Drug-Depository Contact Lens Hasten Healing And Minimize Antimicrobial Loading Doses In Bacterial Keratitis: A Randomized Controlled Trial

To evaluate the efficacy of a novel therapeutic drug-depository contact lens (DDCL) for bacterial keratitis (BK) treatment. The lens was designed to increase the corneal lesion-antimicrobial drug interaction time.

A Randomized open-label clinical trial.

40 BK patients were randomized (1:1) into two groups as topical antimicrobial treatment only (Group 1) and DDCL (with dual base curves resulting in a central reservoir along with fenestrations to enable capture of applied drugs) plus antimicrobial treatment (Group 2). Both groups received standard 0.5 % moxifloxacin in a frequency of 2-Hrly for 2 days (during waking hours) and 4-Hrly for the next 12 days. We evaluated BK recovery clinically and with cornea OCT, anterior chamber (AC) reactions, corneal haze, and pain (on a 10-point scale) 12 hours and 1, 3, 5, and 14 days after treatment. A separate drug retention study (DRS) over time in DDCL was performed.

The baseline corneal infiltration (i.e., BK severity) values were comparable for Groups 1 (18 cases) and 2 (17 cases) (P = 0.92). After 12 hours, the scores improved in both groups and continued to improve throughout the follow-up period; the improvements were more pronounced in Group 2 than in Group-1 (all P <0.05). Complete recovery occurred on Days 14 and 5 in Groups 1 and 2, respectively. Furthermore, the AC reaction resolved by Day 3 in Group 2. The baseline pain scores were also comparable between Groups 1 and 2 (P = 0.52) and decreased throughout the follow-up period (all P <0.05); the decrease was more pronounced in Group 2. DRS established an extended drug-corneal availability for up to 4 hours. 

Novel DDCLs augment the drug-lesion interaction time by prolonging corneal antimicrobial availability, which hastens corneal healing in BK. Thus, a DDCL may decrease the antibiotic regimen and improve patient tolerance, eliminating the necessity for a loading dose.