Abstract
Purpose
To describe the multimodal imaging findings and treatment outcomes in choroidal neovascularization secondary to Choroideremia.
Observations
A 13-year-old male presented with reduced visual acuity in the left eye. He gave a history of nyctalopia. His best-corrected visual acuity (BCVA) was 20/20 in the right eye and 20/40 in the left eye. Based on multimodal imaging, the diagnosis of choroideremia in both eyes with a subfoveal choroidal neovascularization in the left eye was made. He underwent five intravitreal anti-vascular endothelial growth factor (VEGF) injections of Ranibizumab over a period of 3 years, with the final injection given due to recurrence of neovascularization. Post-treatment, his BCVA improved to 20/20 in the left eye with regression of the neovascular network.
Conclusions and importance
This case highlights the role of OCTA in diagnosis of choroidal neovascularization in choroideremia as well as its successful management with anti-VEGF injections with long term follow up.
1
Introduction
Choroideremia, an X-linked chorioretinal dystrophy, is characterized by extensive atrophy of the choriocapillaris, retinal pigment epithelium (RPE) and photoreceptors with relative sparing of the inner retinal layers. , Fundus changes are seen as early fine retinal pigment mottling followed by underlying choroidal atrophy, which start in mid-periphery and slowly progress centrally. Affected males typically present with nyctalopia in the first decade of life, followed by peripheral visual field loss. The central vision usually remains unaffected due to the preservation of macular anatomy till the 5th -7th decade of life.
Loss of central visual acuity at a young age in choroideremia is a rare manifestation of the disease which may occur due to development of cystoid macular oedema or choroidal neovascularization (CNV). We describe the role of multimodal imaging in the diagnosis and monitoring of a case presenting with CNV secondary to choroideremia, and the long-term outcomes following prompt treatment with anti-vascular endothelial growth factor (VEGF) injections.
2
Case report
A 13-year-old boy, presented with complaints of reduced vision in the left eye (LE) for one month. He gave a history of night blindness for the past one year. He did not have any systemic illnesses. Both the parents and his only sibling were asymptomatic and were normal on ocular examination. On examination, his best-corrected visual acuity was 20/20 in the right eye (RE), and 20/40 in the LE. Anterior segment examination was unremarkable in both eyes. Fundus examination of both eyes revealed pigment clumping with areas of widespread chorioretinal atrophy with visible network of large choroidal vessels sparing a large island of perifoveal area with pseudopodia like extensions suggestive of choroideremia. [ Fig. 1 A and B]. Additionally, a small subretinal hemorrhage was seen juxtafoveally in the LE [ Fig. 1 B]. A full field electroretinogram was done initially which revealed a reduced scotoptic response. Swept source ocular coherence tomography (SS-OCT) showed an overall retinal and choroidal thinning with loss of photoreceptor layers sparing the macula in both eyes. SS-OCT of the LE revealed the presence of a type 2 CNV complex subfoveally with small subretinal hemorrhage and subtle subretinal fluid [ Fig. 1 C and D]. Fluorescein angiogram revealed scalloped areas of missing choriocapillaris in the mid periphery appearing hypofluorescent next to a bright hyperfluorescent central island of perfused choriocapillaris in both eyes. A faint lacy pattern of vessels at the edge of foveal avascular zone with late leakage confirmed the presence of subfoveal CNV in the LE [ Fig. 1 E and F]. OCT angiography images were procured using the Zeiss Cirrus HD-OCT 5000 (Zeiss Meditec, Dublin, CA) with Angioplex using 6 × 6 sections at the level of the RPE-RPE fit which also revealed a neovascular network at the level of the outer retina in the corresponding location in the LE [ Fig. 2 A] along with widespread choriocapillaris attenuation and visualization of the medium and large choroidal vessels with relative macular sparing in both eyes. With a diagnosis of active CNV secondary to choroideremia in the LE, the patient was started treatment with intravitreal anti-VEGF injection (0.05 ml of Ranibizumab) in the same eye after taking the written consent from the legal guardian. CNV showed regression with complete disappearance of subretinal fluid, subretinal hemorrhage and reduction in the size of vascularity of the lesion, which required 4 injections of Ranibizumab at one-monthly interval [ Fig. 2 B, C, D]. At this stage, his BCVA in the LE improved to 20/20 with OCT angiography confirming the shrinkage of neovascular complex [ Fig. 2 B]. A reactivation of CNV was noted with reappearance of subretinal fluid at month six after the 4th injection leading to reduction in BCVA to 20/30 in the LE [ Fig. 3 A and B]. A repeat intravitreal injection of Ranibizumab resulted in resolution of subretinal fluid and improvement of BCVA to 20/20 in the LE. Since then, patient has maintained his BCVA (20/20) in the LE without any recurrence of CNV activity during a follow up period of 30 months [ Fig. 3 C, D].
