Efficacy and acceptability of nedocromil sodium 2% and olopatadine hydrochloride 0.1% in perennial allergic conjunctivitis

Therapeutic Targets in Allergic Conjunctivitis

Allergic conjunctivitis (AC) is a common condition resulting from exposure to allergens such as pollen, animal dander, or mold. It is typically mediated by allergen-induced crosslinking of immunoglobulin E attached to receptors on primed conjunctival mast cells, which results in mast cell degranulation and histamine release, as well as the release of lipid mediators, cytokines, and chemokines. The clinical result is conjunctival hyperemia, tearing, intense itching, and chemosis. Refractory and chronic cases can result in ocular surface complications that may be vision threatening. Patients who experience even mild forms of this disease report an impact on their quality of life. Current treatment options range from non-pharmacologic therapies to ocular and systemic options. However, to adequately control AC, the use of multiple agents is often required. As such, a precise understanding of the immune mechanisms responsible for this ocular surface inflammation is needed to support ongoing research for potential therapeutic targets such as chemokine receptors, cytokine receptors, non-receptor tyrosine kinases, and integrins. This review utilized several published articles regarding the current therapeutic options to treat AC, as well as the pathological and immune mechanisms relevant to AC. This review will also focus on cellular and molecular targets in AC, with particular emphasis on potential therapeutic agents that can attenuate the pathology and immune mechanisms driven by cells, receptors, and molecules that participate in the immunopathogenesis and immunopathology of AC.

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.

Mometasone furoate nasal spray reduces the ocular symptoms of seasonal allergic rhinitis

BACKGROUND

Mometasone furoate nasal spray (MFNS), a potent intranasal corticosteroid with proved efficacy in relieving nasal allergic rhinitis symptoms, has demonstrated effectiveness in improving ocular symptoms associated with seasonal allergic rhinitis (SAR) in retrospective analyses.

OBJECTIVE

We sought to evaluate prospectively the efficacy of MFNS in reducing total ocular symptom scores (TOSSs) and individual ocular symptoms in subjects with SAR.

METHODS

Subjects 12 years or older (n = 429) with moderate-to-severe baseline symptoms were randomized to MFNS, 200 microg once daily, or placebo in this 15-day, double-blind, parallel-group study. Subjects evaluated morning instantaneous TOSSs and daily reflective TOSSs, total nasal symptom scores (TNSSs; both instantaneous TNSSs and reflective TNSSs, respectively), and individual ocular and nasal symptoms. Mean changes from baseline averaged over days 2 to 15 (instantaneous) and days 1 to 15 (reflective) were calculated. Quality of life was assessed by using the Rhinoconjunctivitis Quality of Life Questionnaire.

RESULTS

MFNS treatment yielded significant reductions from baseline versus placebo in instantaneous TOSSs (-0.34, P = .026, coprimary end point), instantaneous TNSSs (-0.88, P < .001, coprimary end point), reflective TOSSs (-0.44, P = .005), and reflective TNSSs (-1.06, P < .001). Significant decreases in all individual reflective ocular symptoms and instantaneous eye itching/burning and eye watering/tearing were observed for MFNS versus placebo (P < .05). Numeric improvements in instantaneous eye redness were seen but did not reach statistical significance. Improvements in Rhinoconjunctivitis Quality of Life Questionnaire total scores and individual symptom domains were achieved with MFNS treatment versus placebo (P < .001). MFNS was well tolerated.

CONCLUSION

This prospective study demonstrates that MFNS significantly reduces ocular symptoms in subjects with SAR.

A review of the use of olopatadine in allergic conjunctivitis

Ocular allergies are very common and range in intensity from mild, self-resolving, acute conditions to serious, chronic disease that can severely affect vision. The vast majority of sufferers experience relatively mild symptoms, which are often seasonal in nature. Treatments should be simple, comfortable and very safe. They should be able to respond to an ongoing attack but also provide long-term relief from symptoms. Mast cell degranulation is central to all forms of ocular allergic disease and so treatment has concentrated on preventing this process or antagonizing the effects of the primary mediator, histamine. Olopatadine is a relatively new selective H1 antagonist that has mast cell stabilizing properties and has been shown to affect release of TNFalpha and various cytokines from conjunctival epithelial cells. This paper reviews the local ocular use of olopatadine and discusses the place of the drug in the treatment of allergic eye disease.

Supplementation of fexofenadine therapy with nedocromil sodium 2% ophthalmic solution to treat ocular symptoms of seasonal allergic conjunctivitis

PURPOSE

Ocular symptoms are often under-treated in patients with allergic rhinoconjunctivitis. The efficacy of fexofenadine hydrochloride 60 mg capsules supplemented with nedocromil sodium 2% ophthalmic solution was evaluated to determine the optimal drug regimen for control of ocular allergic symptoms.

METHODS

In this 5-week, open-label, randomized, multicentre comparative study, 89 patients with documented ragweed pollen allergy received fexofenadine b.i.d. with nedocromil rescue, fexofenadine q.d. with nedocromil b.i.d., or fexofenadine rescue with nedocromil b.i.d. during the ragweed pollen season.

RESULTS

For all regimens, mean symptom severity scores for itching, burning, tearing, redness, grittiness, discharge, light sensitivity and swelling improved significantly (P < 0.003). Similarly, all groups experienced significant (P < 0.02) improvement in all clinical signs: erythema, oedema, discharge, conjunctival injection and conjunctivitis, as well as quality-of-life scores (P < 0.0001). All regimens reduced overall symptom severity scores after 5 min (P < 0.05) with relief persisting over 12 h (P < 0.03). Improvements in mean symptoms, signs and quality-of-life scores were similar among the treatment groups as were onset and duration of action even though patients in two of the three study arms were taking one-half or less of the recommended fexofenadine dosage. Patients and physicians judged the regimens containing lower fexofenadine dosages (with nedocromil b.i.d.) to be more effective overall than the regimen containing the highest fexo-fenadine dosage (with nedocromil as rescue only).

CONCLUSIONS

Supplementation of oral fexofenadine therapy with nedocromil sodium 2% ophthalmic solution relieves ocular symptoms of seasonal allergic rhinoconjunctivitis, allowing control of rhinal symptoms with half the recommended dosage of fexofenadine.

Ocular allergy guidelines: a practical treatment algorithm

The treatment of ocular allergy requires a better understanding of the spectrum of clinical disorders involving various components of the immune system, and of interactions at the conjunctival surface. The immune response focuses primarily on the different levels of activity of Th2 lymphocytes and various other immune cells associated with allergic disorders, including mast cells, eosinophils, fibroblasts, and epithelial and endothelial cells. Ocular allergic disorders include seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC), giant papillary conjunctivitis (GPC) and atopic keratoconjunctivitis (AKC), which, through immunopathological and molecular immunological techniques, can all be better appreciated as being part of a larger spectrum of an atopic disease state. In SAC, pathological changes, such as increased mast-cell activation, the presence of migratory inflammatory cells, and early signs of cellular activation at the molecular level, are minimal. In PAC, these changes are more pronounced in line with the increased duration of allergenic stimulation. In more chronic forms of allergic conjunctivitis, such as VKC in children and AKC in adults, the following changes are evident: a persistent state of mast cell, eosinophil and lymphocyte activation; noted switching from connective-tissue to mucosal-type mast cells; increased involvement of corneal pathology; and follicular development and fibrosis. The treatment of acute and more chronic forms of allergic conjunctivitis has focused in the past on symptomatic relief of symptoms, but with a better understanding of the mechanisms involved we can now provide interventional therapeutic strategies and symptomatic relief. Our advances in the basic understanding of these conditions are providing the foundation for guidelines that improve the ocular health of patients with ocular allergies.

Inhibitory effect of olopatadine on antigen-induced eosinophil infiltration and the LFA-1 and Mac-1 expression in eosinophils

The inhibitory effect of olopatadine, a new antiallergic drug, on antigen-induced eosinophil infiltration and its mechanisms were examined using the local sensitized rat allergic rhinitis model and isolated IL-5-stimulated rat peritoneal eosinophils. Olopatadine dose-dependently inhibited antigen-induced eosinophil infiltration in the nasal mucosa. Olopatadine dose-dependently repressed the IL-5-induced expressions of CD11a/CD18 (LFA-1) and CD11b/CD18 (Mac-1) on rat peritoneal eosinophils. However, olopatadine had no effect on IL-5-induced CD49d/CD29 (VLA-4) expression. These results suggest that olopatadine may inhibit antigen-induced eosinophil infiltration through repression of LFA-1 and Mac-1 expression.