Peripapillary choroidal vascularity of paediatric myopic eyes with peripapillary hyperreflective ovoid mass-like structures

Abstract

Purpose: To assess the peripapillary choroidal vasculature in paediatric myopic patients with and without peripapillary hyperreflective ovoid mass-like structures (PHOMS).

Methods: This prospective study includes 60 eyes of 60 myopic (spherical equivalent [SE] <-1.00 dioptre [D]) patients with (n = 30) and without (n = 30) PHOMS (PHOMS [+] and PHOMS [-] groups, respectively), and 30 eyes of 30 age- and sex-matched emmetropic children (control group). Peripapillary choroidal parameters, including total choroidal (TCA), luminal (LA), and stromal areas (SA) and choroidal vascularity index (CVI) calculated from vertical and horizontal single-line enhanced depth imaging-optical coherence tomography scans centred on optic nerve head.

Results: Peripapillary retinal nerve fibre layer thicknesses were not different between the groups (p > 0.05). In the PHOMS (+) group, TCA, LA and SA were lower, and CVI was higher in all quadrants compared to the control (p < 0.05). However, only the mean TCA and LA in the inferior and nasal quadrants and the mean SA in the nasal quadrant were lower in PHOMS (+) than in PHOMS (-) (p < 0.05). In the PHOMS (-) group, higher CVI was observed in all quadrants except temporal compared to the control group. Although the mean CVI of the PHOMS (+) group was also higher than in the PHOMS (-) group, this difference was not statistically significant.

Conclusion: This study indicates that choroidal parameters differ in paediatric myopic patients with PHOMS. Further studies with larger sample sizes are needed to understand the details of choroidal parameters in eyes with PHOMS.

Keywords: choroidal vascularity index; myopia; peripapillary hyperreflective ovoid mass‐like structures.

FIGURE 1

The flow chart of the study enrolment. D, dioptre; MRI, magnetic resonance imaging; PHOMS, peripapillary hyperreflective ovoid mass‐like structure; SD‐OCT, spectral domain optical coherence tomography; SE, spherical equivalent.

FIGURE 2

Sample images of peripapillary choroidal imaging in control (a, b), PHOMS (−) (c, d) and PHOMS (+) (e, f) groups with enhanced depth imaging‐spectral domain optical coherence tomography (EDI‐OCT). Horizontal (temporal‐to‐nasal) (a, c, e) and vertical (inferior‐to‐superior) (b, d, f) optic disc‐centred single‐line B‐scan EDI‐OCT imaging was performed for choroidal analysis. The margins of the peripapillary hyperreflective ovoid mass‐like structures (PHOMS) in a myopic eye are shown as white dots on the near‐infrared reflectance image (e). The white arrowhead in the cross‐sectional EDI‐OCT image indicates the subretinal located PHOMS in the peripapillary area (e, f).

FIGURE 3

Measurement of peripapillary choroidal vascularity index in a patient in the PHOMS (+) group. Both horizontal (temporal‐to‐nasal) (a, b) and vertical (inferior‐to‐superior) (e, f) optic disc‐centred single‐line B‐scan enhanced depth imaging spectral domain optical coherence tomography (EDI‐OCT) was performed. The 1500 μm‐width peripapillary choroidal areas in the cross‐sectional EDI‐OCT images were selected as the region of interest and binarized with the Niblack auto‐local thresholding method (c, g). In these images, dark pixels indicate the luminal area and white pixels indicate the stromal area. Cross‐sectional EDI‐OCT images overlaid on the binarized region of interest are presented in d and h. The white asterisk in Figure 2b indicates PHOMS in the cross‐sectional EDI‐OCT image.

FIGURE 4

Bar graphs showing the mean total choroidal area (a), luminal area (b), stromal area (c) and choroidal vascularity index (d) of study groups according to peripapillary quadrants. PHOMS, peripapillary hyper‐reflective ovoid mass‐like structure. *Statistical significance in one‐way analysis of variance with post‐hoc Tukey test. Error bars indicate standard deviation.