Macular Serpiginous Choroidopathy with Secondary Choroidal Neovascularization: A Case Report

Dear Editor,

Serpiginous choroiditis (SC) is a rare form of chronic, progressive and recurrent posterior uveitis [1,2] and it can present in two main forms. Classic presentation typically originates around optic disc but can extend towards macula in snake-like pattern, characterized by gray-yellowish geographic lesion [2]. Second variant, macular SC, has worse prognosis because it affects macula first and may be associated with subsequent development of choroidal neovascularization (CNV) [3]. Since SC is typically bilateral, patients with macular SC with CNV can experience significant impact on their quality of life. We recently encountered a case of macular SC with CNV and would like to report the multimodal imaging results and treatment outcomes using anti–vascular endothelial growth factor (anti-VEGF) agents. Written informed consent for publication of the research details and clinical images was obtained from the patient.

A 29-year-old Korean woman presented to the clinic with blurred vision in her right eye that began 1 month ago. Her uncorrected visual acuity was 20 / 1,000 and 20 / 32 in right and left eye, respectively, without any of inflammation in chamber or vitreous. There is no information about COVID-19 infection or vaccination during follow-up. The fundus examination revealed macular scar in right eye, and fundus autofluorescence imaging revealed corresponding lesions with hypoautofluorescence, as well as focal subacute lesions with hyperautofluorescence. Optical coherence tomography (OCT) showed retinal pigment epithelium (RPE) disruption with subretinal hyperreflective material in foveal-parafoveal areas (Fig. 1A–1C). Fluorescein angiography (FAG) revealed well-marginated area of early-phase hypofluorescence and late-phase hyperfluorescence within temporal area of lesion, while fovea showed consistent hyperfluorescence without leakage (Fig. 1D, 1E). These findings suggested active macular SC with foveal scar in right eye. Systemic workup showed no abnormalities, and tests for infection, including tuberculosis, syphilis, and toxoplasmosis, were all negative. After being diagnosed with macular SC, treatment with oral prednisone (initiated at 40 mg/day and tapered weekly to maintain 5 mg/day) for 6 months prevented further progression (Fig. 1F).

Fig. 1

Multimodal imaging findings of the patient’s both eyes. (A) Fundus photography showed a macular scar on the right eye. (B) Optical coherence tomography (OCT) showed retinal pigment epithelium disruption with subretinal hyperreflective material in the foveal and parafoveal areas. (C) Fundus autofluorescence image showed a macular scar with hypoautofluorescence. (D, E) Fluorescein angiography revealed a well-marginated area (arrow) of early-phase hypofluorescence and late-phase hyperfluorescence within the temporal area of the lesion, while the foveal area (arrowhead) showed consistent hyperfluorescence without leakage. (F) After oral prednisolone treatment, the subacute hyperautofluorescent lesion decreased compared to baseline. (G) Fundus photography of the left eye showed subretinal turbid exudation at the time of involvement. Retinal hemorrhage (H) occurred during the maintenance treatment with bevacizumab, and (I) absorbed after five injections with ranibizumab. (J) Choroidal neovascularization (yellow arrow) was observed on OCT angiography, along with exudative changes on OCT. Recurrent exudative changes were (K) observed (yellow arrow) despite bevacizumab treatment, and (L) improved (yellow arrow) after switching to ranibizumab.

Fourteen months after, the patient came to the emergency department with blurred vision in the left eye, started 2 weeks earlier. The corrected visual acuity in left eye was 20 / 200. Fundus examination revealed a new lesion of subretinal turbid exudation in macula (Fig. 1G). The OCT showed RPE disruption with subretinal hyperreflective material, and OCT angiography revealed CNV in left eye (Fig. 1J). The FAG showed early-phase hypof luorescence and late-phase pooling, while indocyanine-green angiography showed consistent hypofluorescence. She was treated with oral prednisone and intravitreal bevacizumab injections (1.25 mg/0.05 mL; Avastin, Roche) in the left eye. She received five intravitreal bevacizumab injections over 10 months and the visual acuity improved. However, development of subretinal hemorrhages and CNV size increase (Fig. 1H, 1K) were observed despite repeated injections, leading to a switch to biosimilar formulation of ranibizumab (0.5 mg/0.05 mL; Amelivu, Samsung-Bioepis). After five injections, the left eye maintained corrected visual acuity of 20 / 28, with absorbed hemorrhages and no further progression (Fig. 1I, 1L). No other adverse effects related to intravitreal injections were noted.

Advanced retinal imaging provides definitive evidence that inner choroidal ischemia primarily drives placoid disorders such as SC, acute posterior multifocal placoid pigment epitheliopathy (APMPPE), relentless placoid chorioretinitis, and persistent placoid maculopathy. Multimodal imaging reveals that inflammation of choriocapillaris is also a key pathological mechanism of SC, with potential impacts on the RPE and larger choroidal vessels [4]. Macular variant SC can be difficult to differentiate from other placoid disorders, however, unlike APMPPE, SC is known to be more prone to CNV. Additionally, SC often shows asymmetric patterns even when it presents bilaterally, and lesions tend to have serpentine appearance in contrast to the scattered pattern of APMPPE.

Secondary CNV can develop in approximately 10% to 25% of patients due to such choroidal ischemia or inflammation, and it is a poor prognostic factor for visual function [5]. Morphologically, CNV lesions are deep and often associated with chorioretinal atrophy, subretinal fibrosis, and pigment clumping. Active CNV lesions manifest as gray-white lesions progressing geographically in posterior fundus.

In SC, there are multiple reports demonstrating the efficacy of bevacizumab and ranibizumab injections in improving visual acuity post-treatment [5]. However, macular variant of idiopathic SC is rare condition, and there have been no documented cases of treating secondary CNV with anti-VEGF therapy in Korean population. In this case, we found that anti-VEGF therapy can be effective for secondary CNV in SC patients, and if response is suboptimal, switching to potent drug such as ranibizumab can be good option.