Atrophy of the central neuroretina in patients treated for diabetic macular edema

Purpose To examine the prevalence of central retinal atrophy in patients treated for diabetic macular edema (DME) in a clinical setting. Methods Retrospective data analysis of patients with DME, focusing on those who developed central retinal thinning after DME treatment at the Department of Ophthalmology, Medical University Vienna. Patient characteristics and clinical data including best-corrected visual acuity (BCVA), spectral domain optical coherence tomography and fluorescence angiography images were reviewed and DME treatment strategies analysed using descriptive statistics. The correlation between visual acuity and ocular, systemic or DME treatment factors was calculated using linear regression models and ancovas. Results A total of 6684 outpatient visits by 1437 patients with diabetes were analysed. Out of 149 patients, who had had a central subfield thickness (CST) below 200 mu m, 32 (36 eyes) had previously been diagnosed with a centre involving DME with an average CST of 473 +/- 103 mu m and average visual acuity of 0.62 +/- 0.44 logMAR at first presentation. At the time of central atrophy, 29 (81%) out of 36 eyes had a history of laser treatment, 11 (31%) a vitrectomy, 32 (88%) repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF; mean 5.3 +/- 3.8) and 22 (61%) intravitreal corticosteroid injections (mean 2.5 +/- 2.7). Visual function (0.67 +/- 0.43 logMAR) at the time of atrophy was not significantly correlated to central retinal thickness (191 +/- 7 mu m) or any other ocular, systemic or treatment factors. Conclusions Only 4% of patients treated for DME developed central retinal thinning in our observation period. On average, our atrophy patients had higher CST and lower BCVA when they first presented with DME compared to the overall DME cohort, and they received a combination of intravitreal injections and laser for DME treatment. Central retinal atrophy might not be attributed to excessive use of intravitreally applied anti-VEGF or any other DME therapy alone.