Rodent models for dry eye syndrome: Standardization using benzalkonium chloride and scopolamine hydrobromide

Dry eye disease is a highly prevalent ocular condition that significantly affects the quality of life and presents a major challenge in ophthalmology. Animal models play a crucial role in investigating the pathophysiology and developing effective treatments. The goal of this study was to compare and standardize two dry eye disease rodent models and explore their recovery aspects. We have standardized benzalkonium chloride and scopolamine-induced dry eye disease models which represents two different classes of the dry eye i.e., evapo-rative dry eye and aqueous deficient dry eye, respectively. After the development of dry eye conditions, a self -recovery period of seven days was granted to assess the reversal of the induced changes. The dry eye condition was assessed by measuring tear volume, corneal slit lamp imaging, and histological examination of the cornea, the lacrimal and the harderian gland. The study indicated the development of chronic inflammation of the cornea and lacrimal gland in the case of benzalkonium after five days of the treatment, while the scopolamine treated group showed chronic inflammation of the lacrimal gland after five days and corneal inflammation after seven days of administration. The recovery study suggested that after discontinuation of inducing agent, the dry eye symptoms were still persistent suggesting the utility of the model in evaluating dry eye treatments. The study highlights the comparative changes in both models along with recovery which can serve as a base for drug discovery and development against dry eye disease.

Automated summary

Dry eye disease is a common ocular condition that greatly impacts life quality and presents challenges in ophthalmology. Animal models were used to compare and standardize two rodent models of dry eye disease, and explore their recovery aspects. The study found chronic inflammation in the cornea and lacrimal gland in benzalkonium-treated group, while the scopolamine-treated group showed chronic inflammation in the lacrimal gland initially and later in the cornea. The recovery study suggested the usefulness of the models in evaluating dry eye treatments.