Foveal cyst: Unknown etiology and unexplained response to treatment

Background: Foveal cysts have been associated with vitreous traction due to a taut posterior hyaloid. These eyes may progress to become a full-thickness macular hole, remain stable, or resolve after a posterior vitreous detachment. A foveal cyst in an eye with a complete posterior vitreous detachment and no other obvious pathology is unusual. Case presentation: A 21-year-old male presented with blurred vision in the left eye of 1-month duration. On examination his left-eye vision was 20/60, and anterior segment examination was normal. Fundus examination showed internal limiting membrane folds with a suspected lamellar macular hole. A spectral domain optical coherence scan showed a thin dome-like cyst in the sub foveal region involving the outer retinal layer with a detached posterior hyaloid face. A trial of intravitreal dexamethasone implant was given, following which there was improvement in vision and resolution of the foveal cyst. At the third-month follow-up, the patient presented with a stellate pattern of hyporeflectivity in the macular area both on spectral domain optical coherence scan and multicolor imaging with no change in visual acuity. Conclusion: The presence of a foveal cyst in a young male without any risk factors is peculiar, and the rapid response to intravitreal dexamethasone implant raises questions about the pathogenesis. The stellate pattern of hyporeflectivity on spectral domain optical coherence scan imaging with an intraretinal “filling defect”–like picture on fluorescein angiography suggests a possible ongoing ischemic pathology.