Welcome HomeWelcome Home

THEORY

• LECTURES reduced from 80 --- 40 hours

• 2 x per week [ Tues and Fri.]

• In 7th semester there will be no lectures BUT in your case it is going to be an exception

because of Electives in JUNE

• Cover all major topics

• Text books : Khurana , Parson’s Diseases of the Eye

• Reference books : Kanski

• Reading on your own and consistent

• No more spoonfeeding

• Attendance 75 %

• .

•     

Practicals or clinical posting

• Reduced from 10 weeks to 4 weeks

• 4 weeks meaning morning and afternoon

• In the 7th Semester in H. Melaka. You may do a rotation in other hospitals such as in Muar or Terendak

Practicals or clinical posting

• Log book - 5 cases • Instruments - torchlight and ophthalmoscope

• Dress code in hospital

No jeans, slippers , tee- shirts , hipsters

Skirts – below knee level

Males - proper shoes, shirts with ties

• Hair- neatly combed nto hanging over your face bor BOTH

• Language -courteous• Behaviour - professional

Examinations

• 6th semester – Midsemester + 5o marks -- Sessional • 7th semester -Midsemester -Sessional -EPT -OSCE• Eligibility for University Examinations –

attendance and internal asssesment

LENS

• Development: ectodermal

• Transparent

• Avascular

• Spherical

• Location : between the iris and vitreous

• Suspended by zonules

ANATOMY

cortexcortex

capsulenucleus

Anatomy• Capsule: Thicker anteriorly especially at the equator.• Cuboidal cells form the ant. subcapsular epithelium

It is not present on the post.lens epithelium . Becomes columnar at the equator--- Lens fibres.

• Lens fibres arise from the anterior epithelial cells.• Nucleus• In children it is soft• In adults it is firm• In older age it looses transparency and it is flat on

both surfaces.

PHYSIOLOGY

• Nutrition from aqueous + vitreous

• 66% of water + 34% of proteins[ 85% are soluble proteins]

• Traces of mineral

• Glutathione + Ascorbic acid

[ Reduces with age + cataract formation]

• Carbohydrates-- energy

• Amino Acids ---structure

• Metabolism ---Low metabolism and utilisation of O2 and glucose.

• Carbohydrates—HMP- shunt, glycolysis, citric acid cycle

• Amino acids and fatty acids via the citric acid cycle in the mitochondria of lens epithelium.

Classification of cataract

• Aetiological : Congenital / developmental

: Acquired

• Morphological: location and configuration

Acquired causes

• Senile :Age• Complicated :Uveitis , R.D, endophthalmitis• Traumatic• Metabolic : D.M., Wilson’s disease ,galactosemia• Maternal infections : TORCHES• Drugs [Toxic] : Steroids• Radiation : Gamma rays ,X-Rays, Microwave???• Dermatogenic :Atopic dermatitis• Cataract associated with syndromes e.g. Downs syndrome, Dystrophia myotonica

Acquired causes

• Senile :Age

• Complicated :Uveitis , R.D, endophthalmitis

• Traumatic

Acquired causes

• Metabolic : D.M., Wilson’s disease ,galactosemia• Maternal infections : TORCHES• Drugs [Toxic] : Steroids

Acquired causes

• Radiation : Gamma rays , X-Rays, Microwave???

• Dermatogenic :Atopic dermatitis

• Cataract associated with syndromes

e.g. Downs syndrome, Dystrophia myotonica

Morphological Classification

1. Capsular

2. Cortical

3. Nuclear

4. Polar

1

Morphological Classification

1. Capsular

2. Cortical

3. Nuclear

4. Polar

Cataract

• Is an opacity in a clear lens.• Is the most common cause of

painless visual loss in the elderly.• Is the most common cause of

preventable blindness.• Normally the human lens

converges the light rays.• What happens when there is an

opacity?

What happens when there is a opacity in the lens ?

Senile cataract• Bilateral above 60 yrs• Can occur at a younger age—hereditary tendency• Both sexes are equally affected• Two forms : Cortical

: Nuclear

Development of senile cortical cataract

• Lamellar separation or presenile changes

• Incipient stage

• Intumuscent stage

• Mature cataract

• Hypermature cataract

Stages of maturation in cortical cataract

• Lamellar separation

Collection of fluid between

the lens fibres.

Change in refraction—hypermetropic [mild ]

No symptoms

Stages of maturation in cortical cataract

• Incipient stage

Cuneiform – spokes in the periphery

Cupuliform– opacity in the posterior cortex

Does the vision get affected ?

Clinical features of the incipient form

• Change in refractive index of lens• Polyopia• Haloes • Defective vision in the evening or night• On examination they appear black against the red glow

with the direct ophthalmoscope

Or grey opacities

• Intumuscent stage

Progression of the hydration of the lens fibres Swelling and opacification of the lens Lens pushed forward A.C. shallow and Sec. Angle closure glaucoma Opaque lens Pupil in contact with the lens No iris shadow

• What do you think the vision is ?

Stages of maturation in cortical cataract

• Mature cataract

Loss of fluidEntire cortex is opaque?? visual acuity

• Hypermature Cataract

Signs of hypermature cataract Wrinkled capsule / calcification Iridodonesis Ac may be deep Subluxation due to

weak zonules Sclerotic cataract Morgagnian cataract

Calcification of the capsule in hypermature cataract

Morgagnian cataract

nucleus

Cortex liquifies

Hard nucleus sinks

Nuclear cataract

• Progressive sclerosis in the nucleus

• Brown [brunescent ]

• + refractive index

• Myopic

• Seldom becomes hypermature