Studies: For ocular allergy - an antihistamine contact? Lipisome spray?
Pall et al, Cornea, March 2019
These studies about contact lens use to deliver a drug are pretty cool…. What’s not to like about being able to treat your ocular allergy with your contact lenses themselves?
I guess my one qualm is just about the general trend. We always seem to want to max out people’s people use of contact lenses and I just wonder what things (like dry eye symptoms, which can overlap with allergy anyway) could get masked in the process and delay diagnosis. Hopefully screening for dry eye would be part of the process before dispensing a lens like this. The convenience factor certainly seems tremendous.
Question mark: Where are preservatives in this equation? If there’s no preservative involved, then this is win-win - especially since there are no preservative-free allergy drops on the US market.
A contact lens (CL)-based drug delivery system for therapeutic delivery of the antihistamine ketotifen was tested in 2 parallel, conjunctival allergen challenge-based trials.
Both trials employed the same multicenter, randomized, placebo-controlled protocol. Test lenses were etafilcon A with 0.019 mg ketotifen; control lenses were etafilcon A with no added drug. Subjects were randomized into 3 treatment groups. Group 1 received test lens in one eye and control lens in the contralateral eye; the eye chosen to receive test lens was randomly selected in a 1:1 ratio. Group 2 received test lenses bilaterally, and group 3 received control lenses bilaterally. Allergen challenges were conducted on 2 separate visits: following lens insertion, the subjects were challenged at 15 minutes (to test onset) and 12 hours (to test duration). The primary endpoint was ocular itching measured using a 0 to 4 scale with half-unit steps. Secondary endpoints included ciliary, conjunctival, and episcleral hyperemia.
The mean itching scores were lower for eyes wearing the test lens as compared to those that received control lenses, indicating that the test lens effectively reduced allergic responses. Mean differences in itching were statistically and clinically significant (mean score difference ≥ 1) at both onset and duration for both trials.
This large-scale assessment (n = 244) is the first demonstration of efficacy for CL delivery of a therapeutic for ocular allergy. Results are comparable to direct topical drug delivery and suggest that the lens/ketotifen combination can provide a means of simultaneous vision correction and treatment for CL wearers with ocular allergies.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.
Liposomal Eye Spray Is as Effective as Antihistamine Eye Drops in Patients with Allergic Rhinoconjunctivitis Induced by Conjunctival Provocation Testing.
Grzella et al, International Archives of Allergy and Immunology, March 2019
Hmm. Since antihistamines dry eye out, even without taking account of the toxic preservatives in antihistamine eye drops, I’m all for lower risk alternatives to the extent they can actually work.
In this study, they evaluated eye redness and symptoms of irritation.
The liposomal spray seems to have been pretty much just as effective as the antihistamine, surprisingly, and just barely less effective in improving redness.
Liposomal eye spray (LS) has been introduced for the treatment of dry eye. Whether LS can also relieve symptoms due to allergic rhinoconjunctivitis (ARC) has not yet been sufficiently investigated.
The aim of this study was to assess the onset of action, the reduction of allergy symptoms, and the safety of LS - a nonpharmacological treatment option - compared with those of antihistamine eye drops (AD).
In this open, prospective, controlled, monocenter noninterventional study, adults with ARC received either LS or AD for the relief of eye irritation after a positive conjunctival provocation test (CPT). All patients completed a questionnaire before and after the CPT. Eye irritation was rated on a visual analogue scale (VAS) at 6 time points. Conjunctival redness was analyzed using objective digital analysis based on images taken during the study visit.
Data were collected from 40 patients (20 per group). In both groups, 80% of patients perceived an onset of action within 0-2 min after application of LS or AD following the CPT. Relief of eye irritation (as determined by VAS) increased throughout the visit for both groups. In the digital analysis, the mean proportion of redness of the eye decreased from 10.3 to 7.0% for LS and from 10.4 to 6.5% for AD, with the largest difference observed 10 min after application (LS: 8.9%; AD: 6.0%; p = 0.094).
LS is a nonpharmacological treatment option for ARC, showing no significant difference or relevant numerical inferiority to AD in any parameter studied. It was generally safe and well tolerated.