Table 1.

Severity Grading Criteria for DE Conditions

Group	Symptom Severity Score*	Tear Break-up Time (s)	Conjunctival Staining Score†	Corneal Staining Score‡
No DE	≤20	>7	0	0
DE 1	>20	≤7	≤3	≤2
DE 2	>20	≤7	≥3	<6
DE 3	>20	≤7	≥3	≥6, including central cornea or filaments
DE 4	>20	≤7	≥3	≥12

DE 1–4, dry eye severity levels.

^*Symptom severity score measured by ocular surface disease index (OSDI) questionnaire.¹³

^†Lissamine green staining of the nasal and temporal bulbar conjunctival was graded 0–3 in each area based on the density of the dots.

^‡Corneal fluorescein staining was graded according to the Baylor grading scheme¹⁴ in each of five zones on a standardized 5-point scale: 0 dots, 0; 1 to 5 dots, 1; 6 to 15 dots, 2; 16 to 30 dots, 3; >30 dots, 4. One point was added to the score if there was one area of confluent staining, and 2 points were added if there were two or more.