Abstract
Purpose
The authors present two cases of neuroretinitis caused by Rickettsia rickettsii infection.
Observations
Case 1 is a 24-year-old male who presented with 2 months of vision loss. Case 2 is a 38-year-old female who presented with 4 weeks of eye pain and vision loss. Examination of both patients revealed neuroretinitis characterized by optic disc swelling with macular exudates, and subsequent serological analysis was positive for Rickettsia rickettsii . Both patients responded favorably to treatment with oral doxycycline and prednisone.
Conclusions and importance
Given the potential for neuroretinitis to cause permanent vision loss, the presence of acute vision loss, optic disc edema, and macular exudates should prompt an evaluation for Rickettsial disease in endemic areas, even in the absence of systemic symptoms or known history of a tick bite.
1
Introduction
Neuroretinitis is an inflammatory disorder of the retina and optic nerve characterized by acute vision loss, optic disc edema, and macular exudates, which occasionally form a macular star. It may be infectious, inflammatory, or idiopathic in etiology. , The visual prognosis is generally excellent, although permanent vision loss is possible and early treatment with steroids and antibiotics in some cases may limit disease progression and improve long-term outcomes. Neuroretinitis caused by infection with the bacterial species Rickettsia rickettsii has rarely been reported in the literature. We report the cases of two patients with significant vision loss from neuroretinitis caused by Rickettsia rickettsii infection who had significant recovery of vision after treatment with antibiotics and oral steroids.
2
Case report
2.1
Case 1
A 24-year-old male with no significant past medical history presented with a 2-month history of decreased vision in both eyes. Examination showed best corrected visual acuity (BCVA) of 20/200 in each eye with a normal intraocular pressure (IOP), normal anterior segment exam, and no vitreous cell. Funduscopic examination of both eyes revealed optic disc swelling, disc hemorrhages, peripapillary subretinal fluid and hard exudates in the macula ( Fig. 1 ). Fundus autofluorescence revealed peripapillary hyperautofluorescence in the area of serous retinal detachment. Optical coherence tomography (OCT) revealed disc elevation, peripapillary subretinal fluid and hyper-reflective foci in the retina corresponding to the hard exudates. Upon further questioning, the patient reported discovering a tick bite 2 weeks prior to the onset of his visual symptoms. He denied any rash, fever, or myalgias.
Chest x-ray was negative. Laboratory tests were negative for syphilis (RPR and FTA-ABS), tuberculosis (Quantiferon TB Gold), Lyme, Ehrlichiosis, and Bartonella. However, titers for Rickettsia rickettsii IgM and IgG were both elevated. He was treated with a two-week course of doxycycline and a prednisone taper (starting at a dose of 60 mg daily) for Rickettsial neuroretinitis. After 3 months, his visual acuity improved to 20/25 in the right eye (OD) and 20/60 in the left eye (OS). He had been completely tapered off prednisone, and the optic disc swelling and peripapillary subretinal fluid had resolved. There was, however, mild disc pallor evident in both eyes and outer retinal loss on OCT in the nasal macula.
2.2
Case 2
A 38-year-old female with no significant past medical history presented with 4 weeks of eye pain and blurry vision. Her visual acuity was 20/40 OD and 20/400 OS. Examination of her right eye revealed normal IOP, quiet anterior chamber, and 1+ vitreous cells. Examination of her left eye revealed normal IOP, 0.5+ cells in the anterior chamber, and 2+ vitreous cells. There was mild optic disc swelling in the right eye and moderate disc swelling with macular star formation in the left eye ( Fig. 2 ). Fluorescein angiography of both eyes revealed hyperfluorescence with leakage at the disc and mild peripheral vascular leakage ( Fig. 3 ). Upon further questioning, she reported a recent history of myalgias and intermittent fevers. She denied any history of a tick bite.
