Intravitreal Sustained-release Dexamethasone Implant in Treatment for Chronic Macular Edema in Syphilis Infection: a Case Report

Background: Macular edema results from many conditions, such as diabetic retinopathy, macular degeneration, inflammatory diseases, cataract operation, trauma, and tumors. Specifically, the capillary filtration rate should equal the speed of fluid removal from extracellular retinal tissue, such as the glial and retinal pigment epithelium cells layer (RPE). Once these forces are imbalanced, fluid accumulates in cystoid spaces within the inner layers of the retina. Objective: The main purpose of this case report is to show that macular edema caused by any inflammation, either bacteria, virus, or autoimmune origin, can be treated successfully, even if it is chronic. Case report: A 31-year-old man has been reported to our clinic with symptoms of blurry vision in the left eye, which occurred during the last year. Essential examinations included CDVA, IOP measurement, slit-lamp examination, indirect ophthalmoscopy, and OCT scan that showed significant macular edema (central foveal thickness of 353 microns). We initiated laboratory searches, such as blood, serology, and immunology testing for the next three months after his first visit, together with prescribed topical and periocular corticosteroid therapy. The test to VDRL (venereal disease research laboratory) for Syphilis and Toxocariasis came positive. We took the best decision and recommended further treatment with the intravitreal application of Dexamethasone Implant 0.7mg. One week after the intravitreal application of corticosteroids on the control exam, there were normal findings on the posterior segment with no macular edema (central foveal thickness of 269 microns). Conclusion: It is unexclusive that infection by Treponema pallidum (TP) causes isolated macular edema without any other symptoms on the anterior segment of the eye. It has indirect action on the macula, not just causing papilledema, retinal vasculitis, retinochoroiditis, and inflammatory disc edema, as expected. TP or the bacteria transmembrane protein (treponemal ligands) directly acting on vascular endothelial cells of the RPE cells, will be the key to the most certain mechanism of this condition. It is related to the possibility of the secretion of cytokines and the interactions between immune cells indirectly.