Insulin Eye Drops: A New Hope for Ocular Surface Disorders

Ocular surface disorders are common issues that can affect how well people see. Despite advances in eye care, some of these disorders can be tough to treat. These conditions include persistent epithelial defects (PEDs), diabetic keratopathy (DK) after eye surgery, neurotrophic keratopathy (NK), and dry eye syndrome (DED). These issues can arise due to various reasons like diabetes, injuries, infections, or lack of certain cells in the eye, making healing difficult.

Traditional treatments like eye drops, serum from a patient's own blood, or surgery often do not work well for these challenging cases. Therefore, new treatments must be explored. One potential option is Insulin, a hormone known for controlling blood sugar levels. Recent research suggests that insulin could help heal the surface of the eye.

#Insulin's Role in Eye Healing

Insulin has receptors in the cells of the cornea, the clear front part of the eye. When insulin connects with these receptors, it can help the cells grow and move, which is crucial for maintaining a healthy surface of the eye. This cell activity is particularly important for people with conditions that cause slow or poor healing of the cornea.

Studies on animals with diabetes have shown that using insulin drops can help speed up the healing of injuries to the cornea. Insulin appears to encourage the eye cells to multiply and repair themselves more quickly. This mechanism is especially important for patients who struggle with corneal healing due to various disorders.

#Research on Topical Insulin

This review looks at the current research on the use of insulin eye drops for treating different eye surface disorders. The aim is to evaluate how effective and safe insulin drops are, while also identifying areas where more research is needed.

Many studies were reviewed, focusing on the use of insulin eye drops for conditions such as PEDs, DK, NK, and DED. An extensive search in several medical databases identified relevant studies published until August 2024.

#Selection of Studies

Only studies that included human participants and reported on the effectiveness or safety of insulin drops were included. Studies that were case reports, letters, or animal studies were not considered.

Two reviewers independently assessed the studies' titles and abstracts, and then looked at the full articles for those that met the criteria. The quality of the studies was checked using specific tools to ensure that the results could be trusted.

#Summary of Findings

From the research, 14 studies were identified that explored the use of insulin eye drops. These studies involved a total of 525 participants and included different types of research such as randomized trials and case-control studies. The concentrations of insulin used in the eye drops ranged from 0.5 to 2 units per milliliter, typically applied four times a day.

#Diabetic Keratopathy

Some of the findings related to diabetic keratopathy show that insulin eye drops can significantly speed up the healing of corneal injuries. One study found that diabetic patients treated with insulin experienced complete healing much faster than those receiving standard treatments.

The effectiveness of insulin seemed to be better when lower doses were used. In one trial, patients receiving lower doses had a higher healing rate compared to those who received higher doses.

Other studies confirmed the positive effects of insulin for diabetic patients and neurotrophic keratopathy, demonstrating faster healing rates with insulin compared to traditional treatments like eye drops made from one’s blood.

#Refractory Epithelial Defects and Neurotrophic Keratopathy

Insulin eye drops have also been beneficial for patients suffering from long-lasting epithelial defects and neurotrophic keratopathy. In one study with 23 patients, a significant number showed improvement after using insulin drops for about 50 days. Insulin treatment showed a high success rate, especially for smaller defects.

Comparing insulin drops to other treatments, one study found that a higher percentage of patients achieved complete corneal healing with insulin than those using autologous serum. The time taken for healing was also shorter with insulin.

Further investigation into the stability and effectiveness of insulin formulations indicated positive outcomes. Patients treated with specific insulin preparations experienced successful healing, reinforcing the idea that insulin could be a go-to treatment option.

#Dry Eye Syndrome

Research also looked at using insulin for dry eye disease, especially in diabetic patients. Studies showed that patients using insulin eye drops had significant improvement in their symptoms and overall eye health compared to those using standard artificial tears.

In one study, participants reported improved comfort and less redness in their eyes after using insulin drops, which highlights the potential of insulin in managing dry eye, especially for those who do not respond well to typical treatments.

#Conclusion

The findings from these studies suggest that topical insulin has significant potential as a treatment option for various ocular surface disorders, particularly for those who have not seen success with standard therapies. Insulin eye drops appear to enhance healing, reduce recurrence rates, and improve the overall health of the eye surface.

Insulin treatments could be a vital addition to the management plans for patients with persistent epithelial defects, diabetic keratopathy, neurotrophic keratopathy, and dry eye. However, more well-structured clinical studies are needed to better define how to use insulin in treating these conditions on a broader scale. This research could lead to improved outcomes for patients suffering from these challenging eye diseases.