Table 4
Results of ATP assay: mean percentage of cell viability reduction (SD) following 2 hours of incubation with test agent. 50% serum reduced the viability of cultured cells significantly less than unpreserved hypromellose (p = 0.04). 100% serum maintained cellular ATP levels better than 50% serum (p = 0.11) and serum of patients on systemic immunosuppressive therapy was less toxic than serum of healthy normal individuals (p = 0.08) although these trends did not reach statistical significance
| % Viability reduction | p Value (in comparison with negative control) | p Value for other tests | |
| Hypromellose 0.3% unpreserved (n = 4 tests) | 87 (14) | 0.03 | — |
| 50% serum (serum diluted 1:1 v/v with 0.5% chloramphenicol eye drops, n = 5 patients) | 58 (25) | 0.046 | 0.04 (v Hypromellose 0.3%) |
| 100% serum of normal individual (n = 6) | 34 (10) | 0.03 | 0.11 (v 50% serum) |
| 100% serum of patients with dry eyes treated with autologous serum (n = 4) | 24 (22) | 0.72 | |
| 100% serum of immunosuppressed patients (n = 8) | 26 (7) | 0.17 | 0.08 (v serum of normal individuals) |
