Management of seasonal allergic conjunctivitis (SAC): current therapeutic strategies

A Review of Contact Lens-Related Risk Factors and Complications

The purpose of this article is to develop a modern strategy for handling difficulties related to contact lenses and their care. A growing number of people throughout the world are currently concerned by eye-related undesirable activities in allergy sufferers and those wearing contact lenses. While many wearers who experience ocular discomfort exhibit dryness as a symptom, many other contact lens-related pain symptoms also include irritation and fatigue, and managing coexisting diseases must be done in accordance with aspects of wearing contact lenses, all of which undoubtedly increase discomfort.

It is typical for contact lens storage containers to have persistent microbial contamination, which has been linked to microbial keratitis (MK) and clear corneal invasion. Contact lens-associated MK is an interesting, potentially sight-threatening complexity arising from wearing soft contact lenses. Estimates show that for every 10,000 persons who wear contact lenses each year, there are 2 to 5 occurrences of MK. Investigating separate determinants for contact lens-associated MK and evaluating their impact on infection load is one of the challenges in their administration. It is hoped that this will offer a useful outline of the complicated issues of contact lens wear that are both infectious and non-infectious. Recent epidemiological studies detailing the risk factors associated with contact lens use, and the effect of pathogen and individual immune profiles on the severity of diseases have enlightened how we might interpret the prophylaxis and prevention of contact lens-related corneal infection. The most dreaded side effect of contact lens use, infectious keratitis linked with contact lenses, will be reviewed, along with the most recent advancements in its diagnosis and treatment.

Allergic Conjunctivitis: An Update

Conjunctivitis is a frequent disease of the eye with the typical clinical sign being the "red eye" and comprises a very heterogeneous group with different causes. In general, infectious conjunctivitis must be strictly differentiated from non-infectious conjunctivitis. Allergic conjunctivitis is a subtype of non-infectious conjunctivitis and imposes as an acute, intermittent or chronic, inflammation which is most frequently caused by airborne allergens. The leading clinical sign is chemosis, and patients typically complain about itching. Allergic conjunctivitis is often a reaction to topical and systemic drugs or cosmetics as well as animal hairs from cats and/or dogs. Allergic conjunctivitis is sub-classified into the following forms: seasonal allergic conjunctivitis (also termed: hay fever conjunctivitis), atopic conjunctivitis, vernal conjunctivitis, upper limbal (kerato-) conjunctivitis, and conjunctivitis associated with various oculomucocutaneous syndromes. In each form, there are distinctive features in: clinical appearance, generating agent(s), as well as treatment as listed here.

Review of Contact Lens-Related Complications

The purpose of this article is to provide a review of existing literature describing complications with contemporary contact lenses and their management. It is envisioned that this will serve as a useful summary of noninfectious and infectious complications associated with contact lens wear.

Topical antihistamines and mast cell stabilisers for treating seasonal and perennial allergic conjunctivitis

BACKGROUND

Seasonal/perennial allergic conjunctivitis is the most common allergic conjunctivitis, usually with acute manifestations when a person is exposed to allergens and with typical signs and symptoms including itching, redness, and tearing. The clinical signs and symptoms of allergic conjunctivitis are mediated by the release of histamine by mast cells. Histamine antagonists (also called antihistamines) inhibit the action of histamine by blocking histamine H1 receptors, antagonising the vasoconstrictor, and to a lesser extent, the vasodilator effects of histamine. Mast cell stabilisers inhibit degranulation and consequently the release of histamine by interrupting the normal chain of intracellular signals. Topical treatments include eye drops with antihistamines, mast cell stabilisers, non-steroidal anti-inflammatory drugs, combinations of the previous treatments, and corticosteroids. Standard treatment is based on topical antihistamines alone or topical mast cell stabilisers alone or a combination of treatments. There is clinical uncertainty about the relative efficacy and safety of topical treatment.

OBJECTIVES

The objective of this review was to assess the effects of topical antihistamines and mast cell stabilisers, alone or in combination, for use in treating seasonal and perennial allergic conjunctivitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2014, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2014), EMBASE (January 1980 to July 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 17 July 2014. We also searched the reference lists of review articles and relevant trial reports for details of further relevant publications.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing topical antihistamine and mast cell stabilisers, alone or in combination, with placebo, no treatment or to any other antihistamine or mast cell stabiliser, or both, that examined people with seasonal or perennial allergic conjunctivitis, or both. The primary outcome was any participant-reported evaluation (by questionnaire) of severity of four main ocular symptoms: itching, irritation, watering eye (tearing), and photophobia (dislike of light), both separately and, if possible, by an overall symptom score. We considered any follow-up time between one week and one year.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. Disagreements were resolved by discussion among review authors and the involvement of a third review author. We followed standard methodological approaches used by Cochrane.

MAIN RESULTS

We identified 30 trials with a total of 4344 participants randomised, with 17 different drugs or treatment comparisons. The following antihistamines and mast cell stabilisers were evaluated in at least one RCT: nedocromil sodium or sodium cromoglycate, olopatadine, ketotifen, azelastine, emedastine, levocabastine (or levocabastine), mequitazine, bepotastine besilate, combination of antazoline and tetryzoline, combination of levocabastine and pemirolast potassium. The most common comparison was azelastine versus placebo (nine studies).We observed a large variability in reporting outcomes. The quality of the studies and reporting was variable, but overall the risk of bias was low. Trials evaluated only short-term effects, with a range of treatment of one to eight weeks. Meta-analysis was only possible in one comparison (olopatadine versus ketotifen). There was some evidence to support that topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis when compared with placebo. There were no reported serious adverse events related to the use of topical antihistamine and mast cell stabilisers treatment.

AUTHORS' CONCLUSIONS

It seems that all reported topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis when compared with placebo in the short term. However, there is no long-term data on their efficacy. Direct comparisons of different antihistamines and mast cell stabilisers need to be interpreted with caution. Overall, topical antihistamines and mast cell stabilisers appear to be safe and well tolerated. We observed a large variability in outcomes reported. Poor quality of reporting challenged the synthesis of evidence.

Loteprednol etabonate suspension 0.2% administered QID compared with olopatadine solution 0.1% administered BID in the treatment of seasonal allergic conjunctivitis: a multicenter, randomized, investigator-masked, parallel group study in Chinese patients

BACKGROUND

Seasonal allergic conjunctivitis (SAC) is caused by seasonal allergens and usually manifests as ocular itching and bulbar conjunctival injection (redness). Treatment options for SAC include corticosteroids and dual-acting antihistamine and mast-cell stabilizers.

OBJECTIVE

Our objective was to compare the efficacy and tolerability of loteprednol etabonate (LE), a C-20 ester-based corticosteroid, with those of olopatadine, a dual-acting antihistamine mast-cell stabilizer, in Chinese patients.

METHODS

This was a multicenter, randomized, investigator-masked, parallel group study. Patients with acute SAC experiencing grade 4 ocular itching and grade 2 or higher bulbar conjunctival injection received either LE suspension 0.2% QID at 4-hour intervals or olopatadine solution 0.1% BID at 6- to 8-hour intervals bilaterally for 15 days. Primary efficacy end points included the change from baseline (CFB) in ocular itching and bulbar conjunctival injection at day 15. The primary analysis tested the noninferiority of LE suspension 0.2% to olopatadine solution 0.1%. Tolerability outcomes included the incidence of adverse events (AEs), biomicroscopy findings, visual acuity, and intraocular pressure.

RESULTS

A total of 300 patients were randomly assigned, and 293 were included in the per-protocol population (LE, n = 147; olopatadine, n = 146). Mean (SD) CFB at day 15 in the LE and olopatadine treatment groups, respectively, was -3.74 (0.47) and -3.28 (0.91) for ocular itching and -1.91 (0.52) and -1.71 (0.59) for bulbar conjunctival injection. The 95% CI for the differences in CFB in ocular itching (-0.59 to -0.27) and bulbar conjunctival injection (-0.27 to -0.08) was less than the prespecified noninferiority limit of 0.3. Treatment differences in CFB were significantly better with LE compared with olopatadine for both end points (P ≤ 0.0006). Ocular AEs were few and similar between treatment groups. There were no clinically significant biomicroscopy or visual acuity findings, and no patient experienced a clinically significant increase in intraocular pressure (≥10 mm Hg).

CONCLUSION

Results of this investigator-masked study with Chinese patients suggest LE suspension 0.2% was noninferior to olopatadine solution 0.1% for the treatment of SAC. Both LE suspension 0.2% and olopatadine solution 0.1% were well tolerated. ClinicalTrials.gov identifier: NCT01435460.

Clinical efficacy of a Ginkgo biloba extract in the topical treatment of allergic conjunctivitis

PURPOSE

To investigate the clinical efficacy of a Ginkgo biloba extract associated with hyaluronic acid ophthalmic solution (GB-HA, Trium, SOOFT, Italy), compared to hyaluronic acid ophthalmic solution (HA) alone, in seasonal allergic conjunctivitis (AC).

METHODS

A total of 60 patients with symptomatic AC were enrolled and randomly assigned to the two treatment regimens. After a washout period of 15 days, the treatment with GB-HA eyedrops or HA ophthalmic solution alone was initiated and continued for 1 month. The clinical symptoms such as conjunctival hyperemia, conjunctival discharge, and chemosis, and subjective signs as itching, photophobia, stinging, and lacrimation, were evaluated before and after the treatment. A 0-4 score was used by an independent clinical observer to quantify the above parameters.

RESULTS

Patients treated with GB-HA, compared to patients treated with HA alone, showed a significant decrease in the appearance of conjunctival hyperemia, conjunctival discharge, and chemosis. Furthermore, all patients treated with GB-HA showed a significant improvement of subjective symptoms, compared to HA patients. Compared to their baseline values, patients treated with HA alone showed a small but not significant improvement in only some of the clinical and subjective symptoms.

CONCLUSIONS

The results suggest that Ginkgo biloba extract may exert therapeutic activity in the treatment of seasonal allergic conjunctivitis. Hyaluronic acid did not exert any valuable effect on this pathology.

Pharmacotherapy of allergic eye disease

Allergic eye disease is a term that refers to a number of disease processes that affect about one-fifth of the world's population. Although the more advanced forms of the disease can be sight threatening, the most disabling effects are due to the clinical manifestations, and hence quality of life, with some patients having seasonal exacerbations of their symptoms, whereas others have symptoms that are present throughout the year. Recent increased understanding of the cellular and mediator mechanisms that are involved in the various disease manifestations has greatly facilitated the development of more effective treatment options. Newer topical medications are being used that have multiple actions, such as an antihistaminic effect coupled with mast-cell stabilisation, and which require reduced daily dosing due to their longer duration of action. With greater research into newer therapies and more effective modes of delivery, improved healthcare outcomes with a lower economic burden will be achieved for patients with allergic eye disease.

Health economic impact of olopatadine compared to branded and generic sodium cromoglycate in the treatment of seasonal allergic conjunctivitis in the UK

OBJECTIVE

This study estimated the health economic impact of olopatadine (Opatanol) compared to branded cromoglycate (Opticrom) and generic sodium cromoglycate in the treatment of seasonal allergic conjunctivitis (SAC) in the UK.

DESIGN AND SETTING

This was a modelling study performed from the perspective of the UK's National Health Service (NHS).

METHODS

A decision model was constructed depicting the management of SAC sufferers who are 4 years of age or above over a typical allergy season of 4 months and considers the decision by a GP to initially treat a patient with olopatadine, branded or generic cromoglycate. The analysis assumed both drugs to be equally effective. Consequently, a cost-minimisation analysis was performed to identify the least costly alternative.

MAIN OUTCOME MEASURES AND RESULTS

Starting treatment with olopatadine is expected to lead to a healthcare cost of 92 pounds sterling (95% CI: 46 pounds sterling; 150 pounds sterling) over 4 months compared to 109 pounds sterling (95% CI: 65 pounds sterling; 166 pounds sterling) with branded cromoglycate and 95 pounds sterling (95% CI: 51 pounds sterling; 152 pounds sterling) with generic cromoglycate, resulting in a 16% and 3% reduction in healthcare costs respectively over 4 months of treatment. This cost-difference is primarily due to fewer GP visits among olopatadine-treated patients.

CONCLUSION

Use of olopatadine instead of branded or generic cromoglycate affords an economic benefit to the NHS. Hence, within the limitations of the model, olopatadine is the preferred first-line treatment for use in SAC sufferers, since it is expected to lead to fewer GP visits, thereby releasing healthcare resources for alternative use.

Novel transglutaminase inhibitors reverse the inflammation of allergic conjunctivitis

Steroidal anti-inflammatory drugs induce proteins that inhibit phospholipase A(2) (PLA(2)), including uteroglobin and lipocortin-1 (annexin I). Uteroglobin and lipocortin-1 retain several conserved sequences. Based on these sequences, several nonapeptides (antiflammins) were synthesized. These nonapeptides were shown to have anti-inflammatory effects in vitro and in vivo, possibly by inhibiting PLA(2). Subsequent research showed that PLA(2) is activated by transglutaminase 2 (TGase 2). We hypothesize here that TGase 2 inhibitors may increase the anti-inflammatory efficacy of inhibiting PLA(2) activity. To test this theory, we constructed recombinant peptides containing sequences from pro-elafin (for inhibition of TGase 2), and from lipocortin-1, lipocortin-5, and uteroglobin (for inhibition of PLA(2)). The recombinant peptides, which had dual inhibitory effects on purified TGase 2 and PLA(2), reversed the inflammation of allergic conjunctivitis to ragweed in a guinea pig model. The present work suggests that novel recombinant peptides may be safe and effective agents for the treatment of various inflammatory diseases.