Generality
Retinal detachment is a very serious condition, which occurs when the inner membrane of the eye detaches from its supporting tissues. Retinal detachment can occur with the vision of light beams (photopsias) and / or mobile corpuscles (myopia), associated with blurring and sudden and dramatic reduction in vision. 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.
The retina
The retina is the thin layer of tissue that covers the back of the eye, tightly adhering to the inner wall.
If pathological phenomena occur, the retina can gradually lose contact with the pigment epithelium (which carries nutrients from the choroid and provides a constant supply of blood to the retinal cells), compromising its normal function.
If the layer of visual retinal cells separates from the underlying supporting tissues, it can undergo necrosis (cell death) and damage to the eye can become permanent. Fortunately, contact between the structures can be restored by a surgical operation, but the time between retinal detachment and surgery should not exceed 24-72 hours.
Types
Depending on the pathogenesis, three types of retinal detachment can be found:
- Regmatogenous : the initial event consists in the progressive detachment of the vitreous body, the transparent fluid that fills the space between the posterior surface of the crystalline lens and the walls of the retina, to which it adheres. For various reasons, this gelatinous mass can contract, resulting in one or more retinal breaks, ie small holes (due to the presence of degenerative areas that make the retina fragile or thin) or lacerations (due to abnormal adhesions and traction forces). The retina gradually loses adherence to the pigmented epithelium, rising and allowing the vitreous fluid to filter into the subretinal space.
- Traction : the tractional retinal detachment mainly affects diabetic subjects and can be caused by injury, inflammation or neovascularization. It 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.
- Exudative : it is characterized by an accumulation of vitreous fluid in the area under the retina, in the absence of lacerations or breaks of the same. The exudative detachment represents the outcome of a retinal disease, inflammatory disorders, traumatic events or vascular anomalies.
Symptoms
To learn more: Symptoms of Retinal Detachment
Retinal detachment is considered a medical emergency. Therefore, treatment should not be delayed.
Most people experience warning signs, which characteristically indicate damage to the retina. These symptoms include:
- Mythesopsia : the initial symptoms of retinal detachment consist in the sudden appearance of small mobile bodies (black dots, dark spots or streaks) that float through the visual field. Some people experience a sort of spider web effect, while others report the vision of a single large black corpuscle ("flying flies" phenomenon);
- Flashes of light (photopsia) : another common symptom consists in the sudden and brief appearance of flashes of light in the affected eye, especially in the peripheral part of the visual field (peripheral vision);
- Blurred or distorted vision.
These manifestations are typical of vitreous detachment, which commonly precedes retinal separation. Generally there is no physical pain associated with detachment, as the retina does not contain pain receptors.
Without treatment, you will experience a rapid deterioration of vision in the affected eye. Most patients describe this effect as a shadow or a "black curtain" that obscures a portion of the eye and compromises both central and peripheral vision.
If symptoms of retinal detachment occur, it is important to try to stay calm and avoid sudden eye or head movements. An immediate eye examination is of the utmost importance, since the longer a retina remains detached, the more likely it is that the damage to the eye can be permanent.
Causes
Retinal detachment can occur for several reasons, which may include:
- Vitreous detachment and retinal rupture : it represents the most common cause of retinal detachment (corresponds to the regmatogenic pathogenesis). This etiology is often related to aging.
- Severe myopia : people with severe myopia (greater than 5-6 diopters) have the greatest risk of developing the condition, because they often have a thinner retina than normal.
- Traumatic events : in some cases, the detachment of the retina is consequent to an injury to the face or to the eyeball. The condition can also be caused by a penetrating lesion in the eye. Some cases are, for example, associated with high-impact sporting activities (boxing, karate, soccer, hockey, etc.) or high-speed (for example: racing cars or cycling).
- Surgery complication : some eye surgery procedures can make the retina more vulnerable to damage. In particular, detachment is more frequent after surgery to remove the cataract.
Less common causes of retinal detachment include:
- Diabetes: the result of a complication of diabetes, called diabetic retinopathy, can induce tractional detachment , due to the intense neovascularization (proliferative form) and microvascular alterations (non-proliferative form) that damage the retinal tissue.
- Inflammatory diseases : the retina remains intact, but the vitreous fluid is collected between the underlying tissues. This can occur due to pathologies that cause localized inflammation and intraocular swelling, as in the case of uveitis and some rare types of tumors that develop inside the eye (example: choroid melanoma).
- Spontaneous detachment: the retinal detachment can also be spontaneous, for no apparent reason. This occurs more often in the elderly or in people with severe myopia (perhaps due to an underlying anatomical anomaly).
Retinal detachment is a rare condition. When the condition is associated with aging, most cases involve older adults between the ages of 50 and 75. Retinal detachment caused by a traumatic event can affect people of any age, including children.
Diagnosis
The earlier a retinal detachment is diagnosed, the greater the likelihood of not compromising vision.
During a thorough eye examination, visual acuity and the integrity of the posterior portion of the eye are evaluated.
Ophthalmoscopy
It uses an instrument that projects a beam of light onto the retina, through the pupil of the eye. The ophthalmoscope provides detailed information on the internal ocular structures and allows the doctor to see possible retinal holes, lacerations or more serious detachments.
Slit lamp exam
The patient positions his head on a chin rest, while the ophthalmologist checks the anatomical and functional state of the ocular annexes with a magnifying system (microscope), equipped with a light beam.
Other investigations for the diagnosis of retinal detachment may include:
- Examination of visual acuity and color perception;
- electroretinogram;
- Angiography with fluorescein;
- Measurement of intraocular pressure.
Treatment
Retinal detachment is treated as a medical emergency. If the surgery is immediate, the risk of permanently losing sight in the affected eye is less.
In most cases, only one surgery is needed to successfully reposition the retina and repair the present lacerations. Unfortunately, after treatment, some patients do not completely recover their vision and may experience a permanent reduction in central or peripheral (lateral) vision. This can happen even if the retina is reconnected correctly.
Different types of surgical approaches are available to treat retinal detachment. These include:
- Laser surgery and cryopexy. Photocoagulation (laser) and treatment with a cold probe (cryopexy) can correct a small retinal break.
- For PR. This procedure can be used if the retinal detachment is mild and relatively simple to repair. Pneumoretinopexy involves injecting a small bubble of gas into the eye (in the vitreous body). This presses against retinal rupture and the surrounding area, to seal it. The procedure is accompanied by photocoagulation, to form a scar that helps to fix the retina to the inner wall of the eye. In the days following the pneumoretinopexy, the patient could be forced to keep the head tilted to a certain position, to allow the bubble to press correctly against the retina.
- Scleral buckle. The operation involves placing an elastic silicone band (buckle) around the eyeball, to compress it slightly. The scleral buckle allows the retina to settle again against the posterior wall of the eye. The bands can be positioned permanently and should not be evident after the operation.
- Vitrectomy. This procedure, used in the event of failure of previous treatments, can be recommended if the vitreous fluid under the retina is unusually dense. During vitrectomy, the vitreous humor is removed from the inside of the eye and replaced with a gas or silicone oil. The procedure ended with photocoagulation, to ensure that the retina permanently maintains the correct position.
Possible complications
Complications rarely occur, provided the treatment is timely. However, surgery is not always effective and blindness in the affected eye is the most common complication of a retinal detachment.
The possible complications that can develop during and after the intervention include:
- Intraocular bleeding;
- Bruises around the eye;
- High eye pressure (glaucoma);
- Cataract;
- Double vision;
- Allergy to the administered anesthetic;
- Infection in the eye (very rare);
- Eye loss (due to atrophy of the eyeball);
Recovery
Recovery after surgery usually takes 2-6 weeks. During this period, visual acuity can be reduced, impacting negatively on the performance of some usual activities, such as driving. In the case of pneumoretinopexy or vitrectomy, vision will be temporarily blurred.
After the operation, the eyelids may itch and a small amount of fluid may escape. In order to recover, it is important not to rub the eye. These symptoms are normal and any manifestation should resolve spontaneously within a couple of days. After surgery, your doctor may prescribe eye drops to reduce swelling and prevent infection. If the detachment is exudative and represents the outcome of an inflammation, a therapy can be prescribed to manage the underlying pathology.
Vision improvement can take many months and, in some cases, permanent vision loss may occur, but not complete blindness. Occasionally, a second surgery may be scheduled; however, after the initial treatment, it takes several months to determine whether the patient should actually undergo a further operation.
The recovery of normal vision depends mainly on the extent of retinal detachment, how long the condition was present, damage to the macula and whether intraocular bleeding occurred during and after surgery.
