In subjects with Dry Eye Syndrome (DES):

The primary objective of this study is to confirm the efficacy of TOP1630 0.1% Ophthalmic Solution TID OU compared to placebo treatment at Day 29 on pre-specified sign and symptom endpoints in subjects with moderate to severe DES.

This study is designed to assess the efficacy and safety of TOP1630 ophthalmic solution in subjects with Dry Eye Syndrome (DES).

Eligible subjects will be randomized double masked to either TOP1630 or placebo for a duration of 28 days' treatment.

Inclusion Criteria:

• Be at least 18 years of age;
• Provide written informed consent;
• Have a reported history of dry eye;
• Have a history of use of eye drops for dry eye symptoms;

Symptoms of dry eye syndrome including:

• Ocular discomfort
• Conjunctival redness
• Tear film break up time
• Schirmer test score

Signs of dry eye syndrome including:

• Conjunctival staining score

Exclusion Criteria:

• Have any clinically significant slit lamp findings at entry visit ;
• Be diagnosed with an ongoing ocular infection;
• Have any significant ocular lesion that could interfere with assessment of safety or efficacy or prevent study conduct in the opinion of the PI;
• Have any planned ocular and/or lid surgeries over the study period;
• Have an uncontrolled systemic disease;
• Be a woman who is pregnant, nursing or planning a pregnancy;
• Be a woman of childbearing potential who is not using an acceptable means of birth control;
• Have a known allergy and/or sensitivity to the test article or its components;
• Have a condition or be in a situation which the investigator feels may put the subject at significant risk, may confound the study results, or may interfere significantly with the subject's participation in the study