Retinal Detachment: Preventive Treatment

Retinal gaps

When creating favorable conditions for retinal detachment, any rupture is considered dangerous, but some of them pose a particular threat. The main criteria for selecting patients for preventive treatment are: type of rupture, other features.

Type of gap

• Tears are more dangerous than openings, as they are accompanied by dynamic vitreoretinal traction.
• Extensive ruptures are more dangerous than small ones due to increased access to the subretinal space.
• Symptomatic ruptures are more dangerous than those discovered accidentally, as they are accompanied by dynamic vitreoretinal traction.
• Ruptures of the upper part of the retina are more dangerous than the lower one, since the FG can move faster.
• Equatorial ruptures are more dangerous than in the area of the "dentate" line, and are often complicated by detachment of the retina.
• Subclinical detachment of the retina is associated with a rupture, surrounded by a very small amount of FFA. In some cases, FSW can spread and retinal detachment becomes "clinical" in a very short time.
• Pigmentation around the rupture indicates the prescription of the process with a low risk of developing retinal detachment.

Other Features

1. Afakia is a factor in the increased risk of retinal detachment, especially if a vitreous loss occurred during surgery. Being relatively safe, small peripheral round holes after cataract surgery can in some cases provoke retinal detachment.
2. Myopia is a major factor in the increased risk of retinal detachment. For ruptures in myopia, it is necessary to observe more carefully than for similar changes in the absence of myopia.
3. The only eye with gaps should be observed with care, especially if the cause of loss of vision of the pair eye was a detachment of the retina.
4. Heredity sometimes matters; patients with ruptures or dystrophic changes in the family of which the cases of retinal detachment are noted should be observed especially carefully.
5. Systemic diseases with an increased risk of developing retinal detachment include Marfan syndrome, Stickler syndrome and Ehlers-Danlos syndrome. In such patients, the prognosis for developing retinal detachment is unfavorable, therefore, in any ruptures or dystrophies, prophylactic treatment is indicated.

Clinical examples

• at extensive equatorial U-shaped discontinuities, accompanied by subclinical retinal detachment and localized in the upper temporal quadrant, prophylactic treatment is shown without delay, since the risk of progression to clinical retinal detachment is very high. The rupture is located in the upper temporal quadrant; therefore, early leakage of the FGF into the macular area is possible;
• with extensive U-shaped ruptures in the upper temporal quadrant in the eyes with symptomatic, acute posterior detrimental detachment, immediate treatment is indicated because of the high risk of progression to clinical retinal detachment;
• when ruptured with the "lid", which crosses the vessel, the treatment is shown because the constant dynamic vitreoternal traction of the crossing vessel can lead to recurrent vitreal hemorrhages;
• the gap with a freely floating "lid" in the lower mid-quadrant, revealed by accident, is quite safe, since there is no vitreoretinal traction in this case. In the absence of other risk factors, preventive treatment is not required;
• A U-shaped rupture in the lower part, as well as a detachment surrounded by a pigment, discovered by chance, is referred to as long-term changes with a low risk;
• degenerative retinoschisis, even with gaps in both layers, does not require treatment. Despite the fact that this change is a profound defect in the sensory retina, the fluid in the "shizis" cavity is usually viscous and rarely shifts into the subretinal space;
• two small asymptomatic holes near the "dentate" line do not require treatment; the risk of detachment of the retina is extremely low, since they are located at the base of the vitreous. Such changes are found in about 5% of the world's population;
• small openings of the inner layer of retinosis also constitute an extremely low risk for retinal detachment, since there is no connection between the vitreous cavity and the subretinal space.

Peripheral dystrophy of the retina, predisposing to detachment of the retina

In the absence of concomitant ruptures, "latticular" degeneration and dystrophy like "snail trail" do not require preventive treatment unless they are accompanied by one or more risk factors.

• Retinal detachment in the paired eye is the most common indication.
• Afakia or pseudophakia, especially if there is a need for a posterior laser capsulotomy.
• Myopia of a high degree, especially if it is accompanied by a pronounced "latticular" dystrophy.
• Established cases of retinal detachment in the family.
• Systemic diseases known as predisposing factors in the development of retinal detachment (Marfan syndrome, Stickler syndrome and Ehlers-Danlos syndrome).

Methods of treatment

Selecting a method

K. Preventive treatment methods include: cryotherapy, laser coagulation on a slit lamp, laser coagulation with indirect ophthalmoscopy in combination with sclerocompression. In most cases, the choice is made depending on individual preferences and experience, as well as the availability of equipment. In addition, the following factors are taken into account.

The localization of dystrophies

• With equatorial dystrophies, it is possible to perform both laser coagulation and cryotherapy.
• With postequatorial dystrophies, only laser coagulation is indicated, if there are no incisions of the conjunctiva.
• In dystrophies, a "dentate" line shows either cryotherapy or laser coagulation with the use of an indirect ophthalmoscopy system, in combination with compression. Laser coagulation using a slit lamp system is more difficult in such cases and can lead to inadequate treatment of the base of the U-shaped rupture.

Transparency of media. With clouding environments it is easier to perform cryotherapy.

The size of the pupil. At narrow pupils it is easier to carry out cryotherapy.

Cryotherapy

Equipment

• Anesthesia is performed with a swab soaked in ametocaine solution, or subconjunctival injection of lignocaine, respectively, to the quadrant of dystrophy;
• in post-equatorial dystrophies, a small conjunctival incision may be necessary to best achieve the desired area by the tip;
• with indirect ophthalmoscopy, carry out a gentle compression of the sclera with the tip of the tip;
• the dystrophic focus is limited to one row of cryocoagulants; the effect is completed as the retina turns pale;
• krionakonchnik removed only after a complete defrost, since premature removal can cause a rupture of the choroid and choroidal bleeding;
• eye bandage for 4 hours to avoid the development of chemosis, and the patient is recommended for a week to refrain from significant physical exertion. Approximately within 2 days, the area of exposure is pale due to edema. After 5 days, pigmentation begins to appear. In the beginning it is tender; later becomes more pronounced and is associated with varying degrees of chorio-retinal atrophy.

[1], [2], [3], [4], [5], [6]

Possible complications

• Chemosis and edema of the eyelids are an ordinary and safe complication.
• Transient diplopia, if during extra cryocoagulation, the extraocular muscle.
• Vitreit may be a consequence of exposure to a large area.
• Maculopathy is rare.

Causes of failure

The main reasons for unsuccessful prevention: inadequate treatment, the formation of a new gap.

Inadequate treatment may be due to the following reasons:

• The insufficient limitation of the rupture during laser coagulation in two rows, especially at the base of the U-shaped rupture, is the most frequent cause of failure. If the most peripheral part of the rupture is not available for laser coagulation, cryotherapy should be performed.
• The coagulants are not close to each other when coagulating extensive ruptures and detachments.
• Insufficient excision of dynamic vitreo-retinal traction with extensive U-shaped rupture with the introduction of explant and a failed attempt to use the explant in the eye with subclinical retinal detachment.

Formation of a new gap is possible in the following zones:

• Inside or next to the zone of coagulation, more often due to excess of its dose, especially in the field of "latticular" dystrophy.
• On the retina, which seems "normal", despite adequate treatment of dystrophy, predisposing to its rupture, which is one of the limitations of preventive treatment.

[7], [8], [9], [10], [11], [12]

Violations not requiring prevention

It is important to know the following peripheral dystrophies of the retina, which are not dangerous and do not require preventive treatment:

• microcystic degeneration - small vesicles with fuzzy boundaries on a grayish-white background, giving the retina a thickened and less transparent appearance;
• "Snowflakes" - shiny, yellowish-white spots that are diffusely scattered on the periphery of the fundus. Areas where only dystrophies are detected by the type of "snowflakes" are safe and do not require treatment;

However, it is believed that dystrophy by the type of "snowflakes" is of great clinical importance, as it is often accompanied by "latticular" dystrophy, dystrophy such as "snail trail" or acquired retinosis, as mentioned earlier.

• dystrophy by the type of "cobblestone pavement" is characterized by discrete yellowish-white foci of local chorioretinal atrophy, which, according to some data, is normal in 25% of the eyes;
• Honeycomb or reticular degeneration is an age-related change characterized by a thin network of perivascular pigmentation that can reach the equator;
• druses or colloidal bodies are represented by small pale clusters, sometimes with hyperpigmentation along the edges ..
• paraoral pigment degeneration is referred to as age-related changes represented by the hyperpigmentation band along the "dentate" line.