SYMPATHETIC OPHTHALMIA VS MEWDS: Our patient’s illness is distinctive because the disease process exhibits features that are consistent with multiple evanescent white dot syndrome (MEWDS) as well as sympathetic ophthalmia. The absence of a history of viral illness before the change in vision is consistent with either condition. Mild anterior segment inflammation, which our patient had, can occur in sympathetic ophthalmia as well as in MEWDS. Optic nerve head swelling, periphlebitis, and vitreous cell also have been described in both conditions. While the yellowish-white lesions at the level of the RPE can be seen with either disease, the fact that the lesions were not elevated and spared the fovea is suggestive of MEWDS. The sex and age of the patient are typical for MEWDS. The history of previous trauma as well as the timing of the inflammation in the second eye, however, are suggestive of sympathetic ophthalmia.

DIAGNOSTIC FINDINGS AND EXCLUSION OF MEWDS: Features of the case that do not support the diagnosis of MEWDS or are uncommon features of MEWDS include:
  • 1) The absence of photopsia;
  • 2) The presence of early blocked fluorescence (vs hyperfluorescence) on fluorescein angiography;
   • 3) Disease recurrence within several weeks of stopping steroids (although early recurrences with MEWDS have been    reported, they mostly occur months to years after the initial presentation);
   • 4) The development of focal areas of peripheral RPE atrophy (although this has been reported with MEWDS).

Persistence of the wreath-like pattern of RPE changes may be another important distinguishing feature from MEWDS. It is not clear that the blind spot enlargement was disproportionately large compared to the degree of optic nerve head edema. In MEWDS, typical subfoveal RPE “granularity” tends to occur in patients with a greater degree of deceased visual acuity than this patient exhibited.

DIFFERENTIAL DIAGNOSIS: Conditions that should be considered in this patient’s differential diagnosis include:

• Sarcoidosis;
• Mycobacterial and syphilitic uveitis;
• Vogt-Koyanagi-Harada syndrome (VKH); and
• Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) as well as conditions that may be related to MEWDS (eg, punctate inner choroidopathy and others listed below). Sympathetic ophthalmia and sarcoid uveitis, for example, can exhibit Dalen-Fuchs nodules, papillitis, and choroiditis (1, 2). Sympathetic ophthalmia, VKH, and sarcoid uveitis are associated with choroidal infiltration by T lymphocytes (1-5). Both VKH and sympathetic uveitis can exhibit antibodies directed against retinal antigens (2).

IMMUNOPATHOLOGICAL STUDIES: Immunopathological studies have shown that the majority of patients with sympathetic ophthalmia (and sarcoidosis) have choroidal infiltration by T lymphocytes (1-3, 5, 6). (Early in the disease these are CD4+ T helper cells, and later in the disease they are mainly CD8+ T suppressor cells.) Shah and coworkers, however, found that B lymphocytes predominated in 4 of 29 cases of sympathetic ophthalmia (7). (T lymphocytes predominated in 20 of the cases.) The presence of B lymphocytes was correlated with disease duration greater than 9 months and with phthisis. Clinical and laboratory findings in our patient did not strongly support the diagnoses of VKH, sarcoidosis, vitiliginous choroiditis, presumed ocular histoplasmosis syndrome, punctate inner choroidopathy, multifocal choroiditis and panuveitis, APMPPE, acute idiopathic blind spot enlargement syndrome, or syphilis (8-10).

THIS CASE: Areas of granulomatous inflammation, although not as numerous as typically seen in sympathetic ophthalmia, were present in the injured eye. We believe that this finding, although consistent with the diagnosis of sympathetic ophthalmia, does not confirm it. Patients with sympathetic uveitis can have mild, transient nongranulomatous inflammation (11-15). These findings can occur if the exciting eye is enucleated early or if immunosuppressive therapy is administered concomitantly (14-17). Thus, it is possible that little granulomatous inflammation was evident because the patient was enucleated early in the course of the disease or because the patient received a 1-week course of systemic prednisone.

CONCLUSION: The pathological and clinical findings in this case indicate that sympathetic ophthalmia can mimic MEWDS.