Australian and New Zealand journal of ophthalmology最新文献

Recently many soluble growth factors capable of influencing neovascularisation (angiogenesis) have been isolated and molecularly cloned. As such they are now available in a highly purified and active form. One or several of these already quite well known molecules may be of importance in the control of ocular neovascularisation. This article reviews what is presently known about growth factor control of neovascularisation with particular emphasis on both the eye and those factors that have already been molecularly cloned. In addition several recently reported inhibitors of neovascularisation are discussed. Such research is of particular interest to the ophthalmologist as knowledge gained in this area may allow for the use of both growth factors as well as growth factor inhibitors in the management of several ocular diseases involving neovascularisation.

Failure of the filtering bleb after trabeculectomy with a gonioscopically patent drainage cleft is likely to be due to: encapsulation of the bleb; flattening of the bleb; or cystoid bleb. Encapsulated blebs and flattened blebs are usually associated with a high intraocular pressure (IOP) while cystoid blebs are not, but corneal ulceration due to the prominent cystoid bleb may make revision of the bleb necessary. If the IOP is raised it is best to proceed quickly to needling of the bleb using 5-fluorouracil. Sixteen patients underwent needling of the bleb, eight with encapsulated, six flattened and two cystoid blebs. Chronic open-angle glaucoma (10 cases) was the commonest glaucoma. Twelve patients obtained satisfactory control of IOP with mean pre-needling IOP for encapsulated blebs of 32 mmHg (4.27 kPa), flattened blebs 36 mmHg (4.8 kPa) and cystoid blebs 16 mmHg (2.13 kPa), while post-needling IOP for encapsulated blebs was 12 mmHg (1.6 kPa), flattened blebs 13 mmHg (1.73 kPa) and cystoid blebs 12 mmHg (1.6 kPa). Mean follow-up for encapsulated blebs was 15, flattened blebs 11 and for cystoid blebs nine months. Mean time between trabeculectomy and needling was: for encapsulated blebs 16 days; flattened blebs 24 days; and cystoid blebs 19 months.

A novel dialysing seton made from haemodialysis tubes was implanted into eleven rabbit eyes to establish its biocompatibility. The animals were observed for up to 67 days after implantation. The cannulae were well tolerated clinically. Tissue obtained at seven different time periods was studied by light and electron microscopy and showed only a mild inflammatory reaction of the same grade as or less than that surrounding nylon sutures used to close the scleral trapdoors. The eye containing the seton had consistently lower intraocular pressure compared to the sham-operated fellow eye for up to 24 days. This effect declined over the ensuing five weeks.

A survey of the use of local anaesthesia in cataract surgery by ophthalmologists in Australia is presented. The main conclusions drawn from the survey were: 1. A marked trend towards the use of local anaesthesia in cataract surgery during the years 1983-88 throughout Australia. A less marked trend in country areas and in Western Australia. 2. The use of local anaesthesia did not correlate with the number of cataract operations performed by an ophthalmologist. 3. Day case cataract surgery was more often performed under local anaesthesia in private than in public hospitals. 4. Throughout Australia retrobulbar local anaesthesia was preferred to the peribulbar technique. 5. The most commonly used local anaesthetic mixture was 2% lignocaine and 0.5% marcaine with or without adrenaline and/or hyalase.

Four hundred and twenty nine patients (846 eyes) referred to the glaucoma clinic at Concord Hospital between 1979 and 1989, were included in a prospective study. This study investigated the circulatory status of each eye during tonography, by using a modified Valsalva manoeuvre to induce changes in intraocular pressure (IOP) and amplitude of tonography pulse pressure (TPP). Of the large falls in IOP, 85% of the eyes had a Po/C greater than 150. The average IOP without medication, on the morning of the test, was 20 mmHg (2.67 kPa). Central visual field defects were found in 495 eyes, and these were far more prevalent in the Po/C greater than 150 category. An unexpected finding was the ratio of 67:33 right to left eyes in the Po/C less than 100 category. The commonest reasons for referral were intermittent rises of IOP, suspicious optic disc cupping, and the need to confirm a previously made diagnosis.

Most major eye centres in Australia have now seen patients with corneal infection due to Acanthamoeba. The medical treatment of this condition is difficult; Acanthamoeba isolates show wide variation in their susceptibility to antimicrobial agents and amoebicidal concentrations are difficult to achieve in the cornea. The recent development of animal models of Acanthamoeba keratitis will be important in understanding the pathogenic mechanisms involved. The key to improving the visual outcome for these patients may prove to be the manipulation of the host response.

Granular cell tumours are uncommon benign tumours, occurring in various sites in the body, and very rarely in the orbit or ocular adnexa. Four cases of orbital granular cell tumour are described, with detailed light and electron microscopic description of one tumour arising in the orbital apex of a child. The histogenesis of granular cell tumour is uncertain, with many authors proposing an origin from Schwann cells. In central nervous system granular cell tumours, an astrocytic cell origin has been proposed. Evidence is presented for an origin from astrocytes in a child whose tumour arose in or adjacent to the optic nerve.

A 64-year-old man presented with an arterial macroaneurysm on the optic disc, an unusual location for retinal arterial macroaneurysm. The macroaneurysm resolved spontaneously without sequelae.