Bilateral pale posterior pole sans pain: A "hard" sell.

Case

A 30-year-old Asian man presented with metamorphopsia in left eye since 1 month. He was diagnosed with peripapillary serpiginous choroiditis elsewhere and advised intravenous methylprednisolone. His past medical history was unremarkable. On examination, visual acuity was 20/15 in both eyes. Anterior chamber was quiet and did not show any reaction in either eye.

What Is Your Next Step?

Start intravenous methylprednisolone

High-resolution chest computed tomography (CT) to rule out tuberculosis

Mantoux test

Dilated fundus evaluation.

Findings

Fundus evaluation showed peripapillary reddish-white lesion bilaterally, with well-defined irregular geographic borders forming pseudopodia and sparing the fovea [Fig. 1a]. Ultrasound scan showed high-reflective plaque echoes in peripapillary area of both eyes suggestive of calcification [Fig. 1c]. CT orbit showed hyperdense lesion suggestive of calcification [Fig. 1e]. Optical coherence tomography (OCT) showed choroidal lesion causing shadowing with subretinal fluid (SRF) [Fig. 1d]. Fundus fluorescein angiography (FFA) of both eyes showed early intense hyperfluorescence with staining [Fig. 1b]. Indocyanine green angiography did not show any features of active choroiditis or choroidal neovascular membrane (CNVM). In the absence of CNVM and the tumor edge being very close to fovea, it was decided to observe the condition rather than consider anti- vascular endothelial growth factor (VEGF) or photodynamic therapy. In such eyes with SRF, anti-VEGF is the preferred treatment in the presence of CNV, while observation is the norm without CNV. At 1 and 3 months follow-up, both fundi were stable without CNVM.

Figure 1

Fundus showed peripapillary reddish-white lesion bilaterally, with well-defined irregular geographic borders forming pseudopodia and sparing the fovea (a). Fundus fluorescien angiography showed early intense hyperfluorescence with staining (b). Indocyanine green angiography did not show any features of active choroiditis or CNVM. Ultrasound showed high-reflective plaque echoes suggestive of calcification (c). Optical coherence tomography showed choroidal lesion causing shadowing, with subretinal fluid (d). CT orbit showed hyperdense lesion suggestive of calcification (e)

Diagnosis

Bilateral choroidal osteoma

Correct Answer:

D.

Discussion

Choroidal osteoma is a benign tumor of choroid composed of mature bone. Usually choroidal osteoma is found in young, healthy women in the second or third decade of life and unilateral in 75% of cases.[1] Mostly patients present with symptoms of blurring and metamorphopsia. The tumor is usually juxtapapillary or peripapillary and varies from deep pale yellow to orange red (thinned out retina) color with well-defined scalloped or distinct geographic margins with blunt pseudopod-like projections and branching “spider” vessels on tumor surface, and may show SRF or hemorrhage which usually signifies CNVM.[2] The lesion may decalcify over time and occurs in nearly 50% of eyes by 10 years. Management options include laser photocoagulation, transpupillary thermotherapy, anti-VEGFs, photodynamic therapy, or combination of these therapies. Asymptomatic or stable osteoma can be observed. Indications for treatment of such eyes include the presence of active CNVM or calcified extrafoveal tumor. In such eyes with SRF, anti-VEGF is the preferred treatment in the presence of CNVM, while observation is the norm without CNV.

Serpiginous choroiditis (geographic helicoid peripapillary choroidopathy) is bilateral, chronic, progressive, and recurrent inflammatory disease affecting the retinal pigment epithelium and inner half of choroid. It starts in juxtapapillary or peripapillary region and progresses centrifugally from the disc to involve the macula area.[3] As the lesions resolve, retinal pigment epithelium and choroidal degeneration begin, leading to fibrous scarring and pigment hyper or hypoplasia. Patients present with symptoms such as central or paracentral scotomas, metamorphopsia, visual field loss, and blurred vision. CNVM may develop over time.

In our case, the clinical appearance mimicked peripapillary serpiginous choroiditis. However, investigations such as ultrasound and CT helped to differentiate between these two conditions. The other differential diagnoses to consider are juxtapapillary (postuveitic) CNVM, and organized subretinal hemorrhage (polypoidal choroidal vasculopathy).

Patients with suspected bilateral peripapillary serpiginous choroiditis should have a dilated fundus examination and ancillary investigations such as FFA, OCT, and ultrasonography.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient's parents have given their consent for the patient's image and other clinical information to be reported in the journal. The patient's parents understand that the patient's name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.