PEDIATRIC MANAGEMENT IN

CONTACT LENSNAME: ANG KAI LIID NO: P82502COURSE:NNV6214LECTURER: PROF MADYA DR HALIZA BINTI ABDUL MUTALIB

ANATOMIC CONSIDERATIONS

Axial Length

• Newborns~17mm

Corneal Curvature

• Premature infants→ 49.50D • 1 to 2 months→ 47D • 4 years old→ 43D to 44D

Refractive

Power

• Normal neonate→ Moderately hyperopic with slight astig; premature→ slightly myopic

• Aphakic power at 1 month→31D, age 4 →17D

CornealDiameter

• At birth~9.8mm• By age of 1 year, reach almost adult size~11.6mm

INDICATIONS FOR PEDIATRIC CONTACT LENS FITTING

INDICATIONS

High myopiaAphakia

High hyperopia• Accommodativ

e esotropia

Photophobia• Aniridia• Iris coloboma• Achromatops

ia

Nystagmus

Anisometropia

Irregular astigmatism• Trauma• Scarring• Penetrating

keratoplasty

PEDIATRIC CONTACT LENS SELECTION1. SILICONE ELASTOMER

ADVANTAGES DISADVANTAGES

Comfort Very costly

Excellent DK (DK 340); safe for EW

Hydrophobic (heavy lipid deposition)

Stays in place (low rate of loss) Limited parameters (3D steps, 3 base curves)

Great durability and handling Cannot mask astigmatism

No dehydration of material during wear

No UV protection

ParametersBase Curves 7.5, 7.7, 7.9

mmDiameter 11.3mm

Powers +23.00D to +32.00D (3.00D steps)

Optical Zone 7.00mm

Centre Thickness

0.51-0.71mm

Initial trial lens: 0.40mm-0.60mm flatter than average K readings

Assessment using fluorescein and cobalt blue light

Remove at once if central pooling.

Should show minimal apical clearance and some degree of peripheral clearance.

Recheck fitting pattern after 10 and 60 minutes later.

2. HYDROGEL

ADVANTAGES DISADVANTAGES

Comfort High cost (if custom)

Not easily displaced/dislodged Low DK DK/t ↓ as power ↑

Wide range of parameters Corneal oedema, Neovascularization: toric design

Tints Difficulty in handling

3. RGP LENSES

ADVANTAGES DISADVANTAGES

Low cost, longer life span Prolonged adaptation period

Wide range of parameter Risk of dislodgement

High oxygen transmission (Dk up to 150), Low protein adherence

Need greater skill to fit

UV protection, provide best optics (correct corneal irregularity)

Corneal abrasion from eye rubbing

PEDIATRIC PREFITTING EXAMINATION

Careful evaluation of patient’s lids, bulbar conjunctiva and cornea

Using an UV light of the handheld Burton lamp/handheld slit lamp with cobalt filter illumination, fluorescein dye is applied to the corneal surface.

Although keratometry is helpful, fitting without this information can proceed. Infants and toddlers who are aphakic have steep corneal curvatures and high plus refractive errors

Retinoscopy, with handheld trial lenses, of the pediatric eye before lens fitting (determine starting contact lens power).

Selection of initial trial lens base curve is typically based on patient’s age.

Pediatric Contact Lens Selection (Silsoft)

Parameters of initial fitting- based on age of the child

Children < 2 y/o, start lens fitting with 7.5mm base curve, 11.3mm diameter, +32.00D lens

As the toddler matures, it is expected that the child’s corneal curvature will flatten, aperture will enlarge, and the prescription will require less plus power

The 7.7mm base curve lens is the starting point for children between 2 and 4 years age, whereas the 7.9 mm base curve is for the child than 4 years of age

Pediatric Contact Lens Fitting Assessment (Silsoft)

• Insertion → After 15 minutes of lens equilibrium, fluorescein dye is instilled in the child’s eye

• The UV lights and magnification of the Burton lamp aid in determining the Silsoft lens centration, movement, and thickness of a post-lens tear film

Ideal fluorescein pattern• Minimal apical clearance

• Minimal bearing in the intermediate zone

• Peripheral edge clearance

• Moderate nasal edge lift

• Lens movement of 1-2mm is expected on a normal blink

Steep fitting No fluorescein exchange under

lens base curve

Flat fittingSignificant edge lift

Excessive movement

Flat-fitting has the steepest (7.5mm) base curve,

transition to a hydrogel (6.8mm) or RGP (5.0 mm) lens

is required

Pediatric Contact Lens Insertion (Silsoft) When inserting , the thumb and forefinger of the dominant hand hold a

partially pinched contact lens.

The inferior 1/3 of the lens is pinched closed, yet the top 1/3 of the lens is completely open.

As the palm of the nondominat hand stabilizes the forehead, the thumb of this hand is used to retract the upper eyelid allowing for fanned out superior lens edge to rest on the superior bulbar conjunctiva.

As the middle finger of the lens-holding hand retracts the lower eyelid, the inferior lens edge is allowed to unfold onto the inferior cornea

Pediatric Contact Lens Removal (Silsoft) Two-hand method using both lids to expel the lens.

Fingers from each hand should be placed at the lid margin of both the top and bottom lids.

Pressure should be placed on the lids so the margin presses against the globe.

The lids should then be pushed toward each other. Care should be taken not to evert the lids.

When performed properly, the lens will be expressed from the eye.

PROGRESS EVALUATION Scheduled according to age of child and complexity of the case

Infants < 6 months – seen every 2 weeks

Age: 6-12/18 months – seen monthly

Age: After 18 months- seen every 3 months

Maintained at a minimum of 6 months for minors

Spectacles must be prescribed at all times- to act as a back up during eye infection, flu or other systemic illness that may affect the eyes

Remove lenses when swimming, playing with sand and during flight

CASE

4 y/o patient had a h/o of congenital

cataract (LE)-removed in 1st year of

life

Initially fit with Silsoft CLs, At age

of 3,she became

intolerant to Silsoft lenses.

She was successfully

fit with a hydrogel

lenses (BCR 8.3mm, OAD 13.0mm, RX

+20.00D)

4 mths after that, patient

began to experience discomfort

and lens was decentered.

Mother expressed interest in trying a

different lens

SolutionSilicone hydrogel trial lenses are to be ordered.RefractionOD: pl (20/20)OS: +15.00 (20/60)

The following lens was ordered for her OS: BCR 8.3mm, Dia:13.0mm, RX: +20.00D. (The power was chosen to make the patient artificially myopic to allow clear vision at near-lack of accommodation in aphakic eye)

At f/u visit, the results of testing were:VA OD: 20/20OS: 20/100 with an over-RX of -4.00/+1.00X180; VA still 20/100The lenses centered well. To continue patching for amblyopia.

After 3 months of amblyopia treatment, her VA with contact lens was OS 20/40. Her over-RX was -0.50/+2.00X135 (20/30). A new lens was ordered with the same parameters, except the power was changed to +16.00D, The lens centers well and provides good fit.

REFERENCES Baldwin, W. R., Adams, A. l. and Flattau, P. (1991) Young adult myopia.

In: Refractive Anomalies: Research and Clinical Applications (T. Grosvenor and M. C. Flom, eds). Butterworth-Heinemann, pp. 104-120.

Hom, M. M., Bruce, A. S.(2006). Manual of contact lens prescribing and fitting. Elsevier Butterworth-Heinemann, pp. 599-601.

Duckman, R. H. (Ed.). (2006). Visual development, diagnosis, and treatment of the pediatric patient. Lippincott Williams & Wilkins, pp. 263-265.

Bennett, E. S., & Henry, V. A. (2013). Clinical manual of contact lenses. Lippincott Williams & Wilkins, pp. 481-493.