Preschool Vision Screening in Korea: Preliminary Study

Vision Screening of 1211 preschool children at 6-year-old was done by the visual acuty test, the cover test, and the stereoacuity test primarily. Secondarily, the corrected visual acuity, the refractive state. the amount of ocular deviation, and the cause of amblyopia were evaluated if the monocular acuity was 0.6 or less, or the difference of two or more lines on the Han's chart between right and left eye with the best optical correction was present, or the strabismus was detected on the primary screening. One hundred and thirty-eight children(11.4%) were abnormal on the primary screening. Seventy-nine children showed myopia. 46 hyperopia, and 3 alisometropia with the cycloplegic refraction, and 79 children also had astigmatism. Twelve children showed strabismus with the cover test. Among those, 8 belonged to exotropia and 4 to esotropia. Six children showed amblyopia and the causes of amblyopia were astigmatism, exotropla, and anisometropia. Among these 6 amblyops, 3 showed abnormal findings with the cover test and 2 showed stereocuity over 1200 seconds of arc. Therfore, among these three tests as primary vision screening, the cover test and the stereoacuity test to be inadequate to detect the amblyopia.

Effect of the Viscoelastic Substance on Surgery of the Extraocular Muscles in Rabbit: 1. Histopathologic Study by a Light Microscope

We evaluated histopathologically the effect of the viscoelastic substance on surgery of the extraocular muscle in the 26 rabbits with 1. 6-2. 5kg of weight. The viscoelastic substances were 1% sodium hyaluronate(Healon) and 2% hydroxypropyl methylcellulose(Methocel), which were introduced between the extraocular muscle and its adjacent tissue on surgery. The rabbits were categorized by group 1(the rabbits with Healon), group 2(with Methocel), and group 3(with normal saline as control). These rabbits were enuclated at 3rd, 7th, 14th, 28th and 56th day following operations, and the eyes were fixed in 2.5% glutaraldehyde solution. The tissue was stained with hematoxylin-eosin and Masson's trichrome, and examined under a light microscope. The results were as follows: 1. In the first group(Healon), the tissue adhesion and degeneration of the muscle were milder than those of control(saline) group. 2. The changes in second group(Methocel) was milder than in the first group and more severe than in control group. 3. It is concluded that 2% Methocel can be used clinically in the surgery of the extraocular muscle.

A Case of Inverse Duane's Retraction Syndrome

The retraction syndrome in its classic form is characterized that severe limitation of abduction, slightly limitation of adduction, globe retraction and narrowing of the palpebral fissure on adduction, frequently associated elevation or depression in adduction, and convergency insufficiency. While many authors reported this type, there were few reports about inverse Duane's retraction syndrome, as exotropia in primary position, severe limitation of adduction. globe retraction and narrowing palpebral fissure on abduction. So the authors present a case of inversed Duane's retraction syndrome.