Langerhans' cell histiocytosis of the frontal bone

Two cases of Langerhans' cell histiocytosis of the frontal bone are presented. This condition was previously known as eosinophilic granuloma and rarely involves the orbit but may be associated with widespread and life-threatening disease. Clinical, radiological and histopathological features are presented. A discussion of the light and electron microscopic appearances, investigation and management follows.     

Efficacy and side effects of botulinum toxin treatment for blepharospasm and hemifacial spasm

Purpose : To analyse the effectiveness and rate of side effects of botulinum toxin treatment for blepharospasm and hemifacial spasm.
Methods : In a prospective trial, 81 patients with blepharospasm and 70 with hemifacial spasm were treated with botulinum toxin A in the neuro-ophthalmology clinic at St Vincent's Hospital, Melbourne. Some 989 treatments were given and the mean follow-up time was 28.7 months.
Results : The duration of action was longer for patients with hemifacial spasm than for those with blepharospasm (median 12.0 weeks compared with 7.0 weeks, P <0.0001). There was no change in the duration of effect over time with repeated treatments of the same dose (F = 0.4, P > 0.05). Once an effective dosage was reached, increasing the dose further did not prolong the duration of effect. There were no systemic side effects, but there were a number of local transient side effects. The most significant side effect was ptosis, which occurred in 12% of treatments given to those patients with blepharospasm and hemifacial spasm.
Conclusion : Botulinum toxin is an effective treatment for blepharospasm and hemifacial spasm, but there are a number of side effects, the most significant being ptosis.     

Haemophilus aphrophilus bleb infection after a mitomycin trabeculectomy

Background: Haemophilus aphrophilus is a rare cause of ocular infection. It has been reported once as a cause of late-onset endophthalmitis in a patient with an inadvertent bleb after cataract surgery. We present a case of Haemophilus aphrophilus bleb infection after a mitomycin trabeculectomy.
Methods: A 56-year-old woman presented with a bleb infection 10 weeks after a mitomycin C augmented trabeculectomy at a University tertiary referral practice of one of the authors (GET). The causative organism was Haemophilus aphrophilus , identified by the Toronto Public Health Laboratory, Ontario, Canada.
Results: The bleb infection resolved following topical, subconjunctival and intravenous antibiotic therapy. A formal bleb revision was required to repair a persistent bleb leak.
Conclusion: Patients who have had trabeculectomies augmented with mitomycin C may be predisposed to bleb infection with unusual organisms. Prompt diagnosis and treatment is necessary to control the infection. Increased awareness and communication with laboratory personnel may increase the isolation of this fastidious organism.     

Persisting epithelial herpes simplex keratitis while on cyclosporin-A ointment

Background: This is the first report of cyclosporin-A ointment (CsA) adversely affecting epithelial herpes simplex virus keratitis in a corneal graft.
Methods: The details of this case were obtained from the patient's record at The Wilmer Ophthalmological Institute.
Results: Ceasing CsA ointment resulted in resolution of the epithelial HSV keratitis.
Conclusion: Immunosuppression caused by CsA ointment resulted in persisting epithelial HSV keratitis despite adequate topical treatment.     

Macular holes: Pathogenesis, natural history and surgical outcomes

Idiopathic full-thickness macular holes (FTMH) are a common cause of usually uniocular reduced visual acuity. The accepted pathogenesis has macular hole formation proceeding in stages from an impending hole to a FTMH, with visual acuity deteriorating to less than 6/60 in 85% of cases. Recent surgical advances in the treatment of FTMH, with excellent anatomic and visual results, have changed the surgical indications for both impending and established full-thickness macular holes.     

Optic disc haemorrhages and vascular abnormalities in a glaucoma population

Purpose: To retrospectively examine the optic disc photographs of a glaucoma population for optic disc haemorrhages, vascular occlusions and vascular abnormalities. Methods: The optic disc photographs of 906 eyes of glaucoma and suspect glaucoma patients were examined. Optic disc photographs were taken annually, where possible, with the follow-up period varying between 1 and 14 years duration (mean, 2.89). Glaucoma patients are regularly reviewed every 4–6 months and glaucoma suspects every 1–2 years, depending on the ophthalmologist. Low-tension glaucoma patients were reviewed more frequently (mean, every 2.6 months). The results of the findings were compared to a control group of 39 subjects with a mean follow-up period of 7 years, using Fisher's exact test. Results: It was found that during the period under review, 7.4% (n= 67) of eyes had optic disc haemorrhages. The highest frequency of optic disc haemorrhages (37.5%) was found in the low tension glaucoma group (P= 0.0001) followed by 11.4% of primary open-angle glaucoma eyes (P= 0.03). In the normal group there were three eyes with optic disc haemorrhages and one with a disc collateral, which constitutes 5.1% vascular changes in this sub-group. Of the study eyes 2.8% had central retinal vein occlusions, 1.3% branch vein occlusion, 1.2% disc vessel abnormalities (loops) and 1.1% disc collaterals. Discrete nerve fibre layer haemorrhages and microaneurysms were found in 0.8% and 1.8% of eyes, respectively. Conclusions: A total of 16.8% of the eyes observed in this study had either disc haemorrhages or vascular changes. The underlying trend of vascular and haemorrhagic changes in glaucoma are demonstrated in this sample, which is in general agreement with previous studies. The high percentage of optic disc haemorrhages in low tension glaucoma is highlighted. The presence of microaneurysms and nerve fibre layer haemorrhages is interesting but of unknown significance.     

Tonography, Valsalva manoeuvre and central visual fields. A study of 429 patients

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 > 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> 150 category. An unexpected finding was the ratio of 67:33 right to left eyes in the Po/C < 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.     

Corneal biopsy in microbial keratitis

Presumed microbial keratitis in the absence of a specific microbiological diagnosis is a particularly difficult clinical problem. Corneal biopsy may provide the diagnosis when corneal scrapings have been negative. We present two cases in which corneal biopsy was helpful and discuss the role of corneal biopsy in the management of chronic keratitis     

Betaxolol

Drugs classified as beta-blockers have proved to be valuable in the treatment of patients with glaucoma. Timolol has become the most widely used ocular hypotensive agent. Actual and potential side effects associated with its non-selective beta-blockade have prevented its use in patients with reactive airways disease, and to a lesser extent, with various cardiovascular conditions. Betaxolol is a relatively selective beta-1 blocker which in most patients is almost as effective as timolol in lowering intraocular pressure, and may be partly additive with dipivefrin. It is probably safer in patients unable to tolerate non-selective beta-blockers. However, it needs to be used with caution in these patients, who are unpredictably susceptible to systemic side effects.     

Extended wear disposable soft contact lenses as an alternative to photorefractive keratectomy: Report of 4 years experience

Purpose: To establish whether; in a well-informed population, the use of extended wear disposable soft contact lenses (EWDSCL) poses an unacceptable risk to vision and corneal health due to complications associated with their use. Methods: A 4 year retrospective review of EWDSCL, involving 371 patients in Melbourne from a single general ophthalmology practice. The important aspects of this group were that all patients were given written instructions about the methods of ensuring initial and ongoing cleanliness of lenses, no lenses were cleaned and reinserted, and no solutions other than the saline in the original packaging, and comfort drops, were used. Two types of EWDSCL were used, in powers from - 9.0 to + 6.0 D, and with an initial aim of 4 weeks uninterrupted extended wear. Follow-up was from 2 to 52 months, with an average of 24 months. Results: Of the 354 patients followed up, 236 (66%) regularly wore them on an extended overnight basis, and of these 180 (76%) wore them for the suggested 4 week period before renewal of lenses. In the 471 eyes of 236 patients, adverse reactions occurred at the following rates: marginal infiltrates (12 cases, 2.5%); corneal oedema (10 cases, 2%); peripheral corneal vascularization (2 cases, 0.4%); and presumed infective keratitis (1 case, 0.2%). No eyes lost one or more lines of Snellen acuity. Conclusions: When disposable soft contact lenses do not come into contact with cleaning solutions, saline from bottles or aerosol cans, or storage cases, their use on an extended wear basis (up to 4 weeks continuous) appears to be associated with a low risk of minor or major complications. The results of this review indicate that controlled usage of EWDSCL is safer than previous reports have indicated.