Efficacy Of Insulin Eye Drops In The Treatment Of Corneal Ulcers In Patients With Facial Nerve Palsy And Lagophthalmos

The purpose of this study was to evaluate the efficacy of insulin eye drops in promoting the healing of corneal ulcers in patients with facial nerve palsy, a condition that prevents complete eyelid closure (lagophthalmos). The study compared healing outcomes between diabetic and non-diabetic patients who received insulin drops-specifically, 1 IU/ml of rapid-acting insulin Humulin R dissolved in 10 ml of polyethylene glycol-propylene glycol-based artificial tears prepared in a hospital pharmacy-with a control group that used artificial tears containing an oil component.

This prospective, comparative clinical study was conducted at a tertiary ophthalmology center and included 30 patients with corneal ulcers resulting from ocular surface exposure to desiccation and infection. In the experimental group, 20 patients (10 with diabetes mellitus and 10 without) were treated with insulin eye drops administered four times daily for one month. The control group comprised 10 patients who received artificial tears with a lipid component four times daily for one month.

Follow-up examinations were performed at baseline (day 0), day 7, day 14, and day 30. During these examinations, parameters such as corneal ulcer size (assessed by fluorescein staining and slit lamp biomicroscopy), corneal thickness (measured by anterior segment OCT), inflammation (evaluated through conjunctival hyperemia and anterior chamber reaction), tear film stability (assessed using tear break-up time, TBUT), visual acuity (determined by Snellen chart), and patient-reported symptoms (including pain, dryness, and discomfort) were carefully evaluated. Research hypotheses were tested using the chi-square test and Fisher’s exact test, with the significance level set at P < 0.05.

By day 7, the groups treated with insulin eye drops showed a greater reduction in ulcer size and less inflammation compared to the control group. On day 14, 60% of the patients treated with insulin had complete epithelial closure versus 30% in the control group. However, the chi-square test showed no significant difference (P = 0.121). By day 30, 90% of the patients treated with insulin patients had completely healed ulcers, compared to 50% in the control group, with Fisher's exact test showing significance (P = 0.026). Patients treated with insulin drops also had better corneal transparency and less scarring, with non-diabetic patients healing slightly faster.

In conclusion, insulin eye drops significantly accelerated the healing of corneal ulcers, reduced inflammation, and improved corneal transparency when compared to artificial tears. These findings support the potential of insulin eye drops as a therapeutic option for exposure keratopathy in patients with facial nerve palsy. Nevertheless, due to the relatively small sample size, the results should be interpreted with caution.