Abstract
Purpose :
To determine the time to effectiveness of intravitreal clindamycin in patients with toxoplasmosis chorioretinitis.
Methods :
This is a retrospective review of patients with toxoplasmosis chorioretinitis who had fundus imaging. All patients received intravitreal clindamycin (1mg) as therapy. For this analysis, a masked physician qualitatively marked the first sign of improvement based on fundus appearance. The time from injection to first sign of improvement was calculated for each individual, and averaged amongst the patients. The time to inactivity was calculated as well. Those who were lost to follow-up were excluded.
Results :
19 patients were identified with 276 fundus photos reviewed. 5 patients were treated with clindamycin monotherapy, 2 patients were given oral Bactrim only, and 12 patients were given oral Bactrim and clindamycin therapy. On average, patients showed observed first improvement 20.67 days after their injection (range 7 to 42 days). The fastest time to response was 7 days after treatment with intravitreal clindamycin. 5 patients time to response was within 8-15 days. The average time to complete inactivity was found to be 9.37 weeks (1-35 weeks). The average time to respond for those on oral Bactrim and intravitreal clindamycin was 18.71 days (3 days to 47 days). Average number of injections to signs of improvement was 1.44. Two patients worsened despite intravitreal injections. 6 patients resolved with intravitreal clindamycin only. 5 patients had optic nerve or macular lesions and were treated with oral Bactrim and intravitreal clindamycin.
Conclusions :
In this series, intravitreal clindamycin shows a photographic response lesion improvement on average of 3 weeks after injection. Compared to oral regimens that can take from 4 weeks to several months to reduce activity, intravitreal clindamycin potentially works faster. Intravitreal clindamycin can be considered a first line of therapy for active toxoplasmic chorioretinitis especially in those with macular and nerve threatening disease.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.