Cataract and Glaucoma disease of the eyeppt

Cataract and Glaucoma disease of the eye

1. Cataract and glaucoma
Dentistry students, 2015

2. Normal crystalline
lens
•A transparent, biconvex, avascular structure
•Function
To maintain its own clarity
To refract light
To provide accommodation
•Composition
•Capsule, lens epithelium, cortex,
nucleus
•A ring of zonular fibers, which insert in the
equatorial region, suspends the lens from
the ciliary body.

3. Cataract
•A progressive opacity or
clouding of the crystalline
lens.
•Reduces vision by preventing
light from properly passing to
retina
•The leading cause of visual
impairment and blindness

4. Etiological Classification of Cataract
•Congenital and developmental
•Age related (senile)
•Complicated (secondary) cataract
•Uveitis, pathological myopia, glaucoma, retinal
detachment
•Cataract associated with systemic diseases (pre-senile):
•Diabetes, Hypocalcemia, Hypoparathyroidism...
•Skin Diseases – Atopic Dermatitis, Ichthyosis

5. ...etiologic
•Traumatic Cataract :
- Trauma (Blunt / Perforating)
- Electric Shock
- Radiation
- Chemical injuries
•Drug induced cataract :
•Corticosteroids, Anticholinesterases,
Chlorpromazine, Choroquine, Amiodarone,
Cigarette smoker,

6. Symptoms of
cataract
•Painless, progressive, gradual diminution of vision
•Loss or marked diminution of vision in bright sunlight or bright
light beam
•Monocular diplopia or polyopia
•Glare
• Colored haloes around the light
- in cortical cataract due to irregular refractive index in different
parts of the lens.
•Reduced color perception

7. Normal
lens
Cataractous lens

8. •Signs of senile cataract
•Diminution of vision
•Lenticular opacity: grey or white
opacity in lens.
•Distant direct ophthalmoscopy
will reveal black shadow against
red background in cases of
immature cataract.

9. Management of
cataract
•Medical management
•Attempt to improve visual function in a patient
with cataract
- brighter illumination
- high spectacle adds for reading
- pupillary dilation (in small axial cataract)
- pharmacologic reversal of cataract = not yet!

10. ...management
Surgical management
The only available definitive
treatment of cataract till this
time!
•Indications for surgery
Visual improvement
= the most common
Medical
eg. Lens induced glaucoma,
diabetic retinopathy
Cosmetic.
= rare

11. Types of cataract
surgery
•Intracapsular cataract
extraction (ICCE)
- removal of the entire cataractous lens
along with the capsule
- the surgery of choice only in markedly
subluxated and dislocated lenses
- no capsular support for posterior
chamber intraocular lens (PC IOL)
- but IOL can be put in the anterior
chamber (AC IOL) if pupil is constricted
- high risk of complication
- largely replaced by extra-capsular
cataract extraction (ECCE) nowadays

12. types...
•Extracapsular Cataract Extraction
- 8-10 mm limbal incision
- circumferential incision of anterior
capsule
- extraction of the nucleus
- aspiration of the cortex leaving the
posterior capsule intact
- position of PC IOL in the capsular bag
- suturing of the limbal incision
Markedly improved visual recovery
and reduced complication than ICCE

13. Types...
•Manual Small Incision Cataract
Surgery (SICS)
- modification of limbal ECCE in
which smaller incision (6mm) is
done posterior to the limbus
= sutureless!
- the best technique for
developing countries!

14. Types...
•Automated cataract surgery
=Phacoemulsification
- ultrasonic power of a phaco machine is
used to crack (emulsify) the nucleus
content and aspirate
- uses a very small corneal / scleral
incision (upto 3.5mm) to insert the probes
- foldable IOL inserted through the small
incision
- state of the art technique most preferred
in developed countries
- significant advantage over manual
technique but expensive

15. Glaucoma
•A group of eye diseases
characterized by optic nerve
damage usually due to high
intraocular pressure
•Second commonest cause of
blindness in the world
• Impairment of aqueous
humor drainage raises
intraocular pressure

16. ...glaucoma
Classification of glaucoma
•By angle structure
- open angle
- closed angle
•By course
- acute
- chronic
•By etiology
- primary
- secondary
- congenital

17. ...glaucoma
•Symptoms and signs
•Primary open angle glaucoma is asymptomatic until it causes severe visual
field damage
•Acute angle closure glaucoma = red, painful eye
•Raised intraocular pressure (IOP)
- measured by tonometer
- normal IOP = 10-21 mmHg
•Optic disc changes
- pale and cupped discs
•Visual field loss
- manual or automated VF analyzer
•Enlargement of the eye in children

18. ...glaucoma
•Medical treatment
•The aim of glaucoma treatment is to reduce IOP
•beta blockers: e.g timolol, betaxolol
= reduce aqueous secretion
•Prostaglandin analogues: e.g latanoprost,
bimatoprost
= increase aqueous outflow
•Parasympathomimetic agents: e.g pilocarpine
= increase aqueous outflow
•Carbonic anhydrase inhibitors: eg. Acetazolamide
(systemic), dorzolamide (topical)
= reduce aqueous secretion

19. ...glaucoma
•Surgical treatment
• Peripheral Iridectomy: create a hole in the
iris to connect A/C and P/C = in angle closure
glaucoma
•Trabeculectomy: a guided bypass procedure
= create communication between anterior
chamber and sub conjunctival area
= aqueous drains through episcleral veins