Fundus photograph of the left eye with 5 foci of retinitis.
Fundus photograph of the right eye with 2 foci of retinitis along the superior temporal vessels arcade.
Spectral-domain optical coherence tomographic scan of the largest retinitis spot in the left eye. I indicates inferior; N, nasal; S, superior; and T, temporal.
Fundus photograph of the left eye 6 weeks after the onset of the floaters.
Fundus photograph of the left eye 6 months after the onset of the floaters.
Spectral-domain optical coherence tomographic scan of the left eye at the 6-month follow-up showing complete resolution of the retinitis. I indicates inferior; N, nasal; S, superior; and T, temporal.
Yew YH, Subrayan V. Spectral-Domain Optical Coherence Tomographic Appearance of Acute Multifocal Retinitis. JAMA Ophthalmol. 2013;131(8):1097-1099. doi:10.1001/jamaophthalmol.2013.2489
Acute multifocal retinitis, previously termed acute multifocal inner retinitis by Foster et al1 in 1991, is a very rare presentation of multiple transient, self-limiting posterior uveitis involving the superficial inner aspect of the retinal layer. Very few cases pertaining to this condition have been reported in the literature.1- 4 It typically affects both eyes of healthy, immunocompetent individuals having previously experienced flulike viral prodrome that subsequently resolves over weeks to months, with the patient regaining normal vision. Although it is idiopathic, some have regarded it as an unusual manifestation of ocular bartonellosis (cat-scratch disease) or a variant of ocular syphilis.5,6 We report a case of a rare uveitis entity with its spectral-domain optical coherence tomographic (SD-OCT) appearance to highlight its pathological feature.
A 42-year-old Malay woman who worked as a clinical laboratory technician noted painless floaters in both eyes for 3 weeks. There was no other systemic involvement. She had just recovered from a recent episode of upper respiratory tract infection a week prior to the onset of floaters. She denied previous accidental exposure to any clinical specimen, blood transfusion, and contact with people who had tuberculosis. She kept 2 free-roaming cats as pets but denied being scratched or bitten by them.
Best-corrected visual acuity was 20/20 OU with normal color vision and contrast sensitivity. Anterior segment was unremarkable, and intraocular pressure was normal. However, mild anterior vitritis was noted in both eyes, left more than right. Multiple foci (2 in the right eye, 5 in the left eye) of retinal infiltrates with fluffy edges measuring 200 to 400 μm were scattered in the posterior pole, mostly adjacent to the retinal arteries (Figure 1 and Figure 2). Most lesions seemed superficial except for the largest spot, located adjacent to the superonasal retinal artery in the left eye. It appeared dense and may have infiltrated deeper into the choroid. The vitreous immediately adjacent to these foci of retinitis was hazy. Nevertheless, the optic disc and macula were normal without edema. No other signs of vasculitis, hemorrhage, or retinal detachment were discovered.
An SD-OCT scan (Cirrus HD-OCT; Carl Zeiss Meditec) through the largest retinitis spot mentioned earlier showed a focal area of retinal thickening with infiltration extending from the nerve fiber layer to the outer nuclear layer. The retinal pigment epithelium and choroid were clearly delineated and spared (Figure 3). Furthermore, scans at all other smaller lesions showed similar superficial involvement. Complete blood cell count, erythrocyte sedimentation rate, and antinuclear antibody titer were normal. Serology test results for retrovirus, toxoplasmosis, and cat-scratch disease were negative. Nonspecific Venereal Disease Research Laboratory (VDRL) assay and syphilis-specific Treponema pallidum hemagglutination test results were also nonreactive. Skin test with purified protein derivative tuberculin, chest radiography, and QuantiFERON-TB testing showed no evidence of systemic tuberculosis infection.
The patient was managed conservatively as her visual acuity was normal and the foci of retinitis did not threaten the macula. Although the floaters resolved 6 weeks later without intervention, a few of the larger foci still left faint marks on the retina (Figure 4). However, these marks disappeared by the 6-month follow-up (Figure 5) and SD-OCT showed complete resolution (Figure 6).
To our knowledge, this is the first reported SD-OCT appearance of acute multifocal retinitis, featuring the largest focus of retinal infiltrate in our patient. The lesion extended from the inner retina to the outer nuclear layer, although it appeared dense and deeply infiltrated during ophthalmoscopy. This finding concurred with that by Foster and colleagues, who observed that the foci of retinitis had only affected the inner retina.1
Cunningham et al3 later renamed the condition acute multifocal retinitis. The word “inner” was omitted because they observed that some of the larger retinal infiltrates had involved all layers of the retina. Nevertheless, this observation might be inaccurate without SD-OCT imaging at that time. In all the series published, vision loss was attributed to optic disc or macula edema, serous retinal detachment, and branch retinal artery occlusion involving the artery adjacent to the retinitis.1- 4 Because some of these lesions were similar to neuroretinitis and half the patients had reported cat exposure, Bartonella henselae infection was suspected then. However, it was never proven serologically.
The disease pattern of our patient conformed to most of the reported features of acute multifocal retinitis, especially with regard to the prodromal viral illness, minimal vision impairment, and its benign, self-limiting clinical course.1- 4 Multiple retinitis spots, mostly located adjacent to retinal arteries with associated mild vitritis, were characteristic. However, our patient did not have optic disc edema, branch retinal artery occlusion, or retinal detachment as highlighted in the literature. Hence, she reported floaters instead of vision impairment.
A thorough search for the underlying cause in such a case is warranted because many systemic, autoimmune, and infectious disorders can present with multiple areas of retinal whitening. Infections such as cat-scratch disease, syphilis, tuberculosis, and toxoplasmosis may only manifest as multiple foci of retinochoroiditis and are readily treatable if detected early.3,5,6 Diseases such as acute posterior multifocal placoid pigment epitheliopathy and multiple evanescent white dot syndrome may present similarly with minimal visual disturbance and vitritis and are mostly self-limiting. However, these white dot syndromes usually involve the choriocapillaris layer. Careful ophthalmoscopic examination can usually differentiate these pathologies from acute multifocal retinitis.
The pathophysiology of this rare uveitis remains elusive, although the role of a virus infection is the most suspicious given that almost all patients have an antecedent viral fever prior to the ocular involvement.1- 4 Cunningham and colleagues had suggested 2 possible mechanisms in which the focal retinal infiltrate may represent either active viral replication and inflammation or a hypersensitivity response to the earlier viremia.3 Owing to its rare occurrence, further study to fully understand this disease may prove to be elusive.
In the absence of robust clinical criteria and laboratory means of diagnosis, idiopathic acute multifocal retinitis will remain a diagnosis of exclusion even though it tends to follow a characteristic clinical course. However, SD-OCT may be a helpful diagnostic aid for the clinician when faced with patients with atypical presentation of this disease such as those with concomitant optic disc edema or serous retinal detachment.
Corresponding Author: Yen Harn Yew, MD, A1206, University Towers, Jalan University, Seksyen 11, Petaling Jaya, Selangor 46200, Malaysia (firstname.lastname@example.org).
Published Online: May 23, 2013. doi:10.1001/jamaophthalmol.2013.2489
Conflict of Interest Disclosures: None reported.
Funding/Support: A small sum from Universiti Malaya research grant RG330-11HTM was reimbursed to the patient for the transportation fee and hospital charges.