Related articles: Retinal detachment
Definition
Retinal detachment is a very serious condition, which occurs when neuroretin (composed of nerve cells and photoreceptors) separates from the underlying supporting tissue (retinal pigment epithelium).
The retina is a thin layer of light-sensitive tissue adhering to the inner back wall of the eye. Its function is to convert light signals into nerve stimuli, then sent via the optic nerve to the visual cortex.
If the layer of visual retinal cells detaches from the underlying pigment epithelium, the retina is no longer able to offer the brain an adequate image, and the vision undergoes a sudden and dramatic reduction.
The most frequent cause of retinal detachment is retinal rupture ( rhegmatogenous detachment ), ie small holes (due to the presence of degenerative areas that make the retina fragile or thin) or lacerations (due to abnormal adhesions and forces of traction). The retina gradually loses adherence to the pigmented epithelium, rising and allowing the vitreous fluid to filter into the subretinal space. Risk factors include: myopia, previous surgical interventions (eg for cataracts) and ocular trauma.
The detachment can also be tractional and exudative, therefore it can occur in the absence of lacerations or ruptures of the retina. The tractional retinal detachment occurs when the external fibrous (or fibrovascular) wall of the eye exerts a traction force on the surface of the retina, which causes its separation from the pigment epithelium. This process occurs mainly in proliferative diabetic retinopathy. The exudative detachment, instead, derives from the transudation of liquids in the space immediately under the retina; this event occurs mainly in case of inflammation, vascular anomalies and retinal tumors.
Most common symptoms and signs *
- Movable bodies
- photopsias
- Narrowing of the visual field
- Reduced vision
- Intraocular bleeding
- scotomas
- Double vision
- Blurred vision
Further indications
Retinal detachment is painless. The first symptoms may include the vision of numerous moving bodies that float through the visual field (irregular and dark myosopsias), flashes of light (photopsies) and blurred (or distorted) vision. Some people experience a sort of spider web effect, while others report the vision of a single large black corpuscle (flying flies phenomenon).
As the detachment progresses, the patient notices the appearance of a shadow or a "black curtain" in the visual field, caused by the impairment of the central or peripheral visual function. Patients may have a simultaneous vitreous hemorrhage that obscures the retina.
Suspected or confirmed retinal detachment must be evaluated urgently by an ophthalmologist (should not exceed 24-72 hours). Immediate treatment can, in fact, minimize damage to the eye. To determine the presence and type of retinal detachment, in general, it is sufficient to resort to examining the ocular fundus and ophthalmoscopy.
Since the condition leads to the functional loss of the retinal cells involved, a permanent or partial blindness may occur in the affected eye without immediate treatment. Retinal detachment is therefore treated as a medical emergency, depending on the cause and location of the lesion. The methods may include retinal hole repair (with laser, diathermy or cryotherapy) and scleral plumbing (which involves indenting the sclera). In some cases, it is possible to resort to pneumatic retinopexy (injection into the vitreous body of a small bubble of gas) and to vitrectomy (the vitreous humor is removed from the eye and replaced with a gas or a silicone oil).
