Retinal detachment
In retinal detachment (Ablatio retinae, Amotio retinae), the pigment seperates from the epithelial layer, the retina is not tightly bound to the epithelium. This condition is almost always related with a tear or perforation in the retina. Fluid leaks from the vitreous part through this perforation below the retina and this fluid may seperate the retina from the layer.
Retinal perforations are found at the edges of the retina and mostly occur in the thin regions of the retina. Sometimes, a tighter connection is found between the retina and corpus vitreum at these edges of the retina, and the retina may perforate when corpus vitreum seperates suddenly. Retinal perforation may occur without corpus vitreum. Patients with especially thin retina regions, patients with myopia and patients who have undergone cataract operation have a high risk in terms of retinal detachment. If there is a familial history of retinal detachment, the risk is high. If retinal detachment has occurred in one eye, the risk for the other eye is approximately 10%. Therefore, the other eye should be examined regularly. In this way, retinal perforations can be diagnosed and treated in time. Retinal detachment is a disease which endangers vision, because the detached retina can not be nourished with sufficient nutrients.
The pupils should be dilated with special eye drops for examination of the retina.
The opthalmologist uses an eye mirror (opthalmoscope) for examination of the retina. This mirror is a source of light at the same time. The opthalmologist may also use special eye mirror systems and loupes. With these methods a three-dimensional picture of the retina can be obtained. This examination can also be performed with a microscope.
A contact lens is used to evaluate very small changes on the retina. This lens is directly placed on the eye after applying an anesthetic drop in the eye. The opthalmologist can see all retinal changes in detail with the small mirrors inside the contact lens.
Condensation of the corpus vitreum indicates that it has started losing its endurance. Many people recognize moving black spots or floaters (mouches volantes), especially when looking at a bright background. If the corpus vitreum detaches and strains the retina, lightnings are seen most of the time. These lightnings may also indicate to presence of perforation in the retina. Since the corpus vitreum becomes more liquid throughout the lifetime, vitreous detachments are observed commonly. If a small blood vessel perforates together with the retina, vitreous hemorrhage may occur. The blood drops form small shadows in the retina and are perceived as black rain. Warning symptoms occur in appproximately only 60% of the patients in retinal detachment.
In the beginning of retinal detachment, a darkening or a black covering at the edge of the visual field is noticed most of the time. These have the same size as the detached part of the retina. If retinal detachment advances, the shadow increases in size. Generally, when the macula (the point with best visual acuity) also detaches, visual acuity is primarily affected. Retinal perforation, which is the preliminary phase of retinal detachment, can usually be eliminated with laser treatment. For this, laser beams are directed through a contact lens towards the periphery of the perforation. The laser beam causes to wound scars. Thus, the retina and pigment epithelium are bound tightly to each other. At this point, no retinal detachment will occur any more. Laser treatment is normally painless. Cryocoagulation (cold treatment) may be necessary instead of laser treatment in extensive retina disorders or inappropriate positions.
If retinal detachment has occured, laser treatment is not possible. Surgical intervention is necessary. A plastic sponge is sewn to the place where the perforation which casued to retinal detachment is found. This sponge softly compresses the eyeball from the external side. The external layers of the eyeball approach to the detached retina and the retina sits back to its pace. This operation is performed on the retinal perforation site together with cryocoagulation (cold therapy). Cold leads to formation of wound scar in the site where treatment is applied. Thus, no retinal detachment occurs again. The stuff normally remains on the eyeball for a lifetime and the patient never feels it.
In long-term retinal detachment or in conditions where the corpus vitreum strains the retina to a great extent, vitractomy (operation of the corpus vitreum) is also necessary. In this operation, the corpus vitreum is removed from the eye with very sensitive devices. The retina that is separated with a transient tampon composed of assimilated gasses and transparent slicon fat is pressed against the eyeball wall internally.
If retinal detachment is not treated, it almost always causes to blindness.