Australian and New Zealand journal of ophthalmology最新文献

Purpose: Argon laser photocoagulation slows photoreceptor degeneration in the Royal College of Surgeons (RCS) rat, as does intravitreal injection of basic fibroblast growth factor (bFGF). We hypothesize that up-regulation of retinal bFGF is a consequence of laser lesioning in RCS rats. Therefore, we examined the localization of bFGF after laser and correlated this with Mailer cell glial fibrillary acidic protein (GFAP) expression, which is known to increase after injury.

Methods: A total of 34 RCS rats at postnatal day 23 were anaesthetized (ketamine 40 mg/kg) and their retinas were irradiated with a grid pattern of 40 non-overlapping argon green lesions with a power of 120 mW for 0.2 s using a 50 microm spot size. At 0, 6, 12, 24 and 48 h and 7, 14 and 21 days post-lesion, rats were anaesthetized and their eyes were enucleated and cryostat sectioned and the sections were processed using either an antibody to bFGF or GFAP using the standard avidin-biotinylated peroxidase complex method. Five age-matched RCS rats without laser lesions served as controls.

Results: Basic fibroblast growth factor immunoreactivity (IR) was normally located within cells in the ganglion cell layer inner nuclear layer and in retinal pigment epithelium cells and in the extracellular matrix/cell membranes of the outer nuclear layer (ONL). In lasered retinas, there was elevated bFGF-IR in the coagulated outer segments for the first 24 h. Retinal blood vessels/Müller cells/astrocytes were moderately labelled in and near each lesion immediately after lesion and became more intense after 48 h and persisted for at least 21 days. There was an elevation of bFGF-IR in the ONL on the lesion flanks at 14 days. Muller cell GFAP-IR was first detected at 6 h post-lesion and spread for a considerable distance beyond the lesion site. At 7 and 14 days, Müller cells at the lesion site had sprouted, while those on the flanks were still GFAP-IR.

Conclusions: Following laser lesion there was an increase in bFGF at the lesion core only for the first 24 h. However, elevated levels of bFGF were observed in the ONL at 14 days, which extended into the lesion flanks for a similar distance to that over which increased photoreceptor survival is found. These results provide support for the hypothesis that laser lesions induce bFGF and this may be the mechanism whereby photoreceptors are spared. Müller cell activation is consistent with growth factor stimulation, but was more widespread than the bFGF changes in ONL. However, blood vessel labelling was similarly widespread and so the responses may be linked between Müller cell GFAP reaction and blood vessel bFGF localization after laser lesions.

Background: Subretinal injection of perfluorocarbon liquids (PFCL) can occur during vitreoretinal surgery. The long-term effects of this complication are not well established.

Methods: A case report is presented of a patient with retained subretinal perfluorodecalin following retinal detachment repair for a giant retinal tear.

Results: In the early postoperative period, the macular retinal pigment epithelium (RPE) became opalescent in appearance and by 2 months postoperatively the patient developed macular RPE atrophy with resulting poor central vision.

Conclusions: Toxicity of subretinal perfluorodecalin causing RPE atrophy is proposed. We recommend all traces of PFCL should be removed if possible.

Background: Primary chronic canaliculitis is an uncommon disease usually caused by Actinomyces israelii (streptothrix). Actinomyces israelii is a cast-forming Gram-positive anaerobe that is difficult to isolate and identify. We present a case that demonstrates the typical clinicopathological presentation of this unusual condition and discuss management options.

Methods and results: A 10-year-old girl presented with a 6 month history of intermittent 'conjunctivitis' and discharge from her 'pouted' left lower punctum. Microbiology confirmed probable A. israelii infection, but topical treatment failed. Exploration under anaesthesia revealed a canalicular diverticulum and three canaliculiths. Histological examination of the canaliculiths demonstrated that they consisted of solid casts of Actinomyces. Punctoplasty, removal of the casts, and adjunct antibiotic therapy resulted in resolution of the canaliculitis.

Conclusions: Primary chronic canaliculitis should be considered in any patient who presents with chronic or recurrent conjunctivitis and the eyelid should be inspected for a discharging and 'pouting' punctum. Failure of the condition to resolve on topical treatment requires surgical exploration of the canalicular system and removal of any casts. Extensive surgery is not always required.

Purpose: To review current medical treatments for nystagmus and saccadic intrusions, and their visual consequences.

Methods: Evaluation of studies that have used reliable measurement of eye movements and visual acuity before and after treatment. Interpretation of results in light of physiological and pharmacological studies in animals, and recent immunological advances.

Results: There are many case reports of patients with abnormal eye movements being improved by a variety of drugs, but few double-blind, controlled studies have been carried out. Most promising are agents that mediate their effects through the neurotransmitter gamma-aminobutyric acid; such drugs include baclofen and gabapentin. Botulinum toxin, injected into selected extraocular muscles or the retrobulbar space, can abolish nystagmus for several months, but often produces troublesome side-effects, such as diplopia and ptosis, which limit its value. Optical measures to either reduce nystagmus by manipulating vergence angle, or reduce retinal image motion, help some patients. Opsoclonus occurring in association with cancer may be successfully treated with an immuno-adsorption technique using a protein A column.

Conclusions: There is need for controlled, blinded studies to evaluate the many agents reported to improve visual symptoms in individual patients with abnormal eye movements.

Purpose: A case of trichotillomania, or compulsive hair-pulling, involving the eyelids is presented to alert ophthalmologists to this common, but frequently overlooked cause of eyelash and eyebrow alopecia.

Methods and results: Clinical records of a 33-year-old woman suffering from trichotillomania were reviewed. Compulsive hair-pulling began in childhood and had become chronic. Psychiatric intervention was unsuccessful.

Conclusions: The diagnosis of trichotillomania is made on history and slit-lamp examination findings. A skin biopsy may be necessary to exclude alopecia areata. Adults should be referred to a psychiatrist. Although childhood disease is usually benign, often reflecting a disturbed parent-child relationship, in adults hair-pulling is generally chronic and associated with psychiatric illness.

Purpose: To establish the incidence and severity of retinopathy of prematurity (ROP) in an Australian population of premature infants, and define risk factors for this population.

Methods: A survey of neonates born weighing less than 1501 g and/or with gestational age below 33 weeks, was undertaken at a neonatal intensive care unit in South Australia.

Results: ROP was diagnosed in 16.0% of the 94 neonates who were screened until retinal vascularisation was complete. Threshold disease occurred in 4.2%. Logistic regression identified three significant risk factors for the development of ROP: days of mechanical ventilation, multiple birth and female sex.

Conclusions: The incidence of ROP was relatively low when compared with figures recently published for two large populations studied in the United States and England. This difference was due to a lower incidence of mild forms of the disease. Days of mechanical ventilation, multiple birth and female sex were independently predictive of the occurrence of ROP. As small numbers of infants with ROP are managed at individual Australian centres each year, a national ROP register is recommended to facilitate the study of the disease in this country.