The frequency of entry into an ethmoidal sinus when performing a dacryocystorhinostomy.

Ethmoidal sinuses intervening between the lacrimal sac and the nose can cause confusion when performing a dacryocystorhinostomy (DCR). This study aimed to assess the frequency of entry into ethmoidal sinuses when performing a DCR and to identify any helpful distinguishing features, at surgery, between the ethmoidal and nasal spaces. Ethmoidal sinuses were initially entered in 23 of 50 standard DCRs (46%) in which the ostium was performed via the standard lacrimal fissure. Nasal mucosa was found to be 2 to 3 times thicker than ethmoidal sinus mucosa and less friable. Being aware of the risk of entering an ethmoidal sinus and of the anatomical differences between ethmoidal and nasal tissue greatly aids location during surgery and allows edge-to-edge suturing of sac mucosa to nasal mucosa in all cases.

Sleeves for fixation of Silastic nasolacrimal tubes.

AIMS: To describe a method of securing indwelling O'Donohughe's lacrimal tubes in dacryocystorhinostomy using two 3-4 mm Watski sleeves. METHODS: The operative technique used to secure the sleeves into position on the lacrimal tubes is described. Forty seven procedures with a follow up ranging from 3 to 30 months (mean 10 months) are reviewed. RESULTS: The tubes and sleeves were well tolerated. Upward prolapse of the tubes occurred only once and the tubes were easily repositioned in this case. CONCLUSION: Securing lacrimal tubes with Watski sleeves in dacryocystorhinostomy is a simple, cheap, and effective procedure.

Can retinoscopy be used to screen infants for amblyopia? A longitudinal study of refraction in the first year of life.

One hundred normal babies were refracted by two observers in a double-masked study within 24 hours of delivery and 30 minutes after instillation of 1% cyclopentolate. The procedure was repeated at 6 weeks, 3 months, 6 months and 1 year. At birth agreement between the two refractionists to within 1 dioptre spherical equivalent was 82%, rising to 94% at 1 year. Astigmatism of greater than 1 dioptre increased from 10% at birth to 42% at 6 months but decreased to 15% at 1 year. Myopia was uncommon (4%) but 80% of eyes were hypermetropic more than +2 dioptres and 25% more than +4 dioptres at birth, although these percentages decreased to 5% and 3% at 1 year. Anisometropia of more than 1 dioptre between the two eyes was uncommon but in the two cases where it persisted in the presence of high hypermetropia, reversible amblyopia was encountered in both cases.

Visual assessment of infants: vernier targets for the Catford drum.

Targets comprising a horizontal black line 5' thick offset by 1' were printed on strips to stick to the drums of the Catford Visual Acuity Apparatus. The 'vernier' targets so produced corresponded to the different sizes of Snellen letters from 6/6 to 2/60 when presented at 50 cm. Twenty-five children between the ages of 3 and 12 years with known amblyopia (mostly strabismic) were tested in a double blind trial to compare the visibility of the vernier targets with subjective Snellen acuity. All vernier results, both for better and amblyopic eye, were within one line of Snellen acuity. One hundred and twenty normal preverbal infants with normal eyes under the age of 2 1/2 years were tested with the vernier strips. Normal infants under the age of 6 months recorded a vision of 6/60-2/60; normal infants aged 6 to 12 months recorded 6/24-6/36, and infants between the ages of 1 and 2 1/2 years recorded 6/12-6/18.