Australian journal of ophthalmology最新文献

Angioid streaks were first described by Doyne in 1889. Gronblad proposed in 1929 that they followed disruption of the elastic layer of Bruch's membrane, having noted the association between angioid streaks and pseudoxanthoma elasticum. Several other diseases have been associated with angioid streaks, including Paget's disease and sickle cell disease. Angioid streaks are found predominantly in the 20 to 50 year age-group and may be associated with minimal visual loss, but the problem is the high risk of rapid development of subretinal neovascularisation at the macula with resultant haemorrhage and scarring. Prophylactic light coagulation along the angioid streaks to prevent subretinal neovascularisation is not recommended. However, light coagulation treatment to foci of subretinal neovascularisation is possible if the network is not too close to fixation. As recurrence of neovascularisation is to be expected, very careful follow-up is necessary.

A guide to the ophthalmologist in the choice of the older child with amblyopia most likely to respond to active intensive visual stimulation in short bursts is presented. A series of 99 children treated on a CAM vision-stimulator is described. Visual improvement of at least two rows of letters on the Snellen chart was maintained for at least three years after treatment in 62% of these patients aged between five and nine years with visual fixation within 3 degrees of the fovea. Amblyopia following minor trauma or minor pathology also responded well. Children maintaining the visual improvement were those with esophoria up to 13 degrees, those with hypermetropia up to 11.0 D and those with astigmatism of 1.5 D. Also responding well were children with anisometropia with up to 3.0 D of either hypermetropia or astigmatism.

Herpetic keratitis is a common condition which can produce severe complications. The pattern of disease created by the virus depends on an interaction of virus and host mediated mechanisms. The changes in the epithelium are a consequence of the cytopathic effect of the virus and are related directly to virus replication. Changes produced in the stroma are due to inflammatory mechanisms initiated by the presence of virus antigens. The treatment of epithelial disease is aimed at reducing virus replication. The treatment of stromal disease is directed towards suppressing inflammation without increasing virus replication. Various anti-viral agents are available and each has a different mechanism of action and properties which make each anti-viral agent more suitable in particular situations. Many clinical trials have been conducted which indicate the place of anti-viral agents. The management of stromal disease is more complicated and less information is available from clinical trials to indicate the best possible method of treatment.

The suggestion that cataracts or other organic damage can result from exposure to radiation from visual display units (VDUs) is not supported by the best currently available epidemiological and experimental evidence. Eyestrain is common among VDU operators but is usually due to factors in the office environment, rather than defects in vision. Visual screening tests for operators should be simple, and tests for extraocular muscle balance and colour vision are not recommended.

The survival rate of very-low-birthweight (VLBW) infants has greatly increased due to the introduction of intensive-care methods to neonatal nurseries. It was feared that this would also cause an increase in the amount of ocular morbidity associated with prematurity. In order to estimate this, 111 very-low-birthweight infants (birthweights less than or equal to 1500 g) were reviewed at two years of age. They comprised 63% of the total number of long-term surviving babies born at, or transferred in the neonatal period to, the Royal Women's Hospital, Melbourne, in 1977 and 1978. In 33% a significant ocular problem was detected; 19% had strabismus, 17% had a significant refractive error, 10% had cicatricial retrolental fibroplasia (RLF), and 2.7% were blind, due to optic atrophy associated with cerebral palsy. Other studies have shown that 7% of VLBW infants develop severe (Stage III) RLF, and 18% of these (1.26% of VLBW infants) will be socially or totally blind. In order to estimate the significance of VLBW infants to the ophthalmic health services, and to the organisations for the care of the visually handicapped, these figures can be extrapolated. Based on 1980 figures, it would be expected that approximately 1105 VLBW infants would survive annually, and nine would become blind from RLF, while 110 would have been affected by RLF. Thirty-three children would be blind from optic atrophy associated with cerebral palsy, 210 would have strabismus, and at least 187 would have a significant refractive error. VLBW infants will contribute significantly to the number of children requiring ocular care, and because of the high incidence of ocular abnormalities, it is recommended that routine screening of all VLBW infants be carried out at one year and two years of age.

Analysis of the immunological features of anterior uveitis (AU) revealed a dichotomy of abnormalities defined in terms of the HLA-B27 status of the patient. HLA-B27-positive AU was characterised by the occurrence of iris autoantibodies and an absolute T cell lymphopenia during active disease which returned to normal with recovery. This phenomenon was not observed in HLA-B27-negative AU or in controls and could not be attributed to antilymphocyte antibodies as these were not detected. Furthermore, there were no changes in T-cell subsets (helper and suppressor T lymphocytes). Compared with HLA-B27-positive AU patients, the HLA-B27-negative group demonstrated elevated IgE levels and increased prevalence of smooth muscle autoantibodies.

Since the introduction of specular microscopy into the field of clinical ophthalmology in 1975, many technological and methodological advances have been made. These have for the most part eliminated the previously discussed objections to the use of specular microscopy as a clinical tool. With the advent of new instrumentation, a number of specular microscopes are not available. The advantages and disadvantages of these clinical specular microscopes, current clinical practice with small-field and wide-field specular microscopy, and description of problems and possible future developments of specular microscopy are discussed.