Topical insulin used alone or in combination with drug-depository contact lens for refractory cases of neurotrophic keratopathy

Abstract

Purpose: To report the clinical outcomes achieved in refractory cases of neurotrophic keratopathy (NK) through the utilization of insulin eye drops alone or in conjunction with a drug-depository contact lens (DDCL).

Observations: This multicentric prospective open-label uncontrolled case series included consecutive patients with NK refractory to conventional treatment. Insulin eye drops (1 unit/mL) were prescribed 4 times/day in all cases, and a Therapeutic Hyper-CL™ soft contact lens (EyeYon Medical, Ness Ziona, Israel), designed to act as a drug reservoir, was applied in selected patients. Data about stage and duration of NK, corneal sensitivity, previous treatments, rate and speed of healing, changes of NK area over time were collected. Nine eyes of 8 patients (mean age 52.50 ± 12.03 years [95 % CI, 44.13-60.87]) affected by NK refractory to conventional medical therapy were included. All patients received topical insulin, while DDCL was also applied in 3 cases. At T0, the mean area of the corneal epithelial defect was 21.84 ± 18.35 mm² [95 % CI, 9.86-33.84]. Complete corneal re-epithelialization occurred in all cases, after a mean time interval of 25.78 ± 8.39 days [95 % CI, 20.30-31.26]. Mean reduction rate of epithelial defect areas was -0.81 ± 0.44 mm²/day [95 % CI, -1.16 to -0.46] for patients treated with insulin eye drops, and -0.63 ± 0.30 mm²/day [95 % CI, -0.96 to -0.29] for those treated with insulin eye drops plus DDCL (p = 0.71). Neither adverse events nor episodes of NK recurrence were reported.

Conclusions and importance: Topical insulin, used alone or in combination with DDCL, is an accessible, inexpensive, and effective treatment for refractory NK.

Keywords: Hyper-CL; Insulin eye drops; NK; Neurotrophic keratopathy; Persistent epithelial defect.

Fig. 1

Graph illustrating the changes over time of the epithelial defect. Areas of epithelial defect evaluated over time in patients with neurotrophic keratopathy treated with insulin alone (a) or in combination with a drug-depository contact lens (b).

Fig. 2

Slit lamp photographs of all patients before and during therapy. Slit lamp photographs of the cornea with yellow/blue filter collected at T0 and during subsequent time points until complete healing. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Fig. 3

Slit lamp photographs of patient #6 before and during therapy. Slit lamp photographs of the cornea with yellow/blue filter collected at T0 (a), day 20 (b), and day 30 (c). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)