Role of multimodal imaging in differentiating unilateral APMPPE from unilateral Harada disease - a case report.

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is classified as a part of the spectrum of the white dot syndromes affecting the inner choroid and the outer retina. It is usually bilateral and affects young patients between the second and fourth decades. The authors report an unusual case of unilateral APMPPE mimicking Vogt-Koyanagi-Harada (VKH) disease where the fundus fluorescein angiography was instrumental in confirming the diagnosis. Case presentation: A 35-year-old male presented with decreased visual acuity in the right eye for 3 days. Fundus examination revealed minimal vitritis, disc edema, and multifocal yellowish placoid lesions. Optical coherence tomography (OCT) showed the accumulation of subretinal fluid with subretinal septations closely mimicking VKH. Fundus fluorescein angiography depicted features of early hypofluorescence and late staining of the placoid lesions, suggesting APMPPE. Subretinal fluid partly resolved within a week, and visual acuity improved to 6/9(20/30) in the affected eye after the use of oral NSAIDS. Complete resolution of subretinal fluid was seen after 6 weeks. Clinical discussion: The most distinguishing feature in this case is the unilateral presentation and macular serous retinal detachment with subretinal septa on OCT imaging, which are not the typical features in APMPPE but quite similar to the characteristic features in acute VKH disease. Conclusion: APMPPE and acute VKH disease may share some overlapping clinical manifestations and imaging findings on OCT. APMPPE is a self-resolving disease, unlike VKH, and early diagnosis can avoid unnecessary administration of steroids and related side effects.