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The eye is one of the most important vital organs in the human body, enabling the individual to interact with the outside world through vision.Shared environmental and genetic factors In some cases, diseases occur as a result of the interaction of genes with environmental factors, such as exposure to ultraviolet rays, which may increase the likelihood of diseases such as hereditary macular degeneration.Genetic diseases that affect the eye vary in terms of their impact and symptoms, and include, for example, retinitis pigmentosa, congenital retinopathy, Stargadt disease, age-related macular degeneration of a genetic basis, and corneal disorders and keratoconus.Genetic transmission patterns Genetic eye diseases are usually transmitted based on the inheritance pattern, including: Dominant inheritance: It is sufficient for an individual to carry one copy of the mutated gene to develop the disease, such as some forms of hereditary glaucoma.Recessive inheritance: The disease only appears if an individual inherits two mutated copies of the gene, one from each parent, as is the case with retinopathy pigmentosa.Sex-linked inheritance: transmitted through the sex chromosome (X or Y), and diseases linked to the X chromosome are often more common in males, such as sex-linked retinal dystrophy.Consanguineous marriage In some societies, consanguineous marriage increases the risk of transmitting genetic diseases of the eye, as the chance of meeting similar recessive genes carrying disease-causing mutations increases.Genetic diseases of the eye are health issues that combine medical challenges with genetic complexity, as they result from mutations in the genetic material (DNA) that are passed from one generation to the next or appear randomly as a result of acquired genetic changes.These diseases not only affect vision, but also have profound psychological and social effects on those affected, making dealing with them require great efforts at the individual and societal levels.Changes in genes responsible for eye functions Some genes are responsible for producing proteins necessary for the health of the retina, optic nerve, or lens.However, this delicate organ may be susceptible to many diseases that impede its basic function, including those resulting from genetic factors.This knowledge has provided promising opportunities for developing early diagnosis methods.It has also opened new horizons for treating genetic eye diseases through innovative techniques such as gene therapy, stem cells, and biotransplantation.These diseases are classified based on their genetic transmission pattern, as they can be: 1- Dominant genetic diseases: transmitted when there is only one copy of the affected gene.3- Sex-linked: transmitted through the sex chromosomes, and often affect males more than females .Genetic mutations Genetic mutations occur when there is a permanent change in the DNA sequence, which leads to the production of abnormal proteins or the failure to produce proteins necessary for the proper function of the eye.Some of these mutations are inherited from parents, while others may occur spontaneously during fetal development.Any change in them may lead to diseases such as macular degeneration or hereditary cataracts.Changes in genes responsible for the eye's response to light, such as genes associated with rod and cone cells in the retina, may cause disturbances in night vision or color vision.With developments in the field of genetics and medicine, it has become possible to accurately identify the genetic causes of these diseases.Causes of Genetic Eye Diseases The causes of genetic eye diseases are due to changes or mutations in the genetic material (DNA) that affect the genes responsible for the normal development and functions of the eye.2- Recessive genetic diseases: appear only when there are two copies of the affected gene (one from each parent).The main causes of these diseases include the following : 1.2.3.4.5.6.

The eye is one of the most important vital organs in the human body,
enabling the individual to interact with the outside world through vision.
However, this delicate organ may be susceptible to many diseases that
impede its basic function, including those resulting from genetic factors.
Genetic diseases of the eye are health issues that combine medical
challenges with genetic complexity, as they result from mutations in the
genetic material (DNA) that are passed from one generation to the next or
appear randomly as a result of acquired genetic changes.
Genetic diseases that affect the eye vary in terms of their impact and
symptoms, and include, for example, retinitis pigmentosa, congenital
retinopathy, Stargadt disease, age-related macular degeneration of a
genetic basis, and corneal disorders and keratoconus. These diseases not
only affect vision, but also have profound psychological and social effects
on those affected, making dealing with them require great efforts at the
individual and societal levels.
With developments in the field of genetics and medicine, it has become
possible to accurately identify the genetic causes of these diseases. This
knowledge has provided promising opportunities for developing early
diagnosis methods. It has also opened new horizons for treating genetic
eye diseases through innovative techniques such as gene therapy, stem
cells, and biotransplantation.
These diseases are classified based on their genetic transmission pattern,
as they can be:
1- Dominant genetic diseases: transmitted when there is only one copy of
the affected gene.
2- Recessive genetic diseases: appear only when there are two copies of
the affected gene (one from each parent).
3- Sex-linked: transmitted through the sex chromosomes, and often affect
males more than females
.
Causes of Genetic Eye Diseases
The causes of genetic eye diseases are due to changes or mutations in the
genetic material (DNA) that affect the genes responsible for the normal
development and functions of the eye. The main causes of these diseases
include the following :

1. Genetic mutations
   Genetic mutations occur when there is a permanent change in the DNA
   sequence, which leads to the production of abnormal proteins or the
   failure to produce proteins necessary for the proper function of the eye.
   Some of these mutations are inherited from parents, while others may
   occur spontaneously during fetal development.


2. Genetic transmission patterns
   Genetic eye diseases are usually transmitted based on the inheritance
   pattern, including:
   Dominant inheritance: It is sufficient for an individual to carry one copy of
   the mutated gene to develop the disease, such as some forms of hereditary
   glaucoma.
   Recessive inheritance: The disease only appears if an individual inherits
   two mutated copies of the gene, one from each parent, as is the case with
   retinopathy pigmentosa.
   Sex-linked inheritance: transmitted through the sex chromosome (X or Y),
   and diseases linked to the X chromosome are often more common in
   males, such as sex-linked retinal dystrophy.


3. Changes in genes responsible for eye functions
   Some genes are responsible for producing proteins necessary for the
   health of the retina, optic nerve, or lens. Any change in them may lead to
   diseases such as macular degeneration or hereditary cataracts.
   Changes in genes responsible for the eye's response to light, such as genes
   associated with rod and cone cells in the retina, may cause disturbances in
   night vision or color vision.


4. Shared environmental and genetic factors
   In some cases, diseases occur as a result of the interaction of genes with
   environmental factors, such as exposure to ultraviolet rays, which may increase the likelihood of diseases such as hereditary macular
   degeneration.


5. Consanguineous marriage
   In some societies, consanguineous marriage increases the risk of
   transmitting genetic diseases of the eye, as the chance of meeting similar
   recessive genes carrying disease-causing mutations increases.


6. New or random mutations
   Sometimes, genetic eye diseases may appear due to new mutations that
   occur for the first time in a child without a family history of the disease,
   known as “spontaneous mutations”.
   Conclusion
   The causes of genetic eye diseases are multiple and complex, and are often
   the result of a combination of genetic and environmental factors.
   Understanding these causes helps develop effective strategies for early
   diagnosis and appropriate treatment to reduce the impact of these
   diseases on the lives of those affected.
   Symptoms of genetic eye diseases
   The symptoms of genetic eye diseases vary depending on the type of
   disease, the genes affected, and the severity of the condition. Symptoms
   may appear early in life or develop gradually over time... The most
   important symptoms associated with genetic eye diseases:


7. Poor vision
   Difficulty seeing near or far.
   Gradual or sudden decrease in visual acuity.


8. Night vision loss
   Difficulty seeing in low light or at night, which is a common symptom in
   diseases such as retinopathy pigmentosa.


9. Visual field disturbances
   The appearance of dark or empty spots in the visual field.Loss of side or peripheral vision.


10. Sensitivity to light (photophobia)
    Feeling discomfort or pain when exposed to bright light, which is a
    common symptom in some genetic corneal and retinal diseases.


11. Problems with color vision
    Difficulty distinguishing colors, especially red and green or blue and
    yellow, as in hereditary color blindness.


12. Eye redness or irritation
    Chronic redness or irritation of the eye resulting from genetic diseases
    affecting the surface of the eye or tear ducts.


13. Disorders of the structure of the eye
    Change in the shape of the cornea (as in keratoconus).
    Smaller or larger than normal eye size, as in some forms of congenital
    glaucoma.


14. Squint or eye twitching (nystagmus)
    Squint or involuntary twitching of the eye resulting from disorders of the
    visual system.


15. Appearance of spots or opacities in the eye
    Opacity in the lens (hereditary cataract), which appears as a white spot
    inside the eye.


16. Gradual loss of complete vision
    Some genetic diseases, such as optic atrophy or retinopathy pigmentosa,
    can lead to complete loss of vision over time.


17. Eye problems present from birth
    Including congenital defects in the iris or lens of the eye.
    Timing and importance of diagnosis Some symptoms appear from birth or in early childhood, while others may
    develop gradually and appear in adulthood. Early diagnosis, especially in
    diseases of a genetic nature, is very important to reduce the impact of
    symptoms and preserve what remains of vision with appropriate
    treatments.
    The most important methods for diagnosing genetic eye diseases
    Diagnosing genetic eye diseases depends on a set of basic tests that are
    used to determine the type of disease, its effects, and the mechanism of its
    genetic transmission. The following are the most important and accurate
    diagnostic methods:


18. Comprehensive clinical examination
    Visual Acuity Examination: To determine the extent of vision impairment,
    which is the first step in evaluating the condition.
    Tonometry: To detect hereditary glaucoma.
    Fundoscopy: Using a fundus scope to monitor any changes in the retina or
    optic nerve.
    Corneal examination: To diagnose diseases such as keratoconus.
    2- Advanced eye imaging
    Optical coherence tomography (OCT):
    It is considered the most important in detecting retinal disorders such as
    pigmentary retinopathy.
    It provides accurate images of the layers of the retina to identify changes
    or damage.
    Fluorescein angiography:
    To detect problems with blood vessels in the retina. 3_Functional tests:
    Electroretinography (ERG):
    It is used to evaluate the function of the retina and its response to light,
    and is important for diagnosing genetic diseases such as retinopathy
    pigmentosa.
    Optical electroencephalography (VEP):
    It evaluates the response of the optic nerve to visual stimuli, and is used in
    diagnosing optic nerve atrophy.
    4_Genetic tests: Genetic tests are the most important modern diagnostic methods for
    genetic eye diseases:
    Targeted gene analysis: to detect specific mutations associated with the
    disease.
    Whole exome sequencing (WES): to identify mutations in all proteincoding genes.
    Whole genome sequencing (WGS): to detect comprehensive genetic
    changes.
    Familial mutation tests: to detect inherited mutations within the family.
    Importance:
    Advanced genetic tests and retinal tomography (OCT) are among the most
    important diagnostic methods for genetic eye diseases, as they enable
    doctors to accurately determine the root cause and develop an appropriate
    treatment or rehabilitationplan