A prospective randomised study of local versus general anaesthesia for cataract surgery.

One hundred and sixty-nine patients (aged 65-98 years) were randomised to receive either local or general anaesthesia for cataract surgery. Cognitive function was assessed using a battery of psychometric tests performed pre-operatively, and at 24 h, 2 weeks and 3 months postoperatively. Oxygen saturation, blood pressure and heart rate were monitored and the results recorded throughout the anaesthetic and immediate recovery period. In the general anaesthetic group, 19% of patients experienced at least one episode of oxygen desaturation during the procedure compared with none in the local anaesthetic group. Pulse rate and blood pressure were stable in the local anaesthetic group compared with the general anaesthetic group where marked fluctuations were noted; 61% of patients in the general anaesthetic group experienced falls in systolic blood pressure greater than 30% of the pre-induction value. No evidence of long-term postoperative cognitive dysfunction was detected and there was no significant difference between the performances of the two groups.

Transient loss of peripheral vision as the presentation of left atrial myxoma.

A 42-year-old man developed transient loss of vision in both eyes. On echocardiography to investigate a systolic murmur and determine the potential source of emboli, a large left atrial myxoma was diagnosed. This was removed successfully leaving no visual or neurological deficit.

Diplopia after retinal detachment surgery.

Diplopia following retinal detachment usually responds to simple measures. Fifteen out of 311 cases developed diplopia lasting more than three months after conventional retinal detachment surgery. Binocular single vision was restored in 12 of the 15 cases (80%). The mean follow-up was four years. Diplopia was eliminated stepwise. If prisms were ineffective, our first surgical procedure was removal of the scleral buckle. If the retina was flat, we were prepared to remove the buckle early. When diplopia persisted after buckle removal, we proceeded to strabismus surgery. Our most consistent results followed strabismus surgery on the untreated eye. Prisms alone restored binocular single vision in six patients (40%), one of whom preferred to adopt a compensatory head posture. Removal of the scleral buckle restored binocular single vision in three patients (20%), with the help of a prism in one case and a compensatory head posture in another. Binocular single vision was restored after buckle removal and strabismus surgery in three further patients (20%), one requiring a prism in addition. Binocular single vision was not restored in three patients (20%).

Life on implants.

Seven Ridley Mark I anterior chamber lenses were removed from patients at St Thomas's Hospital. The lenses had been in place for an average of 15 years. The indication for removal was corneal endothelial decompensation with painful bullous keratopathy. Examination of the lenses under the scanning electron microscope showed remarkably similar morphology in each case. A well organised fibrin membrane covered the implants to which iris pigment epithelial cells were adherent. Red blood cells, scattered fibroblasts and pigment granules were also found. Giant cells were not identified while macrophages and lymphocytes were rare. These findings suggest that corneal endothelial decompensation was not due to chronic inflammation but was probably caused by movement of the implants within the eyes.

Assessment of unilateral afferent pupillary defects by pupillography.

A pupillographic technique, an adaptation of the swinging light test, is described for the measurement of unilateral afferent pupillary defects. In normal persons it yielded accurate, reproducible estimates of the magnitude of artificial afferent defects made with neutral filters of 1 to 4 log units density. In 15 studies on 8 patients with unilateral optic neuritis and 2 with unilateral compressive lesions the measured afferent pupillary defects correlated closely with both visual acuity and visual threshold deficits. Measurement of the pupillary defect underestimated severe degrees of impairment revealed by visual threshold determination. Discrepancies between pupillary defect and visual acuity were observed in the 2 patients with compressive lesions and in 1 patient who had a central scotoma 4 months after an attack of optic neuritis.

Efficacy of acycloguanosine (Wellcome 248U) against herpes-simplex corneal ulcers.

Acycloguanosine (9-[-hydroxyethoxymethyl]guanine) (Wellcome 248U) has a highly specific and potent antiviral action against herpes-simplex virus (H.S.V.) types I and II in cell-culture systems and in animal models of H.S.V. infection in the brain, skin, and eye. Its efficacy in man was tested in twenty-four patients with dendritic corneal epithelial ulcers treated by minimal wiping debridement. Patients were randomly allocated to treatment with 3% acycloguanosine eye ointment or placebo. There were seven recurrences or recrudescences of typical corneal epithelial herpetic lesions within 1 week of debridement in the twelve patients who received placebo, and no recurrences in the twelve who received acycloguanosine. Four further patients with dendritic ulcers have been electively treated with topical acycloguanosine alone. Their ulcers all healed briskly. No adverse effects were seen with the acycloguanosine therapy. These results establish that acycloguanosine is a clinically effective antiviral drug against H.S.V. infection in man.