The macula is the central, most sensitive part of the retina. It allows us to read, differentiate colors and it is responsible for high acuity vision. The other part is the peripheral retina which allows us to see the things surrounding the central object we are viewing.
The incidence of Retinal Detachment (RD) in the general population is around 1 in 10,000 per year. That is to say, that in a population of 1,000,000 we would have 100 cases per year. RD is a serious disorder which might occur at any age, although it is more frequent in middle-aged or elderly population. In around 10% of cases it can be bilateral.
WHO IS IN HIGHER RISK OF SUFFERING RETINAL DETACHMENT?
The conditions described herein below describe major causes of retinal detachment:
- RD in the other eye.
- Patients suffering from myopia.
- Patients who have been subjected to cataract surgery, either with or without complications.
- Patients with retinal degenerative diseases.
- Ocular and/or cranial trauma.
WHAT IS THE VITREOUS HUMOR?
The vitreous humor is the clear gel that fills the space between the lens and the retina of the eyeball. With ageing, a liquefying process takes place inside this gel and the vitreous humor contracts and collapses. This is called posterior vitreous detachment (PVD) and in most cases there are no consequences over vision. But in certain cases this process may tract the retina causing it to break and then detaching it.
WHAT IS RETINAL DETACHMENT?
Retinal Detachment is a disorder of the eye in which the sensory retina peels away from the retinal pigment epithelium due to the passage of liquid from the vitreous which is accumulated in the subretinal space forming a bag.
WHICH ARE THE CAUSES OF RETINAL DETACHMENT?
When due to atrophic or degenerative processes the retina becomes thinner forming "holes" or if as a result of vitreous traction there is a “break” (called “tear”), the liquid in the vitreous cavity passes through these “holes” separating the retina from its underlying layers and thus originating the Retinal Detachment.
In certain cases these retinal “tears” may occur without causing detachment, and if early diagnosed they can be treated exclusively with Laser.
There are other causes responsible for retinal detachment such as advanced diabetic retinopathy and inflammatory vitreoretinal processes. Also ocular trauma, either craneal or orbital may cause RD.
HOW IS RETINAL DETACHMENT DIAGNOSED AND WHICH ARE THE SYMPTOMS?
The most frequent visual symptoms are the appearance of:
- Dark spots or threads (floaters). Process of vitreous contraction.
- Flashes of light (contraction of the vitreous over the retina).
- The impression that a veil or curtain was drawn over the field of vision.
In very few occasions there is sudden and total loss of vision. If the RD is not treated promptly, central vision may also be affected.
If any of the symptoms mentioned herein before appear, visit your ophthalmologist for a complete retinal test in which he shall use special instruments and procedures including fundoscopic examination in order to make the correct diagnosis.
WHAT IS THE TREATMENT LIKE?
The aim of any treatment is to close or “weld” the tears or holes in the retina and put it back in place. If the breaks in the retina have not yet caused its detachment, it is possible to treat it using Laser, but if there is already RD, the recommended treatment is surgery.
HOW IS THE LASER TREATMENT?
This procedure takes place at the doctor's office. The pupil is dilated (using eye drops). The Laser light sends out thermal energy producing small burns around the retinal tear, and the scarring that results usually "welds" the retina to the underlying tissue. The laser beam is directed around the retinal tear so that the "welding" prevents the liquid in the vitreous cavity from passing through causing a RD.
HOW IS THE SURGICAL TREATMENT?
The surgical approach used to “weld” the tears or holes shall be determined according to the characteristics and severity of the clinical picture. The most common techniques are the following:
Pneumatic Retinopexy: Your surgeon injects a bubble of air or gas into the vitreous cavity. This pushes the "bag" from inside the eye sealing the retinal tear. This technique shall be applied together with the laser over the retinal tear.
Scleral Buckling: In certain cases it is necessary to approximate retinal tears to the underlying layers. This is achieved by attaching a small piece of silicone sponge or a firmer piece of silicone rubber to the white of your eye (sclera) over the affected area. When tight, this pushes the wall of the eye from the outside bringing the detached sensitive retina near the retinal pigment epithelium thus favoring the adherence of the affected areas.
Vitrectomy: This is a very delicate surgical procedure requiring very sophisticated instruments and great experience of the surgeon. It consists of removing the hemorrhages and membranes formed inside the eye and eventually treat the retina with laser.
Although the post-operative visual prognosis in these cases is guarded, it is true that this treatment is more effective if applied early than late. This complex technique uses a very thin special instrument capable of aspirating the vitreous gel and cutting it at the same time. This is used exclusively for complex retinal detachments.
WHICH ARE THE RISKS OF SURGERY?
As with any surgery there are risks and complications involved. The most serious ones include infection and inflammation, ocular hypertension, hemorrhages and a new retinal detachment.
WHAT IS THE RATE OF SUCCESS OFFERED BY THE SURGERY?
The retina is reattached in almost 90% of the cases. 10% of re-operations involve a higher level of complexity and a guarded prognosis. Even if surgery is successful, it doesn't guarantee normal vision. The patient may experience fixed dark areas in some part of the visual field ("scotomas") or with image distortion especially if the central retina was affected.