Can retinal morphology using spectral-domain optical coherence tomography be a potential biomarker in eyes with diabetic macular edema?
In a cross-sectional observational case series including 102 eyes from 80 individuals, disorganization of the inner retinal layers was strongly associated with disruption of outer retinal layers. Disorganization of the inner retinal layers was more frequently observed in eyes with increasing severity of diabetic retinopathy and was associated with poorer visual acuity.
Disorganization of the inner retinal layer may be associated with morphological changes in the outer retina and worse levels of diabetic retinopathy in eyes with diabetic macular edema, although the cross-sectional design precludes determining cause-and-effect relationships.
In diabetic macular edema (DME), identification of baseline markers on spectral-domain optical coherence tomography (SD-OCT) and their association with severity of diabetic retinopathy (DR) might aid in disease management and the design of future trials.
To examine associations between DR severity, retinal morphology on SD-OCT, and visual acuity in participants with DME.
Design, Setting, and Participants
This cross-sectional observational case series was conducted at a single tertiary care referral center. Demographics, visual acuity, SD-OCT, and color fundus photographs of 80 individuals with DME (102 eyes) seen between December 28, 2013, and April 30, 2014, were analyzed between May 1 and July 31, 2016.
Main Outcomes and Measures
Features captured on SD-OCT and thickness metrics. On SD-OCT we graded type and shape of DME, shape and presence of septae within the intraretinal cystoid abnormalities, presence of hyperreflective dots and foci, integrity of the external limiting membrane and ellipsoid zone, presence and extent of disorganization of the inner retinal layers (DRIL), and the status of the vitreomacular interface and epiretinal membrane. We measured retinal thickness at the fovea and at the site of maximum pathology, choroidal thickness at the fovea, and 1000 μm temporal and nasal to the fovea. Color photographs were graded to derive a DR severity stage.
The mean (SD) age was 63 (11) years, and 30 participants (37.5%) were women. The odds of having DRIL were greater in eyes with disrupted external limiting membrane (odds ratio [OR], 4.4; 95% CI, 1.6-12.0; P = .003), disrupted ellipsoid zone (OR, 2.7; 95% CI, 1.0-7.2; P = .03), presence of epiretinal membrane (OR, 2.8; 95% CI, 1.0-7.4; P = .03), and increase in retinal thickness at the fovea (OR, 1.6; 95% CI, 1.1-2.2; P < .001). Occurrence of DRIL was more likely in eyes with proliferative DR (OR, 7.3; 95% CI, 1.7-31.4; P = .007). Mean visual acuity decreased by approximately 4.7 letters for each 100-μm increase in the average global DRIL (95% CI, −7.9 to 1.4; P = .006).
Conclusions and Relevance
An association was found between DRIL and disruption of the outer retina and increasing DR severity. Further longitudinal studies seem warranted to determine whether DRIL is a clinically relevant noninvasive morphological marker in eyes with DME.
Das R, Spence G, Hogg RE, Stevenson M, Chakravarthy U. Disorganization of Inner Retina and Outer Retinal Morphology in Diabetic Macular Edema. JAMA Ophthalmol. Published online January 11, 2018. doi:10.1001/jamaophthalmol.2017.6256