Opthalmology

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