Abstract
BACKGROUND: Keratoconjunctivitis sicca or dry eye disease (DED) is a multifactorial disorder underpinned by a complex inflammatory cycle. Introduction of topical cyclosporine has been a significant advance in the management of DED. In recent years advancements in formulation technology have led to development of micellar nano-particulate (MNP) cyclosporine formulations that promise better penetration into ocular target tissues and potential for reduced ocular surface irritation. METHODS: We compared two dosing regimes of a proprietary MNP cyclosporine emulsion with the widely marketed topical cyclosporine formulation Restasis™ in a multicenter parallel-group randomised trial in patients with DED. Patients were randomised to one of 3 treatment groups with 90 patients eligible for the per protocol analysis: 30 in the higher dose test arm A; 32 in the lower dose test arm B; and 28 in the Restasis™ control arm C. All scored efficacy endpoints were tested for significance by comparing the mean change in scores from baseline in the test groups with that in the control group at 12 weeks, using the Student's t test. Wilcoxon's rank sum test was used to test individual symptom scores and clinician's global evaluation of treatment grades. RESULTS: Corneal fluorescein staining score, the primary efficacy endpoint, decreased by 6.8 ± 4.0, 5.7 ± 3.9, and 4.6 ± 3.6 points in the 3 groups respectively, indicating superior efficacy in test arm A in comparison to control arm C (p = 0.0026). Schirmer's tear test, conjunctival lissamine staining score, ocular surface disease index, and individual dry eye symptom scores also favoured higher dose MNP cyclosporine over Restasis™. The study failed to differentiate the treatment arms in terms of clinician's global evaluation of treatment, use of tear substitutes, best corrected visual acuity or safety and toleration. CONCLUSION: The results indicate that the dose of 1 drop of a 0.05% w/v ophthalmic emulsion of MNP cyclosporine administered topically twice daily yields better outcomes at 12 weeks than the lower dose tested in the study, and is more efficacious than an equivalent dose of Restasis™, the active control used in the study. TRIAL REGISTRATION: This trial was registered in the Clinical Trials Registry of India on 29/03/2019, and was assigned registration number CTRI/2019/03/018319.