A Phase 2 interventional study of Chlorhexidine and Povidone-Iodine in Acanthamoeba Keratitis, sponsored by University of California, San Francisco. Completed at 2 sites in India. Open to participants aged 13 Years and older. Per ClinicalTrials.gov, last updated 2026-05-07.
Sponsored by University of California, San Francisco · Phase 2, Interventional, and Treatment
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This is a study of optimal treatments for acanthamoeba keratitis. In the first part of the study, participants will be randomized to chlorhexidine monotherapy or chlorhexidine plus povidone iodine. After four weeks of therapy, participants will be re-randomized to early corticosteroids, later corticosteroids, or placebo.
Acanthamoeba keratitis is a rare eye infection that is difficult to treat. The mainstay of therapy is a biguanide agent such as chlorhexidine, though recent studies have found povidone iodine to be effective for killing acanthamoeba organisms in vitro. Thus, we randomize participants to topical chlorhexidine 0.04% monotherapy (i.e., routine care) versus topical chlorhexidine 0.04% plus topical poviodine iodine 2.5%. The primary outcome is clearance of acanthamoeba from the ocular surface at 4 weeks.
The role of topical corticosteroids in acanthamoeba keratitis is controversial. Topical corticosteroids can promote growth of acanthamoeba, but may also reduce inflammation and vision-threatening complications of infection. Here, we randomize participants who have completed a course of anti-amoebic therapy to one of three groups: early prednisolone sodium phosphate 1% (started at 4 weeks), late prednisolone sodium phosphate 1% (started at 6 weeks) or placebo (started at 4 weeks). The primary outcome will be visual acuity at 6 months.
University of California, San Francisco is the lead sponsor of 2,171 studies on the registry; 370 are open to participants now.
Of its 268 completed or terminated interventional studies of FDA-regulated products, 203 (76%) have results posted.
Counted across the registry records on this site, refreshed daily.
Trial 1 Inclusion Criteria:
Trial 1 Exclusion Criteria:
Trial 2 Inclusion Criteria
Trial 2 Exclusion Criteria
Topical chlorhexidine 0.04%
Drug: Chlorhexidine
Topical chlorhexidine 0.04% plus povidone iodine 2.5%
Drug: Chlorhexidine · Drug: Povidone-Iodine
Topical prednisolone sodium phosophate 1% for weeks 4-11
Drug: Prednisolone Sodium Phosphate
Artificial tears for weeks 4-5, then topical prednisolone sodium phosophate 1% for weeks 6-11
Drug: Prednisolone Sodium Phosphate · Drug: Hydroxypropyl Methylcellulose
Artificial tears for weeks 4-11
Drug: Hydroxypropyl Methylcellulose
1 drop half-hourly for days 1-2, then hourly for days 3-6, then 8 times daily until the 4-week visit
1 drop half-hourly for days 1-2, then hourly for days 3-6, then 8 times daily until the 4-week visit
1 drop 4 times daily for weeks 4-9, then 2 times daily for weeks 10-11
1 drop 4 times daily for weeks 4-9, then 2 times daily for weeks 10-11
1 drop 4 times daily for weeks 6-9, then 2 times daily for weeks 10-11
1 drop 4 times daily for weeks 4-5
Trial 1: Microbial clearance
Acanthamoeba culture
Time frame: 4 weeks
Trial 2: Best spectacle corrected visual acuity
Time frame: 6 months
Trial 1: Best spectacle corrected visual acuity
Time frame: 4 weeks
Trial 1: Time to re-epithelialization
Time frame: 4 weeks
Trial 1: Clinical cure
Time frame: 4 weeks
Trial 2: Time to clinical cure
Time frame: 6 months
Plan to share: No
Ran from Jan 2018 to primary completion in Nov 2022, 58 months.
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This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Chlorhexidine · Povidone-Iodine · Prednisolone phosphate · Hypromellose Derivatives
Acanthamoeba Keratitis
University of California, San Francisco →