Notes about: Topical % N-acetyl-cysteine (NAC) QID x 1month
Could meibomian gland probing be unnecessary in the future? Could we be getting closer to a cure for dry eye disease? The answer to both questions is yes, but the question is how long will it take to get there.
There are many underlying causes to dry eye disease and meibomian gland atrophy/dysfunction. A key component is hyperkeratinization of the meibomian gland orifice.
The below company Azura had good news recently as their phase 2 study had positive results. Their new drug is called AZR-MD-001 and breaks open di-Sulfide bonds.
We have been using Mucomyst (topical N-acetylcysteine) or for years to help with very severe dry eye disease where mucus strands cause severe pain. There are a small number of patients who benefit from Mucomyst before they get to an extreme point, but I have not seen a study on this until recently. Mucomyst costs usually about $300/month and needs to be made at a compounding pharmacy. We have used FOERS Pharmacy in the past.
The key issue with Azura’s report and many of these studies is the role of objective versus subjective data collection. Most of the studies noting the benefit of Mucomyst below did not have a double, blinded study which adds bias to results. Additionally, all these studies need to include pre-treatment and post-treatment meibographies which is more objective (thought not perfect) compared to patient symptoms scores, OSDI, meibomian gland secretion quality (Meibomian Gland Score), Schirmers’s, and number of glands secreting (Meibomian Glands Yielding Liquid Secretion Score). Only until recently did we have something more objective than the above. Thus the meibography is crucial.
I am hopeful that Azura’s new drug, AZR-MD-001 will be the beginning of a breakthrough to finally prevent MGD. Going on the record, I believe blue light from electronic screens is increasing hyperkeratinization.
Topline results from Phase 2 study of investigational MGD treatment
Azura Ophthalmics announced with the release of topline data that primary endpoints were met in its Phase 2 study of AZR-MD-001 as a treatment under investigation for MGD. Patients (n=95) were dosed twice weekly with AZR-MD-001 (0.1%, 0.5%, or 1.0%) or control with patient-reported symptoms, OSDI score, meibomian gland secretion quality (Meibomian Gland Score), and number of glands secreting (Meibomian Glands Yielding Liquid Secretion Score) recorded at various time points. According to the company’s press release, there was a statistically significant improvement from baseline in the 0.5% and 1.0% dose groups and significant improvement over the control group at month 3 in the 0.5% group. Overall, the company reported 58% of patients becoming non-symptomatic after 3 months with AZR-MD-001 treatment compared to 16% in the control group.
Purpose: To evaluate the efficacy of topical N-acetyl-cysteine (NAC) therapy in patients with meibomian gland dysfunction (MGD).
Methods: Twenty patients with MGD were prospectively randomized and assigned into 2 groups. The patients were instructed to use either NAC 5% or preservative-free artificial tear topically 4 times a day for a month. All patients were instructed to apply lid hygiene once daily. Preservative-free artificial tears treated group served as control. Paired sample Student’s t-tests were used to detect differences between the baseline and 1 month after treatment initiation in mean ocular symptoms, fluorescein break-up time (FBUT) values, and Schirmer scores in each group. Difference in mean ocular symptoms, Schirmer’s test scores, and FBUT values between the baseline and 1 month after treatment initiation were compared between the groups using Mann-Whitney U test.
Results: One month of topical NAC therapy provided statistically significant improvements in FBUT and Schirmer scores as compared with the initial study visit. The average Schirmer increase rate was significantly better in the NAC group than in the control group. Significant improvements for the symptoms of ocular burning, foreign body sensation, and intermittent filmy or blurred vision were noted in both groups; and only NAC-treated group showed improvement for the symptom of itching, at 1 month as compared with 1 day. NAC provided significantly better improvement in itching symptom when compared with controls.
Conclusions: Topical administration of NAC is thought to be effective and well tolerated in patients with MGD.