"Out of the ashes and into the fire"- Choroidal neovascular membrane at the intersection of traumatic choroidal rupture and brittle bruch's membrane.

A 51-year-old female presented with blurred vision in her left eye (OS) 1 week following blunt trauma. Her best-corrected visual acuity OS was 20/400. Fundus examination revealed angioid streaks (AS) bilaterally, circumferential choroidal rupture temporally along with subretinal hemorrhage OS. Fovea also showed subretinal and intraretinal hemorrhage. There were no signs of peau d’orange in the retina.[1] She had no prior evaluation for pseudoxanthoma elasticum and Paget's disease. Fundus fluorescein angiography OS showed blocked fluorescence in the peripapillary region and macula due to the heme with faint lacy hyperfluorescence in the peripapillary region, which was evident in the later phases. Overlying hard exudates (hyperreflective foci) and few intraretinal cystoid spaces along with break in the Bruch's membrane (BM) and irregular retinal pigment epithelium (RPE) elevation were noted on spectral domain optical coherence tomography (SD-OCT) which confirmed the presence of choroidal neovascular membrane (CNVM) [Figure 1]. Both choroidal rupture and AS were apparent on angiography, seen as hyperfluorescent wavy lines with the peripapillary hyperfluorescent ring and on SD-OCT as BM defects [Figure 1]. Hence, it was concluded that there were multiple breaks in the BM at different sites and the presence of coexisting CNVM at the intersection of the choroidal rupture and AS.[2] In order to displace the heme at the fovea and also to treat the CNVM in the peripapillary region, pneumatic displacement of the heme with intravitreal injection of C3F8 0.3 cc with intravitreal antivascular endothelial growth factor was given. The patient was advised prone positioning and follow-up after a week. However, the patient was lost to follow-up during the COVID-19 pandemic.

Figure 1

(a) Fundus photograph demonstrating the angioid streaks and peripapillary subretinal hemorrhage with a dark multilayered hemorrhage at the fovea, (b) FFA and ICG image showing the peripapillary ring and hyperfluorescent wavy lines denoting the angioid streaks, blocked fluoresence at the macula, and in the peripapillary region with faint lacy hyperfluoresence (denoted by red circle). Inset SD-OCT line scan through the intersection of choroidal rupture and angioid streak showing RPE elevation and subretinal hyperreflectivity and hyperreflective foci in the inner retinal layers, (c) SD-OCT superior to the fovea showing Bruch's membrane breach denoted by asterisk in yellow and subretinal hyperreflectivity, (d) SD-OCT through the fovea showing altered foveal contour, hyperreflectivity in multiple layers, and obscuration of deeper structures. FFA: Fundus fluorescein angiography, ICG: Indocyanine green, SD-OCT: Spectral domain optical coherence tomography, RPE: Retinal pigment epithelium

AS is usually characterized by dehiscence of the elastic lamina of BM. It is characterized by ruptures, undulations, and dehiscence of the BM. The development of CNVM and atrophy are the associated complications. Serous and hemorrhagic detachments associated with the CNVM are seen in 70% of cases of AS, and it usually occurs in the fifth decade of life.[3]

The breaks in the BM are associated with or without the involvement of the RPE and choriocapillaris. Initially, these BM breaks do not cause alterations in the RPE and choriocapillaris layers. Large and evoluted breaks result in RPE atrophy and scarring. SD-OCT shows hyperreflectivity and thickened BM that represents the areas of abnormal calcification. AS typically develops in these areas of abnormal calcification.[4] The loss of elasticity of BM predisposes to the development of ruptures and dehiscences. BM undulations are seen six times more frequently in patients with CNVM secondary to AS. They represent the points of decreased resistance and hence has a higher risk of rupture. Breaks develop at the vertex and margins of these undulations. AS starts from the peripapillary region as that is the area of loci minoris resistentiae and also where the BM is interrupted.[4] Larger dehiscence (>250 μ) may be a preferred pathway for the growth of CNVM, the development of which is hypothesized to be a probable reparative process.[4]

A trivial trauma can cause rupture of the inherently fragile BM in patients with AS, especially at the junction of the two, giving an access for CNVM to grow into subretinal space. These patients should be closely followed up for early detection and treatment of vision-threatening complications and usage of protective eyewear needs to be emphazized.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.