Management of allergic conjunctivitis and dry eye

Ocular allergy is a common eye condition encountered in clinical practice. However, little is known how seasonal allergic conjunctivitis (SAC), the most common subtype, is managed in clinical practice. Further, dry eye, another common eye condition, may be misdiagnosed as SAC and vice-versa as they share similar signs and symptoms. In addition, despite the frequent recommendation of non-pharmacological treatments for SAC, evidenceto support their use has not been identified in the scientific literature. The aim of this thesis was therefore to determine the actual diagnosis and management of SAC and dry eye in clinical practice and investigate the efficacy of non-pharmacological treatments for these conditions. The diagnostic and management strategies for SAC and dry eye employed by pharmacy staff are found to be inconsistent with current guidelines and scientific evidence based upon a mystery shopper design. Cluster analysis of tear film metrics in normal and dry eye patients identified several clinically relevant groups of patients that may allow for targeted treatment recommendations. Using a novel environmental chamber model of SAC, the use of artificial tears and cold compresses, either alone or combined is an effective treatment modality for acute and symptomatic SAC, on a par with topical anti-allergic medication, and has been demonstrated for the first time. In addition, eyelid warming therapy with a simple, readily available, seed filled device is an effective method of treating meibomian gland dysfunction (MGD) related evaporative dry eye, perhaps the most common dry eye subtype. A greater focus on ophthalmology must be implemented as part of the formal education and training of pharmacy staff, while greater professional communication between community pharmacists, optometrists and the population they serve is required. Artificial tears and cold compresses may be considered as front line agents for acute SAC by pharmacy staff and optometrists, to whom pharmacological treatment options are limited.

Pathway to clozapine use:a comparison between a patient cohort from New Zealand and a cohort from the United Kingdom

Background and Objective: Clozapine has been available since the early 1990s. Studies continue to demonstrate its superior efficacy in treatment-resistant schizophrenia. Despite this, numerous studies show under-utilisation, delayed access and reluctance by psychiatrists to prescribe clozapine. This retrospective cross-sectional study compared the prescribing of clozapine in two adult cohorts under the care of large public mental health services in Auckland (New Zealand) and Birmingham (United Kingdom) on 31 March 2007. Method: Time from first presentation to clozapine initiation, prior antipsychotics trialled and antipsychotic co-prescribing were compared. Data included demographics, psychiatric diagnosis, co-morbid conditions, year of first presentation, admissions and pharmacological treatment (clozapine dose, start date, prior antipsychotics, co-prescribed antipsychotic). Results: Overall, 664 people were prescribed clozapine (402 Auckland; 262 Birmingham); mean daily dose of 384 mg (Auckland) and 429 mg (Birmingham). 53 % presented after 1990 and the average duration of time before starting clozapine was significantly longer in the Birmingham cohort (6.5 vs. 5.3 years) but this reduced in both cohorts to a 1-year mean in those presenting within the last 3 years. The average number of antipsychotics trialled pre-clozapine for those presenting since 1990 was significantly higher in the Birmingham cohort (4.3 vs. 3.1) but in both cohorts this similarly reduced in those presenting within the last 3 years. Antipsychotic co-prescribing was significantly higher in the Birmingham cohort (22.9 vs. 10.7 %). Conclusions: There is evidence that access to clozapine has improved over time in both cohorts, with a reduction in the duration between presentation and initiation of clozapine and number of different antipsychotics trialled pre-clozapine. These are very positive findings in terms of optimising outcomes with clozapine and are possibly due to the impact of guideline recommendations, increasing clinician, consumer and carer knowledge, and experience with clozapine and funding changes. © 2014 Springer International Publishing.

Analysis of foveation sequences in congenital nystagmus

Congenital nystagmus (CN) is an ocular-motor disorder that appears at birth or during the first few months of life; it is characterised by involuntary, conjugated, bilateral to and fro ocular oscillations. Pathogenesis of congenital nystagmus is still unknown. Eye movement recording allow to extract and analyse nystagmus main features such as shape, amplitude and frequency; depending on the morphology of the oscillations nystagmus can be classified in different categories (pendular, jerk, horizontal unidirectional, bidirectional). In general, CN patient show a considerable decrease of the visual acuity: image fixation on the retina is disturbed by nystagmus continuous oscillations; however, image stabilisation is still achieved during the short foveation periods in which eye velocity slows down while the target image is placed onto the fovea. Visual acuity was found to be mainly dependent on foveation periods duration, but cycle-to-cycle foveation repeatability and reduction of retinal image velocities also contribute in increasing visual acuity. This study concentrate on cycle-to-cycle image position variation onto fovea, trying to characterise the sequences of foveation positions. Eye-movement (infrared oculographic or electro oculographic) recordings, relative to different gaze positions and belonging to more than 30 CN patients, were analysed. Preliminary results suggest that sequences of foveations show a cyclic pattern with a dominant frequency (around 0.3 Hz on average) much lower than that of the nystagmus (about 3.3 Hz on average). Sequences of foveations reveals an horizontal ocular swing of more than 2 degree on average, which can explain the low visual acuity of the CN patient. Current CN therapies, pharmacological treatment or surgery of the ocular muscles, mainly aim to increase the patient's visual acuity. Hence, it is fundamental to have an objective parameter (expected visual acuity) for therapy planning. The information about sequences of foveations can improve estimation of patient visual acuity. © 2008 Springer-Verlag.

A review of non-pharmacological and pharmacological management of seasonal and perennial allergic conjunctivitis

Allergic eye disease encompasses a group of hypersensitivity disorders which primarily affect the conjunctiva and its prevalence is increasing. It is estimated to affect 8% of patients attending optometric practice but is poorly managed and rarely involves ophthalmic assessment. Seasonal allergic conjunctivitis (SAC) is the most common form of allergic eye disease (90%), followed by perennial allergic conjunctivitis (PAC; 5%). Both are type 1 IgE mediated hypersensitivity reactions where mast cells play an important role in pathophysiology. The signs and symptoms are similar but SAC occurs periodically whereas PAC occurs year round. Despite being a relatively mild condition, the effects on the quality of life can be profound and therefore they demand attention. Primary management of SAC and PAC involves avoidance strategies depending on the responsible allergen(s) to prevent the hypersensitivity reaction. Cooled tear supplements and cold compresses may help bring relief. Pharmacological agents may become necessary as it is not possible to completely avoid the allergen(s). There are a wide range of anti-allergic medications available, such as mast cell stabilisers, antihistamines and dual-action agents. Severe cases refractory to conventional treatment require anti-inflammatories, immunomodulators or immunotherapy. Additional qualifications are required to gain access to these medications, but entry-level optometrists must offer advice and supportive therapy. Based on current evidence, the efficacy of anti-allergic medications appears equivocal so prescribing should relate to patient preference, dosing and cost. More studies with standardised methodologies are necessary elicit the most effective anti-allergic medications but those with dual-actions are likely to be first line agents.

A review of non-pharmacological and pharmacological management of seasonal and perennial allergic conjunctivitis

Allergic eye disease encompasses a group of hypersensitivity disorders which primarily affect the conjunctiva and its prevalence is increasing. It is estimated to affect 8% of patients attending optometric practice but is poorly managed and rarely involves ophthalmic assessment. Seasonal allergic conjunctivitis (SAC) is the most common form of allergic eye disease (90%), followed by perennial allergic conjunctivitis (PAC; 5%). Both are type 1 IgE mediated hypersensitivity reactions where mast cells play an important role in pathophysiology. The signs and symptoms are similar but SAC occurs periodically whereas PAC occurs year round. Despite being a relatively mild condition, the effects on the quality of life can be profound and therefore they demand attention. Primary management of SAC and PAC involves avoidance strategies depending on the responsible allergen(s) to prevent the hypersensitivity reaction. Cooled tear supplements and cold compresses may help bring relief. Pharmacological agents may become necessary as it is not possible to completely avoid the allergen(s). There are a wide range of anti-allergic medications available, such as mast cell stabilisers, antihistamines and dual-action agents. Severe cases refractory to conventional treatment require anti-inflammatories, immunomodulators or immunotherapy. Additional qualifications are required to gain access to these medications, but entry-level optometrists must offer advice and supportive therapy. Based on current evidence, the efficacy of anti-allergic medications appears equivocal so prescribing should relate to patient preference, dosing and cost. More studies with standardised methodologies are necessary elicit the most effective anti-allergic medications but those with dual-actions are likely to be first line agents. © 2011 British Contact Lens Association.

How drug metabolism influences treatment outcomes

Recent developments within the National Health Service have led to an increase in personnel 'qualified' to prescribe a wide range of pharmacological agents. A short (38-day) Continuing Professional Development course in prescribing is deemed adequate to fully train individuals for practice. A sound understanding of prescribing medicines has important implications for patient benefit. For example, a prescriber would require some knowledge of drug absorption, distribution, metabolism and excretion, as well as aspects of drug delivery and drug-drug interactions. Drug metabolism in particular exerts a powerful influence on drug action; this can range from complete failure of efficacy through to life-threatening toxicity. Moreover, it is conservatively estimated that there may be several thousand deaths each year in the UK arising from an inadequate knowledge of drug metabolism when prescribing medicines. This one-day course focused on the importance of understanding drug metabolism on treatment strategies and outcomes, and was accessed by a range of healthcare professionals in the West Midlands area of the UK. © 2007 Informa UK Ltd.

Rehabilitation in Charles Bonnet syndrome:a review of treatment options

People with vision loss sometimes experience visual hallucinations associated with Charles Bonnet syndrome. The appearance of these hallucinations often causes anxiety for the sufferer and can be difficult for the attending eye care professional to manage. A review of the literature highlighted a range of visual, pharmacological and social management regimes that may alleviate these hallucinations, albeit using small samples in uncontrolled trials. Eye care practitioners should be aware of methods of rehabilitation in Charles Bonnet syndrome that may lead to resolution of the visual hallucinations.