Because a child’s vision system is growing and developing, especially during the first 5-6 years of life, glasses may play an important role in insuring normal vision development. The main reasons a child may need glasses are:
Ocular examination and vision screening should actually start AT BIRTH and continue as part of routine check-ups. Your pediatrician should know the essential parts of pediatric vision screening because early detection and treatment of eye disease in children is important. There are four critical periods in the growth of a child’s vision: (1) preterm, (2) perinatal or infantile period, (3) preschool years, and (4) elementary.
Preterm infants are at risk of developing retinopathy of prematurity (ROP) and pediatricians are aware of the guidelines for referral to an ophthalmologist for ROP screening. Preterm babies with ROP should be screened by an ophthalmologist at regular intervals until retinal vascular maturity is complete. Laser treatment should be instituted when indicated. It is not safe to assume that babies born full term will not develop eye problems such as cataract, glaucoma, strabismus, and anterior segment dysgenesis. These are the conditions that should be looked for when screening healthy infants. Preschoolers are likewise not safe from developing eye problems because it is during this stage that conditions such as strabismus, high error of refractions, anisometropia, and amblyopia start to manifest. Amblyopia treatment should be instituted right away. Lastly, children in grade school or elementary should be screened for refractive errors like hyperopia, myopia, astigmatism, or any combination of these. Children are not small adults; they cannot verbalize what they feel (or see) most of the time. Parents only notice the change in behavior or head posture when the child is already symptomatic.
It is the presence of the above critical periods that led to the practice of regular eye evaluation in children. The following are suggested eye exam schedule for children:
Your pediatrician should be aware of indications for referral to an ophthalmologist. The frequency of eye evaluation for children with abnormal findings depends on the abnormality and the severity of the problem.
By doing a complete eye examination, an ophthalmologist can detect the need for glasses even in very young children. Typically, the pupils are dilated in order to relax the focusing muscles, so that an accurate measurement of the error of refraction can be obtained. By using a special instrument, called a retinoscope, your eye doctor can arrive at an accurate prescription. The ophthalmologist will then advise parents whether the measured error of refraction is appropriate or expected for his or her age and whether there is a need for glasses, or whether the condition can be monitored.
Children have great accommodative amplitudes and they can change the measurement of refraction. In a child who has no error of refraction (emmetropic), a significant myopia, and sometimes astigmatism, may be picked up if he or she accommodates. The only way to get an accurate measurement of error of refraction in children is to inhibit accommodation with the use of cycloplegic agents.
There are several agents commonly used in practice and these include tropicamide, cyclopentolate, and atropine. The first two agents have rapid onset of accommodation, short duration and few side effects. The last one has a longer onset, requiring three days of drug application, and longer duration, but provides the greatest amount of cycloplegia. Most children may be refracted using the first two. However, children with dark irides like Asians are not as responsive as Caucasian children to the cycloplegic action of the first two agents. Atropine refraction is therefore recommended for this set of children.
Minor side effects of cycloplegic agents include transient stinging, blurring of vision, and photophobia. The stinging sensation is diminished by the application of a drop of anesthetic prior to the application of the cycloplegic agent. Photophobia may be addressed by wearing wrap-around sunglasses or hats. The duration of photophobia and blurring of vision is related to the duration of the drug’s mydriatic effect. The shorter-acting agents provide faster recovery of accommodation and of resolution of symptoms. Atropine is associated with relatively more adverse effects such as dry mouth, flushing of the face, fever, allergic reaction, irritability, tachycardia, and hallucinations. Therefore, the child’s weight and age are important considerations in the choice of atropine concentration or dose for cycloplegic refraction. Punctal occlusion during drug administration of atropine helps in decreasing the systemic absorption of atropine and greatly diminishes the occurrence of severe adverse drug reactions. Any child with severe adverse drug reaction should be brought to the hospital for immediate treatment.
Any child with an error of refraction that is unexpectedly high for his age should wear corrective glasses. Even 2 month- old babies with very high hyperopia may be given glasses to prevent strabismus and amblyopia. The amount of correction will depend on the degree of the error of refraction and the alignment of your child’s eyes. Regular cycloplegic refraction, usually every 6 months, will indicate whether the error is getting better or worse. This will also help your eye doctor determine how much correction to add or subtract from your child’s previous correction.
There are two ways to do this: (1) the use of spectacles, and (2) the use of contact lenses. Spectacles or eyeglasses have the advantage of being easy to use. They provide protection for the eyes without inciting any corneal problems. Contact lenses, on the other hand, are cosmetically desirable, and they do not magnify nor minify the image that the child sees, as glasses can. However, there is a risk of corneal infection, especially with soft contact lenses. Contact lenses are very important in the treatment of aphakia (patients without the natural lens), as they provide a constant, clear image without significant distortion or magnification. Infants waiting for the proper timing of intraocular lens implantation can be fit with contact lenses, if necessary.
Laser surgery in children is still experimental. Recently, there has been a considerable interest in the surgical correction of hyperopia (farsightedness) using laser. So far, laser surgery is not advisable in children because of the lack of long-term results on these procedures. Hopefully, researchers would better understand the growth of the eye and the factors that result in refractive errors, and learn to manipulate these to create eyes with normal vision.
There are 4 basic types of refractive errors:
No. In fact, the opposite may be true. If a child does not wear the glasses prescribed, normal vision development can be adversely affected.