🔹
CLINICAL PICTURE
SIMPLE MODERATE MYOPIA
Myopia is often discovered in children between 8 and 12 years old.The patient complains of:
- Blurred vision when looking at objects at the distance.
- Holding objects near to the face.
- Skewing of the eye to stimulate a pinhole effect.
- Poor performance in school.
- There might be eye strain, headache or eye squinting (uncommon).
- During the teenage years, when the body grows rapidly, myopia may become worse.
- It usually stabilizes after 18-21 years of age.
It is the optical condition in which the parallel rays of light entering the eye focus in front of the
🔹
- Diagnosis is made in the eye clinic where the vision is corrected fully to 6/6 with glasses.
HIGH MYOPIA
🔹
retina.
PREVALENCE
There has been an explosion in the prevalence of myopia around the world.
- Refractive error of more than 6 D or axial length of more than 26 mm.
- It usually appears earlier than simple myopia and progresses more rapidly and continues to
progress with age.
In 2020 →22.9%
In 2050→ 50%
- May reach to -25-30 D.
- Associated with higher risk of complications as RD, cataract and glaucoma. 🔹 PREVENTION OF MYOPIA
🔹
It is estimated to affect 40% of people in the USA. - When there are pathological changes in the eye it is called pathological or degenerative - Studies show that more time outdoors in natural light reduces a
🔹
RISK FACTORS myopia. child’s risk, so children should be encouraged to spend more time
It is a result of complex of genetic and environmental factors: PATHOLOGICAL MYOPIA outdoors.
- Family history - It is characterized by progressive anteroposterior elongation of the scleral envelope - Daily use of low-dose atropine eye drops slows the progression
- Lack of outdoor activities at young age or too much time indoors doing up-close work (as associated with a range of secondary ocular changes, that relate to mechanical stretching of of nearsightedness in children and teenagers.
MYOPIA (NEARSIGHTEDNESS) 🔹
reading and using personal computers and mobiles phones) increase the risk of myopia Ethnicity.
▪️ CLASSIFICATION
According to the cause:
the involved tissues.
- The changes involve the sclera, retina and choroid.
- There is no scientific evidence to suggest that eye exercises,
🔹
vitamins or pills can prevent or cure myopia.
TREATMENT OF MYOPIA
- Vision might not be corrected to 6/6 with glasses due to the pathological changes or due to
- Refractive (curvatural): the corneal curvature is high so the refractive power is too high for amblyopia. * Concave glasses or contact lenses.
the axial length of the eye. - There might be an apparent exodeviation. * Refractive surgeries:
- Axial: The axial length of the eye IS too high for the refractive power of the cornea. - It is a significant cause of legal blindness, with maculopathy as the most common cause of - Corneal refractive surgeries: LASIK- PRK - Intraocular refractive
▪️
- Index: lens induced.
According to severity:
* Simple myopia (glasses < - 3 D).
🔹
visual loss.
SPECIFIC SIGNS
surgeries
Phakic IOL (Iris fixated, PC- IOL)
Refractive lens exchange
-The eye is usually prominent (large globe), pupil dilated and AC is deep.Pale tessellated
- The eye is otherwise healthy. - Wearing glasses or contact lenses corrects vision to 6/6. fundus.
* Moderate myopia (3-6 D) - Peripapillary atrophy commonly as “temporal crescent''.- Subretinal coin hemorrhage
* High myopia /pathological (> -6 D): - Fuchs spot.
- Myopia continues to progress with age. - Staphyloma at the posterior pole.
🔺
- There might be pathological changes in the eye - Peripheral retinal thinning with lattice degeneration and retinal breaks and holes.
COMPLICATIONS:
🔹OPTICS: - Rhegmatogenous RD.
- Macular hole.
- Choroidal neovascularization (CNV).
- Types of lenses: convex (plus) lens, concave (minus) lens and plano lens.
- Cataract (posterior subcapsular or early nuclear sclerosis).
🔷EYE REFRACTION:
- The refractive power depends on the curvature and the refractive index.
- Glaucoma (POAG, PG, steroid responsiveness).
- Subluxation or dislocation of the lens.
Refractive media of the eye are the cornea, aqueous humor, lens and vitreous. INDEX MYOPIA:
• They are characterized by their high transparency and refractivity. - Nuclear sclerosis (second sight).
• They bend the entering light and focus it on the retina. - DM.
• The total refractive power of the eye is about 60 D.
• Diopters is the unit of the refractive power.
• Maximum refraction of light takes place at the cornea ( ̴42 D).
• The remaining power comes from the lens.
• The refractive ability of the cornea remains constant because its curvature does not change. HYPERMETROPIA (FARSIGHTEDNESS)
• The refractive ability of the lens can be adjusted by changing its curvature as needed for near or for far It is the optical condition in which the parallel rays of light entering the eye focus behind the
vision.
• The mean axial length of the eye is 24 mm. 🔹
retina with the eye totally at rest.
ETIOLOGICAL TYPES
- Refractive (curvatural)
🔹EMMETROPIA - Axial
🔹
It is the state where the light is focused on the retina properly (fovea) when no accommodation is used.
AMETROPIA
🔹
- Index
CLINICAL PICTURE
- Vision is blurred for distance and near.
🔹
Is the presence of a refractive error. -The patient may see distance clearly when he has strong accommodation
REFRACTIVE ERRORS - Visual acuity is reduced when the accommodation is not able to substitute the hyperopia
- Are imperfections in the refractive power of the eye, in which the light entering the eye does not focus - Headache and eye strain are prominent symptoms (especially after near work
- Early presbyopia.
properly on the retina resulting in blurred vision.
- In children, the patient uses excessive accommodation to see clearly which may stimulate
- They are: myopia, hyperopia and astigmatism.
- They are disorders not diseases.
HYPERMETROPIA 🔹
excessive convergence leading to convergent squint.
SIGNS (In axial Hyperopia):
- The eye might be small.
(FARSIGHTEDNESS) - Shallow AC.
- Narrow angle of the AC (prone to develop ACG).
- Accommodative convergent squint in children
- Optic disc: congested with blurred margins and absent physiological cup (pseudo disc
🔹
swelling).
CLINICAL TYPES:
Manifest Hyperopia: is the maximum hyperopia that can be corrected with convex lens when
REFRACTIVE ERRORS accommodation is active.
Total Hyperopia: is the amount of hyperopia when the whole accommodation is suspended (by
cycloplegic drops).Latent
🔹
Hyperopia: is the difference between the total and manifest hyperopia.
TREATMENT
- Convex glasses or contact lenses.
- Corneal refractive surgeries.
- Intraocular refractive surgeries.
It is a condition of physiological insufficiency of accommodation leading to a progressive fall of
near vision.It is not a refractive error.It is insufficiency of accommodation due to advancing age
🔹
(usually after 40 years).
Accommodation:
Is the ability of the eye to alert its focus so that clear images of both near and distant objects
can be formed on the retina.Since the cornea has a fixed shape, its focal length is also fixed.In
order to fix the light on the retina, the lens must change its shape.The shape of the lens can be
altered by suspensory ligaments and the ciliary muscles.Thickening and thinning of the lens
🔹
adjusts the focus.
ETIOLOGY
- Hardening of the lens with age (sclerosis of the lens fibers).
- Weakness of ciliary muscles and suspensory ligaments.
PRESBYOPIA
🔹
- Decrease of the elasticity and steepening of the lens capsule.
SYMPTOMS
-Blurring of vision for near.
-The patient places the reading matter farther than previously.
- Eye strain and headache (common).
- The symptoms depend on the pre-existing error of refraction:
by fatema okoff * symptoms appear early in persons with hyperopia.
🔹
* symptoms appear later in persons with myopia.
TREATMENT
It is corrected with convex lenses added to the distance correcting glasses.If the patient has pre-
existing refractive error, he may use bifocal or progressive glasses to correct both distance and
near vision within one frame.
ANISOMETROPIA
It is the condition where the refractive state of both eyes is different by more than 2.50 D.This
difference causes difference in the image size in both eyes called aniseikonia.It also leads to
🔹
amblyopia in children as it interrupts fusion of aniseikonic images of both eyes.
TREATMENT
It must be corrected in early childhood.If the refractive difference is less than 4 D, full correction
with glasses is done.If the refractive difference is more than 4D: - Contact lens. - Refractive
surgery.
APHAKIA
Is the absence of the crystalline lens.It causes anisometropia when the aphakia is unilateral as
post cataract extraction or post trauma.It is treated with spectacles, contact lenses or
intraocular lens implantation.Intra-ocular lens implantation.
PSEUDOPHAKIA
Is the presence of an artificial IOL.
REFRACTION STEPS
- Autorefractometer.
- Vision examination on Snellen chart first unaided and then with corrective glasses.
- Children and young adults should be examined after cycloplegia to abolish accommodation,
with the use of the retinoscope.
- Duochrome test is used after finishing refraction to avoid over
-correction or under-correction.
CLINICAL PICTURE
SIMPLE MODERATE MYOPIA
Myopia is often discovered in children between 8 and 12 years old.The patient complains of:
- Blurred vision when looking at objects at the distance.
- Holding objects near to the face.
- Skewing of the eye to stimulate a pinhole effect.
- Poor performance in school.
- There might be eye strain, headache or eye squinting (uncommon).
- During the teenage years, when the body grows rapidly, myopia may become worse.
- It usually stabilizes after 18-21 years of age.
It is the optical condition in which the parallel rays of light entering the eye focus in front of the
🔹
- Diagnosis is made in the eye clinic where the vision is corrected fully to 6/6 with glasses.
HIGH MYOPIA
🔹
retina.
PREVALENCE
There has been an explosion in the prevalence of myopia around the world.
- Refractive error of more than 6 D or axial length of more than 26 mm.
- It usually appears earlier than simple myopia and progresses more rapidly and continues to
progress with age.
In 2020 →22.9%
In 2050→ 50%
- May reach to -25-30 D.
- Associated with higher risk of complications as RD, cataract and glaucoma. 🔹 PREVENTION OF MYOPIA
🔹
It is estimated to affect 40% of people in the USA. - When there are pathological changes in the eye it is called pathological or degenerative - Studies show that more time outdoors in natural light reduces a
🔹
RISK FACTORS myopia. child’s risk, so children should be encouraged to spend more time
It is a result of complex of genetic and environmental factors: PATHOLOGICAL MYOPIA outdoors.
- Family history - It is characterized by progressive anteroposterior elongation of the scleral envelope - Daily use of low-dose atropine eye drops slows the progression
- Lack of outdoor activities at young age or too much time indoors doing up-close work (as associated with a range of secondary ocular changes, that relate to mechanical stretching of of nearsightedness in children and teenagers.
MYOPIA (NEARSIGHTEDNESS) 🔹
reading and using personal computers and mobiles phones) increase the risk of myopia Ethnicity.
▪️ CLASSIFICATION
According to the cause:
the involved tissues.
- The changes involve the sclera, retina and choroid.
- There is no scientific evidence to suggest that eye exercises,
🔹
vitamins or pills can prevent or cure myopia.
TREATMENT OF MYOPIA
- Vision might not be corrected to 6/6 with glasses due to the pathological changes or due to
- Refractive (curvatural): the corneal curvature is high so the refractive power is too high for amblyopia. * Concave glasses or contact lenses.
the axial length of the eye. - There might be an apparent exodeviation. * Refractive surgeries:
- Axial: The axial length of the eye IS too high for the refractive power of the cornea. - It is a significant cause of legal blindness, with maculopathy as the most common cause of - Corneal refractive surgeries: LASIK- PRK - Intraocular refractive
▪️
- Index: lens induced.
According to severity:
* Simple myopia (glasses < - 3 D).
🔹
visual loss.
SPECIFIC SIGNS
surgeries
Phakic IOL (Iris fixated, PC- IOL)
Refractive lens exchange
-The eye is usually prominent (large globe), pupil dilated and AC is deep.Pale tessellated
- The eye is otherwise healthy. - Wearing glasses or contact lenses corrects vision to 6/6. fundus.
* Moderate myopia (3-6 D) - Peripapillary atrophy commonly as “temporal crescent''.- Subretinal coin hemorrhage
* High myopia /pathological (> -6 D): - Fuchs spot.
- Myopia continues to progress with age. - Staphyloma at the posterior pole.
🔺
- There might be pathological changes in the eye - Peripheral retinal thinning with lattice degeneration and retinal breaks and holes.
COMPLICATIONS:
🔹OPTICS: - Rhegmatogenous RD.
- Macular hole.
- Choroidal neovascularization (CNV).
- Types of lenses: convex (plus) lens, concave (minus) lens and plano lens.
- Cataract (posterior subcapsular or early nuclear sclerosis).
🔷EYE REFRACTION:
- The refractive power depends on the curvature and the refractive index.
- Glaucoma (POAG, PG, steroid responsiveness).
- Subluxation or dislocation of the lens.
Refractive media of the eye are the cornea, aqueous humor, lens and vitreous. INDEX MYOPIA:
• They are characterized by their high transparency and refractivity. - Nuclear sclerosis (second sight).
• They bend the entering light and focus it on the retina. - DM.
• The total refractive power of the eye is about 60 D.
• Diopters is the unit of the refractive power.
• Maximum refraction of light takes place at the cornea ( ̴42 D).
• The remaining power comes from the lens.
• The refractive ability of the cornea remains constant because its curvature does not change. HYPERMETROPIA (FARSIGHTEDNESS)
• The refractive ability of the lens can be adjusted by changing its curvature as needed for near or for far It is the optical condition in which the parallel rays of light entering the eye focus behind the
vision.
• The mean axial length of the eye is 24 mm. 🔹
retina with the eye totally at rest.
ETIOLOGICAL TYPES
- Refractive (curvatural)
🔹EMMETROPIA - Axial
🔹
It is the state where the light is focused on the retina properly (fovea) when no accommodation is used.
AMETROPIA
🔹
- Index
CLINICAL PICTURE
- Vision is blurred for distance and near.
🔹
Is the presence of a refractive error. -The patient may see distance clearly when he has strong accommodation
REFRACTIVE ERRORS - Visual acuity is reduced when the accommodation is not able to substitute the hyperopia
- Are imperfections in the refractive power of the eye, in which the light entering the eye does not focus - Headache and eye strain are prominent symptoms (especially after near work
- Early presbyopia.
properly on the retina resulting in blurred vision.
- In children, the patient uses excessive accommodation to see clearly which may stimulate
- They are: myopia, hyperopia and astigmatism.
- They are disorders not diseases.
HYPERMETROPIA 🔹
excessive convergence leading to convergent squint.
SIGNS (In axial Hyperopia):
- The eye might be small.
(FARSIGHTEDNESS) - Shallow AC.
- Narrow angle of the AC (prone to develop ACG).
- Accommodative convergent squint in children
- Optic disc: congested with blurred margins and absent physiological cup (pseudo disc
🔹
swelling).
CLINICAL TYPES:
Manifest Hyperopia: is the maximum hyperopia that can be corrected with convex lens when
REFRACTIVE ERRORS accommodation is active.
Total Hyperopia: is the amount of hyperopia when the whole accommodation is suspended (by
cycloplegic drops).Latent
🔹
Hyperopia: is the difference between the total and manifest hyperopia.
TREATMENT
- Convex glasses or contact lenses.
- Corneal refractive surgeries.
- Intraocular refractive surgeries.
It is a condition of physiological insufficiency of accommodation leading to a progressive fall of
near vision.It is not a refractive error.It is insufficiency of accommodation due to advancing age
🔹
(usually after 40 years).
Accommodation:
Is the ability of the eye to alert its focus so that clear images of both near and distant objects
can be formed on the retina.Since the cornea has a fixed shape, its focal length is also fixed.In
order to fix the light on the retina, the lens must change its shape.The shape of the lens can be
altered by suspensory ligaments and the ciliary muscles.Thickening and thinning of the lens
🔹
adjusts the focus.
ETIOLOGY
- Hardening of the lens with age (sclerosis of the lens fibers).
- Weakness of ciliary muscles and suspensory ligaments.
PRESBYOPIA
🔹
- Decrease of the elasticity and steepening of the lens capsule.
SYMPTOMS
-Blurring of vision for near.
-The patient places the reading matter farther than previously.
- Eye strain and headache (common).
- The symptoms depend on the pre-existing error of refraction:
by fatema okoff * symptoms appear early in persons with hyperopia.
🔹
* symptoms appear later in persons with myopia.
TREATMENT
It is corrected with convex lenses added to the distance correcting glasses.If the patient has pre-
existing refractive error, he may use bifocal or progressive glasses to correct both distance and
near vision within one frame.
ANISOMETROPIA
It is the condition where the refractive state of both eyes is different by more than 2.50 D.This
difference causes difference in the image size in both eyes called aniseikonia.It also leads to
🔹
amblyopia in children as it interrupts fusion of aniseikonic images of both eyes.
TREATMENT
It must be corrected in early childhood.If the refractive difference is less than 4 D, full correction
with glasses is done.If the refractive difference is more than 4D: - Contact lens. - Refractive
surgery.
APHAKIA
Is the absence of the crystalline lens.It causes anisometropia when the aphakia is unilateral as
post cataract extraction or post trauma.It is treated with spectacles, contact lenses or
intraocular lens implantation.Intra-ocular lens implantation.
PSEUDOPHAKIA
Is the presence of an artificial IOL.
REFRACTION STEPS
- Autorefractometer.
- Vision examination on Snellen chart first unaided and then with corrective glasses.
- Children and young adults should be examined after cycloplegia to abolish accommodation,
with the use of the retinoscope.
- Duochrome test is used after finishing refraction to avoid over
-correction or under-correction.
