Retinal detachment is a condition in which the retinal nervous system is detached from the functionally layer associated with the choroidal layer, in other words the epithelial epithelium.
The traditional division of retinal detachments is distinguished by three types: rhegmatogenous, traction and exudative. Rhegmatogenous retinal detachment occurs in the world with a frequency of 6.5-18 cases per 100,000 inhabitants.
In children, rhegmatogenous retinal detachment occurs on average at the age of 13 years and more often in boys.(1)
According to some reports, it occurs more often in warm months - June or July. It may be related to dehydration of the vitreous body and greater production of free oxygen radicals. (2)
The risk factor is accelerated and rapid detachment of the vitreous, which can occur in myopic eyes, after injuries or surgery. Also the eyes with the inflammatory process predispose to retinal detachment.
Retinal detachment results from the posterior detachment of the vitreous body as a result of changes in its morphology and as a result of the existence of traction in a place more prone to tear, which facilitates the passage of fluid under the retina.
The process of the posterior detachment of the vitreous body, i.e. its liquefaction, is a natural aging process, but in predisposed eyes it may proceed in a pathological way. Premature aging of the vitreous body occurs in myopic eyes or in eyes with an inflammatory process such as uveitis, after injuries or other surgical procedures. Accelerated flow of the vitreous also occurs in the course of general diseases in which there is disturbed metabolism of II type of collagen - Marfan's syndrome, Ehlers-Danlos and Stickler’s syndrome. The aging mechanism of the vitreous body is not fully understood. According to various theories, it may start with the gradual degradation of glycosaminoglycans, secondarily it causes a change in interaction with II, IX and XI type of collagen. In addition, the role of free oxygen radicals and metalloproteinase enzymes is important(3).
Retinal photoreceptors are metabolically dependent on pigmented epithelial cells, after losing this contact, they gradually degenerate. These changes occur several hours after the separation of both layers.
According to studies on an animal model, apoptosis of photoreceptors may start as early as 8 hours after the detachment, and 90% of cells die within the first 3 days.(5) As a response of retinal cells to the new anatomical situation, the hyperplasia of astrocytes mediated by Muller cells and vimentin protein occurs. In the future, inhibition of vimentin protein expression may prevent the retinal proliferation.
Risk factors for retinal detachment:
- symptomatic posterior detachment of the vitreous,
- high myopia with biometrics > 26.00 mm, which corresponds to - 6.0 Dsph. It is believed that 55% of retinal detachment is not related to trauma myopic eyes. (2.4)
- Injury - 10% of all retinal detachments are associated with an eye injury. The time from the injury to the detachment can vary from minutes up to 40 years, but 80% of the detachments are diagnosed within 1 year of the injury.
- Checkered degeneration - risk in 30-40% retinal detachment.
Retinal surgery is based on two basic principles:
- tamponade of the hole,
- restoration of retinal adhesion.
In order to resume the function of the pigment epithelium as a photoreceptor nourishing pump. There are two surgical techniques: conventional surgery- epidural implant or cerclage with a puncture or intraocular procedures - PPV.
Indications for conventional surgery include:
- a single hole,
- a small number of peripheral degenerations,
- primary and local delamination,
- low traction,
- lack of PVR,
- young age.
In publications created since 1990, the percentage of primary application ranges from 85% to 90%, and the final 95%. If the spot before the procedure is applied, the chance of visual acuity above 0.4 is 80%, , if the layer is delaminated the chance is 30%.(6) Already in 1923 Jules Gonin- presented the results of his work in the surgery of retinal detachment at the meeting of the French Society of Ophthalmology and he was named the "father" of the retinal detachment surgery. Ernst Custodis has earned a role in retinal detachment surgery by introducing scleral malformations treatment. Charles Schepens, in 1953, introduced a scleral enlacement technique.
In the case of traction retinal detachment, the most common cause is proliferative diabetic retinopathy, trauma that frequently penetrates the presence of a foreign body and retinopathy of premature babies. Treatment of traction retinal detachment is usually a vitrectomy procedure through the flat part of the ciliary body.
The causes of exudative retinal detachment include:
- idiopathic causes - Coats' disease,
- congenital- nodular developmental n II, gladiola flower syndrome,
- Postoperative - panfotocoagulation, in hemorrhagic choroid disconecction,
- associated with inflammation - sinusitis, secondary to uveitis,
- proliferative diseases - choroidal melanoma, retinoblastoma, lymphomas.
Exudative retinal detachment may also occur in the course of hypertensive retinopathy, preeclampsia, eclampsia, leukemia. Treatment of exudative retinal detachment depends on pathomechanism and etiology.