Effects of Cataract Extraction Surgery and Limbal Relaxing Incision on Corneal Sensation and Dry Eye

The percentage of subjects at month 3 with corneal sensitivity < 50 mm at any of the locations measured. Corneal sensitivity is evaluated by using a nylon filament to measure the capability of the cornea (clear front portion of the eye) to respond to touch. The longest filament length at which a minimum of the 3 out of 5 stimulus applications produce a positive response from the subject was the corneal touch threshold (sensitivity). Measurements were taken at 5 different locations in each cornea.

Change from baseline in OSDI total score at month 3. The OSDI is a 12-question survey for subjects to document their dry eye disease symptoms. The OSDI consists of a 5-point scale (0=none of the time and 4 = all of the time), with higher scores representing greater disability. The scores are totaled over the 12 questions and converted to a score of 0-100 (0=no disability and 100=complete disability). A negative number change from baseline represents an improvement.

Change from baseline in corneal staining at month 3. The cornea is the transparent front part of the eye which covers the iris and pupil. Corneal staining following administration of fluorescein dye in the eye is graded using a 6-point scale (0= no staining, 5 = severe staining) over 5 areas of the clear central part of the eye for a minimum score of 0 and a maximum score of 25. The higher the grade score, the worse the dry eye condition. A positive number change from baseline represents an increase in corneal staining (worsening of dry eye).

Change from baseline in conjunctival staining severity score at month 3. The conjunctiva is the clear membrane covering the white surface of the eye. Conjunctival staining following ocular administration of lissamine green dye was graded using a 6-point scale (0= no staining, 5= severe staining) over 6 areas of the white part of the eye for a minimum score of 0 and a maximum score of 30. The higher the score, the worse the dry eye condition. A negative number change from baseline represents a decrease in the severity of conjunctival staining (improvement)

Change from baseline in tear break-up time (TBUT) at month 3. TBUT is the time required for dry spots to appear on the surface of the eye after blinking. The longer it takes, the more stable the tear film. A short TBUT is a sign of poor tear film. A negative number change from baseline indicates a decrease in TBUT (worsening).

Change from baseline in Schirmer's Test result at month 3. The Schirmer's Test measures the rate of the secretion of tears produced by the eye over 5 minutes. The results indicate the presence of dry eye (Normal = greater than or equal to 10 millimeters (mm) of tears, Dry Eye = less than 10 mm of tears). The smaller the number, the more severe the dry eye. A positive number change from baseline indicates an increase in tears (improvement).