Screening for problems in eyes of children study (SPECS)

Eye problems which threaten vision (including amblyopia, strabismus and
significant refractive errors) are estimated to occur in 2% - 5% of pre-school
children (1). Earlier identification of visual abnormalities is intended to
lead to earlier treatment and a better long-term visual outcome (2).
In the Netherlands visual function is tested 8 times between birth and the ages
of 8 years 3. This screening is performed at the Well Baby Clinics or during
visits by the school doctor. Screening of children with developmental problems
is not carried out systematically.
The present methods for screening eye function in children are time consuming.
Therefore a reliable and rapid screening method could be of great benefit (4).
Two new screening methods have recently become available. These are a) the
method using computerized videoretinoscopy (Plusoptix ®) and b) the method
using a handheld refractometer (Retinomax®).
Before a screening method is considered for large scale screening in the
Netherlands it must be evaluated and validated. A study using the Plusoptix ®
method has recently been carried out in Flanders in Belgium and has shown
promising results (5). A study using the Retinomax® has been carried out in
Brussels (6). The screening tests are not uncomfortable, painful, invasive nor
time consuming. No eye drops, waiting or other special preparation is
necessary.

The aim of this study is to compare the results of 2 methods for screening of
eye function in children with the standard investigation by the orthoptist. The
outcome of the tests and the time involved will be compared.

Two screening methods will be studied.

I Computerized videoretinoscopy (Plusoptix ®) is a relatively new method for
screening of eye function and is suitable for use in young children and in
people with developmental problems as co-operation is not required. Dilation of
the pupils is not necessary. Binocular measurement of both eyes together is
possible within a few seconds.

II The handheld autorefractometer (Retinomax®). This is a monocular
autorefractor using a fogging technique which aims to minimize accommodation.
Dilation of the pupils is not necessary. Measurements are repeated and the
complete screening takes about half a minute per eye.

This is a prospective study. The cohort consists of all children fulfilling the
inclusion criteria during the period of the study.
Both the user of the screening methods (using the Plusoptix® and Retinomax®)
and the orthoptist using the standard method will be *masked* as to the child*s
outcome using the other method.
The student will screen children using the Plusoptix® and the Retinomax®.
The orthoptist will perform the standard investigation.
The results of screening using Plusoptix® and Retinomax® of each child will be
recorded, as well as the results of the standard examination (retinoscopy after
instillation of cycloplegic eye drops and autorefraction when possible) by the
orthoptist. Screening using the Plusoptix® and Retinomax® will be repeated
after instillation of cycloplegic eye drops. Furthermore eye alignment,
presence of nystagmus and, if applicable, the angle of strabismus will be
noted.
The results of the screening tests and standard investigation will be kept
separately and the student and orthoptist will not be able to see each other*s
results. The time needed per test will be noted as well as the co-operation of
the child. The outcome of each method will be noted. The possibility to detect
strabismus with the Plusoptix® and Retinomax® will be evaluated
The results of the standard investigation and the screening methods will be
compared after every 50 children who have been included and at the end of the
study period.

Parents of children attending the Department of Paediatric Ophthalmology of the
Leiden University Medical Centre will be invited to let their children
participate in this study. They will be given spoken and written information
about the tests and if they agree a written consent form will be signed.

There are no risks involved in the use of the screening methods. They do not
cause pain or discomfort.
The time involved for parents is approximately 10 minutes extra on top of the
time for the regular investigation.
Participation in this study has no advantages for the individual child at
present. It is hoped that these and other children will be able to be screened
more quickly and easily if these methods are introduced in the future.

If this study shows that the Plusoptix® and/or Retinomax® give results
comparable to those of the investigation by the orthoptist it may provide data
which will influence the form in which the eye screening of young children is
carried out by ophthalmologists and orthoptists as well as at the Well Baby
clinics and school doctor*s visit the Netherlands. These methods may also be
useful for screening children who are difficult to investigate (with
psychomotor developmental delay or other problems). The findings may later
contribute to changes in international screening programmes.