Table 1. Dry eye (DE) staging according to the DE severity level proposed by the report of the Diagnostic Methodology Subcommittee of the International Dry Eye Workshop and modified according to Sullivan et al 27 .
| Dry eye severity grade | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| OSDI score | 5–15 | 16–30 | 31–45 | 46–100 |
| TFBUT (s) | 7–10 | 5–6 | 2–4 | 0–1 |
| Corneal staining (NEI score) | <3 | 3–8 | 9–12 | 13–15 |
| Conjunctival staining score | <4 | 5–8 | 9–12 | 13–18 |
| Schirmer score (mm/5 min) | 7–10 | 5–6 | 2–4 | 0–1 |
| MGD score | <5 | 5–12 | 13–20 | 21–27 |
Abbreviations: MGD, Meibomian gland dysfunction; NEI, National Eye Institute; OSDI, Ocular Surface Disease Index; TFBUT (s), tear film break up time (seconds).