Histopathological features of congenital fundus lesions in familial adenomatous polyposis.

We report the light and electron microscopic findings for two lesions from two patients who died of complications of familial adenomatous polyposis. In the first case microscopy of a small (100 to 200 mu), uniformly dark lesion (the commonest type seen in this condition) showed enlarged retinal pigment epithelial cells with an increased number of pigment granules. This is consistent with the term "hypertrophy of the retinal pigment epithelium", currently used to describe these lesions. In the second case we sectioned a larger (1000 to 1500 mu), oval, grey lesion from the posterior pole. The pigment epithelium was normal, but between it and outer retina was an unusual choristoma consisting largely of myelinated axons and astrocytes.

Lidocaine attenuates the intraocular pressure response to rapid intubation in children.

To determine the effect of intravenous lidocaine on the intraocular pressure (IOP) response to laryngoscopy and intubation, twenty unpremedicated children, ages one to ten years were studied. After administration of either intravenous sterile water (control) (n = 10) or preservative-free lidocaine (1.5 mg X kg-1) (n = 10), anaesthesia was induced with pancuronium (0.15 mg X kg-1), thiopentone (5 mg X kg-1), and atropine (0.02 mg X kg-1), and maintained with halothane, nitrous oxide and oxygen. The trachea was intubated one minute after administration of thiopentone. IOP (measured by applanation tonometry), heart rate, and systolic blood pressure were measured at the time of loss of the eyelid reflex (time 0), immediately after endotracheal intubation, and each minute thereafter for five minutes. In the control group, IOP increased (27 per cent) significantly after intubation (p less than 0.05), whereas in the lidocaine group, IOP did not increase (9.8 per cent) significantly after intubation. IOP decreased below time 0 values within three minutes after loss of the eyelid reflex in the lidocaine group (p less than 0.05). At each measurement (except time 0), IOP was significantly greater in the control group than in the lidocaine group (p less than 0.05). Heart rate and systolic blood pressure did not increase significantly in either group after intubation. We conclude that intravenous lidocaine (1.5 mg X kg-1) significantly attenuates the IOP response to laryngoscopy and intubation in children anaesthetized with pancuronium, thiopentone, and atropine.

Corneal diameter and axial length in congenital glaucoma.

The corneal diameter was recorded and the ocular axial length measured by A-scan ultrasonography in 31 eyes of 17 children (ages 0.05 to 7.0 years) who had undergone or were about to undergo surgery for primary congenital glaucoma. These measurements were also done in 60 normal eyes of 33 children (ages 0.20 to 9.6 years) undergoing nonophthalmic surgery. Both measures were usually greater than normal in the glaucomatous eyes. However, the corneal diameter was more sensitive than the axial length in identifying congenital glaucoma. The axial length measurement did not provide additional useful information for any of the eyes. We conclude that the corneal diameter is a more reliable guide than the axial length in the assessment of congenital glaucoma. A transparent plastic gauge for rapid and accurate measurement of the corneal diameter is described.

Effects of radial and circular keratotomy in rabbits.

Nine rabbits underwent radial keratotomy in one eye and circular keratotomy in the other. The follow-up period ranged from 9 to 12 weeks. There was no significant change in the axial length of the eye with either type of surgery, and circular keratotomy produced no significant changes in the curvature or the refractive error of the cornea. However, radial keratotomy produced significant spherical changes in both corneal curvature (mean -3.09 D, P less than 0.01) and refractive error (mean +2.18 D, P less than 0.01); the refractive changes can be explained entirely by the changes in curvature.