No abstract

Pars plana vitrectomy with gas tamponade is an effective method of treating this form of retinal detachment. Some macular holes close after this surgery.

SUMMARYWe undertook a prospective slit lamp examination of 56 eyes which had undergone routine phacoemulsification, in order to determine the incidence of metallic intrao The use of phacoemulsification in cataract surgery is increasing in the United Kingdom. The post operative finding of intraocular metal particles has long been recognised, such particles having been considered inert. 1 , 2 We attempted to examine and quantify this phenomenon, in the light of recent interest in 'metallosis' and the bioreactivity of titanium alloy. 3 -8 PATIENTS AND METHODS Clinical StudyFifty-four consecutive phacoemulsification patients (56 eyes) were studied. The phacoemulsification equipment contained a Venturi pump with two piezo-electric crystals operating at 28 kHz. The diameter of the needle barrel and the width of the phacoemulsification tunnel were 1 mm and 3.2 mm respectively.All patients were examined within 2 weeks of surgery by slit lamp biomicroscopy. Using maximum illumination and magnification, the iris stroma was examined with an angled beam (45°) directed first from the right and then the left. The patient's eye was examined in the primary position and then in upgaze and in downgaze. Particles often glinted when illuminated from one direction only. The number and position of particles were recorded by a single observer (CM.D.). Study of Phacoemulsification NeedlesTwelve phacoemulsification needles were examined under the operating microscope and the pattern of wear recorded by colour photography. One new and four used needles were further examined using a J eol JSM-35CF scanning electron microscope operating at 12 kV. RESULTS Clinical StudyFifty-six eyes of 54 patients were studied; average patient age was 73.4 years and the male to female ratio was 17 to 37. All operations were performed at Aberdeen Royal Infirmary by one of four consul tants.Metallic particles were noted in 48 eyes (86%). The number per eye ranged from 1 to 103 with a mean of 5.1. Only the largest reflected sufficient light to appear on a slit lamp photograph (Fig. 1). Many appeared no larger than a white blood cell. Particles appeared to be randomly distributed over the iris stroma, often within crypts. No accompanying clinical problems were seen. Under the reduced Eye (1995) 9, [434][435][436]

The aim of this study was to determine whether capsulotomy size influences visual performance. Snellen visual acuity and forward light scatter (light scattered towards the patient's retina, but out of the focussed retinal image) measurements using simple computer graphics based on van den Berg's technique were used to measure visual performance. Twelve patients were studied: 4 had small central capsulotomies through undilated pupils and 8 had wide capsulotomies through dilated pupils. The two groups were matched for age and pre-laser Snellen acuity. Following treatment, both groups had equal improvements in Snellen acuity. There was only a significant (p < 0.001) improvement in forward light scatter readings in the group who received wide capsulotomies. Measurements of forward light scatter are more sensitive than Snellen acuity testing in demonstrating loss of visual performance in patients with media opacities. It is recommended that pupils are dilated prior to Nd:YAG capsulotomy if forward light scatter from capsule remnants and the consequent glare disability are to be minimised.