Ophthalmology (Eye Health and Eye Diseases)
Areas of Interest of Ophthalmology
Visual Impairments
Myopia
Myopia, which is defined as being nearsighted, is a condition where the rays that come to the eye focus in front of retina. It is a structural feature and its genetic inheritance is common. It usually starts at school age and shows an increase as the growth process continues.
Hyperopia
In general, it is failure to see near objects. Structural and hereditary characteristics are the most common reasons of hyperopia. Untreated hyperopia increases the risk of amblyopia in children . Therefore, all preschool children should have an eye examination.
Astigmatism
Astigmatism is an eye condition that makes blurred vision at all distances. It can either be structural or develop as a result of degenerative diseases, infections and trauma causing a change in cornea layer.
Cataract
Cataract is a condition where the lens inside the eye loses its transparency and becomes cloudy. Loss of transparency by the lens obstructs rays coming to the eye from passing to the nerve layer. This results in progressive reduced vision.
The only treatment of cataract is surgery.
In phaco technique, a tiny incision is made in the eye and the cataract is broken into pieces, aspirated and removed using ultrasound energy. By the courtesy of phaco machine, the operation time is short and it is a safe procedure that doesn’t require sutures. This method allows very fast recovery after the operation.
In phaco method, after the cataract is removed, an artificial lens made of a special material is placed instead of the patient’s own lens. It is also possible to produce these lenses with such features that eliminate vision defects, including visions defects concerning seeing far, near, medium distances and astigmatism.
Glaucoma
It is a disease that causes damage to the optic nerve as a result of increased intraocular pressure, leading to loss of visual field. Accordingly, the person’s visual field gradually narrows down. If it isn’t noticed and left untreated, it may result in permanent blindness.
Eye pressure usually does not produce symptoms in the early stages. In a rare type of eye pressure, nausea, vomiting, pain, blurred vision may occur. Progression of glaucoma can be stopped by early diagnosis.
An important point about glaucoma is that treatment can only stop the damage. The resulting optic nerve damage is permanent. Detailed eye examination is essential for diagnosis .
When starting treatment, a variety of factors such as the state of the ocular tension , the extent of damage is assessed. Treatment is started with an appropriate option among those including medication treatment, laser or surgical intervention.
Treatment of glaucoma can be made in three ways.
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Drug therapy
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Laser Treatment
In the case of glaucoma, laser procedure can be applied for many purposes. In case of an acute glaucoma attack, timely laser treatment is very useful.
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Surgical Treatment
A hole is made in white section of the eye by surgery. This hole is too small to be visible from the outside and excess fluid inside the eye is drained through this hole. Glaucoma often disappear after the operation.
Retinal Diseases
Retina is a net-like layer lining back wall of the eyeball like a wall paper and consisting of vision cells; it is the innermost layer of the eye. It has vision cells on it. 95% of the act of vision takes place in the yellow spot in the center of the retina.
Retinal diseases can be exemplified by the following diseases:
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Bleeding due to diabetes and hypertension
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Retinal vein occlusions
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Retinal detachments / tears
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Yellow spot disease
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Diabetics
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Congenital retinal diseases
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Retinal edema
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Foreign bodies which have entered the eye
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Macular holes
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Vitreoretinal surface disorders
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Retinal tumors
Retinal Hemorrhage
Vitreous is the transparent liquid with a gel structure filling inside the eyeball. Bleeding into vitreous may develop as a result of diseases including diabetes, hypertension, trauma, etc. Blood filling inside of vitreous impairs the patient’s sight and prevents the physician from diagnosing the cause in the retina leading to intraocular bleeding.
Patients with intravitreal hemorrhage typically would suffer sudden loss of vision.
In the case of mild intravitreal hemorrhage, patients refer to objects floating in the air or an image resembling soot pouring.
Unless vitreus bleeding is caused by trauma or retinal detachment, it is allowed to stand without treatment for some time due to the possibility of self-absorption. During this period, it is recommended that the patient drinks plenty of water and lies upright in bed with a pillow placed behind his neck. However, where bleeding isn’t reduced, surgery is required to treat vitreous hemorrhage. This procedure ensures removal of vitreous gel and is called pars plana vitrectomy.
Retinal Detachment and Tears
Retinal tears develop as a result of the thinning of the retinal layer associated with the growth of the eyeball most commonly in people with high myopia. However, retinal tears may develop in healthy eyes following a trauma or lifting heavy loads. Retinal thinning may also develop after retinal infections or some degenerative retinal diseases, and retinal tears may occur from these areas thereafter.
Retina is in contact with vitreous gel covering the insdei of the eye. In a healthy eye, vitreous is homogenous, has a gel-like consistency and supports the retina. The consistency of this gel structure changes, liquefies as a result of aging of vitreous over time. Intraocular gel that has liquefied loses its ability to support retina and detaches from its underlying retinal layer. This detachment is called posterior vitreous detachment. This detached vitreous gel fluctuates inside the eye by eye movements and this is referred to by patients as floating black spots or veils.
While intraocular gel detaches from the retina, it causes tractions. As a result of these tractions, mechanical impulse created in the retina is perceived as flashes of light or flashes of lightning. These tractions may cause tears in the retina that has thinned. If torn retinal layer passes over a vessel, bleeding into the eye may occur. Liquefied intraocular gel enters into the tear in the retina and causes detachment of retinal nerve layer from the underlying layer, leading to retinal detachment. Visual function of the area of retina that has detached from the underlying tissue is reduced.
Retinal tears in which retinal detachment hasn’t developed are surrounded by argon laser and seeping of liquid is prevented.
Retinal detachment is a disorder that may progress up to blindness, a medical emergency, and can only be treated by surgery. In this case, the vitreous gel is removed and inside of the eye is filled with special buffering agents(a gas bubble or silicon oil).
Retinal Vein Occlusions
Retinal vein occlusions are in second place among retinal vascular diseases after diabetes. The main problem is damage in the walls of retinal vessels.
It manifests itself by sudden, painless loss of vision which is not transient. Depending on the vein which has been affected by the disease, either a minimal loss in vision may occur or very serious loss of vision may be encountered.
If a section of retinal vein has been occluded and there is accumulation of fluid in visionary center, laser treatment is applied and cortisone treatment is applied into the eye.
Macular Degeneration
It is a condition in which the macula in retina is impaired and vision is reduced because of aging.
Patient sees straight lines as broken. He cannot see the point he is looking at but can see its surroundings. Near vision and reading are affected the most.
There are two types: dry type and wet type.
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In dry type, capillaries are intact and there is no bleeding. Vision is reduced but it doesn’t lead to blindness.
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In wet type, capillaries are susceptible and there is bleeding. It carries risk of blindness. Argon laser, photodynamic therapy, and intraocular injections are used to treat the wet type.
Treatment of dry type is applied by oral support medications. Argon laser, photodynamic therapy, and intraocular injections are used to treat the wet type.
In photodynamic therapy, capillaries causing bleeding in the retina are stained by a special medication injected into the arm of the patient, and diseased area is destroyed by laser applied to the region stained.
In the case of intraocular infections, medications called anti-VEGF are used. Injection procedure is easy and painless for the patient. Intraocular injections are made for 3 times with one month in between.
It is also possible to significantly help patients with reduced vision with special glasses called LVA. Most of the patients gain vision with these glasses to the extent that they can comfortably read a newspaper.
Patients with macular degeneration are required to be examined every 4 months.
Corneal Diseases
The cornea is the transparent, curved front part of the eye that serves to focus the light and protect the eye from outside factors, plays a major role in visual function of the eye, and it is the most important refracting lens of the eye. Transparency of the cornea can be impaired by many diseases. These diseases can be congenital, genetic or microbial.
Keratitis
Inflammation of the cornea is called keratitis. Transparent cornea tissue can be blurred, thinned or even ruptures due to keratitis.
Keratitis can be caused by bacteria, viruses, fungus or rheumatism.
Bacterial Keratitis
Use of contact lenses without conforming to hygienic conditions, eye surgery, eye surface trauma (that sand gets into the eye, etc.) are the main reasons for formation of bacterial keratitis.
It is frequently treated with antibiotic drops on an outpatient basis.
Virus Keratitis
The most common types of virus keratitis are herpes keratitis and adenovirus keratitis.
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Adenovirus Keratitis: It appears following intense ocular discharge and eye redness. Spots in the cornea may require a long course of treatment that lasts several months.
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Herpes simplex keratitis (dendritic keratitis): Herpes virus is known as blister virus. Some people have a blister in their lips whereas in the case of herpes keratitis, they have it in cornea layer of the eye. It can be repetitive and each time, it heals by leaving a spot in the cornea. It causes reduced vision. Antiviral drugs and drops are used in the treatment . When corneal haze caused by herpes keratitis reaches a level that will reduce vision, it is treated with corneal transplant.
Fungal Keratitis
It is treated with antifungal drugs in the long-term. Fungal keratitis leaving spots to the extent that vision is reduced in the corneal center is also treated by corneal transplant.
Keratoconus
It is a corneal disease in which the cornea thins and its shape becomes more conical than the normal curve; in other words, it is deformation of the cornea.
The disease has several reasons and patients usually have genetic predisposition. Allergic eye disorders, frequent rubbing of the eyes, myopia, astigmatism, and refractive impairments set the scene for the disease.
Keratoconus is a disease that progresses insidiously, and is not detected during routine eye examination.
Treatment methods can be listed as follows.
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use of contact lenses
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Treatment by intrastromal corneal ring segments
If the patient isn‘t suitable for contact lens use and isn’t at an advanced stage of the disease, insertion of intrastromal corneal ring segments can be performed. Under anesthesia ensured by drops, corneal channels are created inside the cornea of the patient using laser. Special rings are placed in these channels. By the courtesy of these rings, current refraction is partly reduced and better vision is achieved as well as the rings correct the shape of the cornea, creating a better medium in case a need for glasses or contact lenses arises. The rings can be removed where necessary.
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Corneal Transplant
Corneal transplant is the last treatment option in the latest stage of keratoconus.
Ocular Tumors
An eye examination should be performed for eye tumors if a white reflection is seen in the pupil, change of color develops in colored part of the eye(iris) and in case of reduced vision without any reason.
In addition, a biopsy should be conducted on masses growing on eyelids, frontal section of the eye in order to make a diagnosis. Cryotherapy, radiotherapy, laser or surgical treatment can be applied depending on the type, location of ocular tumors and the patient’s age.
Family history is important in the case of ocular tumors.
Retinoblastoma
This tumor occurs in babies and children. It manifests itself by a whitish glow through the pupil in one or both eyes. Its symptoms also include crossed eyes in the child. Treatment options include chemotherapy, enucleation (removal of the eye by surgery), radiotherapy (beam or radioactive plaque therapy), laser, cryotherapy(freezing).
Uveal Melanoma
They usually appear at the age of 55-60. It appears in the form of a visible stain on the iris or a change in the iris color of the eye. Those located at the back may cause vision impairment and floating specks. They are sometimes detected accidentally during a routine eye examination. Surgery and plaque radiotherapy can be applied during treatment.
Metastatic Tumors of the Eye
Such condition involves a tumor spreading to the eye from another organ of the body. They most commonly manifest themselves by impaired vision. The most common cancers that spread to the eye are breast cancer in women and lung cancer in men.
Eye Aesthetics
Drooping of Eyelid
Drooping of the upper eyelid is called ptosis. The drooping eyelid can be seen in newborns as well as adolescents and the elderly.
Treatment of drooping of eyelid is by surgery.
Bags
The most important reason for the formation of bags is a genetic predisposition . Bags make a person look older than he really is, and tired. They are treated with removal of excess fatty tissues or changing the places they have settled in.
A Congenitally Small Eye or Congenital Absence of The Eye
Size and presence of the eye allow the development of the tissues around the eye so where the eye hasn’t developed, the eye lids, soft tissues and bone framework around the eye don’t reach sufficient size. Such condition is treated with surgery.
Diagnostic Methods in Use
Eye Ultrasonography
Ultrasonic sound waves are used to view the posterior segment of the eye during eye examination.
Pachymetry
This device is utilized to measure the thickness of the protective cornea layer, which is located at the front of the eye. This method is used before Excimer Laser Surgery and in the diagnosis of glaucoma disease.
Wave-front
3-D mapping of our eye is performed by Wavefront technology. This map shows all deformed areas on the cornea and thus a very successful, personalized laser treatment can be performed.
Ultrasonic Biometry
During cataract surgery, after removing the damaged portion of the lens, an artificial lens according to the size of the patient’s eye is placed instead. Ultrasound biometry is used to measure the size of lenses to be placed in the eye.
Humphrey Visual Field Test
By the courtesy of the device that allows visual field test to be conducted, not only the center of the eye that focuses but also the area surrounding it can be measured. It is one of the most important detection tools for early diagnosis and monitoring of glaucoma disease in particular.
Auto Refractometer
It is the device used to measure refractive errors of the cornea. Refraction is defined as falling onto the retina after refraction of light beams coming onto the cornea. According to the extent of this refraction, myopia, hyperopia or astigmatism values of people are established.
The measurement conducted within seconds while looking at the picture inside the device produces both simple and very reliable values.
OCT ( Optical Coherence Tomography)
With OCT, the retina layer can be examined in thin sections and in particular glaucoma diagnosis and development can be followed. It gives important tips and information to physicians in the diagnosis of numerous retinal diseases.
Eye Angio (FFA and ICG)
FFA gives information about the retina layer and the structure of blood vessels. It is used to see vision center of the retina and its vascular structure. It is performed by intravenous injection of a special stain. It is displayed with a camera or a video camera.
While normal retina tomography shows the vessels on the retina, ICG technique is used to display vessels on choroid. In this method, a special medication is administered to the arm of the patient. When the medication reaches the eye by blood circulation, it dilates the vessels, and choroidal vessel structure becomes much more visible. By this test, it is possible to see the back side of the retina as well as determine any leakage or abnormal vasculature in choroidal vessels.
Corneal Topography
Corneal layer of the eye can be displayed to the finest detail by pentacam device. It also provides detailed information about corneal thickness.
Through these measurement and photographs, doctors can also determine if the patient’s eye is suitable for Laser treatment or whether there is any disease in the cornea.
Treatment Methods in Use
Corneal Transplant
The cornea is the transparent, curved front part of the eye that serves to focus the light and protect the eye from outside factors, plays a major role in visual function of the eye, and it is the most important refracting lens of the eye. Transparency of the cornea can be impaired by many diseases. These diseases can be congenital, genetic or microbial.
This surgery involves replacement of a corneal tissue deteriorated as a result of various disorders by a healthy corneal tissue. It is performed under general anesthesia.
Excimer Laser
Excimer Laser technology is the most common method applied to treat myopia, hyperopia and astigmatism worldwide. It is also utilized in the case of corneal surface irregularities after a disease or trauma, corneal spots, corneal transplants and for correcting eye defects developing after a transplant.
Laser Technology
Lasik
In this method, a thin flap is created on top surface of the cornea, then excimer laser is applied to the surface of the corneal tissue revealed under the flap and eye’s optical power is corrected.
This method is performed without any needle and suturing process under topical anesthesia. The patient doesn’t feel any pain during and after the operation.
ILasik
ILASIK is a totally personalized method.
In the first stage, personal vision profile is prepared by Wavescan technology. Wavescan system creates a 3D map of your visual defects. Then, with personalized treatment process, a personalized treatment is designed using digital information received from this map.
Then, corneal flap is created using Intralase without knife. Information reflected from the light sent to the eye is detected by a special camera. This information is sent to the laser and the treatment planned is applied.
PRK
It is a method that involves ablation of epithelium, which is a membrane tissue in top part of corneal layer, from the surface, followed by laser application to the resultant area to correct a person’s vision.
PTK (treatment of corneal stain / disorders)
As a result of certain diseases or eye injuries, spots may develop on the cornea. In this case, a laser application called PTK is performed on the eye in order to remove these spots. For PTK application, it is essential that the spots are superficial. If the spots are in deeper layers of the cornea PTK cannot be applied; a corneal transplant is required.
PTK is applied in the following cases:
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Eye injuries
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That the cornea catches an infection
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Hereditary corneal diseases
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Corneal spots remained on the eye after a surgery
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Corneal surface irregularities
Enucleation
Enucleation refers to removal of the whole eye that has become unable to serve because of a disease, injury, etc. In the operation, the muscles that move the eye are left intact. A ball(implant) is placed to compensate for the volume lost.
Evisceration
One of the techniques applied when the eye has to be removed is evisceration. Here, the hard, white layer comprising the outer part of the eye is left intact and diseased tissues inside the eye are removed.
Exenteration
It is a surgical method used to treat malignant eye tumors arising from eyelids, eye or orbita and spreading to surrounding tissues.
Ocular Prosthetics
Ocular prostheses are devices which are applied following a surgery such as enucleation or evisceration, in the case of congenital absence of eye and severely small eyes, and provide facial symmetry by imitating the other eye. It is primarily made of glass and acrylic (a type of plastic).