Management

31.1 Management

Parental management

Sympathetic management is essential. With infants, parents are naturally concerned about eye problems which become evident within a few weeks of birth, whether the treatment is surgery or simply optical correction. Ametropic children as young as 4 or 5 years may be brought in for contact lenses because the parents cannot accept the idea of spectacles. A contact lens trial may also help appreciation of vision where children have reacted against spectacles.

31.1.2 Child management

Babies are easy to manage as no communication is necessary, whereas infants need the stimulation of toys to help with attention. Children of 5 years and older need a great deal of patience and kindness at the initial fitting for the essential building up of confidence. Apart from fear of the unknown, they are disturbed by the manipulation necessary for insertion and removal and can be frightened of the optical equipment.

31.1.3 Insertion and removal

Insertion

•Insertion of rigid gas-permeable lenses is easier than soft.

•The quicker the lenses are applied to the cornea the better.

©2010 Elsevier Ltd, Inc, BV

DOI: 10.1016/B978-0-7506-7590-1.00011-X

Section SIX Children and therapeutic lenses

•Rigid gas-permeable lenses should be put directly onto the cornea if at all possible as moving from the conjunctiva prolongs any distress.

•Keep talking to the child to aid where to look and keep the alternate eye open.

•Often only one lens is managed at the first visit.

•Schedule a second visit for the other or both eyes to finish the fitting.

•Try to evaluate the fitting from only one diagnostic lens to minimize handling.

•Soft lenses may need to be squeezed from below under the top lid.

•If a thin soft lens with Rx makes insertion difficult, try a more rigid silicone hydrogel first; return to the preferred material at a later stage.

•Limit head movement with firm positioning on the head-rest.

•Sitting on the hands limits any ‘fending off’ by the child.

•If all else fails, it might be possible to teach insertion to the child.

•If insertion is difficult or fails, before the next visit ask the child to practice touching the conjunctiva with a clean finger or have the parent instill rewetting drops to allay some of the fears.

•At the teaching visit, the parent should watch the process to guide the hand or finger as appropriate.

Removal

•Rigid gas-permeable lenses are usually easy to remove with manipulation of the lids.

•At the teaching visit, rigid gas-permeable removal may be difficult with ‘stare-pull-blink’ if compliance is not perfect, so lid manipulation may be the best method.

•Soft lenses are most easily pinched off the temporal or inferior conjunctiva but sometimes removing directly from the cornea may prove the best option. Even small children can usually manage this technique.

•Lenses can be dispensed as long as removal is accomplished, even if the parent has to help with insertion.

31.1.4 Anaesthetics

The use of anaesthetics is dependent on the child’s reaction and the practitioner’s preference. For rigid gas-permeable lens fitting there is the argument that it will help the initial reaction and aid fitting assessment. The argument against is that it is better to have the worst reaction at the initial fitting. Then for all subsequent visits the comfort improves, especially at the dispensing visit when it is important for the child to feel positive about wearing lenses.

31.1.5 Hypnosis

If an adolescent cannot manage insertion and removal but there is strong motivation and good clinical need, hypnosis can be considered. It is not a common procedure but has proven successful.1

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Table 31.1  Approximate corneal dimensions for children*

*Adult dimensions are reached at approximately 10 years of age.

31.2 Instrumentation

Keratometry and slit lamp examination can be performed from an early age with a cooperative child, who can be held by the parent, kneel on a stool or stand at the instrument (Table 31.1). A hand-held keratometer can also be useful in these cases.

31.3 Non-therapeutic fitting

If a child is happy wearing spectacles, the parents are best dissuaded from the idea of contact lenses. Nevertheless, they can sometimes be very successful with children as young as 5–7 years old, although 10–12 years is a more usual age to consider fitting.2 The following criteria apply:

•Visual correction is required all the time.

•The child wants lenses.

•The parents want the child to have lenses.

•The child is old enough to understand handling, maintenance and hygiene.

Keratometry readings are in the same range as those for adults and the fitting technique is the same. It is important to use a diagnostic lens close to the required power so that the child can see when the first lens is inserted. The main difference from adult fitting may be the total diameter because of a smaller corneal size. With rigid gas-permeable lenses, the TD chosen is often 9.00 mm and a material with high Dk should be used.

Hydrogel or silicone hydrogel lenses should where possible be disposable. Daily disposables offer the further advantages that there is no maintenance required and there is minimum cost in the event of loss or damage. A conventional hydrogel or silicone hydrogel lens should be used only for specialist  prescriptions. Even in these cases it is often worthwhile using the nearest  feasible disposable to confirm that the child is able to cope with lenses before ordering the full Rx. With soft lenses, the usual fitting criteria are used (see Chapter 16).

Aftercare is imperative because of the potential number of years lenses may be worn and the material with the best physiological characteristics should be used.

The advantages and disadvantages of the various lens types are mainly as given in Section 5.3, but rigid gas-permeable lenses are still a possible first choice

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Section SIX Children and therapeutic lenses

for myopes, with silicone hydrogel or high water content hydrogel lenses for hypermetropes. Conventional torics should initially be avoided because of the expense and risk of loss.

31.4 Refractive applications

31.4.1 Myopia

The correction of high myopia may improve both acuity and the field of view. Near vision develops without any optical correction. The first choice is often silicone hydrogel to avoid the thick edge of a high minus lens leading to vascularization in the long term. Hydrogel lenses must be of the highest practicable Dk.

Rigid gas-permeable materials of medium Dk are usually the most suitable, representing a balance between lens stability and physiological performance.

Myopia control

Myopia control has been achieved with PMMA3 and to a lesser extent with rigid gas-permeable lenses4 which are physiologically superior. The results of the Contact Lens and Myopia Progression (CLAMP) study showed a small but inconclusive advantage for rigid gas-permeables over soft lenses.5

Orthokeratology

Orthokeratology (see Chapter 14) has proven very successful with children and teenagers but must be monitored carefully for ethical reasons. Recent studies suggest that the technique can produce some degree of myopia control because of the effect of peripheral spherical aberration on axial length but the long-term results are not yet predictable.6

31.4.2 Hypermetropia

Strabismic children, especially those with accommodative esotropia,7 derive greatest benefit from contact lens wear. Normal hypermetropes will find vision better with spectacles but comments at school may initiate contact lens wear.

Silicone hydrogel lenses are the first choice for infants under 6 years, where extended wear may be an advantage, and for most older children. The final choice depends on lens power, degree of astigmatism, the acceptance or otherwise of a rigid lens and school or sporting activities.

31.4.3 Anisometropia

Unilateral myopes or hypermetropes, whether axial or refractive, may benefit from a combination of contact lens wear and part-time occlusion. Success is often greater than with spectacles as lenses will provide better stereopsis, although in some cases the lenses merely keep an amblyopic eye straight.8

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