Abstract
BACKGROUND: Hydatid disease, caused by Echinococcus species, is a parasitic infection that rarely affects the eye. However, reports of ocular lesions associated with systemic hydatid disease, in the absence of hydatid cysts in the eye, are scarce. CASE PRESENTATION: A 22-year-old male presented with blurred vision for one month. He had a 7-year history of systemic hydatid disease and had been undergoing long-term albendazole treatment. Retinal examination revealed two choroidal elevations near the nasal ora serrata in the right eye. Fluorescein angiography confirmed the presence of bilateral retinal vasculitis. To address the choroidal elevations, a transscleral choroidal approach was performed, followed by pars plana vitrectomy. Notably, no hydatid cysts were found during the surgery. Instead, a dark green lesion was observed beneath the retina and within the choroidal tissue. Histopathological analysis of the surgical specimens confirmed the absence of hydatid cysts in both the vitreous and the dark green lesion. Additionally, next-generation sequencing of samples from the vitreous and dark green lesion yielded negative results for Echinococcus DNA. The diagnosis of bilateral retinal vasculitis, alongside systemic hydatid disease was confirmed. After surgery and subsequent steroid therapy, the patient's ocular inflammation and choroidal lesions showed significant improvement. CONCLUSIONS: The ocular manifestations of systemic hydatid disease are not solely due to the presence of intraocular hydatid cysts; they can also include ocular inflammation in the absence of cysts, as seen in this case. Surgical resection of the large choroidal lesion, combined with steroid treatment, significantly improved the patient's ocular condition.