Answer:
This patient had a choroidal neovascular membrane in the left eye associated with multifocal choroiditis (MFC). There were punched-out chorioretinal scars in the macula of each eye. The right eye had areas of extrafoveal deep fibrosis, indicated prior choroidal neovascularization that spontaneously involuted. The OCT of the right eye shows areas of atrophy and areas of disrupted outer retinal layers with some focal thickening indicated fibrosis, as well as areas of normal retina. The OCT of the left eye shows a central area of subretinal reflective material and a small amount of serous material. The OCTA of the left eye shows a small, central choroidal neovascular membrane. The patient was treated with bevacizumab (Avastin), and the vision improved to 20/40 and the subjective vision also improved. The vision in the left eye two years later was 20/30, and there was no evidence of choroidal neovascular membrane recurrence.
Multifocal choroiditis has a broad range of clinical manifestations. The most characteristic findings are round, “punched-out” lesions with a depigmented center and some hyperpigmentation at the outer border of the lesions. They can vary in size and be present anywhere in the fundus. Our patient’s lesions were restricted to the macula of each eye. Another common feature is peripapillary atrophy, and our patient had mild peripapillary atrophy with scarring, right eye more than left.
MFC can closely resemble presumed ocular histoplasmosis syndrome (POHS). Both predispose to choroidal neovascular membrane formation and the CNVMs tend to respond well to anti-VEGF treatment. Visual recovery can be remarkable, as long as there is no significant damage to foveal photoreceptors, because uninvolved tissue is usually healthy. In contrast, patients with age-related macular degeneration less frequently experience a significant improvement in vision after anti-VEGF treatment, because serous and lipid exudates tend to be more harmful to unhealthy adjacent RPE and neurosensory retina. There are several features that help differentiate MFC from POHS. Patients with POHS typically have a history of exposure to the fungus Histoplasma capsulatum while living in or traveling through the Ohio and Mississippi River Valley areas. Patients with MFC, such as our patient, often have moderate myopia. Patients with MFC often have vitreous cells, unlike patients with POHS. The vitreous in MFC patients can clear if there has been no recent active inflammation. Patients with MFC can develop new punched-out lesions over time, while this is very atypical of patients with OHS. Unlike MFC patients, those with POHS typically will have a positive skin reaction to intracutaneous injection of 1:1000 histoplasmin and a positive HLA-DR2.
