uveitis

There are several causes for uitis, the most important of which are:

• Viral causes: such as shingles and herpes virus
• Fungal causes: such as histoplasmosis
• Parasitic causes: such as toxoplasmosis
• Diseases that involve other parts of the body, such as collagen-vascular diseases (rheumatic diseases)
• History of injury to the eye

Uveitis may be associated with the following complications:

• Glaucoma
• Cataract
• Creating intraocular adhesions
• Retinitis and damage to the visual cells

In case of any of these complications, it is necessary to see an ophthalmologist and after the examination, drug treatment, surgery, intraocular injection, or laser therapy may be prescribed.

This disease has different symptoms depending on the type of involvement in the anterior or posterior chamber. If it is in the anterior chamber, it is associated with symptoms such as eye redness, fear of light, blurred vision, and sometimes tears. In the posterior chamber, eye redness and pain are less, but vision loss is felt more clearly.
It is also necessary to mention that this disease has two infectious and non-infectious causes. It may also be caused by internal diseases or be unique to an eye problem. For this reason, before starting the treatment, the patient should be examined for secondary diseases such as rheumatism and internal infections. Of course, it is not possible to correctly diagnose the disease just by observing the symptoms. For accurate diagnosis, we need paraclinical tests, accurate imaging and blood tests; But remember that the final diagnosis is the responsibility of the ophthalmologist.
Again, it is emphasized that in the event of uveitis, sudden redness of the eye may be observed, with or without pain, and lead to blurred vision; For this reason, if you experience eye pain or redness, it is necessary to visit an ophthalmologist for an examination. Uveitis is a dangerous disease that may lead to permanent eye damage. Therefore, treatment as soon as possible is the most important recommendation.
The treatment of the disease usually has a step-by-step process, starting from the simplest treatments with eye drops and can reach the next steps, such as the use of steroid pills and drugs that modulate the body's immune system. In some cases, it is necessary to use intraocular or intraocular injections, and sometimes surgery is necessary to control and stop the disease. It should be noted that uveitis is not a disease but includes a wide range of diseases. In other words, this disease is like a fever that has different causes. Many times the eye itself acts as an antigenic tissue and the defense system reacts against this tissue; In this case, symptoms of uveitis also appear. It should be noted that if uveitis is accompanied by an infection in other parts of the body, it is necessary to use appropriate antibiotics (according to the ophthalmologist) along with corticosteroids.

Retinitis Pigmentosa

Retinitis pigmentosa or RP is a group of uncommon eye diseases in which cylindrical rod photoreceptor cells of the retina are involved with or without cone photoreceptor cells. Although this disease progresses over time, the progress of this disease is different in different people. Its prevalence in America is 1.5000 people. This disease is the most common cause of night blindness.

Retinitis pigmentosa is a hereditary disease that has different forms
(Autosomal Recessive, Autosomal Dominant, X-Linked) is inherited. A type of it that is observed individually and without family history is also seen.

In some cases, the symptoms of this disease show themselves from childhood, but in most cases, they do not have many symptoms until the beginning of adulthood. The symptoms of this disease are:

• Nyctalopia
• Tunnel Vision 
• In some types of RP and in advanced cases, central vision loss is also seen.

A symptom that may be seen during the fundus examination by an ophthalmologist is the observation of black lines in the retina.

Currently, there is no specific treatment for this disease, but the following care can help the patient.

• Using sunglasses that protect the retina from ultraviolet rays.
• It seems that the use of some antioxidants, such as vitamin A, slows the progression of the disease. Recent studies show that using the right dose of vitamin A supplements can delay blindness by up to 10 years.
• Visiting a low vision specialist and regular ophthalmological examinations will lead to early diagnosis of cataracts and retinal swelling, both of which are treatable complications.
• Several microchips are in the early stages of design, which in the future may be implanted inside the retina and used to treat blindness caused by this disease.
• Stem cell transplantation is in the early stages of research and may play an effective role in the treatment of this disease in the future.

Intravitreal hemorrhage

This problem can have different causes, but the most common causes are:

1. Diabetic retinopathy with angiogenesis (Proliferative Diabetic Retinopathy): The most common cause of spontaneous intravitreal hemorrhage. Because in diabetes, new blood vessels grow in the eye, which are fragile and prone to bleeding.
2. Detachment of the retina and Retinal Tear may tear one of the retinal vessels and cause intravitreal bleeding.
3. Posterior detachment of the vitreous membrane (separation of the vitreous from the retina), which is common in the middle years and later, can cause a rupture of one of the retinal vessels and, as a result, cause bleeding inside the vitreous.
4. Obstruction of the central retinal vein or its branches can cause intravitreal bleeding and is especially common in patients with diabetes or high blood pressure.
5.  Shaken Baby Syndrome

It is important to examine both eyes, as examining the non-involved eye can help the doctor determine the cause.

1.  Visual Acuity
2. Pupil response test to light
3. Slit-lamp examination
4. Direct and indirect fundus examination

Treatment of intravitreal hemorrhage

1. Examination by a retina specialist is essential.
2. The treatment of intravitreal hemorrhage depends on the underlying cause. Laser cryotherapy or surgery is required for retinal detachment or hole. Despite underlying diseases, it is necessary to carry out maintenance treatments for the patient, such as sleeping in a semi-sitting position for the patient until the bleeding is absorbed.
3. Except when the bleeding is the result of trauma or retinal detachment, careful and regular follow-up for 1 to 2 weeks can absorb some of the bleeding, but it may take several months for vision to return. Pars plana vitrectomy surgery can improve vision if the macula is healthy.
4. Bilateral dressing of the eyes, which restricts their movement, and recommending the patient to a sitting position can accelerate recovery.
5. There are new methods such as clot liquefaction or hemolysis (with ultrasound or anti-Rh immunoglobulin) or phagocytosis using intravitreal interleukin-1, which are mainly in research stages and their effectiveness has not yet been proven.

Neonatal retinopathy

Retinopathy (retinal problems) in premature babies (Retinopathy of Prematurity - ROP), which is also called Retrolental Fibroplasia, can also cause blindness. Doctors do not know the exact cause of ROP, but they know that blood vessels in the eye develop naturally during the last few weeks before birth. Premature babies leave the mother's womb before the blood vessels in their eyes have a chance to fully develop. These musicians are then exposed to elements such as drugs, high oxygen levels, changes in light and temperature. These factors may interfere with the normal development of blood vessels in the eye and cause ROP.

In the past, this disease occurred due to the use of large amounts of oxygen in the devices for keeping premature babies, but today, with the progress in the methods of keeping premature babies, the incidence of this disease has decreased. Currently, the factors that put the baby at a higher risk for retinopathy are low birth weight (less than 1.5 kg) and premature birth (26 to 28 weeks).

As mentioned, in premature children, the growth and development of retinal blood vessels are defective and abnormal blood vessels begin to grow. The problem with abnormal vessels (which is called neovascularization) is that they do not deliver enough oxygen to the retina, and the progression of this disease can cause retinal ulcers and complications such as retinal detachment, vitreous bleeding, deviation and lazy eye. It should be noted that some babies with retinopathy are at risk of developing Myopia They also encounter

Considering that the baby cannot express its symptoms, parents, pediatricians and ophthalmologists should be aware of the risk factors that increase the possibility of contracting this disease. These factors include:

• Premature delivery (week 26 to 28)
• Low birth weight (1.5 kg or less)
• Oxygen requirement in the first week after birth
• The presence of problems in the health of the baby immediately after birth

Children who were diagnosed with this disease in infancy should be considered for the following symptoms:

• Keeping objects close to the eyes
• Difficulty seeing far away
• Closing one eye
• Reluctance to use one eye
• Poor vision (not previously diagnosed by a doctor)
• Sudden loss of vision
• eye deviation

Usually, an ophthalmologist can diagnose ROP when examining a baby's eyes in a hospital's neonatal intensive care unit (NICU) or in the neonatal unit.

Of course, sometimes the symptoms of retinopathy do not appear until a few weeks after birth. Therefore, babies who are at risk of ROP should undergo an ophthalmological examination in the 4th to 6th week after birth. The ophthalmologist first opens the pupil and examines the retina using a dropper. Regardless of whether the child needs treatment or not, he should be re-examined at intervals determined by the ophthalmologist until the abnormal blood vessel growth resolves on its own or appropriate treatment is administered by the ophthalmologist.

Some children who have a mild illness will recover without treatment; In advanced cases, however, treatment is necessary.

In these stages, in order to prevent the spread of abnormal blood vessels, the ophthalmologist may freeze areas of the retina with a method called cryotherapy. Sometimes the doctor will use laser for treatment, and fortunately, in most cases, these methods are successful in preserving the patient's central vision.

Detachment (tear) of the retina

The retina is a light-sensitive nerve tissue that is placed as a thin layer inside the posterior part of the eyeball and converts light into nerve messages and sends them to the brain. Therefore, the retina plays a key role in the vision process.

The retina receives most of its oxygen and nutrients from a vascular layer called the choroid, which surrounds the retina. Whenever the connection of the retina with the underlying choroid is interrupted due to the lack of oxygen and nutrients, the retina first loses its function and the person suffers from vision problems, moreover, if this situation lasts long, the retinal tissues gradually die or so called become necrotic, which is an irreversible condition. For this reason, retinal detachment is considered an ophthalmic emergency.

A retinal hole is usually caused by a sudden stretching of part of the retina. The eyeball is naturally filled with a jelly-like substance called the vitreous. In childhood and youth, the vitreous has a relatively high consistency like egg white, and as a result, it does not move much, and with the pressure it puts on the retina inside, it keeps it in place, attached to the outer wall of the eye. The young vitreous has strong connections to the retina in some areas. But gradually, with increasing age, the vitreous loses its consistency and becomes loose and watery, as a result, its movement rate increases and its connection to the network becomes loose. In this case, the rear parts of the vitreous usually separate from the retina, this condition is called posterior vitreous detachment, which is a very common condition and eventually happens in most elderly people. Posterior vitreous detachment is harmless in itself and only causes nystagmus (a moving shadow in the visual field), but sometimes when the vitreous detaches from the retina, part of the retina is also stretched and a tear or A hole is created in the retina. Since a hole in the retina is the main cause of retinal detachment, it is necessary for all people who have recently found fly flies to undergo a careful ophthalmological examination so that if there is a hole in the retina, the necessary treatment can be done for them.

Retinal detachment actually means the separation of the sensitive nerve layers of the retina from the pigmented layer of the retina (which is responsible for nutrition and metabolism of the retina). Since this complication causes severe vision loss if not treated properly, it is very important to diagnose and treat it quickly.

Retinal detachment occurs in three ways:

• The first type, which is the most common form of retinal detachment, occurs as a result of creating a hole in the retina, in such a way that after creating a hole in the retina, the vitreous, which has become watery, penetrates through the hole to the back of the retina and removes it from the retina. It separates the outer layers. Liquid waves along with head movements and the effect of gravity cause retinal detachment to spread, for this reason this type of retinal detachment can progress quickly and cause complete retinal detachment.
• The second type, which is called tractional detachment, happens when the vitreous fibers or abnormal tissues pull on the inner part of the retina and lift it from the underlying tissues. This condition is more common in diabetics.
• The third type of retinal detachment, which is not very common, occurs as a result of abnormal leakage or secretion of fluid between the retina and the underlying tissues. This condition is usually caused by inflammation, bleeding, or abnormal masses inside the eye and rarely occurs spontaneously.

Symptoms of retinal detachment

• Seeing flashes of light in the visual field (especially if part of the retina is under tension, this symptom is more likely to occur)
• Seeing objects floating in front of the eyes that may be seen as flies, dark spots or spider webs.
• Deformation and distortion of objects like when a person looks at something from behind a wavy glass.
• Sensation of a curtain or shadow in front of the eyes
• Sudden loss of vision

It should be noted that detachment of the retina does not cause pain or redness of the eye and does not cause any change in the appearance of the eye in the initial stages. Therefore, if any of the above problems occur, see an eye doctor as soon as possible.

The only effective treatment for retinal detachment is surgery. Retinal detachment does not improve by itself or with medication, and surgery should be performed as soon as possible. The appropriate type of surgery is determined based on the location, size, type and severity of the retinal detachment. The two basic principles in the treatment of retinal detachment are:

1. Close the holes
2. Bringing the retina closer to the underlying layers and outer wall of the eye, so that the retina can stick in place.

Based on this, there are different treatment methods for retinal detachment:

Attaching the retina using laser or freezing: (Laser Retinopexy)

This method is an effective way to close retinal holes, but it alone cannot cure retinal detachment. In cases where the retina has been perforated but retinal detachment has not yet occurred, this method can prevent retinal detachment by closing the hole. In this method, which can be performed with local anesthesia, or using a laser (from the inside of the eye) or using a cryotherapy pen (from the outside of the eye), burns are created around the edge of the hole. These burns cause tissue adhesion, creating strong connections between the retina and the eye wall. As a result, the hole is closed all around and the entrance of the liquid to the back of the retina is closed. (The laser causes a thermal burn, the cryotherapy pen freezes and burns the tissue)

Attaching the retina using gas (Pneumatic Retinopexy)

In this method, after creating local anesthesia, the doctor injects a small gas bubble into the eye. This gas bubble expands inside the eye and presses on the retina from the inside and holds it in place, and by pressing on the edges of the retinal hole, it closes the hole and prevents fluid from leaking back. It becomes the retina. Since the gas moves up inside the eye, this method is only effective when the retinal detachment has occurred in the upper part of the eyeball. In order for the gas bubble to be placed in the right place, the patient is usually advised to keep his head straight for a while and even sleep in a sitting position. The gas bubble is usually absorbed within 10 days to two weeks, after which time it is usually burned around the retinal hole using a laser or cryotherapy pen to prevent the hole from reopening.

(Scleral buckle)

This method is the most common method of treating retinal detachment. In this method, a buckle (a sponge or soft silicone band) is sewn to the sclera (sclera or the white of the eye) with sutures, and like a tight belt, it pushes the outer wall inward and brings it closer to the detached retina. Slow down so that the retina has time to stick in place. If there is a lot of fluid behind the retina, this fluid will be drained during surgery so that the retina adheres to the outer wall of the eye faster. In addition, during the operation, the edge of the retinal holes is also closed using a laser or a cryotherapy pen.

The scleral buckle remains permanently in place and does not need to be removed (unless it causes a specific problem). The buckle is not visible from the outside and does not cause a significant change in the appearance of the eye, but it can cause myopia due to the pressure and change in the shape of the eyeball.

Vitrectomy

In cases where simpler methods cannot treat retinal detachment, a more complicated surgery called vitrectomy is used. In cases where retinal holes are numerous or very large or a large part of the retina is detached, in cases where bleeding has occurred inside the eye or the retina is under tension, usually simpler surgical methods are not effective and vitrectomy surgery should be used. to be (The word vitrectomy means removing the vitreous fluid from the eye). In this method, the vitreous is first removed from the eye with a special device. This special device uses a very fine guillotine-like blade to cut the vitreous fibers and pull them out of the eye, thereby removing tension from the retina, plus if there is bleeding inside the eye, the blood will also be removed. The order is washed. Then, sterile saline is injected into the eye instead of the vitreous. (Replacing the vitreous with saline serum does not cause a disturbance in a person's vision). Finally, the retinal holes are closed using a laser.

Sometimes, in order for the retina to be better in place, heavy liquids (such as Perfluron) are injected into the eye to keep the retina in place, then this liquid is replaced with saline serum. Sometimes, in addition to the saline solution, an expandable gas bubble is injected into the eye to keep the upper parts of the retina in place.

Sometimes, together with vitrectomy surgery, a scleral buckle is also used so that the external pressure helps to reattach the retina.

In certain cases where the above methods are not effective, after vitrectomy, a special substance called silicone oil is injected to fill the eyeball from the inside and keep the retina in place with internal pressure. When silicone oil is inside the eye, vision is severely impaired. After a few months, when the retina is stuck in place, the oil is removed with another surgery and saline serum is injected in its place.

After surgery, especially the sclera and vitrectomy, the eye is painful and sensitive for several days. It is usually necessary to use antibiotic drops for a week or two and anti-inflammatory drops for a few weeks after surgery. Sometimes other drops (such as eye pressure lowering drugs or pupil dilating drops) are also used. If the gas bubble has been injected into the eye, the person should keep his head straight for a week or two, and even to sleep, he should be in a semi-sitting position and should not sleep in an arched position.

In general, after retinal surgery, it is necessary to visit an ophthalmologist regularly to control the condition of the retina and prevent possible complications.

The result of surgery

The result of retinal detachment surgery depends on two important factors:

1. The length of time the retina has been detached.
2. Condition of the center of vision (macula)

The macula is the central part of the retina that is responsible for accurate direct vision. If the macula is not removed from its place before the operation, the result of the operation is relatively good, so that more than 2/3 of the patients will have enough vision to study after the operation, but if the macula is removed from its place, the patient after the operation It will have poor vision.

The best result of the surgery happens when the retinal membrane is glued in place within a week or two, in cases where the detachment of the retinal membrane takes a long time, the patient will not have satisfactory vision after the operation.

In general, in 90 to 95% of cases, the retina will stick in place with one or more surgeries, but it should be noted that sticking the retina in its anatomical place will not necessarily improve the person's vision. As mentioned, the condition of the vision after the operation depends on the condition of the macula and the length of time that the retina has been detached from its place. In general, the smaller the detachment of the retinal membrane and the farther from the center of the retina, the better the surgical result, and the larger the detachment and the closer to the center of the retina, the worse the result.

Color blindness

Color blindness is a recessive X-linked hereditary disease that is more common in males and is almost always inherited from mother to son. (Explanation: Women have two X chromosomes and men have one X chromosome and one Y chromosome. In recessive X chromosome-related diseases in women, both X chromosomes must be defective for the disease to occur. If one X chromosome is defective, the disease does not occur. But it can be transmitted to children. In males, only the X chromosome causes the disease. Therefore, a person who is color blind is either a color blind person or a carrier of the disease.) In this chromosomal disorder, cone cells in the retina which are responsible for the perception of color are disturbed and therefore the patient does not recognize colors correctly.

Color blindness may also occur as a result of diseases of the retina or optic nerve. In these cases, only the affected eye becomes color blind and the disease worsens over time so that it may become complete color blindness in which the patient has gray vision. These patients usually have difficulty distinguishing between blue and yellow.

There is no cure for color blindness. Early detection of color blindness can prevent the occurrence of education problems in school children. In this case, it is better for the child's parents to talk to the school officials and his teacher.

Some patients use special lenses that are both contact lenses and spectacle lenses.

In many cases, patients may remember the order of placement instead of recognizing the color. For example, the patient remembers that the red light is always above the traffic light and the green light is below.

Floaters and Flashes)