Assessment of Tamarind Seed Polysaccharide (TSP) and Hyaluronic Acid (HA) Containing Ophthalmic Solution to Maintain Tear Osmolarity, Ocular Surface Temperature (OST) and Tear Production.

Background: The enhancement of ocular drug delivery is achieved by using biopolymer carriers in liquid ophthalmic preparations. Using natural polysaccharides to formulate ocular medications is attractive because they are economical and readily available. The primary goal of the study was to assess the safety and effectiveness of Tamarind seed polysaccharide (TSP)/Hyaluronic acid (HA) containing Rohto eye drops (TSP/HA drops) in alleviating the signs and symptoms of dry eye disease (DED) under dry environmental conditions using controlled environmental chamber (CEC).

Methods: 12 participants were subjected to harsh environmental conditions in a CEC with a relative humidity (RH) of 5% and an ambient temperature of 21°C. TSP/HA drops were used in the two treatment modalities, protection (drops instilled before exposure to the dry environment and relief (drops instilled after exposure to the dry environment. Before and after administering drops, patients undergo screening for ocular symptoms, tear osmolarity, ocular surface temperature (OST), and tear production using the ocular Surface Disease Index questionnaire (OSDI), OcuSense TearLab Osmometer, FLIR System ThermaCAM P620, and phenol red test (PRT) respectively. Tear production was calculated by the Tear Function Index test (TFI).

Results: Before (protection) and after (relief) exposure to the dry environment, TSP/HA resulted in a mean tear osmolarity of 296.0 mOsm/L and 292.0 mOsm/L, with no significant statistical difference. The presence of TSP/HA in both protection and relief modes led to an increase in tear production. TSP/HA drops did not significantly affect OST compared to the absence of TSP/HA drops at 5% RH. There was a significant increase in mean symptom score from 14 at 40% RH to 128 at 5% RH (p=0.003). A substantial reduction in symptoms was found in both protection (before exposure) (35) (p=0.003) and relief (after exposure) (50) (p=0.005) compared to when no drop was used.

Conclusion: It was apparent that using TSP/HA for protection was superior to relief for osmolarity and eye comfort. To optimise the therapeutic efficacy of TSP/HA, it is advisable to instruct patients to administer it before exposure to dry atmospheric conditions. The small sample size limits the ability to generalize the findings. Future studies should evaluate the tear supplement with a larger sample to improve statistical power.