Effect of Chitosan-N-acetylcysteine on Subjective Pain Sensation in Corneal Abrasion

Effect of Chitosan-N-acetylcysteine (Lacrimera®) on Subjective Pain Sensation in Corneal Abrasion: a Pilot Study

Aim of this study is to investigate the effect of Chitosan-N-acetylcysteine (C-NAC; Lacrimera®, Croma-Pharma GmbH, Leobendorf, Austria) in patients with corneal abrasion less than one third of the corneal surface on subjective pain sensation.

Commonly, standard of care for corneal abrasion is topical antibiotics. Bandage contact lenses may be used in addition, which significantly decrease pain sensation in a vast majority of patients. Recently, a new preservative-free agent consisting of a novel biopolymer, Chitosan-N-acetylcysteine (C-NAC; Lacrimera®, Croma-Pharma GmbH, Leobendorf, Austria) has been approved for the treatment of dry eye syndrome (DES). This agent electrostatically binds to the mucine layer of the tear film, forming a glycocalyx-like structure. In an animal model, the beneficial effect of Chitosan-N-Acetylcysteine on recovery time has been observed. Aim of this study is to investigate the effect of Chitosan-N-acetylcysteine (C-NAC; Lacrimera®, Croma-Pharma GmbH, Leobendorf, Austria) in patients with corneal abrasion less than one third of the corneal surface on subjective pain sensation. It will further explore the extend of corneal healing after use of Lacrimera® over 5 days in those patients initially treated with Lacrimera®.

Patients will either be randomized to group 1 (instillation of 1 drop of C-NAC) or group 2 (no instillation of C-NAC) in a 1:1 fashion.

Patients will either be randomized to group 1 (instillation of 1 drop of C-NAC) or group 2 (no instillation of C-NAC) in a 1:1 fashion. Afterwards one drop of C-NAC will be instilled into the study eye of group 1. 1 hour after treatment VAS and the symptom questionnaire will be performed repeatedly in both groups. Both groups will receive antibiotic ointment bandages and antibiotic eye drops for 5 days. Patients assigned to group 1 will receive Lacrimera® for home treatment over the following 5 days. 1 drop of Lacrimera® is supposed to be installed into the eye 20 minutes prior to installation of the respective antibiotic eye drops or ointments.

A new preservative-free formulation of eye drops consists of a novel biopolymer, chitosan-N-acetylcysteine (C-NAC; Lacrimera®, Croma-Pharma GmbH, Leobendorf, Austria), which electrostatically binds to the mucine layer of the tear film forming a glycocalyx-like structure.

Relative defect size difference as measured by fluorescein slit lamp photography between the visits between the two groups

Relative defect depth difference as measured by AS-OCT at 1-week visit compared to baseline between the two groups

Inclusion Criteria: Age older than 18 years Corneal abrasion less than one third of the cornea Exclusion Criteria: Ocular surgery within prior 3 months in the affected eye Ocular injury within prior 3 months before abrasion in the affected eye Ocular herpes of eye or eyelid within prior 3 months Active ocular infection Active ocular inflammation or history of chronic, recurrent ocular inflammation within prior 3 months Ocular surface abnormality that may compromise corneal integrity Presence of diseases that reduce experience of pain (e.g. Diabetes mellitus) Pregnancy