Diabetic Macular Edema With and Without Subfoveal Neuroretinal Detachment: Two Different Morphologic and Functional Entities

Abstract

To assess specific morphologic and functional characteristics in eyes with diabetic macular edema (DME) with subfoveal neuroretinal detachment (SND+) vs DME without SND (SND-). Cross-sectional, prospective, comparative case series. Seventy-two patients (72 eyes: 22 eyes SND+ and 50 eyes SND-) with treatment-naïve, center-involving DME were evaluated. Data gathering included fundus color photographs, fluorescein angiography, spectral-domain optical coherence tomography (SD-OCT), best-corrected visual acuity (BCVA), and microperimetry. The following parameters were evaluated with SD-OCT: central macular thickness (CMT [including SND]); central retinal thickness (CRT [excluding SND]); choroidal thickness (CT); nasal and temporal retinal thickness (RT) at 500μm and 1500μm from the fovea; the number of hyperreflective retinal spots (HRS) in the central 3000μm; and the presence of SND and integrity of the external limiting membrane (ELM). Retinal sensitivity (RS) was evaluated within 4 degrees and 12 degrees of the fovea. Correlation among CT, RS, and HRS in patients with and without SND was determined. CMT (P= .032), temporal RT at 1500μm (P= .03), mean CT (P= .009), and mean number of HRS (P= .0001) were all higher in SND+ vs SND- eyes. CRT, BCVA, HbA1c, and prevalence of systemic arterial hypertension were not different between the 2 groups. RS within 4 degrees (P= .002) and 12 degrees (P= .015) was lower in SND+ vs SND- eyes. SND correlated significantly with disruption of the ELM (54.55% vs 24%, P= .01) and lower RS. A direct correlation was found between the number of HRS, presence of SND, CT, and RS within 12 degrees in SND- eyes, and an inverse correlation was found between CT and RS within 12degrees in SND+ eyes. These data may improve characterization of DME in eyes with SND. DME with SND correlates with greater CT, more HRS, disruption of the ELM, and significant macular functional impairment (RS decrease) vs SND-.