Sir,

Frosted retinal branch angiitis is a rare manifestation of retinal perivasculitis.1 Cases have also been identified in subjects suffering from HIV, early cytomegalovirus (CMV) retinitis, and systemic herpes simplex virus (HSV) infection.2, 3

Case report

A 37-year-old man with HIV and CMV+, after 9 weeks of treatment with highly active antiretroviral therapy (HAART) for acute retinal necrosis in OS, was referred for a mild visual acuity (VA) loss in OD (from 20/20 to 20/25). At fundus examination, he presented a perivascular creamy sheathing of retinal veins in the whole vascular net (Figure 1a1−a2). Frosted branch angiitis with CMV retinitis was diagnosed, and therapy with gangiclovir and foscarnet was recommended. The patient underwent spectral-domain optical coherence tomography (SD-OCT) using Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany). The images showed a thickening of vessel walls, swelled by hyperreflective material (Figure 1a3, white arrows), and little hyperreflective spots (Figure 1a3, white arrowhead) more localized at the boundaries of plexiform layers, even if also notable in the nuclear layers and more dense in perivascular areas.

Figure 1
figure 1

Colour photographies (a1–b1) and infrared (a2–b2) with simultaneous SD-OCT, normal and magnified (a3–b3) imaging. a1−3: first examination, b1−3: 12-weeks examination.

Full size image

Twelve weeks later, VA in the OS improved to 20/60 (Figure 1b1−b2). An SD-OCT examination showed a normal vessel wall thickness corresponding to the restored vessels, and also where the creamy sheathing was still visible, the walls appeared thinned compared with the previous examination (Figure 1b3, white arrows). The diffuse hyperreflective retinal spots were reduced, but were still present, especially at the boundaries of the outer plexiform layer (Figure 1b3, white arrowheads).

Comment

In this case of frosted branch angiitis, SD-OCT scans showed a hyperreflectivity at the level of the vessel walls, corresponding with the perivascular material, possibly because of immune-complex deposition.1, 4 The presence of diffuse small hyperreflective spots could be explained by the Muller cells' involvement and suffering outside the perivascular area.5 SD-OCT examination seems to be a valid imaging technique to follow the evolution of frosted branch angiitis, especially monitoring the ultrastructural changes in this rare condition.