New Possible Clinical Variant of Syndrome Associating, Posterior Microphthalmos, Retinitis Pigmentosa, Foveoschisis, and Optic Disc Drusen: Report Case and Review of the Literature

Abstract

To report a possible new clinical variant of the syndrome: posterior microphthalmia - retinitis pigmentosa – retinoschesis and papillary drusen and review the literature for this clinical entity. This is a 9 years old child without particular pathological story. His parents had had consanguineous marriage. His best visual acuity was improved to 3/10 with +16.00 SD (diopter spherical) OD (right eye) and 2/10 OS (left eye) with +17.00 SD. Anterior segment examination was normal. On the dilated fundus, we found a crowded optic disc associated to a bilateral maculopathy with white spots at the retinal periphery in the both eyes. Therefore we realized: Ultrasound imaging, Fluorescent angiography, Optical coherence tomography, and visual evoked potential with electroretinography. A and B scan ultrasonography revealed a posterior microphtalmia. Autofluorescence images and fluorescent angiography showed peripapillary atrophy with drusen. Optical coherence tomography (OCT) analysis of the macula at the vertical scan line revealed retinoschesis and prominent retinal fold in the papillomacular region. An OCT section across a retinal white spot shows a hyper-reflective deposit in the subretinal space, pushing the line of the photoreceptors. The electroretinogram showed a very marked decrease in rod response and cone hypovoltage in favor to retinal dystrophy compatible with retinitis pigmentosa. This case shows a new clinical variant of the posterior microphthalmia syndrome - retinitis pigmentosa, papillary drusen and retinoschisis described only once in the literature characterized by the presence of retinal white spots. In this clinical situation, the contribution of electroretinigraphy in diagnosis is crucial. From this clinical description other studies may be realized to discover the new gene mutations related to this entity.