The document discusses the embryology, anatomy, growth and development of the human lens. It begins by describing how the lens forms from the surface ectoderm during early gestation. It notes the changes in lens size, weight and composition that occur from birth through adulthood. The majority of the document then focuses on pediatric cataracts, including definitions, etiologies, associated conditions, morphological classifications, evaluation, timing of surgery and considerations for intraocular lens implantation versus other management strategies. Key points include the various hereditary and metabolic causes of pediatric cataracts and challenges in predicting postoperative refractive outcomes in children.

1. Congenital & Developmental
Cataract
Dr Divya Kesarwani

2. Lens: Embryology
• Human lens is first visible at 3 to 4 weeks
of gestation.
• The surface ectoderm over the eye field
thickens into the lens placode, then
invaginates toward the developing optic
cup, forming the lens pit.

3. Lens: Embryology
• The lens pit closes and the resulting lens
vesicle pinches off from the surface
ectoderm

4. Lens
• The lens transmits light with wavelengths
from 390 to 1200 nm. limit of visual
perception (about 720 nm).
• Lens transparency results from appropriate
architecture of lens cells and tight packing
of their proteins
• At birth, lens weighs 65 mg. It grows to
about 160 mg in the first decade and then
more slowly to about 250 mg by 90 years of
age.

5. Lens
• Crystallins: Mostly water soluble proteins
that are found in high concentration in the
lens.
– critical structural role for transparency
and refraction
– The soluble fractions are the α-, β-, and γ-
crystallins.
– In the mature human lens α-crystallins
40%, β-crystallins 35%, and γ-crystallins
25%

6. Growth of Eye
• Newborn eye has a mean axial length of
16.8 mm and a mean K power of 51.2 D;
• In adults, the mean axial length is 23.6 mm
and the mean K power is 43.5 D.
• More than half of this growth in axial length
occurs before 1 year of age
• slower rates of increase in axial length until
15 years of age.

7. Growth of the Lens
• The change in K power occurs within the
first 6 months of life, with only minor
changes after that.
• Axial Length changes >> K changes
• Therefore, lens changes significantly 1st
year of life

9. Pediatric cataracts: Overview
• Prevalence
– 1 / 2,000 – 1 / 10,000
• 1/3 of cases of blindness in infants
• 25% hereditary, AD, AR and X linked
• Cataracts associated with systemic and
metabolic diseases tend to be bilateral and
symmetric

10. Definition
• Paediatric < 15 years
• Congenital < 1 year
• Developmental > 1 year

11. Etiologies: Overview
• Pediatric cataracts:
–Bilateral
•¼ hereditary: most commonly, AD
•¼ associated diseases
•½ idiopathic
–Unilateral
•Idiopathic
•Trauma

12. Etiologies
• Prenatal causes:
– Infections
– Rubella directly involves the lens; other
infectious agents (toxoplasmosis, mumps,
measles, influenza, chickenpox, herpes
simplex, herpes zoster, cytomegalovirus,
and echovirus type 3) result in ocular
inflammation (uveitis).

13. Etiologies
• Metabolic
– Galactosemia: cataract and galactosuria
in galactokinase deficiency (oil droplet
cataract)
– Hypo and hyperglycemia
– Wilson disease: Sunflower cataract, K-F
ring
– Fabry disease
– Refsum disease: peripheral neuropathy,
RP

14. Etiologies
• Renal:
– Lowe syndrome: mental retardation,
aminoaciduria, Autosomal Recessive,
– Alport syndrome: X linked, AR (10%)
glomerulonephropathy, deafness, anterior
lenticonus
• Musculoskeletal:
– Mytonic Dystrophy: Myotonia, Christmas
tree cataract, ocular myotonia

15. Etiologies
• Association with other ocular abnormalities:
– Reiger syndrome or anomaly
– PHPV,
– aniridia,
– Norrie disease
– microphthalmia

16. Etiologies
• Perinatal or postnatal problems
– hyperglycemia and hypocalcemia
– signs of diabetes and tetany

17. Etiologies
• Developmental abnormalities associated
with prematurity.
– retinopathy of prematurity
– Laser treatment
• Trauma

18. Galactosemia
• Most common metabolic disturbance
causing cataract (1 / 40,000 newborns)
• Galactose converted to water-absorbing
Galactitol
• Oil droplet to Lamellar to Total cataract
• REVERSIBLE if galactose is eliminated
from diet

19. Galactosemia
• Systemic manifestations
– Failure to thrive, developmental delay,
ataxia
• May have cataract ONLY – no systemic
findings

20. Congenital rubella
• Non-ocular features
– Hearing loss
– Microcephaly
– Growth retardation
• Ocular features
– Cataract, glaucoma
– Mild microphthalmos
– Salt-and-pepper retinopathy

21. Lowe syndrome
• X-linked recessive
• Non-ocular features:
– Aminoaciduria, proteinuria, hematuria
– Mental retardation, hypotonia, areflixia
• Family Members:
– Mothers have punctate snowflake
opacities
• Ocular features:
– Cataract (Posterior Lenticonus)
– glaucoma

22. Types of Cataract

23. Morphologic cataract types
• Polar
– Anterior polar, Posterior lenticonus
• Zonular
– Nuclear, Lamellar, Sutural, Capsular
• Total
• Membranous
• PHPV (PFV)

24. Polar

26. Anterior polar cataract
• Nonprogressive
• Small (1-2 mm)
• Surgery rarely required
• Beware anisometropia!
• Anisometropic amblyopia
• Anterior Lenticonus: Look for renal
disease!

27. Nuclear or Lamellar

29. Lamellar cataract
• Often acquired and progressive
• Opacification peripheral to Y sutures
• Clear nucleus
• Bilateral

30. Sutural or Stellate

32. Total or Mature

33. Nuclear cataract
• Congenital
• Often autosomal dominant inheritance
• Microphthalmia frequent
• Dense, Axial opacity

34. PHPV or PFV

35. PFV (PHPV)
• Microphthalmia
• Glaucoma
• 90% unilateral
• Elongation of Ciliary process
• Poor prognosis

36. Posterior lenticonus/lentiglobus
• Bulging posterior lens capsule
• Lowe syndrome
• Acquired; better prognosis
• Thinning of Posterior capsule
• Caution during surgery!

37. Cataract evaluation: General
• Family history
• Examine family members
– May be X linked
• Prenatal history
• Slit lamp examination OU
• Dilated fundus examination OU

38. When to defer laboratory
studies:
• Most unilateral cases
• subtle bilateral disease
• Bilateral cases with a definite
hereditary basis

39. Further Cataract Lab Workup
• Urine
– Reducing substance (after milk feeding)
– Amino acids IF Lowe suspected
• Blood
– Fasting blood sugar
– Plasma calcium/phosphorous
– RBC transferase/galactokinase
– TORCH
– IF maternal rash during pregnancy:
• Varicella antibody titers
• Genetic Testing

40. When to intervene
• Dense cataracts
– Urgent removal and optical correction
– Provide focused image by age 8 weeks
– Nystagmus = poor prognosis
• Partial cataracts
– Judgment call
– Party line: 3 mm or greater
• Central and posterior cataract: more visually
significant

41. My approach:
• Retinoscopy
– If you can’t refract, then baby can’t see
• Direct ophthalmoscopy
– If you can’t see, then neither can baby

42. Timing of Surgery
• Unilateral dense congenital cataract:
surgical emergency
• Bilateral dense cataract: can be scheduled
in a more routine fashion.
• Poor Prognosis:
– unilateral cases, dense opacities.
associated with other ocular
abnormalities or systemic disease,

43. Surgical Considerations?
IOL or No IOL?

44. Intraocular lens implantation:
Mitigating factors
• Ocular anatomy
– Anterior chamber size (microphthalmia)
– Coexisting ocular disease
– Glaucoma
– Inflammation
– Dislocated lens
– Aniridia
– ROP

45. IOL consideration
– Bilateral cataracts
– Nystagmus
• Contact lenses difficult to fit and position
– Dry eye
• e.g. previous radiation therapy
– Dirty or sandy living conditions
– Limited access to contact lens care
– Compliance concerns
– Behavioral issues
– Cost
– Follow up issues

46. IOL Contraindication
• children with chronic inflammatory disease
– Active Uveitis or JRA iritis
• microcornea, nanophthalmos, or
microphthalmia, with corneal diameters of
less than 9 mm, because of difficulties with
lens size.

47. AC IOL Contraindication
• Aniridia, either congenital or traumatic, and
in cases in which trauma has left the angle
and iris unable to provide support to the
lens.
• Eyes with shallow ACs (e.g., in retinopathy
of prematurity).

48. If NO IOL
• Aphakic Correction
– Glasses
– Contacts
• Silicone elastomer: safe
• RGP: microcornea
• Hydrogel: comfortable
– Secondary IOL

49. Pediatric IOL
• Since 1990, 26 articles published
• Pediatric IOL implanted for 54 years
• 2001 AAPOS survey: 81.9% IOL under 2
yo (1993 12.9%)

50. Types of IOL
• One piece PMMA lens
• Hydrophobic acrylic IOL
– Three piece (MA series)
– One piece (SA or SN series)

51. IOL Calculation Dilemma
• Difficult Issue: varying degrees of refractive
myopic shift after surgery

52. IOL Calculation Dilemma
• Ocular growth has many influencing factors
– No study to date provides the information
necessary to predict with any certainty
how an aphakic or pseudophakic eye will
grow.
– The refractive status of the fellow eye
and familial patterns of myopia or
hyperopia are also likely to be factors in
growth of the pseudophakic eye.

53. IOL Calculation Dilemma
• No information is available to determine the
effect of how cataract surgery is performed
(posterior capsule intact, partially removed,
completely removed; vitrectomy performed,
extensive or limited), or whether the
presence of an IOL (in the capsular bag, in
the ciliary sulcus, or in the AC) has a role in
growth of the eye.

54. IOL calculations
• Refractive growth of eye is logarithmic
• McClatchey’s Pediatric IOL Calculator
– http://med-
aapos.bu.edu/AAPOS/programs. Html

55. IOL power: Target refraction
• Problems:
– Anticipation of ocular growth with
Individual variability
– Growth and other optical factors mean
possible shift of 20 D from age 1-20 yr.
– Lens position changes with ocular growth

56. IOL power: Target refraction
• Two Schools of Thought
– Emmetropia
• Easier to treat amblyopia
• Deal with high myopia later
• An implant of 28 D producing emmetropia
in an 8-month-old may induce 7 D of
myopia and anisometropia when the child is
3 yo.
– Low power IOL – aim for 6-10 D
hyperopia
• Supplement with contact lenses for first year

57. Commonly used Age Adjusted
Target Refraction
• Age
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9 and over
• Refraction
• +4.0
• +3.5
• +2.5
• +2.5
• +2.0
• +2.0
• +1.0
• +1.0
• emmetropia

58. IOL, How Young?
• Intraocular lens implantation
– OK for age 2 and up
• Some say older; many will go younger
• Under 6 months questionable
• Under 3 months discouraged

59. Which Formula?
• A study comparing the predictive accuracy
of four common IOL power formulas (SRK-
II, SRK-T, Holladay, and Hoffer Q) in
children did not reveal any significant
predictive differences between the formulas.

60. Surgical Technique

61. Anterior Capsulotomy

62. Anterior Capsule
• Capsulorrhexis is much more difficult in
children
• If the tear begins to extend too far to the
periphery of the lens, the technique should
be abandoned rather than risk an area of
zonulolysis.
• The anterior capsulectomy is then fashioned
with a cutting irrigation/aspiration
instrument

63. Lensectomy
• Hydrodissection may be performed
• Removal of all, or as much as possible, of
the lens cortex is required, even more so
than in the adult, because of the vigorous
inflammatory response

64. IOL Position
• Advantage of Capsular Fixation
• Sulcus fixation of the haptics:
– iris chafing and pigment dispersion;
– contact with the ciliary body, or erosion
of lens haptics into the ciliary body;
– chronic uveal tissue chafing with
breakdown of the blood-aqueous barrier;
– easier explantation if necessary.

65. Posterior Capsule Management
• 100% opacify under age 6
• Very high rate over age 6 also
• AcrySof no help
• Many perform primary posterior
capsulotomy
• Alternative: YAG in OR
• Problem: Recurrence is common after
YAG

66. Surgical Management
• Primary posterior capsulectomy
– Pars plana approach using vitrector
– Limbal approach
• One year or less: 2 mm
• One to four: 2.5 mm
• Older than 4: 3 mm
• Irrigation in AC (flows around optic)

67. Post-Op Considerations

68. Post-Op management
• Depot subconjunctival steroid
• Topical steroids every 1-2 hours for 1-2 weeks
• Taper slowly for IOL, quickly for contact lens
• Maintain antibiotic coverage for 2 to 3 weeks
• +/- Atopine for first day
• Then use judiciously to prevent IOL capture

69. Long-term Issues
• Contact lens management issues
• Constant surveillance for amblyopia
• Don’t over-patch! : reverse amblyopia
• Prompt institution of penalization or
patching

70. Long Term Issues
• Strabismus is common
• Constant surveillance for glaucoma
– May not show up for 10 years
• EUA to check IOP for sudden myopic shift

71. Decentration

72. IOL decentration
• Lens decentration is more common in
children because of their propensity for
proliferation of residual lens epithelial cells,
secondary membrane formation, and
synechiae formation.
• lenses with 6-mm or larger diameters are
preferred in children because the optic
effects of lens decentration are reduced
compared with lenses of smaller diameters.

73. PCO
• 100 % pediatric patients develop capsular
opacification over time
• In patients less than 2 years of age, the risk
of developing a thick membrane on which it
would be difficult to perform YAG
capsulotomy is significant and all these
patients should have primary posterior
capsulotomy-anterior vitrectomy procedures
performed.
• If older, YAG can be considered in OR or
in office

74. Thank You