Journal of Neuro-Ophthalmology, December 2003, Volume 23, Issue 4

Rocky Mountain Spotted Fever as a Cause of Macular Star Figure

An 86-year-old woman with a history of tick bites in the previous months developed subnormal visual acuity in both eyes, keratic precipitates, anterior chamber and vitreous cells, optic disc edema, retinal hemorrhages, and retinal arteriolar sheathing. She had no fever or skin rash. Three weeks later, binocular macular star figures appeared. Brain imaging was negative; cerebrospinal fluid disclosed a lymphocytic pleocytosis and elevated protein. The serum Rickettsia rickettsii antibody test was markedly positive, establishing a diagnosis of Rocky Mountain Spotted Fever (RMSF) as the cause of the ophthalmic findings. Despite treatment with oral doxycycline, these findings improved only modestly. Although neuroretinitis has been previously described in RMSF, macular star has not been documented.

PHOTO ESSAY Rocky Mountain Spotted Fever as a Cause of Macular Star Figure Michael S. Vaphiades, DO FIG. 1. Optic fundi at presentation show optic nerve swelling in both eyes with retinal arterial sheathing in the OD and a splinter hemorrhage off the optic nerve in the OS. Abstract: An 86- year- old woman with a history of tick bites in the previous months developed subnormal visual acuity in both eyes, keratic precipitates, anterior chamber and vitreous cells, optic disc edema, retinal hemorrhages, and retinal arteriolar sheathing. She had no fever or skin rash. Three weeks later, binocular macular star figures ap­peared. Brain imaging was negative; cerebrospinal fluid disclosed a lymphocytic pleocytosis and elevated protein. The serum Rickettsia rickettsii antibody test was markedly positive, establishing a diagnosis of Rocky Mountain Spotted Fever ( RMSF) as the cause of the ophthalmic findings. De­spite treatment with oral doxycycline, these findings im­proved only modestly. Although neuroretinitis has been pre­viously described in RMSF, macular star has not been documented. From the Departments of Ophthalmology, Neurology and Neurosur­gery, University of Alabama, Birmingham, Alabama. Address correspondence to Michael S. Vaphiades, DO, UAB Depart­ment of Ophthalmology, Suite 601, 700 South 18th Street, Birmingham, AL 35233; E- mail: vaphiades@ eyes. uab. edu This work was supported in part by an unrestricted grant from the Re­search to Prevent Blindness, Inc., New York, New York. Case An 86- year- old woman noted visual loss in both eyes for 1 month. She had had several tick bites over the previous 6 months and had no constitutional symptoms, fever, or skin rash. Medical history included bilateral hearing loss for greater than 20 years and exposure to tuberculosis ( TB) FIG. 2. Optic fundi 3 weeks later show macular star figures in both eyes. Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 276 JNeuro- Ophthalmol, Vol. 23, No. 4, 2003 Rocky Mountain Spotted Fever as a Cause of Macular Star Figure JNeuro- Ophthalmol, Vol. 23, No. 4, 2003 30 years previously with a history of positive TB skin tests since. Examination showed a normal blood pressure and heart rate. Best- corrected visual acuity was 20/ 30 in the OD, 20/ 200 in the OS, with normal color vision. Pupils were pharmacologically dilated from a previous examination. She had normal intraocular pressures, keratic precipitates, and anterior chamber and vitreous cells binocularly. She had optic nerve edema in both eyes with retinal artery sheathing in the OD and flame- shaped hemorrhages in the OS ( Fig. 1). Cranial and orbital magnetic resonance imaging showed only periventricular white matter changes, con­sidered normal for age. Complete blood count, electro­lytes, glucose, syphilis testing, antinuclear antibodies, erythrocyte sedimentation rate, angiotensin converting enzyme, serum protein electrophoresis, anti- neutrophilic cytoplasmic antibody, and chest x- ray were normal. Tuberculin skin test was positive at 13 mm ( previous expo­sure). A lumbar puncture showed an opening pressure of 13 cm water, white blood cells 58/ mm3 ( 100% monocytes), red blood cells 26/ mm3, glucose 69 mg/ dl, protein 109 mg/ dl ( normal less than 60 mg/ dl), and normal Venereal Disease Research Laboratory ( VDRL) test, cryptococcal antigen, gram stain and fungal cultures, cytology, and vit­reous biopsy. Three weeks later, the visual acuity had fallen to 20/ 40 OD and count fingers OS, with a 1.2 log relative af­ferent pupillary defect in the OS. Ophthalmoscopy now showed a partial macular star figure in the OD and a com­plete star figure in the OS ( Fig. 2). Goldmann visual fields showed constriction binocularly ( Fig. 3). Bartonella henselae, Borellia burgdorfi, Toxoplasma gondii, and Ehrlichia chaffeensis tests were all normal. A serum Rickettsia rickettsii antibody test showed an IgG of 2.6 IV ( normal = 0- 0.9 IV) and IgM of 1.5 IV ( normal = 0- 0.9 TV). Oral doxycycline 100 mg BID for 14 days was prescribed. Follow- up examination 3 weeks later showed improvement of the optic nerve edema binocularly with a visual acuity remaining at 20/ 40 in the OD and improved to 20/ 100 in the OS. The macular star figures persisted. This patient developed Leber's stellate neuroretinitis caused by RMSF without the fever and rash usually associ­ated with this disease. There are only nine cases of neurore­tinitis from RMSF reported in the literature ( 1- 4). Unlike this case, all other cases had associated constitutional symp­toms and none had a macular star figure ( 1^ 1). Hudson et al. ( 5) reported two patients with retinal findings from the related infection murine typhus { Rickett­sia typhi) and noted a similarity to cat- scratch disease. This implied the presence of a macular star, but none was docu­mented in their cases ( 5). Other reported ophthalmic signs of RMSF are keratic precipitates, ulcerative keratitis, con­junctivitis, uveitis, Roth spots, papilledema, and third and sixth cranial nerve palsies ( 1- 4,6). RMSF was first recognized by Major Marshall Wood in 1896 ( 7). Ten years later, Ricketts demonstrated tick transmission of the organism that would eventually bear his name, Rickettsia rickettsii ( 7), an obligate intracellular gram- negative coccobacillus for which ticks serve as vec­tors and reservoirs. The organism is usually harbored by the wood tick ( Dermacentor andersoni) and dog tick ( Derma-centor variabilis) ( 7,8). Only 56% of patients remember dog or tick contact ( 9). The disease is endemic in the south­eastern United States but has been reported in 46 states .( 10) RMSF is the most frequent cause of fatality from tick- borne disease in the United States ( 7). Without therapy, the mor­tality rate may be as high as 80% ( 10). Unlike this patient, most afflicted patients experience fever greater than 102° F, headache, and a petechial rash on the palms of the hands and soles ( 7,8). Only 52- 62% of patients experience the com­plete triad ( 9). Two- thirds of patients have cerebrospinal fluid abnormalities, including elevated protein levels and a mononuclear pleocytosis, as did my patient ( 9). Pulmonary edema and symptoms of an acute abdomen may also de­velop ( 8). Neurologic symptoms include aphasia, hemipa-resis, deafness, confusion, and encephalitis ( 11), none of which were present in my patient. FIG. 3. Goldmann perimetry shows constricted visual fields in both eyes. Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 277 JNeuro- Ophthalmol, Vol. 23, No. 4, 2003 Vaphiades Treatment consists of oral doxycycline ( 7,8). Of the nine cases of RMSF- associated neuroretinitis, doxycycline improved the constitutional symptoms and uveitis in one patient, but there was no change on the fundoscopic exami­nation ( 4). In another patient treated with intravenous chlor­amphenicol, there was near complete resolution of the retinopathy ( 3); in one patient treated with neomycin, the clinical course progressively improved without specific mention of the retinal findings ( 1). In the other six cases of reported RMSF with neuroretinitis, there was no mention of clinical outcome ( 2). References 1. Raab EL, Leopold IH, Hodes HL. Retinopathy in Rocky Mountain spotted fever. Am J Ophthalmol 1969; 68: 42- 6. 2. Presley GD. Fundus changes in Rocky Mountain spotted fever. Am J Ophthalmol 1969; 67: 263- 7. 3. Smith TW, Burton TC. The retinal manifestations of Rocky Moun­tain spotted fever. Am J Ophthalmol 1977; 84: 259- 62. 4. Duffey RJ, Hammer ME. The ocular manifestations of Rocky Mountain spotted fever. Ann Ophthalmol 1987; 19: 301- 6. 5. Hudson HL, Thach AB, Lopez PF. Retinal manifestations of acute murine typhus. Int Ophthalmol 1997; 21: 121- 6. 6. Cherubini TD, Spaeth GL. Anterior nongranulomatous uveitis as­sociated with Rocky Mountain spotted fever. First report of a case. Arch Ophthal 1969; 81: 363- 5. 7. Snyder RH, Spevak M. Rocky Mountain spotted fever. In: Gorby GL, Talavera F, Glatt A, Mylonakis E, Cunha BA, eds. eMedicine Journal, January 3, 2002, Volume 3, Number 1. © Copyright 2001, eMedicine. com, Inc. 8. Lam B. Rocky Mountain spotted fever. In: Sheppard J, Fong DS, Walton RC, Brown LL, Roy H, eds. eMedicine Journal, April 27, 2001, Volume 2, Number 4. © Copyright 2001, eMedicine. com, Inc. 9. Kirk JL, Fine DP, Sexton DJ, Muchmore HG. Rocky Mountain spotted fever. A clinical review based on 48 confirmed cases, 1943- 1986. Medicine 1990; 69: 35^ 15. 10. Kirkland KB, Wilkinson WE, Sexton DJ. Therapeutic delay and mortality in cases of Rocky Mountain spotted fever. Clin Infect Dis 1995; 20: 1118- 21. 11. Archibald LK, Sexton DJ. Long- term sequelae of Rocky Mountain spotted fever. Clin Infect Dis 1995; 20: 1122- 5. Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 278 © 2003 Lippincott Williams & Wilkins