Topical insulin to treat dry eye in patients with diabetes shows promise in improving Ocular Disease Index (OSDI) scores, but falls short in other dry eye tests, according to a study published in Eye Contact Lens.

Malaysian researchers found patients with both diabetes and dry eye who were treated with topical insulin showed significant improvements on their OSDI scores—and the results were similar to those who used artificial tears. Still, other dry eye tests showed worsening results in both groups.

The investigation looked at short-term treatment results of one unit/drop of topical insulin four times a day for four weeks.

The study included 160 patients (320 eyes) who either received the topical insulin treatment (80 eyes) or standard artificial tears (80 eyes).

After week four of treatment, both groups showed significant improvement in their OSDI scores: 66% in the topical insulin group and 63% in the artificial tears group. Researchers noted the results in each group were not significantly better than the other.

Conversely, both groups showed worsening in the Schirmer I test and tear break-up time. Also, most of the participants in both groups had no change in their ocular Sjögren's International Collaborative Clinical Alliance score.

Further research is required to understand the long-term effects of topical insulin on the ocular surface, researchers said.