Updates in the treatment of ocular allergies

Comparison of the preventive effect of colchicine versus diphenhydramine, prednisolone, and a combination therapy on intraperitoneal adhesion bands: an experimental study in rats

BACKGROUND

Peritoneal adhesion formation is an inevitable consequence of abnormal repair of the peritoneum following different peritoneal injuries of intra-abdominal operations with the subsequent morbidity that they represent. Vast efforts have been made to elucidate the cause and prevent the development of abdominal adhesions. The aim of our study is to compare the capability of colchicine versus diphenhydramine (DPH) and methylprednisolone (MP), and also prednisolone in adhesion prevention.

METHODS

Sixty-one male Wistar stock rats were divided into four groups. The first group attended as the control group. Groups 2, 3, and 4 received oral combination of MP + DPH solution (20 mg/kg), colchicine (0.02 mg/kg), and prednisolone (1 mg/ kg), respectively. Adhesion bands were induced by standardized abrasion of the peritoneum through a midline laparotomy. All rats were sacrificed on the 15^th-day post medication administration and the subjects underwent an exploratory laparotomy. The presence of adhesions was evaluated with the modified using Nair's classification.

RESULTS

The proportion of the control group with substantial adhesion bands (73.3%) was significantly higher than that of the MP + DPH (13.3%), colchicine (33.3%), and prednisolone (31.3%) groups. There were significant differences between the scores of the control and the MP + DPH, colchicine, and prednisolone groups (P = 0.001, 0.028, and 0.019, respectively). There was no statistically significant difference to favor colchicine against MP + DPH (P = 0.390) or MP + DPH against prednisolone (P = 0.394).

CONCLUSIONS

Both colchicine and combination of DPH + MP prevented postoperative abdominal adhesions separately in our study. However, the lowest adhesion formation rate was observed in the DPH + MP group, even lower than the prednisolone group.

Ocular Biodistribution of Once-Daily 0.6% Bilastine Eye Drops Reveals Highest Levels in Conjunctiva Up to 24 h Postadministration

Purpose: Bilastine is a second-generation antihistamine that has been shown to be effective for treatment of allergic conjunctivitis. The objective of this study was to evaluate the pharmacokinetics (PKs) and biodistribution of 0.6% bilastine preservative-free eye drops. Methods: Bilastine was quantified in the conjunctiva, cornea, aqueous humor, vitreous humor, iris/ciliary body, retina/choroid, crystalline lens, and plasma, following a single topical administration to male Dutch-belted rabbits. Results: Concentrations of bilastine were highest in the conjunctiva [C_max: 2,545.04 ng/g, at 6 h postadministration; area under the concentration-time curve (AUC_t): 11,382.40 ng·h/g] and cornea (C_max: 609.11 ng/g, at 1 h postadministration; AUC_t: 1,993.88 ng·h/g), followed by the iris/ciliary body, retina/choroid, aqueous humor, plasma, vitreous humor, and crystalline lens. Quantifiable bilastine concentrations were observed up to 24 h after instillation in the conjunctiva (388.45 ng/g), cornea (28.68 ng/g), iris/ciliary body (12.42 ng/g), retina/choroid (1.91 ng/g), and crystalline lens (0.12 ng/g). In plasma, aqueous humor, and vitreous humor, bilastine was detected up to 12 h postadministration (0.18 ng/mL, 0.40 ng/mL, and 0.32 ng/g, respectively). Conclusions: PKs and biodistribution of 0.6% bilastine eye drops in rabbits revealed a marked preferential distribution in the conjunctiva (target tissue), with sustained levels up to 24 h. These findings are consistent with clinical efficacy trials supporting once-daily administration of topical bilastine for treatment of 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.

Relevance of IgE, allergy and eye rubbing in the pathogenesis and management of Keratoconus

Keratoconus (KC) is an ectatic disease of the cornea characterized by localized thinning and protrusion causing irregular astigmatism, which can lead to significant visual impairment. KC has often been associated with allergy and/or atopy, which are immune-mediated inflammatory reactions primarily driven by IgE. A higher proportion of KC patients were reported to have history or suffer from systemic and/or ocular allergy with elevated allergen-specific IgE and/or total serum IgE. Eye rubbing, one of the risk factors for worsening of the disease and developing related complications in KC, is associated with IgE driven conditions. The current review enumerates and contextualizes the evidence related to IgE in mediating KC pathogenesis, including aberrant extra-cellular matrix remodeling. This review also discusses clinical strategies directed at modulating IgE-mediated responses in the management of KC, and the emerging academic and plausible clinical relevance of assessing serum and tear IgE (allergen-specific and total) status in improving the understanding of disease pathobiology, treatment planning, and prognosis.

Symptoms of titanium and nickel allergic sensitization in orthodontic treatment

Aim

The study aimed to evaluate to which extent self-reported symptomatology, age, and sex are predictors of titanium and nickel allergic sensitization in patients in treatment with fixed orthodontic appliances.

Methods

The study analyzed 228 subjects aged 11–45 years (median 18, interquartile range 16–22); 68% of them were females, and 52% were adolescents. The allergic sensitization testing included epicutaneous patch test to titanium, titanium dioxide, titanium oxalate, titanium nitride, and nickel sulfate. The questionnaire on symptoms potentially linked to titanium and nickel sensitization was used.

Results

Prevalence of the allergic sensitization to titanium in patients undergoing orthodontic treatment was 4% (2% only to titanium without nickel) while to nickel 14% (12% nickel without titanium). Hypersensitivity to both metals at the same time was present in 2% of subjects. Sensitization to nickel was more common in females than in males (17 vs. 8%) and much more common in adults than in adolescents with small effect size (20 vs. 8%; p = 0.013). Sensitization to titanium was more common in females than in males (6 vs. 1%) with no difference in age. Multiple logistic regression analysis revealed that adult age increases the odds for being sensitized to nickel for 2.4 × (95% CI 1.1–5.6; p = 0.044) while watery eyes for 3.7 × (95% CI 1.2–11.1; p = 0.022). None of the symptoms were significant predictors of titanium sensitization.

Conclusion

Allergic sensitization to titanium and nickel are not very frequent in orthodontic patients, and self-reported symptomatology is a weak predictor of those sensitizations.

Efficacy, Safety and Steroid-sparing Effect of Topical Cyclosporine A 0.05% for Vernal Keratoconjunctivitis in Indian Children

Purpose

To evaluate the efficacy, safety, and steroid-sparing effect of topical cyclosporine A (Cs A) 0.05% in patients with moderate to severe steroid dependent vernal keratoconjunctivitis (VKC).

Methods

A prospective, comparative, placebo controlled study was carried out on 68 VKC patients, with 34 patients treated with topical Cs A 0.05% and the remaining 34 with topical carboxymethyl cellulose 0.5% (placebo). Both groups also received topical loteprednol etabonate 0.5%. Symptom (itching, photophobia, tearing, and discharge) score, sign (tarsal and limbal papillae, corneal involvement, and conjunctival hyperemia) score, and drug score (steroid drop usage/day/eye) were recorded at baseline and each follow-up visit. The intraocular pressure (IOP) measurement and evaluation of any ocular side effects were carried out.

Results

Significant reduction in symptom score and sign score was seen in both groups. Cs A group significantly showed more reduction in symptom (P < 0.0001 in all follow-up visits) and sign (P < 0.0001 in all follow-up visits) scores compared to the placebo group. At day 7, mean steroid usage reduced from 4 to 3.44 ± 0.5 and 3.79 ± 0.4 in Cs A and placebo groups, respectively (P < 0.0001). Steroid drops completely stopped in 21 patients at day 60 in the Cs A group compared to none in the placebo group. No significant rise in IOP or any side effects were noted in either group.

Conclusion

Topical Cs A 0.05% is effective and safe in patients with moderate to severe VKC with good steroid-sparing effect.

Dietary ω-3 fatty acids alter the lipid mediator profile and alleviate allergic conjunctivitis without modulating Th2 immune responses

Allergic conjunctivitis (AC) is one of the most common ocular surface diseases in the world. In AC, T helper type 2 (T_h2) immune responses play central roles in orchestrating inflammatory responses. However, the roles of lipid mediators in the onset and progression of AC remain to be fully explored. Although previous reports have shown the beneficial effects of supplementation of ω-3 fatty acids in asthma or atopic dermatitis, the underlying molecular mechanisms are poorly understood. In this study, a diet rich in ω-3 fatty acids alleviated AC symptoms in both early and late phases without affecting T_h2 immune responses, but rather by altering the lipid mediator profiles. The ω-3 fatty acids completely suppressed scratching behavior toward the eyes, an allergic reaction provoked by itch. Although total serum IgE levels and the expression levels of T_h2 cytokines and chemokines in the conjunctiva were not altered by ω-3 fatty acids, eosinophil infiltration into the conjunctiva was dramatically suppressed. The levels of ω-6–derived proinflammatory lipid mediators, including those with chemoattractant properties for eosinophils, were markedly reduced in the conjunctivae of ω-3 diet–fed mice. Dietary ω-3 fatty acids can alleviate a variety of symptoms of AC by altering the lipid mediator profile.—Hirakata, T., Lee, H.-C., Ohba, M., Saeki, K., Okuno, T., Murakami, A., Matsuda, A., Yokomizo, T. Dietary ω-3 fatty acids alter the lipid mediator profile and alleviate allergic conjunctivitis without modulating T_h2 immune responses.

Efficacy and safety of topical cyclosporine A 0.05% in vernal keratoconjunctivitis

INTRODUCTION

While corticosteroids are an effective choice of treatment for severe vernal keratoconjunctivitis (VKC), their long-term use is restricted due to side effects. This study was conducted to evaluate the efficacy and safety of topical cyclosporine A (CsA) 0.05% in the treatment of VKC.

METHODS

A total of 30 patients with VKC that was resistant to topical corticosteroids, antihistamines and mast cell stabilisers were treated with topical CsA 0.05%. Patients were evaluated at Weeks 4, 8 and 12 after the initiation of therapy. Symptoms and signs observed before and after treatment were recorded and scores were assigned. Scores for symptoms and signs, the need for topical corticosteroids and ocular side effects were evaluated.

RESULTS

At baseline, the median values of the symptom and sign scores were 10.0 (range 5.0-18.0) and 6.0 (range 2.0-13.0), respectively. At Week 4 of treatment with topical CsA 0.05%, the median values of the symptom and sign scores were 3.0 (range 0-14.0) and 3.0 (range 0-8.0), respectively. The reductions in the symptom and sign scores were statistically significant. The reduction in the need for corticosteroid was statistically significant by Week 12 of therapy. No significant side effects were reported.

CONCLUSION

Topical CsA 0.05%, which can help to reduce corticosteroid usage, is an effective and safe alternative for the treatment of resistant VKC. Further studies are needed to determine the optimal duration of therapy and possibility of recurrence.

[Immunosuppressives to prevent rejection reactions after allogeneic corneal transplantation]

In order to prevent rejection of an allogeneic corneal transplant after perforating (high risk) keratoplasty, active agents from different classes of pharmacological substances are used, as with solid organ transplantation. In addition to glucocorticoids, antiproliferative agents, small molecule inhibitors and antibodies, those belonging to the group of macrolides with their many derivatives represent an interesting class of substances in this context. As a supplement to cyclosporin A (CSA) the most successful macrolide in transplantation medicine, animal experiments are currently being carried out to test newer macrolide derivatives, such as sanglifehrin A (SFA). This overview describes the classes of drugs and modes of action of currently administered standard medications in the clinical routine and new developments are presented.

Hydrocortisone concentration influences time to clinically significant healing of acute inflammation of the ocular surface and adnexa - results from a double-blind randomized controlled trial

Background

The efficacy of topical ophthalmic corticosteroids depends upon small modifications in preparations, such as drug concentration.

The aim of this study was to confirm that hydrocortisone acetate (HC-ac) ophthalmic ointments of 2.5% and 1% are more effective than a 0.5% eye ointment.

Methods

In this randomized, double-blind, placebo-controlled, parallel-group clinical study, the change of signs and symptoms of acute inflammation of the ocular surface and adnexa was evaluated in 411 subjects.

Results

Median time to clinically relevant response as estimated by 50% reduction in clinical signs and symptoms (CSS) total score over the entire trial was similar for subjects treated with HC-ac 2.5% (73.5 h) and for subjects treated with HC-ac 1.0% (67.7 h) and was considerably and significantly longer for subjects treated with HC-ac 0.5% (111.8 h) [p < 0.001 for both dosages]. All trial medications were safe and well tolerated.

Conclusion

Hydrocortisone acetate 2.5% and Hydrocortisone acetate 1% eye ointments are efficacious and safe treatments for acute inflammations of the ocular surface or adnexa, and showed significantly better efficacy than a control group treated with Hydrocortisone acetate 0.5% therapy.

Trial registration

Current Controlled Trials ISRCTN15464650.

Sublingual immunotherapy for experimental allergic conjunctivitis in a murine model induced by Dermatophagoides farinae allergen

BACKGROUND

Sublingual immunotherapy (SLIT) is a clinically effective treatment in allergic conjunctivitis (AC); however, the mechanism of the underlying pharmacodynamics remains unclear. Here, we investigate the efficacy and the mechanism of a sublingually administered Dermatophagoides farinae (Der f) vaccine in a murine AC model.

METHODS

A murine model of AC caused by Der f extract was developed in BALB/c mice by repeated application of allergen. Sensitized mice were SLIT treated by Der f drops and subsequently analyzed for AC symptoms, histopathological and immunological parameters.

RESULTS

In this study, Der f extract successfully induced the symptoms of AC in BALB/c mice. In these sensitized mice, clinical symptoms (scratching behavior, lacrimation, conjunctival hyperemia and edema), immunological and histopathological findings (inflammatory cell infiltration) were very similar to those in human AC. SLIT treatment of sensitized mice markedly reduced the clinical and histopathological symptoms and decreased the expression levels of total immunoglobulin E (IgE), Der f-specific IgE and T helper cell 2 (Th2) cytokine interleukin-4, with a significant increase in Der f-specific IgG4 and Th1 cytokine interferon-γ.

CONCLUSIONS

SLIT with Der f drops is a potentially effective means of immunotherapy for Der f-induced AC by modulating the Th2-biased allergic immune response.

Allergic conjunctivitis: a comprehensive review of the literature

Ocular allergy represents one of the most common conditions encountered by allergists and ophthalmologists. Allergic conjunctivitis is often underdiagnosed and consequently undertreated. Basic and clinical research has provided a better understanding of the cells, mediators, and immunologic events, which occur in ocular allergy. New pharmacological agents have improved the efficacy and safety of ocular allergy treatment. An understanding of the immunologic mechanisms, clinical features, differential diagnosis, and treatment of ocular allergy may be useful to all specialists who deal with these patients. The purpose of this review is to systematically review literature underlining all the forms classified as ocular allergy: seasonal allergic conjunctivitis, perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratocongiuntivitis, contact allergy, and giant papillary conjunctivitis.

The role of anemia management in improving outcomes for African-Americans with chronic kidney disease

Chronic kidney disease (CKD) is a serious threat to African-American public health. In this population CKD progresses to end-stage renal disease (ESRD) at quadruple the rate in Caucasians. Factors fueling progression to ESRD include diabetes and hypertension, which show high prevalences and accelerated renal damage in African- Americans, as well as possible nutritional, socioeconomic, and genetic factors. Anemia, a common and deleterious complication of CKD, is more prevalent and severe in African-American than Caucasian patients at each stage of the disease. Proactive management of diabetes, hypertension, anemia, and other complications throughout the course of CKD can prevent or delay disease progression and alleviate the burden of ESRD for the African-American community. Currently, African-Americans with CKD are less likely than Caucasian patients to receive anemia treatment before and after the onset of dialysis. Although African-Americans often require higher doses of erythropoiesis-stimulating agents, this may result from late treatment initiation, lower hemoglobin levels, or the presence of comorbidities such as diabetes and inflammation, although racial differences in response cannot be excluded. This review explores racial-specific challenges and potential solutions in renal anemia management to improve outcomes in African-American patients.