Comparison of Prevalence of Diabetic Macular Edema Based on Monocular Fundus Photography vs Optical Coherence Tomography

Abstract

IMPORTANCE Diagnosing diabetic macular edema (DME) from monocular fundus photography vs optical coherence tomography (OCT) central subfield thickness (CST) can yield different prevalence rates for DME. Epidemiologic studies and telemedicine screening typically use monocular fundus photography, while treatment of DME uses OCT CST. OBJECTIVE To compare DME prevalence from monocular fundus photography and OCT. DESIGN, SETTING, AND PARTICIPANTS Retrospective cross-sectional study of DME grading based on monocular fundus photographs and OCT images obtained from patients with diabetic retinopathy at a single visit between July 1, 2011, and June 30, 2014, at a university-based practice and analyzed between July 30, 2014, and May 29, 2015. Presence of DME, including clinically significant macular edema (CSME), on monocular fundus photographs used definitions from the Multi-Ethnic Study of Atherosclerosis (MESA) and the National Health and Nutrition Examination Survey (NHANES). Presence of DME on OCT used Diabetic Retinopathy Clinical Research Network eligibility criteria thresholds of CST for trials evaluating anti-vascular endothelial growth factor treatments. MAIN OUTCOMES AND MEASURES Prevalence of DME based on monocular fundus photographs or OCT. RESULTS A total of 246 eyes of 158 participants (mean [SD] age, 65.0 [11.9] years; 48.7% women; 60.8% white) were included. Among the 246 eyes, the prevalences of DME (61.4%) and CSME (48.5%) based on MESA definitions for monocular fundus photographs were greater than the DME prevalence based on OCT (21.1%) by 40.2% (95% CI, 32.8%-47.7%; P < .001) and 27.2% (95% CI, 19.2%-35.3%; P < .001), respectively. Using NHANES definitions, DME and CSME prevalences from monocular fundus photographs (28.5% and 21.0%, respectively) approximated the DME prevalence from OCT (21.1%). However, among eyes without DME on OCT, 58.2% (95% CI, 51.0%-65.3%) and 18.0% (95% CI, 12.9%-24.2%) were diagnosed as having DME on monocular fundus photographs using MESA and NHANES definitions, respectively, including 47.0% (95% CI, 39.7%-54.5%) and 10.3% (95% CI, 6.3%-15.7%), respectively, with CSME. Among eyes with DME on OCT, 26.9% (95% CI, 15.6%-41.0%) and 32.7% (95% CI, 20.3%-47.1%) were not diagnosed as having either DME or CSME on monocular fundus photographs using MESA and NHANES definitions, respectively. CONCLUSIONS AND RELEVANCE These data suggest that many eyes diagnosed as having DME or CSME on monocular fundus photographs have no DME based on OCT CST, while many eyes diagnosed as not having DME or CSME on monocular fundus photographs have DME on OCT. While limited to 1 clinical practice, caution is suggested when extrapolating prevalence of eyes that may benefit from anti-vascular endothelial growth factor therapy based on epidemiologic surveys using photographs to diagnose DME.

Evidence‐based Danish guidelines for screening of diabetic retinopathy

“…In addition, it is also possible to rule out CSMO at an early stage which may reduce concerns of the patients (Mackenzie et al 2011;Wong et al 2017). In a comparative study of 246 eyes, Wang et al (2016) concluded that there was a considerable inconsistency in the detection of DMO and CSMO when fundus photography and OCT were compared. This led to a false-positive rate of referral for CSMO of 86.6% in a screening setup without OCT.…”

“…1 Supplementary macular OCT should be performed if possible in the case of suspected or overt CSMO, or clinically significant loss of vision (at least two Snellen lines) which cannot be explained by concurrent disease (Virgili et al 2007;Wang et al 2016). In such cases, it is possible to qualify the suspicion of CSMO, thereby optimizing referral for further examinations and/or treatment.…”

“…These results were confirmed in the UK screening programme which reported that spectral domain OCT could rule out macular oedema in 42.1% of cases that met the screening definitions (Mackenzie et al 2011). In a comparative study of 246 eyes, Wang et al (2016) concluded that there was a considerable inconsistency in the detection of DMO and CSMO when fundus photography and OCT were compared. Differences went both ways, but in general the prevalence of DMO and CSMO was higher by fundus photography (61.4% and 48.5%) as compared to OCT (21.1% and 21.3%).…”

Diabetic Macular Edema: Traditional and Novel Treatment

“…DME, but not DR per se, is nowadays the main cause of vision loss in patients with diabetes 7 . Although estimations may diff er upon the diagnostics used 8 , studies revealed up to 21 million DME and 28 million vision threatening DR 7 . Diabetic macular edema is a special form of diabetic retinopathy, a highly specifi c microvascular complication of diabetes on the eyes.…”

Improving Ocular Telehealth Outcomes

“…In the setting of diabetic retinopathy, this “store-and-forward” paradigm has been validated against clinical examination and as well as the research gold standard 7-field Early Treatment Diabetic Retinopathy Study images 1 ; it has been demonstrated that remotely acquired images can allow clinicians to reach the same diagnosis and management plan as these more traditional methods. While there have been questions about the possible role for ultrawidefield imaging 1 and optical coherence tomography in ocular telehealth paradigms, 2 monoscopic photographic imaging has become the foundation of large diabetic retinopathy screening programs. 3 …”