Effects of Goshajinkigan on corneal sensitivity, superficial punctate keratopathy and tear secretion in patients with insulin-dependent diabetes mellitus

Goshajinkigan (Niu-che-shen-qi-wan in Chinese), a traditional herbal medicine, has been used in Japan to treat clinical symptoms of diabetic neuropathy. A double-masked study was performed to evaluate its effects on corneal sensitivity, superficial punctate keratopathy and tear production in patients with insulin-dependent diabetes mellitus. Fifty diabetic patients were randomized into two groups: Group A, in which 25 patients received Goshajinkigan orally, 7.5 g/day for 3 months; Group B, in which 25 patients were orally administered placebo, 6.0 g/day for 3 months; and in Group C, 25 non-diabetic subjects were orally administered Goshajinkigan, 7.5 g/day for 3 months. Corneal sensitivity was measured with an aesthesiometer. The area of superficial punctate keratopathy was expressed as a fluorescein staining score. Reflex tearing was determined with a Schirmer test without anesthesia. Goshajinkigan was analyzed by high-performance liquid chromatography. Corneal thresholds after treatment with Goshajinkigan (2.03 g/mm(2)) in Group A were significantly lower than those before treatment (2.47 g/mm2). Those in Groups B and C did not change after treatment. Fluorescein staining scores after administration of Goshajinkigan (0.64) in Group A were significantly lower than those before treatment (1.32). Those in Groups B and C did not change after treatment. Schirmer test results after Goshajinkigan administration (11.0 mm/5 min) in Group A were significantly higher than those before treatment (9.3 mm/5 min). Those in Groups B and C did not change after treatment. Hemoglobin A1c levels in Groups A, B,and C did not change after treatment. Several components in Goshajinkigan were found on high performance liquid chromatography. In conclusion, Goshajinkigan improved ocular surface disorders in patients with insulin-dependent diabetes mellitus.