When ocular surface treatment fails: exploring neuropathic ocular pain in aqueous-deficient dry eye due to Sjögren's syndrome treated with mirogabalin: a case study.

Dry eye disease can be classified as aqueous-deficient, evaporative and mixed-type. Recently, neuropathic pain has been indicated to be involved in the subjective symptoms of aqueous-deficient dry eye. However, the mechanism underlying neuropathic ocular pain in such patients remains elusive. Here, we present the case of a patient with aqueous-deficient dry eye disease and severe corneal and conjunctival epithelial damage due to Sjögren's syndrome. Despite considerable improvements in ocular surface conditions with local treatments, such as punctal plugs, autologous serum eye drops, rebamipide eye drops, and tacrolimus eye drops, the patient experienced severe ocular pain for two years, which was disproportionate to the objective clinical findings. The pain worsened during the exacerbations of systemic symptom, such as arthritis and interstitial pneumonia, without correlating with the ocular surface findings. The administration of mirogabalin, a neuropathic pain medication, effectively alleviated the patient's subjective ocular pain symptoms. Ocular pain in patients with Sjögren's syndrome is not necessarily linked to an aqueous deficiency or ocular surface findings. It can arise as neuropathic ocular pain due to inflammation spreading to the trigeminal nerve. Given the systemic inflammatory condition and characteristics of the ocular pain, administering neuropathic pain medications should be considered as a treatment option.