Posterior segment manifestations of Rickettsia conorii infection

To characterize and analyze the posterior segment manifestations of Mediterranean spotted fever (MSF), an infectious disease caused by Rickettsia conorii.

Prospective, noncomparative case series.

Thirty patients (60 eyes) with serologically proven MSF at the acute stage.

Patients underwent complete ophthalmic examination, including dilated biomicroscopic fundus examination, fundus photography, and fluorescein angiography. Sequential follow-up examinations were performed in patients with evidence of posterior segment involvement.

Of 30 patients, 25 (83.3%) had unilateral (n = 5) or bilateral (n = 20) posterior segment involvement related to MSF. Of those 25 patients, 16 (64%) had no ocular symptoms, and 9 (36%) had ocular complaints. Findings included mild vitreous inflammation (45 eyes [75%]), white retinal lesions (18 eyes [30%]), focal vascular sheathing (5 eyes [8.3%]), multiple arterial plaques (1 eye [1.7%]), intraretinal hemorrhages (14 eyes [23.3%]), white-centered retinal hemorrhages (2 eyes [3.3%]), subretinal hemorrhages (2 eyes [3.3%]), serous retinal detachment (3 eyes [5%]), macular star (2 eyes [3.3%]), cystoid macular edema (1 eye [1.7%]), optic disc edema (1 eye [1.7%]), branch retinal artery occlusion (1 eye [1.7%]), optic disc staining (30 eyes [50%]), retinal vascular leakage (27 eyes [45%]), delayed filling in a branch retinal vein (1 eye [1.7%]), and multiple hypofluorescent choroidal dots (10 eyes [16.7%]). One eye (1.7%) had retinal neovascularization at the 6-month follow-up examination. All posterior segment findings at the acute stage resolved in 3 to 10 weeks, and the final visual acuity was 20/20 in 42 of 45 affected eyes (93.3%). Retinal pigment epithelium changes developed in 9 eyes (15%), with resolved full-thickness white retinal lesions. No other abnormalities were noted in the eye with retinal neovascularization over a further follow-up of 6 months.

Posterior segment involvement, frequently asymptomatic, is common in patients with acute MSF. Because the diagnosis can be easily overlooked, a careful dilated funduscopic examination, complemented by fluorescein angiography in selected cases, is recommended. Mild vitritis, retinal vasculitis, optic disc staining, white retinal lesions, retinal hemorrhages, and multiple hypofluorescent choroidal dots are the most common manifestations of MSF. Posterior segment changes in a patient with fever and/or skin rash living in or returning from a specific endemic area, especially during the spring or summer, strongly suggest R. conorii infection.