A real-world clinical study suggests Manuka honey eye drops may offer superior relief from post-surgical dry eye. Still, experts caution that larger trials are needed to confirm the benefits.
Study: Efficacy of Manuka honey eye drops in managing dry eye disease after cataract surgery: a prospective controlled study. Image credit: wasanajai/Shutterstock.com
Manuka honey eye drops are associated with greater improvements than sodium hyaluronate eye drops in reducing dry eye symptoms and inflammation after cataract surgery, reports a new study published in Frontiers in Ophthalmology.
Cataract surgery frequently triggers or worsens dry eye symptoms
Dry eye is a complex disease associated with discomfort, vision problems, and reduced overall quality of life. It is a highly prevalent disease and one of the most common reasons for visits to general ophthalmologists.
Inflammation, neurosensory abnormalities, environmental triggers, and certain surgical interventions can significantly contribute to dry eye disease. Cataract surgery is a common ophthalmic procedure that can both induce and exacerbate dry eye symptoms. Approximately 34-37 % of patients experience persistent dry eye symptoms even six months after cataract surgery.
Although no curative treatment is currently available, lubricating eye drops, topical cyclosporine A, mucin secretagogues, anti-inflammatory agents, eyelid hygiene, and punctal occlusion are among the available interventions to improve dry eye symptoms.
Manuka honey is a monofloral honey derived from the manuka tree (Leptospermum scoparium), which is commonly found in New Zealand and eastern Australia. Manuka honey has strong antioxidant, anti-inflammatory, and antimicrobial properties, which collectively make it a potential treatment for wound healing. Two types of manuka honey-based formulations have been approved for dry eye treatment, including Optimel Manuka honey Dry Eye Drop and Optimel Manuka honey Forte Eye Gel.
Given that cataract is the most commonly performed eye surgery and a frequent contributor to postoperative dry eye disease, researchers at the Ophthalmology Department of Hospital Clinico San Carlos, Spain, examined and compared the effects of manuka honey eye drops and sodium hyaluronate-containing artificial tears on dry eye symptoms after cataract surgery.
Prospective controlled study compares Manuka and artificial tears
The study included 53 eyes from 53 patients who underwent cataract surgery. Of them, 25 received a manuka honey-based eye drop, and 28 received a sodium hyaluronate-based eye drop (formulated with additional agents including xanthan gum, glycine, and betaine). The treatment regimen included one drop of either manuka honey or sodium hyaluronate every six hours, beginning on the day of cataract surgery and continuing for 30 days.
The assessment of eye conditions was performed before surgery (baseline) and one day, one week, and one month after surgery.
Manuka drops show greater symptom relief than control
The assessment of eye conditions revealed that patients receiving manuka honey eye drops experienced greater improvements in dry eye symptoms, with limited evidence of differences in visual function, than those receiving sodium hyaluronate eye drops at 1-month follow-up. These findings remained significant even after adjusting for baseline symptoms and the patient's gender.
Regarding vision-related difficulties in daily activities, improvements were observed among 87 % of patients in the manuka group and 78 % in the sodium hyaluronate group. Regarding overall satisfaction with current vision, improvements were observed among all patients in the manuka group and 92 % of patients in the sodium hyaluronate group.
Regarding near and distant vision, a significant improvement was observed in the manuka group compared to the sodium hyaluronate group. However, no statistically significant differences between groups were observed at one month for these measures, and the authors note these findings may reflect baseline differences rather than a true treatment effect.
Furthermore, a significant reduction in conjunctival redness was observed in the manuka group compared to the sodium hyaluronate group.
Findings support Manuka as a promising adjunct therapy
The study reveals that manuka honey-based eye drops are associated with greater improvements than sodium hyaluronate-based eye drops in improving dry eye disease symptoms and reducing conjunctival redness following cataract surgery.
Despite significantly higher dry eye symptoms than the sodium hyaluronate group at baseline, the manuka group experienced significant symptomatic relief and visual functioning improvements one month after cataract surgery. These findings suggest that the observed benefits are not driven by baseline differences.
As observed in the study, conjunctival redness significantly reduced in the manuka group and increased in the sodium hyaluronate group. However, the within-group reduction in redness in the manuka group was modest, and the key finding was a significant difference between groups after adjustment. This improvement can be attributed to the anti-inflammatory effect of manuka honey, which reduces pro-inflammatory cytokine levels in inflammatory ocular surface conditions like dry eye disease.
Regarding tear film stability, the study found no statistically significant differences between the groups. In this context, previous studies with longer treatment duration (2 to 3 months) have reported improvement, indicating that long-term treatment with manuka honey may provide better eye comfort.
Taken together, the study identifies manuka honey eye drops as a promising adjunctive treatment for managing postoperative dry eye disease. The inclusion of a real-world surgical setting further increases the clinical applicability of these findings.
As stated by researchers, the non-randomized study design may have introduced selection bias and contributed to baseline differences between the groups. Because of these limitations, the findings should be interpreted with caution and considered hypothesis-generating.
Furthermore, cataract surgeries in the study population were performed by many surgeons operating under diverse baseline conditions. Such variation in surgical techniques and the reliance on patient-reported questionnaires could also have influenced the findings.
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The study was funded in part by L’Acuité LU, which supported the products used and publication costs. However, the funder was not involved in the study design, analysis, interpretation, or writing of the report.
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