A Study of Sodium Carboxymethylcellulose for Post Cataract Surgery Dry Eye Symptoms

TBUT is the time required for dry spots to appear on the surface of the study eye after blinking. The longer it takes, the more stable the tear film. A short TBUT is a sign of poor tear film.

TBUT is the time required for dry spots to appear on the surface of the study eye after blinking. The longer it takes, the more stable the tear film. A short TBUT is a sign of poor tear film.

The cornea is evaluated following ocular administration of fluorescein stain in the study eye. The cornea is the transparent front part of the eye which covers the iris and pupil. The cornea is divided into 3 regions. Each region is scored according to the extent of staining, with scores ranging from 0 to 3 points: 0=non-staining, 1=staining range < 1/2 of the cornea, 2=staining range ≥ 1/2 of the cornea, and 3=regional whole staining of the cornea. The total score ranges from 0 to 9 points. The higher the staining score, the worse the dry eye condition.

Conjunctival and corneal staining are evaluated following ocular administration of lissamine green dye in the study eye. The conjunctiva is the clear membrane covering the white surface of the eye. The cornea is the transparent front part of the eye which covers the iris and pupil. The conjunctiva and cornea are divided into 5 regions that are scored based on the extent of staining. Scores range from 0 to 3 points: 0=non-staining, 1=staining range < 1/2 of the conjunctiva and cornea, 2=staining range ≥ 1/2 of the conjunctiva and cornea, and 3=regional whole staining of the conjunctiva and cornea. The total score ranges from 0 to 15 points. The higher the grade score, the worse the dry eye condition.

The Schirmer I test consists of anesthetic drops being placed into the lower eyelid of the study eye. Patients then close their eyes. Test paper is placed on the lower eyelid of the patient's closed eyes. The paper is then removed and the moisture length on the paper recorded. Shorter distances indicate worse dry eye symptoms.

The OSDI is a 12-question survey for patients to document their dry eye disease symptoms in the study eye. 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).

The following 11 subjective symptoms are evaluated in the study eye: foreign body sensation, photophobia, itching, pain in the eye, dry eye, eye heaviness, blurred vision, eye fatigue, eye discomfort, eye secretions and tears. Each of these symptoms is divided into 4 classes: no symptom=0; occasional symptoms=1; intermittent mild symptoms=2; and persistent obvious symptoms=3. The total score ranged from 0 (best) to 33 (worst).