This document provides information on managing pediatric cataracts. It discusses that childhood cataracts are a major cause of blindness worldwide and disrupt visual development. Timely cataract removal and rehabilitation is important. Examination of pediatric cataract patients involves assessing visual acuity, eye alignment and function. Surgical techniques aim to remove the cataract while preserving the capsular bag for intraocular lens implantation. Post-operative care and amblyopia management are crucial to optimize visual outcomes. Complications include inflammation, glaucoma, posterior capsule opacification and membrane formation.
2.
Childhood cataracts are responsible for 5% to
20% of blindness in children worldwide and for an
even higher percentage of childhood visual
impairment in developing countries.
The prevalence of childhood cataract varies from
1.2 to 6.0 cases per 10,000 infants.
Cataracts in children not only blur the retinal
image but also disrupt the development of the
immature visual pathways in the central nervous
system.
Hence timely removal of cataract followed by
prompt visual rehabilitation is of utmost
importance in children.
3. History..
Careful history including a family history from
the parents.
• Ask about any illnesses or drugs used during the
Pregnancy
• Find out if the child is developing normally
• Child should be examined by a paediatrician,
to look for other congenital anomalies
4. Ocular examination
Visual acuity
Preverbal child:
Fixation behavior
A baby can hold fixation on a target & follow it
around in the space as the target moves,in a normally
illuminated room- ‘fix&follow’
CSM method: central, steady, and maintained fixation
on a target. If each eye fixates centrally rather than
eccentrically, holds steady fixation on that target
rather than searching for it or wandering, and
continues to stay fixated on that target even when
occlusion is removed from the fellow eye, the vision is
noted "CSM".
6. Optokinetic nystagmus:
It is a rapid screening method for gross integrity of
visual pathway.
Optokinetic response is generated with the use of
moving field stimulus which induces pursuit
movement.
OKN is an involuntary pursuit response to moving
stripes.
A child with some vision will demonstrate a
nystagmus as the stripes moves across the field
of veiw.(catford drum)
7. Visual evoked potential:
It measures EEG pattern created by visual
stimuli.
Electrodes are placed on the occipital region &
visual stimuli-bright flash square wave/phase
alternating checker boards,shown to child.
Response is compared with age matched
controls.
8. Verbal Child -preschool(2-5yr)
2yr old child can easily match simple forms &
responds well to learning through
demonstration.
Visual acuity testing – matching task.
The child has to find out the matching block or
point to the shape that matches the target kept
at a distance of 3meters.
9.
Lea symbol charts
HOTV test
Landolt C rings
Tumbling E
Cardiff acuity test
>5yrs : Snellen visual acuity charts.
11. Biometry & IOL power
calculation
At birth axial length of globe is 16 mm and
increases to 20 mm on the completion of 2
years.
At birth the human lens is more spherical than in
adults.
It has a power of about 30D, decreases to
about 20-22D by the age of five i.e. Myopic
shift.
This means that an IOL which gives normal
vision to an infant will lead to significant myopia
in adulthood.
12. There is also change in size of capsular bag
from 7mm at birth to 9mm at 2 years.
An ideal IOL power should aim at prevention of
amblyopia in childhood and least possible
residual refractive error in adult.
Undercorrect the IOL power at the time of surgery
to prevent significant myopia later.
Keratometry- handheld keratometer
A-scan-immersion technique.
15. Indications of surgery
Visually significant central cataracts
Dense nuclear cataracts
Cataract a/w strabismus
Cataract obstructing examiners view of the
fundus
16. Timing of surgery
Bilateral cataract
1.Bilateral dense
• Early surgery – before10 wks of age
• To prevent simultaneous deprivation amblyopia.
• Denser eye should be addressed first
2. Bilateral partial
• Monitor lens opacity and visual function
• Intervene latter if vision deteriorates.
17. Unilateral cataract
1. Unilateral dense
• urgent surgery with in 6 wks.
• Followed by aggressive anti-amblyopia
therapy
2. Unilateral partial
• Can be observed or treated non-surgically
with pupillary dilatation and possibly part time
contra lateral occlusion to prevent amblyopia.
18. Pediatric cataract surgery differs
from adult:
Small size of eyes
Highly elastic anterior capsule
Low scleral rigidity
Dense vitreous
Propensity for severe post-op inflammation
Constantly changing refractive status
Tendency to develop amblyopia
19. Surgical techniques:
Lensectomy + primary posterior capsulotomy &
anterior vitrectomy with/without primary IOL
implantation.
Primary IOL implantation in infants – controversial
-high tissue reactivity
-marked changes in AL & Refractive status.
Safe & effective alternative to contact lens/spects.
Aids amblyopia treatment by eliminating period of
uncorrected aphakia.
20.
Pars plana Lensectomyif no IOL implantation is planned.
Performed through pars plana incision with
vitreous cutting instrument/manual aspirating
device.
Disadvantage- capsular bag is not preserved,
so in-the-bag IOL implantation is not possible.
Limbal lensectomy –
Most preferred approach especially when
primary or secondary IOL implantation is
21.
If IOL is being implanted-partial thickness scleral
incision , 2-2.5 mm from limbus or a clear corneal
incision.
Scleral tunnel- preffered- maintains AC & prevents
iris prolapse.
2. Management of anterior capsule:
Manual continuous curvilinear capsulorhexis using
Uttrata forceps.
Anterior capsule in tough & elastic
22. It is facilated by using highly retentive viscoelastic
e.g.Healon GV, force lens posteriorly and reduce its
anterior convexity-combat the effect of vitreous
upthrust.
Anterior capsule-stained with Trypan blue.
Small CCC – 5mm diameter.
Capsular flap is frequently released to inspect
size,shape & direction of the tear.
23. More pull is needed centripetally
to avoid extension of CCC.
2 incision pull-push technique:
2 small incisions superior & inferior
Grasp the centre of flap of superior incision &
push towards centre-semicircular tear.
Grasp the centre of flap of inferior incision & pull
towards centre-semicircular tear.
25. 3.Lens matter is aspirated by using vitreous
cutter or a
Simcoe cannula.
4. Primary IOL is implanted in the bag for long
term stability & safety.
children < 2yrs :Downsize IOL to 10mm
diameter.
To prevent- capsular bag stretching-PC folds.
Lens epithelial cells migrate towards the visual
axis through folds-PCO.
26.
Single piece acrylic IOL is best,less capsulorhexis
ovaling & capsular bag stretch.
PMMA IOL can be used.
5.Management of Posterior capsule:
Child < 5 yrs
Primary Posterior capsulotomy+
anterior vitrectomy
to prevent opacification.
Manually or vitrector
27.
Children > 5yrs: PC left intact
Nd:YAG laser posterior capsulotomy in early postop period.
Intraop miotics-avoided-to prevent ant.segment
inflammation.
Use of LMW Heparin(5IU in 500ml) irrigating
solution reduces ant.segment inflammation.
Low scleral rigidity-wound is not self sealing-fish
mouthing. Suture the wound at the end.
28. Visual rehabilitation
Spectacles
Useful for older children with bilateral aphakia
In infant inappropriate because of
weight, unpleasent
appearance, prismatic distortion and constriction of
visual field.
Contact lenses
Provide superior optical option for unilateral
aphakia
Tolerance is reasonable until the age of 2 years
CL become dislodged leading to period of visual
deprivation with the risk of amblyopia.
29. Part time occlusion of better eye in cases of
unilateral cataract.
IOL implantation
Performed in younger children and even infant.
Most effective and safe.
Piggyback IOL in infants-temporary
polypseudophakia.
Post.lens-in the bag; ant.lens-ciliary sulcus
1-2 yrs after surgery,ant lens is
explanted/exchanged.
30. Post-op Complications
1. Uveal inflammation:
Common complication-increased tissue
reactivity in children in early post-op period.
Uveitis-membrane formation,pigment
deposition, Posterior synechia.
topical & systemic steroids.
31. 2.Glaucoma
glaucoma occur in the immediate post operative
period is secondary to pupil block or PAS
formation esp in small eyes.
Glaucoma may occur after lensectomy, if it is
carried out in the first week of life.
This glaucoma is very difficult to treat and frequently
leads to blindness.
Delaying surgery until after the child is 3-4 months
old makes it unlikely that the eyes will recover 6/6
vision but it reduces the risk of glaucoma
32. Open angle glaucoma- commonest type
Occur about 7 years after surgery.
The mechanism of glaucoma is not exactly
understood.
decreased incidence of open-angle glaucoma
in pseudophakic eyes compared to aphakic
eyes after cataract surgery.
Probably, the IOL acts as a barrier between
the vitreous and trabeculum, preventing a
vitreous chemical component from acting on
the trabeculum.
33.
Vision threatening complication, IOP should be
recorded periodically.
Every 3monthly-1st postop yr
Twice yearly- 10th yr
Once yearly thereafter.
Glaucoma filtering surgery/ drainage implant is
often require to control the IOP.
34. 3. Posterior Capsular opacification:
Late onset,begins 18months after surgery
Nearly universal if posterior capsule retained
More significance in younger children
because of
more amblyogenic effect
Opacification of anterior hyaloid face may
occur
despite capsulorhexis if the anterior vitreous is
left intact.
Nd:YAG laser capsulotomy.
35. Proliferation of lens epithelial cells
with in the remnants of
anterior and posterior
capsule and is referred as
Soemmerring ring.
36. 4.Secondary membrane.
Late onset
In the pupillary region
Fibrinous post operative uveitis in normal eye
unless
vigorously treated may also result in membrane
formation.
Thin membrane opened with Nd:YAG laser
Thick ones may require membranectomy.
37. 5.Pupillary capture
Commonly seen in children <2yrs,size of optic
less than 6mm, IOL placed in ciliary sulcus.
Left untreated if
asymptomatic.
Retinal detachment,CME
-less common complications
- Too much undercorrection will lead to post-op. hypermetropia with the possibility of developing amblyopia.
Keratometry is performed using handheld keratometer.- Ultrasound biometry is performed using the contact/immersion technique for AL measurment.
-manual CCC – gold standard for maintaining the integrity of the capsular edge. (difficult ).
diathermy- shows coagulated capsular debries on the edge of the ccc.- fugo blade – emplys plasma for ablating the tissue. Makes perfect ant. Capsulotomy of any size without the risk of radial tear. Recommended for fibrotic capsule in white cataract in abscense of red reflex.