Increased choroidal thickness: a new indicator for monitoring diabetic macular oedema recurrence

Abstract

Purpose The aim of this study was to determine whether choroidal thickness (CT) increases at the time of exudative recurrence in diabetic patients with unilateral diabetic macular oedema (DME) treated with intravitreal injections of anti‐VEGF or dexamethasone. Methods A real‐life, prospective, two‐centre study was conducted over a 9‐month period investigating diabetic patients presenting with unilateral DME treated with anti‐VEGF or dexamethasone intravitreal injections, and CT was measured manually, using the enhanced depth imaging module of the spectral domain optical coherence tomography. Choroidal thickness (CT) was measured in the morning, in both the affected and healthy eye of each patient at two timepoints: when the macula was ‘dry’ (T0) and at the time of exudative recurrence (T1). Results A total of 51 patients with unilateral DME were included. Mean CT in the affected eye was significantly thicker at the time of exudative recurrence (210.8 ± 44.1 μm at T0 versus 238.0 ± 49.0 μm at T1, p < 0.001). There was no significant variation in CT in the fellow eye (214.4 ± 52.3 µm at T0 versus 218.9 ± 53.4 µm at T1, p = 0.53). The type of intravitreal injection, the number of injections and the CT at T0 had no influence on the change in CT. Conclusion This study found that CT increased significantly in the affected eye at the time of recurrence of DME treated with anti‐VEGF or dexamethasone injections. Choroidal thickness (CT) could constitute an interesting new indicator for monitoring patients with DME.

Indicators of Visual Prognosis in Diabetic Macular Oedema

“…Conversely, a thick choroid post anti-VEGF may also indicate an eye that is a poor responder to anti-VEGF and an indicator of chronicity of DMO. However, thick choroid is not an indicator for DMO recurrence or higher number of injections [ 89 ]. On the contrary, other investigators have suggested that choroidal blood volume, flow and velocity decreases in diabetic eyes with DMO, which may lead to hypoxia of the outer retina, thereby leading to increase in VEGF levels [ 90 , 91 , 92 ].…”

The value of choroidal thickness in diabetic macular oedema is contradictory

“…In the work of Mathis et al (2020), there was a relation of CT increase with the anti‐VEGFs' subsiding effect on the choroid, but it was not clear that monitoring CT would be more useful to detect recurrence than monitoring CRT. It is possible that an anti‐VEGFs' waning effect on the choroid does not imply a need for another treatment if the CRT remains stable, that is, changes in CT do not necessarily forecast a DMO recurrence and a need for an additional injection (Mathis et al 2020). Furthermore, it is to be expected that the choroid thickens as the anti‐VEGF effect subsides, because CT decreases as a side effect of anti‐VEGF administration (Campos et al 2018).…”

“…T he choroidal thickness (CT) or the subfoveal choroidal thickness (SFCT) have been indicated as prognostic factors for the treatment of diabetic macular oedema (DMO), including in recent works (Mathis et al 2020;Endo et al 2020). Authors usually engage the decrease in CT and the decrease in central retinal thickness (CRT) under the action of anti-vascular endothelial growth factor (VEGF) agents, in a cause-effect relationship.…”

Effect of Dexamethasone Implant on Subfoveal Choroidal Thickness in Early Period in Vitrectomized Eyes with Diabetic Macular Edema

“…Whitney U test; SFCT, subfoveal choroidal thickness; SD, standard deviation; μm, micrometer; DME, diabetic macular edema.Journal of Ophthalmology segment-outer segment layer could be OCT biomarkers for better functional success in eyes that received IVD implant injection for DME treatment[20]. In their multicenter and retrospective study, Zur et al reported for the first time in the literature that the IVD implant could ameliorate disorganization of retinal inner layers which is a biomarker in eyes with DME[21].In a prospective study, Mathis et al reported that the increase in choroidal thickness in eyes with DME is an indicator for exudative recurrence that regressed with anti-VEGF or IVD implant injection[22].Kim et al investigated the effect of IVD implant on eyes with DME resistant to anti-VEGF drugs and reported that IVD implant causes an increase in BCVA and a decrease in the central fovea and SFCT thickness [23]. Lee et al reported that IVD implant may cause thinning not only in eyes with DME but also in eyes with retinal vein occlusion…”