Diseases, Eye Disease, Diseases of Eyes, eyes Related Diseases, Eyes problems, Eyes infections, Eyes Issues

1. Diseases of eye
By ; Dr. Bushra Ahmad

2. GLUCOMA;
Group of diseases characterized by increase intraocular pressure which causes damage
of optic nerve resulting in blindness.
CAUSES;
• drainage of aqueous humor thru trabecula is blocked
• Inc. intraocular pressure
• rises above 60 mmHg
• optic nerve fibers at optic disk are compressed
• initially Dec. visual field
• eventually blindness

3. Early treatment eyes protected
otherwise lost
Infants Infantile Glaucoma
Child hood Juvenile Glaucoma

4. Types ;
Two types
• Primary opera angle glaucoma ( POAG )
• Primary angle closure glaucoma ( PACG )

5. POAG ;
• Common 80 %
• No visible obstruction
• Cause not known
• Gradual Inc. pressure

6. PACG ;
• Visible obstruction of drainage
• Iris is pushed against corners preventing drainage of aq.
Humor
• Pressure rises over period of few hours
CAUSES ;
• Diabetes
• Inflammation
• Injury
• Drugs

7. SYMPTOMS ;
POAG :
• Silent chronic disease without any early symptoms
• Later heaviness around eyeball
• Headache
• Visual field reduction
EARLY SYMPTOMS ;
• Pain in eye brows
• Headache
• Nausea
• Blurred vision

8. TREATMENT ;
No cure but prevent further damage of optic nerve
• Eye drops or Medicine alone
• Laser Treatment
• Surgery

9. CATARACT ;
Opacity or cloudiness in natural lens of eye.
• Major cause of blindness worldwide
• Develop in old age after 55 to 60 years
• Lens cloudy light rays can’t pass vision blurred
• Lens in sealed capsule old cells die & accumulate within
capsule accumulation of fluid + degeneration of
pretension lens fiber

10. CAUSES ;
• Eye injuries
• Previous eye surgery
• Diabetes
• Drugs
• Sunlight
• Alcoholism
• Large quantity of salt

11. SYMPTOMS ;
• Glared
• Blurred vision
• Poor night vision
• Diplopia in affected eye
• Fading of colors

12. TREATMENT ;
• Only surgery
Natural lens replaced with permanent plastic IOL implant
2 Methods
1. Extra capsular extraction cold technique
2. Phacoemulsification

13. NIGHT BLINDNESS ;
Loss of vision when light in the environment becomes dim.
CAUSES ;
• Deficiency of vit. A
Deficiency of vit. A is due to
• Diet
• Dec. absorption of vit. A from intestine
TREATMENT ;
• Vit. A before visual receptors start degenerating

14. EFFECTS OF LESION AT DIFFERENT
LEVELS OF :
ANOPIA ;
loss of vision in one visual field is known as anopia.
HEMIANOPIA ;
loss of vision in one half of visual field is known as hemianopia.
TYPES OF HEMIANOPIA ;
1. Homonymous hemianopia
2. Heteronymous hemianopia

15. EFFECT OF LESION OF OPTIC NERVE;
Lesion in one optic nerve will cause total blindness or
anopia.
CAUSE ;
• Increased intracranial pressure

16. EFFECT OF LESION OF OPTIC
CHIASMA ;
Pressure on uncrossed lateral fibers by aneurgsmal dilation of
carotid artery causes blindness in temporal part of retina of
same side.
If lateral fibers of both sides are affected the vision is lost in
nasal half of both visual fields causing biursal hemianopia.
Compression of nasal fibers i.e. crossed fibers by pituitary tumor
causes bitemporal hemianopia

17. EFFECT OF LESION OF OPTIC TRACT , LAT.
GENICULATE BODY & OPTIC RADIATION;
Lesion of optic tract or lat. Geniculate body or optic
radiation causes homonymous hemianopia.

18. EFFECT OF LESION OF VISUAL CORTEX ;
Lesion of upper or lower part of visual cortex leads to inferior
or superior homonymous hemianopia
MACULAR SPARING ;
The phenomena in which the muscular vision is retained
(unaffected) in conditions of hemianopia is called macular
sparing.
Only the bilateral lesion of visual cortex causes total blindness.

19. ARGYLL ROBERTSON PUPIL ;
Clinical condition in which the light reflex is lost
but the accommodation reflex is present. It is
common in tertiary syphilis. It also occur bcz of
lesion in Edinger Westphol nucleus , diabetes &
alcoholic neuropath.

20. HORNER SYNDROME ;
It is eye disorder caused by damage to cervical sympathetic nerve. It is
also called Bernard Horner Syndrome, Claude Bernard Storner
Syndrome or oculosympathetic palsy.
SYMPTOMS ;
• Ptosis
• Swelling of lower eyelid
• Meiosis
• Enophthalamus
• Absence of sweating on affected side of face

21. PRESBYOPIA ;
In old age the amplitude of accommodation is
decreased & the near point is a way from the eye. This
condition is called presbyopia.

22. COLOR BLINDNESS ;
CAUSES ;
• Trauma
• Chronic diseases
• Drugs
• Toxins
• Alcoholism
• Aging

23. CLASSIFICATION OF COLOR
BLINDNESS ;
Based on Young Helmholtz Trichromatic Theory , color blindness is divided
into 3 types
Monochromatism Dichromatism Trichromatism
• rod monochromatism protanopia protanomaly
• cone chromatism deuteranopia deuteranomaly
tritanopia tritanomly

24. FIELD OF VISION ;
Part of external world seen by one eye when it is fixed in one
direction is called field of vision or visual field of eye.
Binocular Vision;
Vision in which both eyes are used together.
Monocular Vision;
Vision in which each eye is used separately.

25. DIVISION OF VISUAL FIELD ;
• Temporal field (extend up to about 100 )
• Nasal field (extends up to 60 )
• Upper field (extends up to 60 )
• Lower field (extends up to 75 )

26. CORRESPONDING RETINAL POINTS;
These are the areas in retina of both eyes on which the light
rays from the object falls. It occurs in Binocular vision.
The two images developed on retina of both eyes are fused into
single sensation so we see the objects with single image.

27. DIPLOPIA ;(Means Double Vision)
While looking at an object if the eyeballs are directed in
such a way that the light rays from object do not fall
upon the corresponding point on the retina of both
eyes a double vision occurs i.e. one single object is seen
as two

28. CAUSES;
• Paralysis
• Myasthenia gravis
• Alcoholic intoxication
• Lesion in 3, 4, & 5 cranial nerves, oculomotor
nucleus, red nucleus also result in diplopia.

29. EXPERIMENTAL DIPLOPIA;
Diplopia can be produced experimentally by following
methods ,
1. Applying pressure from outer side of one eye.
2. By holding an object like pen or pencil vertically in
front of face at about 5cm from roof of nose.

30. BLIND SPOT ;
Small area of retina where visual receptors are absent.
VISUAL FIELD & RETINA ;
Light rays from different halves of each visual field do
not fall on same halves of the retina. Light rays from
temporal part of visual field falls on half of retina of
that eye.

31. MAPPING OF VISUAL FIELD ;
The shape & extent of visual field is mapped out
by means of an instrument called Goldman
Perimeter & this technique is called perimetery.