Purpose: This study investigates the intraocular pressures and dry eye signs before and after botulinum toxin (botox) injections for patients with essential blepharospasm. Methods: From November 2021 to July 2022, a prospective study examined 78 eyes of 39 patients diagnosed with essential blepharospasm. Before injection and 1 and 3 months after injection, intraocular pressures (IOPs) were measured using a Goldmann applanation tonometer. The noninvasive breakup time (NIBUT), lipid layer thickness (LLT), tear meniscus height (TMH), and meibomian gland clearance were assessed with the aid of the IDRA platform (SBM Sistemi, Turin, Italy). Results: The average IOPs were 14.33 ± 3.47 (7-21), 13.45 ± 3.54 (9-21), and 13.28 ± 2.98 (7-20) mmHg before, and 1 and 3 months after, botox injection respectively (p = 0.002 , p = 0.004). Twenty-four eyes of 12 patients with dry eye symptoms evidenced a significant difference in the NIBUT 1 month after Botox injection, but no significant difference in any of the LLT, TMH, or meibomian gland areal loss percentage (p = 0.007, 0.201, 0.586, and 0.435 respectively). After 3 months, no dry eye parameter change, including the NIBUT, was significant (p = 0.202, 0.542, 0.240, and 0.721 respectively). Conclusions Botulinum toxin A injection temporarily relieved dry eye symptoms and reduced the IOP in patients with essential blepharospasm.

Purpose: To determine the risk factors of meibomian gland loss in dry eye disease. Methods: The medical charts of 229 dry eye disease patients who had a meibography were retrospectively reviewed. They were divided into 4 groups according to the degree of meibomian gland loss. Telangiectasia and irregularity of eyelid margin, Ocular Surface Disease Index (OSDI), non invasive breakup time (NIBUT), lipid layer thickness (LLT) and tear meniscus height (TMH) were compared. Age, gender, history of eyeline tattoo, history of hypertension, diabetes, dyslipidemia, chemotherapy, radiation therapy, hormone therapy and autoimmune diseases were also investigated to analyze the correlation with the severe meibomian gland loss. Severe meibomian gland loss was defined as loss of more than 75% of the conjunctival area, and risk factors were evaluated using logistic regression analysis. Results: Comparing the four groups divided according to the degree of meibomian gland loss, the group with severe meibomian gland loss was older (p = 0.001), had lower LLT (p < 0.001), had a higher frequency of eyeline tattoos. The ratio of hyperlipidemia (p < 0.001) and chemotherapy (p < 0.001) was also high in the group with severe meibomian gland loss. As a result of multiple logistic regression analysis, age, eyeline tattoo, hyperlipidemia, and chemotherapy were variables that had a significant effect on sever meibomian gland loss. (p < 0.05) Conclusions Age and history of eyeline tattoo, hyperlipidemia, and chemotherapy are significant variables that cause severe meibomian gland loss in dry eye disease patients. J Korean Ophthalmol Soc 2023;64(12):1152-1157