolental fibroplasia.
Elevated concentrations of oxygen have been proven as a risk factor, but today by transcutaneous monitoring of oxygen levels in the blood this danger is minimized. The irony is that with improving technology, helping children with low birth weight to stay on life increased incidence of retinopathy in premature children due to an increasing number of smaller children surviving.
Application of calf lung surfactant in the treatment of neonatal respiratory distress is associated with reduced risk of retinopathy of prematurity, probably due to better lung function.
It is very likely that low-light environment also reduces the risk for the untimely born ones.
Traditionally it is considered that this disease occurs postnatally. However, it appears that chronic intrauterine hypoxia and growth failure of a fetus also risks for the development of retinopathy of prematurity. In fact, in some premature infants developed form of the disease is found already a day or two after birth, which means that it existed even before birth. About a third of all cases are caused by prenatal factors.
Treatment:
The eye background of the premature baby should be examined with indirect ophthalmoscope in mydriasis every week until the term when they should normally be born; after that less often. In developed retinopathy, criocoagulation or photocoagulation of the affected retina are conducted to prevent further progression of changes.