Lecture Note on Cataract


Any opacity of the human crystalline lens and/or its capsule is called cataract.

Etiological classification;
 1. congenital: Born with cataract
 2.Developmental: Not present at birth, manifests afterwards but before 30 years which      is determined in intrauterine life.
                     a. Age related cataract: manifests at 50 years or above
                         Morphological types:
                     1.Subcapsular cataract-Anterior
                     2.Nuclear cataract
                     3.Cortical cataract
                     4.Christmas tree cataract
                          According to maturity:
                   b.Cataract in systemic diseases:
                     1.Diabetes mellitus
                     2.Myotonic Dystrophy
                     3.Atopic Dermatitis
                  c.Secondary/complicated cataract:
                    1.Chronic anterior uveitis
                    2.Acute congestive angle closure glaucoma
                    3.High myopia
                    4.Hereditary fundus dystrophies
                   d.Traumatic cataract:
                     1.Penetrating injury
                     2.Blunt trauma
                     3.Electric shock and lightening strike
                     4.Ionizing radiation for ocular tumours
                   e.Cataract related to drugs


Mechanism of ARC formation
Aging Process → ↑Acid in the body (H3PO4, Lactic Acid) → Activates some proteolytic enzyme (β Protease, α Protease) → Breaks α,  β,  γ  crystalline protein of lens → Osmotic particles → Osmosis → Opacity of lens

Pathogenesis: Cataract develops mainly due to imbalance of H2O content of lens

1. Any Pathological cause leading to raise water content of lens
2. Necrosis of lens capsule →Imbibitions of h2o → raised water content → Cataract

Congenital Cataract

Morphological types:
  1. Nuclear Cataract
  2. Lamellar Cataract
  3. Coronary/ Supranuclear Cataract
  4. Blue dot Cataract
  5. Sutural
  6. Anterior Polar
  7. Posterior Polar
  8. Central oil droplet
  9. Membranum Cataract


  1. Inheritance: 25% the mode is most frequency AD sometime AR/ X.L

  1. Systemic Metabolic Associations:
a.       Galactosemia
b.      Lowe Syndrome
c.       Fabry disease
d.      Menonosidosis e.t.c
Others: hypothyroidism, pseudohypoparathyroidism, hypoglycemia, hyperglycemia etc

  1. Associated intrauterine infection
    1. Congenital Rubella
    2. Toxoplasmosis
    3. Cytomegalovirus Infection
    4. Varicella

  1. Associated chromosomal abnormality
    1. Downs syndrome
    2. Edward syndrome
    3. Cri du chat syndrome

  1. Associated skeletal syndrome
    1. Nancy- Horan Syndrome

Surgical treatment of congenital Cataract
  1. Anterior capsulorhexis
  2. Aspiration of lens matter
  3. Capsulorhexis of the posterior capsule
  4. anterior vitrectomy
  5. IOL implantation

Ectopia Lentis

Ectopia lentis refers to a displacement of the lens from its normal position.
The lens may be; completely dislocated.
Rendering the pupil Aphakia (luxated)
Partially displaced, still remaining in the papillary area. ( subluxated)

Types: Acquired

Acquired: 1. Trauma
                 2. A Large Eye: High myopia
                 3. Anterior Uveal tumour
                 4. Hypermature cataract
Hereditary (cause)
Without systemic association
  1. Familial Ectopia lentis
  2. Ectopia lentis pupillae
  3. amiridic

with systemic association
  1. Marfan’s syndrome
  2. weill- marchesani syndrome
  3. homocystinuria
  4. others 1. sulphate oxidase deficiency 2. hypertysinaemia 3. Stickler syndrome 4 Ehlers Danlos syndrome

Abnormalities of shape
  1. Anterior lenticonus
  2. Posterior lenticonus
  3. Lentiglobus
  4. microspherophakia
  5. microphakia
  6. coloboma

Management of age related cataract.

Management has two parts:

v  Diagnosis: Histology

v  Treatment:
1.      general treatment
2.      Specific treatment
3.      treatment of complication
4.      advice
5.      counseling
6.      follow up
7.      explain prognosis

Complaints: 1. Gradual dimness of vision, usually painless
                    2. Diplopia/ Polypia
                    3. In congenital cataract parent complains of something within the eye


Proper ocular history taking to find out the etiology of cataract
General Medical History is taken and any problem manage accordingly.
  • Diabetes Mellitus
  • Systemic Hypertension
  • Acute or Suspected MI in the Past
  • Angina
  • Respiratory Disease
  • Rheumatic Fever, Transplanted or prosthetic heart valves
           , Previous endocarditis
  • Stroke is the past
  • Jaundice in the past
  • Rheumatoid arthritis
  • HIV infection
  • Sickle status
  • Parkinson’s Disease
  • Epilepsy
  • Myotonic dystrophy

Ophthalmic Preoperative Assessment
  • Torch
  • Slit lamp
1. Visual acuity test by snellen’s chart
2. Cover test: to see amblyopia, diplopia, squint etc
3. Pupillary examination
4. Ocular examanition

  • Lids: Blephartis, Ectropion, Entropion, Tear film abnormality, lagophthalmous, requires, effective preoperative resolution
  • Conjunctiva: Chronic Conjunctivitis
  • Cornea: Corneal ulcer, scar, decreased endothelial cell count has increased vulnerability to postoperative decompensation secondary to operative trauma.
  • Anterior chamber: A shallow anterior chamber can render cataract surgery difficult.
  • Pupil: Poorly dilating pupil allows intensive preopretive mydriatic drops, planned mechanical dilatation prior to capsulorhexis and/or intracemeral injection of mydriatic
  • Lens: hard nucleus require more pheco, power
  • Black nuclear opacities are extremely dense and extra capsular cataract extraction rather than phecoemulsification may be the superior opinion.
Pseudoexfoliation indicates weak zonules, a fregile capsule and poor midriasis
1.      Fundus examination: by A. Opthalmoscopy
 B. Scan Ultrasonography

To see disease like:
Opthalmoscopy—Age related macular degeneration
Ultrasonography—Retinal detachment
Stephyloma in eyes with very dense opacity that precludes fundoscopy


  1. Blood sugar level to see diabetic status
  2. ECG to see the cardiac status
  3. Urine R/M/E
  4. SPT to see dacrocystitis or duct obstruction
  5. IOP to see glaucoma
  6. Conjunctival swab for c/s
  7. Biometry: calculation of lens power
1.      Keratometry: Determination of the curvature of the anterior corneal surface.
2.      A scan ultrasonography to see axial length of the eye ball
                                             P= A -2.5 * L – 0.9*K
3.      10 L power calculation: SRK formulae

*previous refractive surgery  is likely to make significant difference in IOL power

  1. Macular function test:
Moddox rod test
Color Vision
Card board test

  1. Retinal function tests
    1. PL
    2. PR
    3. Pupillary Reaction

Intra ocular lens

An IOL consists of an optic and the haptics.optic is the central refractive element.

Haptics the arm or loops sit in contact with the ocular structure (capsular bag, ciliary saleus or anterior chamber angle) for stable optimal positioning of the optic.

  1. Flexible IOL ; Components
Silicon IOL= 1 or 3 piece
Acrylic IOL = 3 piece or 1 piece
Collamer composed of collagen
  1. Rigid IOL made of PMMA
  2. Shape/Square edged optics
  3. blue light filters
  4. aspheric optics
  5. Heparin coating reduces the attraction and adhesion of inflammatory cells
  6. Tonic IOL
  7. adjustable IOL
  8. Multifocal IOL


  1. General Anesthesia is case of children, young adults, anxious patients, epilepsy, dementia and those having head tremor
  2. Local anesthesia in vast majority of cataract surgery
    1. sub tenon block
    2. Peribulbar block
    3. Tropical Anaesthesia

Gels: (Proxymetacaine 0.5 %, tetracaine 1% drops, lidocaine 2% gel, oxibuprocaine drops)
Combined viscoelastic/ lidocaine preparation are also commercially available.

 Note: Akinesia= Facial Block
           Anesthesia = Ciliary block
Surface A= Oxibuprocaine
Peribulbar block= Anaesthia +Akinesia

Principles of treatment of cataract;
1.      No treatment: Assurance  only
When opacity is in the periphery, not in the pupil.

2.      Medical treatment:
Almost no indication only in case of congenital cataract. Atropine like drugs are used though there is no improvement.

3.      Optical correction: In immature cataract concave lens as there occur some myopic changes.
4.      surgical treatment: extraction of lens.
Old methods:
1.      Couching
2.      ICCE
3.      ECCE
4.      ECCE with IOL implantation

   New Methods
1.      Phacoemulsification with PCIOL implantation
2.      SICS (small incision cataract surgery) with PCIOL implantation

Note:  1. Intracapsular: removal of lens with its capsule
3.      Extracapsular: Removal of the lens by leaving part of the anterior capsule with the posterior capsule.

Indication or timing of cataract surgery

  1. Visual impairment is by far the most common indication for cataract surgery when the opacity develops to a degree sufficient to cause difficulty is performing essential daily activities.
  2. Medical indication those threatened for vision
Eg phecolytic glaucoma
     Phecomorphic glaucoma
                 Diabetic retinopathy where clarity of the ocular media for further treatment

  1. Cosmetic indication: In order to obtain black pupil

Pre operative Medications.

  1. Pre medication
  2. Anesthesia
  3. Patient in the operation table
  4. Antiseptic wash around the eye ball
  5. Drapping with linnen
  6. Exposure of eyeball by speculum
  7. fixation of the eyeball by stitching superior rectus muscle
  8. incision: 2 types
                                                              i.      Ab Externo
                                                            ii.      Ab Interno
Ab Exterma
i.                    Incision in the conjuctiva
ii.                  Hemostasis
iii.                ½ thickness of sclerocorneal junction along the limbus from 10 to 2 o clock position.
iv.                A. Punctate wound is made
v.                  Incision is enlarged

  1. Peripheral iridectomy
  2. lens extraction
  3. closure of the wound by 10% vergin silk (monofilament)
Interrupted or continuous suture.
Formation of anterior chamber by normal saline or by BSS ( Basal salt solution)
Stitch the conjunctiva
Drugs: Atropine 1%
  1. release of superior rectus muscle and lid
  2. Close the eye by pad and bandage.

Anesthetic: Same as before
Steps of operation up to incision same as ICCE
09.Puncture wound is made
  1. anterior capsulotomy by introducing anterior capsulotomy needle through the puncture
  2. extension of incision
  3. exession of lens nucleus
  4. irrigation & aspiration of cortical matter by Z way cannula
  5. introduction of IOL is caspsular bag
  6. Fomation of ARC
  7. Closure of wound
  8. Subconjunctival injection: gentamycin+ oradexon
  9. pad bandage

Phacoemulsification (Phaco)
Phacoemulsification (Phaco) has become the preferred method over the last 15 years.

  1. Smaller incision so no chance of decompression of the eyeball.
  2. Very little chance of astigmatism.
  3. Early stabilization of  refraction( usally 3 weeks for 3mm incision)
  4. no chance of post operative iris prolapse.

  1. it requires complex machinery to break up the lens nucles and remove it through a small incision.
  2. considerable training is required to learn the techniques.

  1. topical anesthesia/ retrobulbar block
  2. povidone iodine 5% instilled in the conjunctival sac and also skin of eyelid.
  3. careful drapping

a.       Two side port stab incision 180 apart.
b.      corneal incision may be clear/limbal               
  1. Visco elastic injected into anterior chamber
  2. capsulorrhexis: Continious, central and curvilinear (CCC) by cystotome
  3. Hydrodissection:to separate the nucleus and cote from the capsule
  4. The pheco: probe is inserted and the superficial cortex and epinucleus is aspirated.
  5. Nucleus is removed by four quadrant or nuclear  pheco chop technique.
  6. Cortical clean up.
  7. Insersion of IOL in the capsular bag
  8. centration of IOL
  9. Viscolastic is aspirated
Side porte incision are sealed with jet of saline.
  1. Subconjunctival injection of steroid and antibiotic is given.
  2. Pad bandage

Small incision manual cataract surgery

SICS is very good altenative to phaco
I.                   Very high volume surgery can be performed.
II.                Inexpensive is instrumentation is required
III.             Procedure is fast
IV.             Low rate of complication
V.                Can be performed in the dens cataract

A high incision of PCO due to round edge PMMA

  1. A self sealing paetial thickness scleral tunnel is dissected and anterior chamber is entered.
  2. capsulorrhexis is performed.
  3. Hydrodissection and delineation are performed and nucleus is prolapsed into the anterior chamber.
  4. A glide is inserted into the anterior chamber and the nucleus expressed. It is also possible to extract the nucles with an irrigating rectis.
  5. the epinucleus and residual cortex are aspirated with a simco cannule.
  6. the IOL is inserted.

Operative complications:
Pre operative :1. Exacerbation of HTN, Angina attack
2.Attack of Ach de to dialation of pupil in shallow A/C
3.Complication of anaesthesia
* Retrobular or peribulbar stage
*Accidental perforation of globe with intraocular injection of anaesthetic
*Anaphylactic shock
*vasovagal shock

  1. Rupture of the the posterior lens capsule-vaso vagal shock
Capsular rupture may be accompanied by vitreous loss. Posterior migration of lens material and rarely expulsive hemorrhage.
  1. Posterior loss of lens fragments
  2. Posterior dislocation of IOL
  3. suprachoroidal hemorrhage
  4. Iris prolapse
  5. Early entry. Late entry. Button hole during tunnel formation.
  6. Injury to ocular structure by instruments like; corneal epithelial abrasion.
Corneal endothelial injury.
  1. Extension of capsulartoxin to periphery etc

Post operative
  1. Acute postoperative endophthalmitis almost 0.3%
2.Corneal oedema, corneal stricture
3.Wound leak
      6.retained lens matter
7.iris prolapse
8.↑ IOP

  1. coagulase- negative staphy lococci (S. Epidermidis)
  2. other gram positive organism (S. aureus, streptococcs)
  3. gram negative organism (Pseudomonas SPP, Proteus SPP)

Sources if infection
  1. Floor of eyelids and conjunctiva
  2. Contamination via incisions,contaminated solution and instruments

  1. Delayed onset postoperative endophthalmitis
  2. posterior capsular opacification (PCO)
  3. Anterior capsular fibrosis and contraction
  4. malposition of IOL
  5. Cystoid macular oedma
  6. Retinal detachment etc
  7. Astigmatism

PCO (Posterior Capsular Opacification)
It is a membranous white opacity formed by the remnants of anterior and posterior capsules of the lens following cataract surgery.

Prevention of After cataract formation
  1. Lager circular anterior capsulotomy
  2. Good cortical cleaning including the peripheral and equatorial parts.
  3. Polishing of the posterior capsule.
  4. Polishing of the under surface of the remaining anterior capsular ring.
  5. Insertion of PC IOL in the bag
  6. use biconvex PC IOL or planoconvex with convexity toward the posterior capsule
  7. In case of capsulorrhexis the margin of the capsular opening must overlap 0.5 – 1 mm within the margin of the optic of IOL that means if the IOL optic is 6.0 mm the rhexis diameter should e 5-5.5mm. Square edge optic designed IOL

Difference between conventional SICS Phecoemulsification
Small Incision
Retrobulbar & Peribulbar surface
Half thickness limbal incision 10-12mm
6mm tunnel incision
Straight, Circikness, circmferential, frown
3mm tunnel incision clear corneal
Suture is required
No need of suture
No need of suture

Phakia: Individual with normal crystalline lens.
Aphakia: Absence of human crystalline lens
Peudophakia: Replacement of human opaque lens by an artificial transparent IOL is called pseudophakia.
    1. Patient has H/O cataract surgery with IOL implant
    2. VA: Good
    3. Anterior Chamber: Well depth
    4. Shiny papillary reflex
  1. rapid visual improvement
  2. no alteration of visual field
  3. binocular vision present
  4. No change in colour vision
  5. image size very similar etc

Sites of IOL implantation
    1. Post chamber (In The Bag)
    2. Ciliary sulcus
    3. Anterior chamber
    4. Scleral fixation
Visco Elastic substance
viscoelastics are biopolymers whose main constituents are glycosaminoglycans and hydroxypropylmethylleulose
All have the propensity to case raised intraocular pressure unless carefully removed at the end of surgery.


  1. Methyl cellulose
  2. 1% sodium hyaluronate
  3. chondroitin sulphate
  4. hydroxy propyl methyl cellulose
  5. viscoat

Properties: i. they are non toxic
ii. Non antigenic
            iii. Transparent
            iv. viscus and elastic
v.                  Sterile
vi.                Do not interfere with normal wound healing

Use: 1. Cataract surgery with IOL implantation to maintain A/C and inflation of the capsular leaf.
2.Penetrating keratoplasty
  1. Glaucoma filtration surgery
  2. vitreoretinal surgery


 Lens induced ocular diseases
    1. Phacolytic Glaucoma: (Lens Protein Glaucoma)

Pathogenesis: Phacolytic glaucoma is open angle glaucoma occur in relation to hypermature cataract patient who present late. Trabecular meshwork obstruction is caused y high molecular weight lens proteins which have leaked through the intact capsule in the aqueous humor. Lens protein containing macrophage may also contribute to block trabecular meshwork.

Presentation: Poor Vision
Slit Lamp Finding:
Corneal Oedema
Deep anterior chamber
Floating white particles in aqueous

Gonioscopy: Shows an open angle

  1. Medical Treatment to control I0P
  2. cataract extraction with/without IOL implantation

Phacomorphic glaucoma:
1.It is an acute secondary angel closure glaucoma. Precipitated by intumescent cataractous lens. Crystalline lens continues to grow throughout life.
2.Equatorial growth moves the lens anterioly
 3.Anteroposterior growth increase iridolenticular contact and cause papillary block and iris combe, that raise 10P due to difficulty in drainage of aqueous.

Sudden loss of vision
Pain in the eye
Redness of eye

  1. Conjunctiva: Congested
  2. Cornea: Hazy
  3. Anterior Chamber: Shallow
  4. Pupil: Dilated non reacting
  5. Lens: Cataract

  1. Medical Treatment to contoll I0P
  2. Laser iridotomy if I0P controlled
  3. Cataract surgery when the eye is quite with surgical iridectomy.

Phacotoxic Uveitis
  1. Accidental Trauma to lens capsule.
  2. Liberation of lenticular protein within the eye.
  3. Granulomatous uveitis develops, sometimes secondary glaucoma through lens: Proteins are relatively poor antigens.

  1. Treatment by corticosteroid.
  2. Cataract extraction after control of inflammation.

Phaco-anaphylactic Uveitis:
Rare condition. It may develop after ECCE.
The immune system appear to be sensitized to lens protein.
Extracapsular extraction with retention of cortical material in the eye may sometime cause endophthalmitis.
Dislocated lens fragment during surgery also cause severe uveitis

Aphakia mean absence of the crystalline lens from the eyeball.

  1. Congenital absence of lens (rare)
  2. Acquired
i.                    Post operative
ii.                  Post traumatic- Blunt trauma
       Penetrating injury
                        Subluxation of the lens
                        Dislocation of the lens
  1. Post inflammatory: Following large perforated corneal ulcer
  2. Couching: Ancient surgery where the lens is forcibly dislocated into the vitreous by a needle via limbus.

Optic Defects in aphakia
  1. High hypermetropia
  2. total loss of accommodation
  3. Change in colour vision.

  1. Blurred vision for distance and near
  2. history of cataract surgery in most cases.

  1. VA: unaided: counting finger
  2. Suture or linear scar may be visible in upper limbus
  3. Deep anterior chamber
  4. Iridodonesis: Tremolousness of iris due to loss of support from the lens.
  5. iridectomy mark may present
  6. jet block pupillay reflex
  7. Retinoscopy  reveals high hypermetropic and antigmatism
  8. Ophthalmoscopy: Hypermetroic fundus with a small optic disc.

  1. Specticle correction: By +10 D lens for distant vision ,+3 D addition for near vision
  2. Contact lens
  3. Secondary IOL implantation AC 10L/ PC IOL
  4. Epikeratophakia


Hyper mature
Considerable vision present
Limited to finger count
Anterior Chamber
Normal/ Shallow
Colour of the lens
Greyish white
Pearly white
Milky white
Iris Shadow
Fundal glow
Present Black spots in the reddish background
Spectacle correction
May improve vision
No improvement
No improvement

D/D of senile cataract
  1. Cataract (Different type)
  2. Retinoblastoma
  3. Endophthalmitis

Complication of hyper mature cataract
  1. Subluxation of lens
  2. dislocation of lens
  3. phacolytic glaucoma
  4. phacomorphic glaucoma
  5. phacotoxic  uveitis

Grading of Hardness
Appearance Of nucleus

Grade I  +  Soft

Grade II  +

Grade III  +

Grade IV + (Rock Hard)


Yellow Nucleus


Brown to black