Download Aetiology of Cataract

Cataract
By
Col Rana Intisarul Haq
MCPS, FCPS (AFIO)
Lens
The lens is a biconvex
structure located directly
behind the posterior
chamber and pupil
It is the lesser of the two
refractive elements in the
dioptric system
The equatorial diameter in
adult is about 9-10 mm
The anteroposterior width of
the lens is about 6 mm
The lens has certain unusual
features. It lacks innervation
and is avascular.
Detail view of the anatomy
of the eye
cataract
Definition

Any congenital or acquired opacity in the
lens capsule or substance of the lens ,
irrespective of the effects on vision is
called cataract.
Classification of
Cataract
According to Age
According to Morphology
According to Etiology
According to maturity
Congenital and acquired
Age Related Senile
Cataract
Age related cataract is universal in
persons over 70 years of age. Both
sexes are involved equally.
There is considerable genetic influence.
Average age of onset of cataract is
approximately 10 years earlier in
tropical countries.
6
Age Related Cataracts senile
Presenile Cataracts
Diabetes Mellitus
Myotonic Dystrophy
Atopic Dermatitis
Neurofibromatosis-2
Traumatic Cataract
Direct Penetrating Injury
Concussion
Electric Shock & Lightening
Ionizing Radiation
Toxic Cataracts
Steroids
Chlorpromazine
Miotics
Busulphan
Amiodarone
Gold
Secondary Cataracts
Ch Ant Uveitis
Ac Congestive Glaucoma
High Myopia
Hereditary Fundus Dystrophy
According to
Morphology
Posterior Subcapsular Cataract
Ant Subcapsualr Cataract
Nuclear Cataract
Cortical Cataract
Mature Cataract
THE LENS
CATARACT
F This diagram illustrates the different morphological characteristics of
cataract together with their depth and location within the lens. The
following illustrations demonstrate clinical examples of these
anatomical entities.
CLASSIFICATION ON
BASIS OF MATURITY
IMMATURE CATARACT
MATURE
HYPERMATURE
MORGAGNIAN
Causes
Hereditary
Age
DM
Steroids
UV Rays
Poor Nutrition
Smoking
Epidemiology
Cataract surgery is the most commonly
performed surgery in elderly patient
Any Age
Two peaks
<10 Years
>65 Years
Pathology
Depends on type of Cataract
Early Changes – tiny areas of
liquefaction called morgagnian
degeneration seen as cortical spokes
Progress to involve entire cortex
Later on homogeneous appearance
Etiopathogenesis of
Cataract
Caused by degeneration and
opacification of existing lens fibres,
formation of aberrant fibres or
deposition of other material in their
place.
Loss of transparency occurs because of
abnormalities of lens protein and
consequent disorganization of the lens
fibres
15
Etiopathogenesis of
Cataract
Any factor that disturbs the critical intra and
extra cellular equilibrium of water and
electrolytes or deranges the colloid system
within the fibres causing opacification.
Fibrous metaplasia of lens fibres occurs in
complicated cataract.
Epithelial cell necrosis occurring in angle
closure glaucoma leads to focal opacification
of the lens epithelium (Glaucomflecken)
16
Etiopathogenesis of
Cataract
Abnormal products of metabolism,
drugs or metals can be deposited in
storage diseases (Febry), metabolic
diseases (Wilson) and toxic reactions
(Siderosis)
17
Nuclear Cataract
Mature Cataract
Hypermature Cataract
Traumatic Cataract(Penetrating Trauma)
Vossius Ring
PSC in Atopic Dermatitis
Congenital Cataract
Stellate PSC in Myotonic Dystrophy
Shield Anterior Subcapsular Cataract
(Atopic Dermatitis)
PSC in Atopic Dermatitis
Progression of Steroidinduced Cataract
Anterior Subcapsular Opacities
(Ch Ant Uveitis)
Adv Cataract &
Posterior Synechiae
(Ch Ant Uveitis)
Symptoms of Cataract
1. Blurring of vision
2. Frequent change of glasses due to
rapid change in refractive index of the
lens
3. Painless, progressive, gradual
diminution of vision due to reduction in
transparency of the lens
4. Second sight or myopic shift in case of
nuclear cataract causing index myopia,
improving near vision.
31
Symptoms of Cataract
5. Loss or marked diminution of vision in
bright sunlight or bright light beam in
central posterior sub-capsular cataract.
6. Monocular diplopia or polyopia in
presence of cortical spoke opacities
7. Glare in posterior sub-capsular cortical
cataract due to increased scattering of
light
32
Symptoms of Cataract
8. Colored haloes around the light as
seen in cortical cataract due to irregular
refractive index in different parts of the
lens.
9. Color shift , reds are accentuated
10. Visual field loss, generalized reduction
in sensitivity due to loss of transparency
33
Signs of senile cataract
Positive findings
1. Diminution of vision
2. Anterior chamber is shallow in cases
of intumescent cataract and deep in
cases of hypermature (shrunken)
cataract
3. Tremulousness of iris in cases of
hypermature shrunken cataract
34
Signs of senile cataract
4. Lenticular opacity , grey or white
opacity in lens. Iris shadow in immature
cataract. No iris shadow in mature
cataract
5. Morgagnian Cataract- is characterized
by liquefied cortex, which is milky and
nucleus is seen as brown mass, seen
as semicircular line, altering its position
with change in position of head
35
Signs of senile cataract
6. Distant direct ophthalmoscopy will
reveal black shadow against red
background in cases of immature
cataract.
36
Thank you
Management of
Cataract
HISTORY
Age of Onset
Decreased Vision



Painless,
effecting daily routine? If the patient is bothered
about his decreased vision.
Trauma
Any Ophthalmological Problems
Drugs Intake
Exposure to Radiations
Systemic Diseases

Skin disease, joint pains, etc.
Family History
Examination
GPE
SYSTEMIC EXAMINATION
OCULAR EXAMINATION
VISUAL ACUITY
 ADNEXA
 CORNEA
 ANTERIOR CHAMBER
 PUPIL
 VITROUS
 RETINA

Investigations
Blood Glucose
ECG
Chest x-rays (PA view)
Blood Complete Picture
Any specific relevant investigation
(if indicated)
Indication for Surgery
Visual Improvement

When the patient is bothered.
Medical Indications

When cataract is adversely affecting the
health of the eye e.g.:
Phacolytic Glaucoma
 Intumescent Cataract
 Diabetic Retinopathy

Cosmetic Indications

To restore black pupil
Optimal Post Op
Refraction
If monocular correction is reqd. e.g.
in contralateral dense or amblyopia
best post op refraction is -1DS.
If binocular correction is reqd
difference between the two eyes should
not be more than 3DS.
SURGICAL TECHNIQUES
ICCE
ECCE
ECCE with posterior chamber IOL
implant
Phacoemulcification
ECCE
IOL Implantation
Phacoemulcification
Operative Complications
Complications of Local Anaesthesia
 Retrobulbar Hemorrhage
 Perforation of the globe, optic nerve
or sheath
Operative Complications:
 Bridle Suture Perforation of the globe
 Stripping of Descemet’s Membrane
 Damage to ciliary body
Operative
Complications(Contd)
Rupture of the Posterior Capsule

Capsular Rupture without Vitreous Loss
Small Tear
 Large Tear or Zonular Tear


Capsular Rupture with Vitreous Loss

vitrectomy
Posterior Loss of Lens Fragments
Small Fragments
 Large Fragments

Nuclear Material in Vitreous
Operative
Complications(Contd)
Suprachoroidal Hemorrhage

Source


long or short ciliary artery
Contributing Factors
sudden in IOP
 coughing
 Valsalva Manoeuvre
 Vitreous Loss
 Sudden rise in B.P.
 Retrobulbar anaesthetic without adrenaline

Operative
Complications(Contd)
Suprachoroidal Hemorrhage(Contd)

Presentation


after lens delivery, progressive shallowing of
anterior chamber, increased IOP & iris
prolapse, vitreous extrusion, loss of red reflex.
In severe cases all intraocular contents may be
extruded
Immediate Treatment
Closure of the Incision
 Administration of Hyperosmotic Agent

Operative
Complications(Contd)
Suprachoroidal Hemorrhage(Contd)

Subsequent Treatment
Topical & Systemic Steroids
 Between 7 & 14 Day drainage of the blood,
pars plana vitrectomy & air-fluid exchange

Early Post-Operative
Complications
Iris Prolapse
 Cause - inadequate
suturing
 Complications defective wound
healing,
ch ant uveitis,
epithelial ingrowth,
cystoid
macular edema,
excessive
astigmatism.
 Treatment
Early Post-Operative
Complications
Striate
Keratopathy
 Cause damage to
corneal
endothelium
Hyphema
Early Post-Operative
Complications
Acute Bacterial Endophthalmitis

Pathogenesis

Causative Organisms

Staph Epidermidis, Staph Aureus, Pseudomonas sp
etc
Source of Infection
 Prevention





Treatment of local infections of the Patients
Preoperative instillation of Povidine-iodine
Meticulous draping Technique
Postoperative injection
Draping of Eyes
Early Post-Operative
Complications
Acute Bacterial Endophthalmitis(contd)

Clinical Features
severity
 Time Interval




Staph Aureus - 1st to 3rd day
Staph Epidermidis - 4rth to 10th day
Differential Diagnosis



Retained Lens Matter
Toxic Reaction
Difficult or Prolonged surgery
Fibrinous Exudation in Severe
Acute Endophthalmitis
Small Hypopyon
Acute Bacterial Endophthalmitis(contd)

Clinical Features
Differential Diagnosis
Retained Lens Matter
Toxic Reaction
Difficult or Prolonged
surgery
Early Post-Operative
Complications
Acute Bacterial Endophthalmitis(contd)
 Management
 Identification of causative organism
 aqueous samples
 vitreous samples
 Antibiotics
 Vitrectomy
 Steroids
 Subsequent therapy
Late Post-Operative
Complications
Opacification of the Posterior Capsule




Types
 Elschnig’s Pearls
 Capsular Fibrosis
Indications for Treatment

Visual Acuity
 Impaired Visualization of Fundus
 Monocular Diplopia or severe glare
Nd:YAG Laser Capsulotomy
Complications
Elschnig Pearls
Fibrosis of Posterior Capsule
Technique of
Nd:YAG
Laser
capsulotomy
Late Post-Operative
Complications
Malposition of IOL



Tilting
Decentration
Treatment
Corneal
Decompensation


Causes
Treatment
Late Post-Operative
Complications
Retinal Detachment

Risk Factors



Disruption of
Posterior Capsule
Vitreous Loss
Lattice Degeneration
Sunset Syndrome


Cause
Traetment
Late Post-Operative
Complications
Chronic
Endophthalmitis

Causative Organism




Propionibacterium
Acnes
Staph Epidermidis
Clinical Features
Treatment Strategy


steroids & antibiotics
Removal of IOL,
remaining cortex
& entire capsular bag