PURPOSE: To report findings through 24 months of a 36 month trial of signs of corneal health, subjective symptoms and safety with continuous wear of NIGHT&DAY (N&D) lenses and low DK daily wear (DW) 2-week replacement soft contact lenses.

METHODS: 317 patients were dispensed to wear N&D for up to 30N CW and 81 neophyte patients were dispensed in a lens for DW. Clinical and subjective data were collected at follow-up visits for each group.

RESULTS: A cohort of 240 N&D and 58 DW patients completed all visits through 24 months. 30N CW was recommended for all N&D patients by the 24 month visit. For the N&D cohort, improvements in biomicroscopy grades were most dramatic within 1 week for limbal (p<0.001) and conjunctival (p<0.001) redness with 5 of 10 signs improving and 5 unchanged through 24 months. For the DW cohort, 4 of 10 signs worsened and 6 unchanged through 24 months. For subjective symptoms, end of day dryness improved in both frequency (p<0.001) and severity (p<0.001) among 11% of patients in N&D, while 11% more patients in the DW group reported more frequent (p=0.014) and severe (p=0.014) end of day dryness. The percentage of eyes achieving 20/20 VA in the N&D cohort improved from 78% at dispensing to 86% at 12 months (p=0.995) and 86% at 24 months (p=0.011). For DW, 87%, 64% and 66% of eyes had 20/20 VA or better at dispensing, 12 (p=0.001), and 24 (p=0.001) months, respectively. Discontinuations totaled 24% for N&D and 27% for DW, with 1 discontinuation in each group from a potential adverse event. Microbial keratitis did not occur in either group.

CONCLUSIONS: N&D worn for 30N CW performed very well for biomicroscopy signs while DW results were mixed. In the N&D group, 5 signs of corneal health improved and none declined. In the DW group no signs improved and 4 signs declined. VA improved in the N&D group and declined in the DW group. N&D also showed improvement in end of day dryness symptoms. Through 24 months, N&D worn for 30N CW may be healthier than DW lenses based on signs of corneal health, improvement in end of day dryness, and VA.