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204
Annual Report of the London Ccunty Council, 1912.
During the year 1912 thirty-two cases of squint, in which the condition, either by reason of age
or variety of squint, was irremediable by other methods, were operated upon for the readjustment of
the eye muscles with satisfactory results.
The extreme importance of securing early treatment for squint cannot be too strongly insisted
upon; if the case be neglected the squinting eye may become blind from disuse; treated early the
deformity may be reduced, and the sight of the eye recovered.
Errors of refraction (including those found in the squint cases) numbered 1,420.
Errors of
refraction
Reference should be made to the manner of ascertaining and recording the refraction of the
children under examination. In about 75 per cent, of the cases the refraction was determined after
an ointment of atropine sulphate of 1 per cent, had been used at home for one week. In the remaining
25 per cent. the mydriatic used was a solution in castor oil of the pure alkaloids of homatropin and
cocaine 2 per cent. of each, and the oil was instilled into the conjunctival sac of the eyes at the hospital,
when the child had to wait with the eyes closed for one hour to ensure the full effects of the mydriatic.
Both methods have their advantages and disadvantages. The use of the quickly acting mydriatic
has the advantage of saving one attendance at hospital and the possible risk of non-attendance for
complete treatment. It has the disadvantage that the actual waiting at the hospital for both child
and parent is long; a yet more serious disadvantage is that the oil causes some smarting on instillation so
that a timid, or, more usually a spoiled child, will scream and disturb all the other children in attendance.
The balance of convenience is found to rest with the use of the ointment; the parents are told how to
use it, and it is rarely found that they fail to carry out the directions. They appear to prefer themselves
to apply the ointment at home.
The refraction is determined by retinoscopy with a plane mirror, the results obtained at the
distance of 1 metre are corrected for infinity, xD being the retinoscopy x-1D = the real refraction of
the eye. With this result there should be obtained the best visual acuity whilst the eye is Under the
influence of the mydriatic; the actual glass to be ordered depends upon the nature of the refractive
error.
The character of the conditions found is best seen when presented in tabular form. The following
table shows the varieties of refraction.
Varieties of refraction.
Variety. Number. Per cent.
Emmetropic 44 309
Hypermetropic. 349 24.51
Compound hypermetropic astigatism 458 32.25
Hypermetropic astigmatism 87 6.12
Mixed astigmatism 110 7.74
Myopia 167 11.7
do. with astigmatism 177 12.4
Odd eyes 28 1.9
1,420 ...
Of the eight classes the first includes a few cases referred for some failure to attain the visual
standard in which no defect of the eyes could be found at the centre. In a few there was a history of
temporary indisposition or mild conjunctivitis; in some the failure arose from misunderstanding; a
few were children with mental defect; and a very few were children who apparently were interested in
the possibilities of a visit to hospital.
Of the other classes only the last ("odd eyes") needs explanation. The term does not connote
"anisometropia," of which there were very many cases, it includes only those cases where .one eye was
found to be hypermetropic and the other myopic in some degree, either with or without astigmatism.
These eight groups may be considered as forming sections of two main groups: hypermetropia
and myopia. Ranged thus, the percentage of defects approximates very nearly to that published in
1908:—
Date. Hypermetropia. Myopia.
per cent. per cent.
1912 66 34
1908 71 29
Age
incidence of
the defects
The figures are fairly comparable; no stress should be laid on the small differences, for the situation
of the centres, and the method of transmission of the cases to them were not the same.
Owing to the inequality of the age distribution of the cases comparison is somewhat difficult.
Diagram J shows the age incidence of the several groups of errors by numbers and by per-