We read with interest the article titled “Spectral-Domain Optical Coherence Tomography of Subretinal Hyperreflective Exudation in Myopic Choroidal Neovascularization” by Bruyère and associates. The authors investigated a series of myopic choroidal neovascularization (CNV) patients with subretinal hyperreflective exudation and performed both qualitative and quantitative assessments of the lesion before and after intravitreal anti–vascular endothelial growth factor (anti-VEGF) injections. Subretinal hyperreflective exudation seemed to correlate well with onset of myopic CNV and may be a useful spectral-domain optical coherence tomography (SD OCT) indicator to prompt for fluorescein angiography (FA) to confirm onset or reactivation of myopic CNV, as well as for monitoring treatment response.
In the study, 31 highly myopic eyes that showed subretinal hyperreflective exudation with subsequent FA confirmation of myopic CNV were included. It would be helpful to the readers if the authors provide the number of myopic CNV cases without the detection of subretinal hypperreflective exudation from their center. According to the study, the subretinal hypperreflective exudation seemed to be a specific sign for myopic CNV onset and reactivation; however, we do not know its sensitivity for diagnosing active myopic CNV.
The mean age of patients in this study was older (63 years) when compared with a review of most publications on myopic CNV. CNV associated with age-related macular degeneration (AMD) tended to be larger than CNV in young highly myopic subjects. There were no data regarding the size of CNV from this study and whether the size of CNV was correlated with the presence and dimensions of subretinal hyperreflective exudation. It could be that the accompanying subfoveal hypperreflective exudation in myopic CNV was also tiny, rendering it less sensitive to detection when compared with AMD patients. Furthermore, the size of myopic CNV had been shown to be a strong predictor of visual outcomes after anti-VEGF treatment. It would be interesting to find out if the size and regression of subretinal hypperreflective exudation can be a prognostic factor for functional outcome, myopic CNV recurrence, and the number of injections required.
The scan protocol performed in the study using a dense macular cube 49-line raster with 20 μm interline spacing could be time consuming and required the patient’s eye to fixate steadily. The mean spherical equivalent refractive error in this study was −12.8 diopters (D), and steep curvatures were commonly observed in OCT images of posterior poles in high myopes (< −8D). Acquisition artifacts may hinder the quality of OCT images in highly myopic subjects because of the extreme axial length and steep curvature of the posterior staphyloma frequently observed with myopic CNV occurrence. It would be useful if the authors could provide information on the quality of OCT images included in the study, and how to obtain proper sequential alignment for accurate longitudinal quantitative analysis of the subretinal hyperreflective exudation in highly myopic eyes.