This document discusses various types and causes of cataracts. It provides details on cataracts caused by diabetes, radiation, trauma, genetics and other medical conditions. Examination steps for evaluating a patient for cataract surgery are outlined, including testing visual acuity, slit lamp examination, dilation, and assessing the lens, anterior chamber, retina and other structures. Considerations for cataract surgery like intraocular lens implantation and managing comorbidities are also mentioned.

1. Dr. Atul Kumar Anand
Senior Resident
AIIMS Patna

2. VA: - depending upon maturation & location VA
may be 6/9 to PL +(PL always +nt, what ever
the grade of maturation in isolated catar.)
Test for iris shadow: +nt in IMC, -nt in MC &
clear lens
Distant direct ophthalmoscopy: show black
shadow against red glow in IMC, not even red
glow in MC.
SLE:- in dilated pupil show color of lens, type of
cataract, hardness of nucleus.

7. Diabetes mellitus
Morphologically, same as in age related cataract in
older individuals but appears earlier than the non-
diabetic individuals & matures rapidly.
Accumulation of sorbitol and subsequent hydration and
increased glycosylation of protein
True diabetic cataract occurs in young individuals-
Snow flake cataract
.(fluctuating refractive error & cataract in DM)

8. High levels of sorbitol
Increase in osmotic pressure
Indrawing of water
Swelling of fibers, disruption of cytoskeletal structures
Lens opacification

10. cataract - diabetes
Juvenile
• White punctate or snowflake
posterior or anterior opacities
• May mature within few days
Adult
• Cortical and subcapsular
opacities
• May progress more quickly than
in non-diabetics

11. Galactosemia: Occurs due to deficiency of one of
three enzymes(mainly Gal-1-P uridyl trasferase)
required for conversion of galactose into glucose.
Cataract is due to the accumulation of galactitol
causing osmotic swelling of the lens. (OIL
DROPLET CATARACT)

12.  lightening/industrial/domestic
cause cataract.
 Earliest change is ring-shaped
vacuoles in mid periphery of
lens.
 Later grayish white streaks
along lens fibers.
 Finally these forms anterior
subcapsular opacity.

13. Causes of traumatic cataract
Penetration
Concussion
‘Vossius’ ring from
imprinting of iris pigment Flower-shaped
• Ionizing radiation
• Electric shock
• Lightning
Other causes

14.  Concussion with intact
capsule- anterior and
posterior fibers are
thickened and edematous.
 Later whitening of fibers –
flower pattern.
 With capsule rupture
Mature cataract.

15. Radiation cataract
Y -rays, x-rays, U-V rays causes ionization of water
and generation of free radicals--damage cell DNA
causes decrease mitosis.
Infrared( non ionizing) -causes localised temp. rise
of iris pigment epithelium hence causes true
exfoliation of ant. Lens capsule

16. Fabry’s disease.
Lowe’s syndrome or oculocerebrorenal
syndrome.
Alport’s syndrome.
Myotonic dystrophy :christmas tree cataract

17. Christmas tree cataract
Polychromatic, needle-like opacities May co-exist with other opacities

18. Uncommon
Characterized by striking, polychromatic,
needle-like deposits in the deep cortex
& nucleus which may be solitary or
associated with other opacities

19. Myotonic dystrophy
• Myotonic facies
• Frontal balding
• Stellate posterior subcapsular opacity
• No visual problem until age 40 years

20.  Both skin and lenses develop from Ectoderm.
 In Atopy, shield cataract (ant subcapsular with
cortical rider) and post. Subcapsular cataract.

21. Atopic dermatitis
• Cataract develops in 10%
of cases between 15-30 years
• Bilateral in 70%
• Frequently becomes mature
• Anterior subcapsular plaque
(shield cataract)
• Wrinkles in anterior capsule

22. Many drugs and chemicals.
Corticosteroids.
Chlorpromazine
Miotic drugs.(ecothiophate)
Phenothiazines.
Gold.
Amiodarone.
Busulphan

23. Drugs
Chlorpromazine
• Long-acting miotics
Other drugs
• Amiodarone
• Busulphan
- initially posterior subcapsular
Systemic steroids
- central, anterior capsular
granules

24.  One third of congenital cataract is hereditary –
Without any systemic association.
 Autosomal dominant(most common), Autosomal
recessive or X-linked
 Chromosomal disorders: Down’s syndrome
(Trisomy 21), Patau syndrome, Edward
syndrome, Turner syndrome etc…

25. Some carotenoids are associated with decreased cataract
 Increased frequency of intake of lutein-rich spinach was
associated with a moderate decreased risk of cataract
 One of the major highlights in cataract research in the past 5
years was the definitive establishment of an association
between smoking and cataract formation.
 Recent studies also confirm that cataract development may
be delayed by protection from ultraviolet ray exposure
 for example, by wearing sunglasses and a hat with a brim.

26. Non surgical measures
(in presenile cases)
Treatment of cause(DM, removal of steroid
irradiation)
Delay progression (e/d of salt of Ca++ or K+
Attempt to improve vision(refraction)

27.  Indications For Surgery
Visual Improvement
Medical Indications
Cosmetic Indications

28. 1. Visual Improvment:
• Most Common Indication
• Only if & when cataract develops to a degree sufficient to
cause difficulty in performing daily essential activities
• (varies from person to person, depend upon indivisual
visual need & occupation)

29. 2.Medical Indications
• Person have comfortable vision but when the cataract is
adversely affecting the health of the eye eg. Phacolytic
Glaucoma (mature, hypermature cataract) or
Phacomorphic Glaucoma (intumescent cataract)
Phacoantigenic uveitis (traumatic cataract) Dislocation of
lens into AC
• To improve the clarity of ocular media in dense cataracts
• in the context of fundal pathology (Eg. In Diabetic
Retinopathy) requiring monitoring treament with
photocoagulation or even diagnosis.

30. 3. Cosmetic Indications
• Rare
 Eg. When a mature cataract in an otherwise blind
eye is removed to restore a black pupil.
 May require cataract surgery:
* Posterior subcapsular cataracts (near VA < N8
even though far VA still 6/12).
* Nuclear cataracts that far VA 6/18 even though
near VA still N5.

31.  GENERAL HEALTH
* Diabetes mellitus
* Ischemic heart disease
* HTN
* Chronic obstructive pulmonary disease
* Bleeding disorder
* Drug sensitivities & medications:
immunosuppressant or anticoagulant…

32.  OCULAR HISTORY
* H/o of trauma
* Inflammation
* Amblyopia
* Glaucoma
* H/o has already had cataract extraction
(complication: vitreous loss….)

33.  EXTERNAL EXAMINATION
* Look for abnormalities of external eyes and adnexa:
. Blepharitis
. Entropion, ectropion
. Decrease of corneal sensation
. Abnormal tear function, Exposure keratitis
. Dacryocystitis (syringing done)
. Other condition: head tremor…
* Motility: EOM, Cover test, Strabismus + Amblyopia..
* Pupil: Reacting to light…RAPD (+/-)

34.  SLIT-LAMP EXAMINATION(SLE)
a)- Conjunctiva:
. Scarring
. Symblepharon
. Conjunctivitis

35.  SLIT-LAMP EXAMINATION (Cont.)
b)- Cornea:
. Specular reflection with slit-lamp can
estimate the endothelium cell count and
morphology.
. Corneal dystrophy
. Keratoconjunctivitis sicca

36.  SLIT-LAMP EXAMINATION (Cont.)
c)- Anterior chamber:
. Shallow (intumescent of lens or forward
displacement by posterior pathology)
. Gonioscopy to rule out the angle abnormalities
(PAS, neovasculization).
 . IOP :
• Any Glaucoma or ocular hypertension must be noted
d)- Iris:
. Pupil size after dilation is noted:- poor dilating
pupil-- cataract surgery difficult
. Posterior or anterior synechia (+/-) .
Exfoliation syndrome is the best seen after dilation.

37.  FUNDUS EXAMINATION
a)- Ophthalmoscopy (direct & indirect)
* Macula
* Optic nerve
* Retinal vessels
* Retinal periphery

38.  FUNDUS…….
b)- In DM patient, we should look for: Macular
edema, retinal ischemia, vitreous retinal traction,
lattice degeneration, macular hole.
c)- Mature cataracts, evaluated by B- Scan
Ultrasonography that helpful in RD & posterior
segment disease or tumor.

39.  SPECIAL TESTS (Cont.)
Testing for macular function
PL, PR, & RAPD(Marcus-Gunn pupil)
Cataract never produces an afferent pupillary defect Its
+nce implies additional pathology, which may influence
the final visual outcome
* Two light discrimination indicates normal macular function, if
two point light sources can be distinguished when held 2
inches apart & 2 feet from the eye.
Color vision
* For macular function
* Maddox Rod: large scotoma (macular disease)

40.  REFRACTION
 BIOMETRY (keratometry & A-Scan)
Performed to calculate the approximate IOL power
implantation.
Use SRK formula (Sanders, Retlaff & Kraff)
P = A – 2.5L – 0.9K or A – (2.5L+0.9K)
P : Lens implant power for emmetropia (D)
L : Axial length (mm)
K : Average keratometric reading (D)
A : Constant specific to the lens implant to be used
That A = 113 for AC lenses & 119 for PC lenses.

41.  CORNEAL PACHYMETRY
* Ultrasonic pachymeters can accurately & reliably
measure endothelial cell function.
* If thickness > 600 µm maybe consistent with
corneal edema & endothelium dysfunction that
increase the likelihood postoperative clinical
corneal edema.

42.  SPECULAR MICROSCOPY: (endothelium cells)
* A normal cell count > 2400 cells/mm2
* If a cell count fewer than 1000 cells/mm2 is risk of
postoperative corneal decompensation.

43. B-Scan ultrasonography Not routinely done
Useful whenever it is impossible to view the retina
& can determine of posterior segment with regard
to the potential for:
* RD
* Vitreous opacity
* Posterior pole tumor
 Blood sugar (R) in DM ( F &PP)
 Conjunctival swab culture(not routinely)

44. Cataract surgery: ICCE, ECCE, Phaco
emulsification.
Lens aspiration with or without IOL and
treatment of amblyopia in case of children.

45. To be continued …..