Case Report: Multimodal Imaging in a Rare Case of Morning Glory Disc Anomaly Complicated With Choroidal Ossification

Abstract

Purpose: The authors described a 7-year-old boy who was diagnosed with morning glory disc (MGD) anomaly in the right eye via fundus examination. However, during the head CT examination, a hyperdense choroidal lesion was discovered around the optic disc. Comprehensive investigations revealed that the lesion's characteristics were extremely consistent with choroidal osteoma (CO), so the patient was diagnosed with MGD with CO on his second visit. However, in the subsequent follow-up, the author discovered pigmentary alterations in the retinal pigment epithelium (RPE) in the patient's right eye. Finally, the diagnosis was corrected to MGD with choroidal ossification following a thorough etiological analysis. Meanwhile, the characteristics of choroidal ossification were described in detail through multimodal imaging in this article.

Methods: Retrospective review of a case note.

Conclusions: Similar to CO, choroidal ossification is the consequence of structured osseous tissue formation regulated by osteoblasts and osteoclasts. It consists of bone trabecular and vascular components and is difficult to be distinguished from CO on imaging examinations. In contrast to the congenital prevalence of CO, there are often incentives for the occurrence of choroidal ossification. These inducements will eventually mediate the inflammation in the eye, resulting in the activation of many cytokines and the production of choroidal ossification. Around one-third of patients with MGD will experience retinal detachment, and in certain cases, the subretinal fluid will be absorbed spontaneously, resulting in alterations to the RPE. These processes can activate inflammatory factors in the eye, bringing about a cascade of abnormalities, including the development of CO. Therefore, the proper diagnosis of disease should not be made exclusively on the basis of the imaging findings. A thorough analysis of the epidemiology and etiology is crucial.

Keywords: choroidal ossification; choroidal osteoma; etiology analysis; morning glory disk anomaly; multimodal imaging.

Figure 1

(A) Widefield color fundus photograph of the right eye revealed a large optic disc centrally covered with glial tissue and encircled with chorioretinal pigmentary disturbance, as well as straight retinal vessels radially issuing from the disc margin with increased numbers. (B) Spectral-domain optical coherence tomography (SD-OCT) revealed the conical excavation of the optic disc (yellow star) with a central tuft of glial tissue on top (white arrow).

Figure 2

Computerized tomography scan of the orbit demonstrated a hyperdense choroidal plaque with the same density as bone at the level of the optic disc in the right eye.

Figure 3

(A) B-scan ultrasonography demonstrated a highly reflected mass covering the optic disc, and a high echo spike originating from the surface of the lesion was detected on the combined A-scan. (B) Fundus photography showed a yellowish-white lesion around the optic disc (white arrow) and mottling of the retinal pigment epithelium (RPE) (yellow stars). (C) On enhanced depth imaging OCT (EDI-OCT), a well-defined peripapillary choroidal lesion with hyperreflective lamellar lines in the inner part and spongiform pattern in the outer part were depicted. (D) The late phase of FA revealed diffuse late staining around the optic disc and punctate hypofluorescence inferiorly. (E) The indocyanine green angiography (ICGA) illustrated early hypofluorescence and diffuse late staining in the juxtapapillary area. In the early phase, the patterns of vessels were obtained supranasally to the optic disc (red arrow). (F) The blood flow signals were demonstrated among the lesion on OCT angiography (OCTA).