Subfoveal Choroidal Thickness in Patients with Histiocytosis and Multimodal Imaging Features of Choroidal Infiltrates.

Purpose: To evaluate choroidal findings in patients with histiocytosis, including subfoveal choroidal thickness (SFCT), and multimodal imaging in eyes with choroidal infiltrates visible by ophthalmoscopy and determine if abnormalities change with histiocytosis-directed (kinase inhibitor) therapy.

Design: Retrospective comparative study at single tertiary cancer referral center.

Participants: Ninety-one patients with histiocytosis and 41 age- and sex-matched controls.

Methods: Clinical examination, fundus photography, and OCT were used to assess choroidal findings. Clinically evident choroidal infiltrates by ophthalmoscopy were recorded, and choroidal vascular architecture was qualitatively examined. Subfoveal choroidal thickness and was measured using enhanced depth imaging spectral domain OCT from the outer portion of Bruch membrane to the choroidal scleral interface.

Main Outcome Measures: Subfoveal choroidal thickness was compared with matched controls; that secondary outcome was change in SFCT on histiocytosis-directed (kinase inhibitor) therapy. Multimodal imaging of choroidal infiltrates was visible by ophthalmoscopy.

Results: One hundred and eighty-two eyes of 91 patients (46 males, 45 females) with histiocytosis (Erdheim-Chester 35, Rosai-Dorfman 21, xanthogranuloma 7, mixed histiocytosis 11, Langerhans cell histiocytosis 15, and other 2) were examined. In patients with histiocytosis, the mean SFCT was 336.2 ± 94.9 μm compared with 250.3 ± 60.7 μm in the control group (P < 0.0001). Notably, 69% of patients with histiocytosis had SFCT >275 μm compared with 27% in controls (P < 0.0001). Subtype of histiocytosis, sites of bone or central nervous disease, posterior segment/other sites of ophthalmic disease, or mutational profile did not correlate with SFCT. In a subgroup analysis of 35 patients naïve to prior treatment, with >6 months follow-up, the proportion of SFCT >275 μm significantly decreased (P = 0.0016) on histiocytosis-directed (kinase inhibitor) therapy. Notably, 19.8% of patients had clinically evident choroidal infiltration: majority were yellow creamy, geographic, located posteriorly and hyperautofluorescent; with enlarged Haller vein bordering the infiltrate, choriocapillaris compression and loss of choroidal architecture by OCT.

Conclusions: In this cohort, 19.8% of patients with histiocytosis had clinically evident infiltration of their choroid. Furthermore, the majority of patients with histiocytosis had increased SFCT compared with age- and sex-matched controls. The thickened choroid decreases on histiocytosis-directed (kinase inhibitor) therapy and may be a marker of response to systemic treatment.

Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.