Contact Lenses in Pediatrics

Ling Sook YeeP 82495

Why fit children with contact lenses? Aphakia

Cataract, persistent hyperplastic primary vitreous (PHPV), post-partum trauma

Refractive error Anisometropia & amblyopia Binocular vision Appearance Myopia control

Cataract & Aphakia Congenital cataract : surgery as early as

possible Infantile cataract : surgery once

vision interferedUnilateral CataractCome with concomitant

strabismus

Associated with ocular anomalies

Higher risk of ambloypia

Correction of Aphakia

Optical Correction

Glasses

Contact Lenses

Intraocular Lens

Epikeratophakia

Modify refractive error from cornea donor Rarely used due to complications

May affect the function of ciliary muscle

Required when patient not suitable for IOL

Post Operative CorrectionSpe

ctacles

•Narrow visual field to 30°•Retinal size disparity•Heavy and large frame

Co

ntac

t Lenses

•Best choice for post-operative aphakia•Allow changes for visual correction with IOL upon visual maturity•Good visual quality

Intraocular lens (IOL)

•Excellent visual quality•High risk of complications (eg: PCO)•Challenging in predicting future refractive shifts due to immature visual system •Induced corneal astigmatism

Contact Lens Considerations Power changes

First 11 – 18 months: expected to decrease ~ 10D Need for supplementary spectacles? Wound healing Ocular medications Systemic condition Compliance

Contact Lens in Pediatric Fitted immediately after cataract surgery

Available in a) Hydrogel lensb) Silicone elastomerc) RGP

Require near correction: Until age 2 : overcorrect by +3.00 D Age 2 – 3 : overcorrect by +1.00D to +1.50D After age 3 : bifocal with +3.00D add

Fitting CL in Pediatric 79% success rate in congenital cataract

Using contact lenses for a few years and having lens implants later could work better. (National Eye Institute)

There was no difference in the vision between the eyes treated with CL compared to IOL. But the IOL group had more complications and required more eye surgeries. (Infant Aphakia Treatment Study)

1. Hydrogel Lens

Advantages Disadvantages

Initial comfort In high power, lens central thickness , oxygen permeability , risk to complications

Can be custom-made Prone to dehydration

Stable position Do not correct significant corneal astigmatism Required skill for insertion due to large diameter

• Diameter: 2mm larger than HVID

Water ContentWater Content

Low

Minimize hydration

Minimize lens deposits

Maximize durability

HighMaximize O2

transmissibility

2. Silicone Elastomer

Advantages Disadvantages

Comfort Very expansive Easy handling Heavy lipid deposits

(hydrophobic) High dk Limited power (highest +32.0D) Less loss rate Large diameter

No UV protection

• Example: B&L Silsoft• Base curve: flattest K + 0.1mm

3. RGP The best choice for elder children & small

palpebral fissure.

Fitting: Diameter: 1-2mm smaller than cornea diameter Power : retinoscopy & correct for vertex

distance Base Curve : slightly steeper

[flattest k – 0.1mm ] Movement : 1.0 – 1.5mm

RGP

Advantages Disadvantages

Large range of parameters Risk of abrasion

Correct corneal astigmatism Initial discomfort

Durable Requires skill in fitting/removal

High oxygen permeability Higher loss rate due to small diameter

Challenges & Complications Lens frequently loss Too expansive Time consuming Difficulty in lens handling Non compliance Greater risk of infection

Failure of treatment is related to treatment of amblyopia, and not related to the fitting and wearing of contact lenses.

(Moore BD, 1993)

References Moore, BD. (1993) Pediatric aphakic contact

lens wear: rates of successful wear. J Pediatr Ophthalmol Strabismus, 30(4):253-8.

Szczotka, LB. Pediatric contact lenses. California Optometric Association.

Daniels K. (1999) Contact lenses. SLACK Incorporated, 141-145.

Extract from: http://web1.sph.emory.edu/IATS/. Infant aphakia treatment study.

Phillips AJ and Speedwell L. (2007). Contact lenses. Butteworth Heinemann, 505-512.