Simultaneous choroidal melanoma and rhegmatogenous retinal detachment.

A case is reported of a 30-year-old man who presented with the unusual combination of a unilateral inferonasal choroidal melanoma and an unassociated rhegmatogenous retinal detachment attributable to a large horseshoe tear in the superotemporal quadrant. Over 20 cases of simultaneous occurrence of these two phenomena have now been reported but this patient appears to be the youngest. The reports of this uncommon association are reviewed.

Results of screening low-birth-weight infants for retinopathy of prematurity.

Retinopathy of prematurity (ROP) continues to be an important cause of potentially preventable blindness worldwide. The pattern of visual impairment from ROP in some middle-income countries--high rates affecting larger and more mature infants--resembles that seen in more developed countries two decades ago and has been called a "third epidemic" of the disease. Expert bodies in the United Kingdom and the United States have recently issued new guidelines for screening for ROP that utilize both birth weight and gestational age criteria. Studies in both countries suggest these criteria might be further revised to decrease time spent on screening without missing any significant disease. Population-based follow-up studies of extremely preterm infants suggest that although more preterm infants are surviving, with adequate screening and treatment, rates of blindness from ROP may be declining. Further information on the longer-term impact of ROP comes from a number of studies and particularly the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study. The risk of both myopia and strabismus is increased with any and each higher stage of ROP. Evidence is emerging that laser therapy for threshold disease may be associated with better visual outcome than cryotherapy, although complications following the former remain a concern. The fight against ROP may be enhanced by new information on the pathogenesis, including possible genetic predisposition and the role of vascular endothelial growth factor.

Survival and disability at 7-8 years of age in New Zealand infants less than 28 weeks gestation.

AIMS: To determine the survival and disability rates at 7-8 years in infants of less than 28 weeks gestation born in New Zealand in 1986 and admitted to a neonatal unit. METHODS: In 1986, all infants with birthweight less than 1500 g and admitted to neonatal units were enrolled in a prospective audit of retinopathy of prematurity. Surviving infants, including the subset born at less than 28 weeks gestation, have been assessed at a home visit. Parents completed a comprehensive questionnaire and children underwent a visual assessment and were tested on the Wechsler Intelligence Scale for Children. RESULTS: Of 126 liveborn infants less than 28 weeks gestation, 80 (64%) survived to 7-8 years. Sixty eight children (97% survivors resident in New Zealand) were assessed: 72% had no, and 86% no or only mild disability, 77% had some visual problem, with close to one-third having myopia, strabismus or requiring spectacles and 32% received Ministry of Education funded special needs assistance. CONCLUSIONS: There have been few long-term follow-up studies of infants of less than 28 weeks gestation born in a defined geographical area. The outcome for New Zealand infants is comparable with that in other published data.

Primary choroidal malignant melanoma occurring in a New Zealand Maori.

PURPOSE/METHOD: A case of a 28-year-old Maori with an aggressive primary choroidal malignant melanoma is presented. RESULTS/CONCLUSION: Melanoma and particularly intra-ocular melanoma is very rare in pigmented races. This is the first reported case in the Maori.

High iron status in very low birth weight infants is associated with an increased risk of retinopathy of prematurity.

OBJECTIVE: To explore the hypothesis that excessive iron loads may increase the formation of free radicals and the development of retinopathy of prematurity in preterm infants, we carried out a prospective observational study of the association between transfusion volume, iron status, and retinopathy.

Prospective study of New Zealand very low birthweight infants: outcome at 7-8 years.

OBJECTIVE: To determine the survival and sensorineural outcome at 7-8 years in very low birthweight (VLBW) infants born in New Zealand in 1986. METHODOLOGY: In 1986 all VLBW New Zealand infants admitted to neonatal units were enrolled in a prospective study of acute retinopathy of prematurity. Surviving infants were traced and were assessed at a home visit. Parents were asked a comprehensive questionnaire, and children underwent a visual assessment including photorefraction and were tested with the Revised Wechsler Intelligence Scale for Children (WISC-R). RESULTS: Four hundred and thirteen VLBW infants were admitted to neonatal units in 1986, 338 (81.8%) surviving to discharge, 12 children died after discharge, 17 were traced to overseas, seven declined to participate and four were untraced, leaving 298 (96% survivors resident in New Zealand) who were assessed at a mean age of 7.6 (+/- 0.4 years, 15 children (5.0%) had severe disability, 14 (4.7%) moderate disability, and 46 (15.4%) mild disability. Blindness (vision worse than 6/60) occurred in eight children (2.7%), deafness requiring aids in four (1.3%), any form of cerebral palsy in 17 (5.7%), and an JQ score on the WISC-R > 1 SD below the mean in 62 (20.8%). There was no significant difference in outcome for children with birthweight < 1000 g and 1000-1499 g. CONCLUSIONS: Long-term (7-8 year) survival and disability rates in this national cohort of VLBW infants is comparable with that reported from other populations. Although a majority of children have no disability a sizeable proportion do perform poorly on the WISC-R. This may relate in part to problems such as a short attention span and poor visual-motor integration.

Prospective study of New Zealand infants with birth weight less than 1500 g and screened for retinopathy of prematurity: visual outcome at age 7-8 years.

AIM: To determine the visual outcome at 7-8 years in very low birth weight (VLBW: birth weight < 1500 g) infants screened for retinopathy of prematurity (ROP). METHODS: In 1986 all 413 VLBW infants admitted to neonatal units in New Zealand were enrolled in a prospective study of acute ROP. Surviving infants were traced and assessed at a home visit. Visual assessment comprised examination for abnormal and range of eye movements, visual fields, distance and near visual acuity, stereopsis, and photorefraction. RESULTS: Of 338 infants surviving to discharge, 313 (93%) had been examined for acute ROP. ROP was present in 66 (21%: ROP+), absent in 247 (ROP-), with 25 not examined (NA). 298 children (96% survivors resident in New Zealand: 91% all survivors) were assessed. Any visual problem occurred in 79% ROP+ and 60% ROP-/NA (p < 0.01). Distance visual acuity less than 4/10 in the worse eye occurred in 29% ROP+ and 15% ROP-/NA (p < 0.05); and in the better eye in 19% ROP+ and 5% ROP-/NA (p < 0.001). Any myopia in the worse eye occurred in 36% ROP+ and 18% ROP-/NA (p < 0.01); and in the better eye in 25% ROP+ and 11% ROP-/NA (p < 0.01). Strabismus, including treated, occurred in 33% ROP+ and 19% ROP-/NA (p < 0.05). Overall, 11% had astigmatism and 18% hypermetropia with no difference between the groups. CONCLUSION: In a population based study it was confirmed that VLBW is associated with an increased risk of visual problems at school age. A history of ROP is associated with an additional risk of poor outcome, including a near doubling of poor distance acuity, myopia, and strabismus.

An anatomical study of retinal arteriovenous crossings and their role in the pathogenesis of retinal branch vein occlusions.

To elucidate the anatomical features which predispose artery over vein (AV) crossings to be the preferential sites for retinal branch vein occlusions (RBVO), 11 AV and six vein over artery (VA) crossings in 12 eyes from non-hypertensive donors who were aged 35 to 82 years, were studied by light and electron microscopy. At AV crossings the veins were often observed to abruptly alter direction to pass under the artery. Here focal stratification of the vein basement membrane opposite the point of contact with the artery was seen. A focal reduction in the vein lumen occurred at three of 11 AV crossings. In contrast, deviation of the vein, focal basement membrane stratification or focal narrowing was not seen at VA crossings. Both types of crossings had a common adventitial sheath when each vessel was of large calibre. This study demonstrated anatomical features which predispose AV crossings to be the preferential site for venous occlusion.

Retinopathy after low-dose retinal irradiation.

A 28-year-old man, after subtotal resection of a Grade I-II frontal lobe astrocytoma, received 5600 cGy of radiotherapy in 200 cGy fractions to residual intracranial tumour. One year later he presented with severe bilateral retinopathy which, in appearance was consistent with retinopathy from irradiation. Total irradiation received by the retina of each eye (< 50 to 1500 cGy) was far less than the dose which commonly produces radiation retinopathy. Also, the pattern of retinopathy did not reflect the distribution of radiation received by the eye. Alternative causes for the retinopathy were sought but not found. Proliferative retinopathy occurred in each eye and one eye developed a dense vitreous haemorrhage. Argon laser pan-retinal photocoagulation controlled the neovascularisation in the other eye. This patient has developed severe retinal ischaemia after a low dose of retinal irradiation.

Fusidic acid prophylaxis before cataract surgery: patient self-administration.

In a placebo-controlled, randomised, double-blind clinical trial, the authors evaluated the efficacy of patient-administered 1% fusidic acid viscous eye drops in clearing the commonest organisms causing pseudophakic endophthalmitis (Staphylococcus epidermidis and aureus) from the lids and conjunctivae of 79 patients before cataract surgery. The treatment group self-administered fusidic acid viscous eye drops four times daily for seven days before surgery; the placebo group received inert ophthalmic drops. Fellow eyes of both groups remained untreated as a natural control. Lower fornix and lid margin cultures were taken from both eyes before and after treatment. Before treatment, there was no statistical difference in organism counts between the groups. After treatment, eyes receiving fusidic acid were more likely to be free of clinically relevant Staphylococcus spp. than all pre-treatment eyes (for lids, P << 0.001; conjunctivae, P = 0.02). A highly significant (P < 0.001) number of lid margins were rendered 'clinically clean' (i.e., 0-49 organisms/swab) by fusidic acid when compared with untreated eyes. Treatment also effectively (P < 0.05) reduced the numbers of bacteria isolated from conjunctivae. This study indicates that there is a highly significant reduction of Staphylococcus spp. (P << 0.001), non-Staphylococcus spp. (P << 0.001) and attainment of sterile eyes (P << 0.001) at operation gained by patient self-administration of 1% fusidic acid four times daily for seven days before surgery.

Radiation hazards during cobalt 60 plaque therapy for choroidal melanoma.

Prompted by the concerns of the staff and patients, radiation hazards from Cobalt 60 (Co 60) plaque therapy for choroidal melanoma were recently assessed when two patients were concurrently treated at Christchurch Hospital. The risks from radiation to the attending medical staff, nursing personnel from the operating theatre and ward, and the patients' visitors were investigated. The radiation dose for all staff and visitors involved with the two patients was found to be well below the recommended weekly limits set by the International Commission on Radiological Protection. Our department code of practice to minimise radiation hazard during plaque therapy has been revised.

Retinopathy of prematurity: risk factors in a prospective population-based study.

A prospective study of risk factors for retinopathy of prematurity (ROP) in all very low birthweight (less than 1500 g) infants born in New Zealand in 1986 is reported. Of 413 liveborn infants admitted to neonatal units, 338 (81.2%) survived to be discharged home. Of surviving infants, 313 (93%) were examined by indirect ophthalmoscopy, as were eight infants who died before discharge. Sixty-nine infants (21.5% of 321) had acute retinopathy. On multiple logistic regression analysis, three variables made statistically significant independent contributions to the risk of any acute retinopathy; gestational age (P less than 0.0001), principal hospital caring for the infant (P less than 0.01) and treatment with indomethacin (P less than 0.01). Only two variables, gestational age (P less than 0.0001) and hospital (P less than 0.01), made significant contributions to the risk of stage 2 or more ROP. For both categories of ROP, timing of the examination also had a statistically significant effect (P less than 0.001). After adjustment for other significant predictor variables, it was estimated that approximately 70% of infants of less than 26 weeks' gestation were at risk of ROP and nearly 50% of stage 2 or more ROP, in comparison with less than 2% of infants of 32 weeks' gestation or more; infants treated with indomethacin were over 1.5 times more likely to have ROP than infants not so treated. Failure to enforce uniform timing of examination was the most serious defect in the study; only 205 (64%) of the 321 infants were examined at the recommended time. However, reanalysis of the model with information limited to these 205 infants yielded similar risk factors. The incidence of ROP, both observed (P less than 0.05) and adjusted for other significant variables in the regression model (P less than 0.01) was lowest in the two largest level III hospitals. These hospitals also had the best survival rates after adjustment for birthweight, gestation and gender (P less than 0.01). We speculate that the larger level III units obtained better results because their size and experience enabled them to provide a better overall quality of care.

An unusual ciliary body tumour: a haemangioblastoma.

A 23-year-old woman who presented with blurred vision in her right eye from increasing astigmatism had a vascular ciliary body tumour. After slow growth was documented over a 15-month period the tumour was excised with an iridocyclectomy. Microscopically the tumour consisted of sheets of large polygonal cells with round nuclei and foamy cytoplasm, separated by numerous capillaries, findings consistent with a diagnosis of a haemangioblastoma. Haemangioblastomas occur in the retina in von Hippel's disease and this occurrence in the ciliary body is a rare event. Investigation of the patient with a CT of the head and an abdominal ultrasound revealed no systemic lesions suggestive of systemic angiomatosis or von Hippel-Lindau disease.

Vitelliform dystrophy: long-term observations on New Zealand pedigrees.

Long-term observations on 29 patients from four pedigrees with vitelliform dystrophy (Best's disease) are described. The majority of patients were examined at yearly intervals and had a mean follow-up of 7.4 years. For analysis, eyes were staged according to Mohler and Fine's classification. Although vitelliform dystrophy exhibited considerable polymorphism in the study group 'recognisable stages', such as egg-yolk cysts, scrambled cysts or pseudohypopyon, were present in 48% of eyes at the initial examination. Egg-yolk cysts and pseudohypopyons were found to be the most evanescent of stages lasting on average 2.0 and 2.4 years respectively. Evolution of lesions did not necessarily follow a regular progression through the later stages of the vitelliform classification. Several unusual features such as recurrent pseudohypopyon, apparent regeneration of retinal pigment epithelium, exudative retinal detachments and development of stellate pigment figures were observed during the study. The majority of patients retained 6/12 or better visual acuity until the fourth decade when vision deteriorated. Correlations between changes in visual acuity and staging of the fundal lesions were made. Similarities between the group of patients reported, and a comparative group from overseas' have been discussed.

Serum and neutrophils alter the rate of excretory/secretory antigen release by Toxocara canis infective larvae in vitro.

Infective larvae of Toxocara canis are well suited for studies of nematode antigen expression in vitro. Larvae were labelled with 3H-glucosamine, an approach permitting dual analysis of antigen quantity and composition. Their excretory/secretory (E/S) glycoproteins were efficiently labelled and antigen identity confirmed by immunoprecipitation, SDS-PAGE and fluorography. Compartmental analysis revealed that common components of Mr 100-120 kD were present in somatic, surface and soluble material. The application of biosynthetic labelling and compartmental analysis of parasite responses in vitro to antibody, complement and neutrophils was tested. Results indicated that test larvae in vitro respond by quantitative rather than qualitative changes in antigen production. Specifically, human serum was shown to raise, and neutrophils depress, the rate of antigen release. The implications of these findings for establishing an in-vitro model for analysis of host/parasite reciprocal adaptive responses are discussed.

Retinopathy of prematurity: screening and optimal use of the ophthalmologist's time.

In recent years it has been standard practice to recommend that indirect ophthalmoscopy be carried out between six and nine weeks of age in very low birthweight infants to screen for the presence of retinopathy of prematurity (ROP). Following this recommendation we examined 85 infants over a two-year period. Acute ROP occurred in 29 (34%), and two (2.4%) developed cicatricial disease. One-third of infants were initially examined slightly earlier or later than the strict six to nine week limits, but all except three infants were examined between 35 and 42 weeks gestation. One infant born at 26 weeks gestation, was examined 'too late' in that she had stage 4 disease when first seen at 11 weeks of age. Recent information on the natural history of ROP, and confirmation of the efficacy of treatment with cyotherapy, suggested that the timing of an initial screening examination for ROP needed reassessment. From our experience and a review of the literature we recommended that infants of less than 1000 g birthweight or less than 28 weeks gestation have an initial examination at six weeks of age; for infants of 1000 to 1250 g birthweight or 28 to 30 weeks gestation examination continue to be at six to nine weeks of age; and for infants of more than 1250 g birthweight or 31 weeks gestation screening at six to nine weeks of age is only necessary if the infant has had an unstable course or prolonged oxygen requirements. Such a protocol would not place too great a burden on ophthalmological services and would direct efforts towards the group of infants most at risk of severe visual handicap.

Sunglasses: are they necessary in Christchurch?

Concern over potential eye injury from sunlight prompted this study to see if the levels of sunlight in Christchurch posed a particular risk to our population's eyes, whether the populace was aware of any risk and whether effective sunglasses were freely available to the public. While there has been a 4% to 9% increase in UV radiation since 1969 due to global ozone depletion, no firm evidence was found that focal ozone depletion was a particular problem in New Zealand. Christchurch residents were poorly informed about the ocular hazards of sunlight. A questionnaire completed by 200 adults disclosed 32% were unaware of the particular danger of UV light and only 3% knew that snow blindness, eclipse burns and cataracts could all be caused by sunlight. Fifty-four sunglasses were analysed for labelling and for transmission characteristics of their lenses. The standard of labelling of the sunglasses was poor with only 53% making reference to UV transmission characteristics and only three pairs stating that they adhered to the New Zealand Sunglass Standard. Attention is drawn to the need to improve public awareness of the potential for eye injury from sunlight and to improve the standard of labelling of sunglasses.