Evaluation of Therapeutic Effect of Rifampin for Acute Central Serous Chorioretinopathy

Purpose: Rifampin which is an anti-tuberculosis (TB) drug, can increase metabolism and thus reduce endogenous steroid. So it is mentioned as a probable drug for acute central serous chorioretinopathy (CSCR) treatment. Therefore we have decided to evaluate its beneficial effects in CSCR treatment. Methods: A non-randomized clinical trial involving 39 patients with acute CSCR (less than two weeks) were studied. Initially, complete visual examinations including determination of spectacle best corrected visual acuity (SBCVA) using Snellen chart, anterior and posterior segment examinations were performed on all patients. Fundus fluorescein angiography (FA) and ocular coherence tomography (OCT) were performed to confirm the diagnosis. Twenty-three patients were treated with 600 mg rifampin per day up to maximum 4 to 6 weeks (treatment group) and 17 patients did not receive any treatment (control group). In the treatment group, one of the patients suffered from severe headache a few days after using the drug. So the drug was discontinued and the patient was excluded from the study. The patients were examined once in two weeks and totally up to fourth or sixth weeks. In each time of examination, the best clear visual acuity determination and funduscopy were done, and if necessary (cases of obvious macular edema) OCT was performed at the end of 4th to 6th week. Primary gain was reduction in macular thickness (MT) and secondary gain was the SBCVA during the study. Results: The mean age of patients was 38.5±6.7 years. The mean age of the treatment group (37.7±6.2 years) was not significantly different from control group (39.7±7.3). Gender distribution shows that 76.9% of samples were male. In the treatment group, the average MT changed from 339.9±44.36 μm at the beginning of treatment to 297.4±29.09 μm at the end of treatment and this reduction in MT was equal to 12.58% (p<0.001) and in the control group, the initial and final thickness were 310.06±20.31 and 296.71±17.22, μm respectively. The reduction was equals to 4.3% (p<0.003). In the treatment group MT reduction was significantly more than the control group (p<0.018). In the treatment group, average of SBCVA before and after treatment was 0.2±0.18 and 0.6±0.34 Snellen visual acuity (SV), respectively (p<0.0001) and in the control group, this average was 0.2±0.1 before and 0.37±0.35 SV after treatment (p<0.024). The difference in SBCVA between two groups was more or less important (p=0.055). At the end of study, macula in 45.5% of the treatment group and 29.4% of control group had dried out Odd's Ratio (OR)=2 (0.52-7.6, CI: 95%) (p<0.307). Conclusion: Rifampin has beneficial effects in the treatment of acute CSCR. These early findings suggest a novel treatment of CSCR and warranted further study.