DRIL after macular oedema treatment in BRVO
Reviewed by Sofia Rokerya

The authors report the analysis of a single-site, retrospective, cross-sectional study to evaluate the association between disorganisation of the retinal inner layers (DRIL) and visual acuity (VA) after anti-VEGF treatment for macular oedema (MO) due to branch retinal vein occlusion (BRVO). Sixty eyes of 60 consecutive patients with macular oedema due to BRVO, treated with Ranibizumab or Aflibercept, and were followed up for more than six months after the last injection of the anti-VEGF drug. All patients thereafter underwent OCT examination at monthly intervals. Resolution of MO was defined as a central subfield thickness <300µm, no subretinal or intraretinal fluid and no retinal cystoid spaces. The mean age of the 60 patients (22 male and 38 female) was 72.03±9.92 years. The mean number of anti-VEGF injections was 1.80±1.23, and the mean interval between the most recent anti-VEGF treatment and the final visit was 13.40±8.70 months. VA in logMAR significantly improved from 0.41±0.30 to 0.20±0.22 upon treatment, but some patients were not satisfied with their treatment outcome, which resulted in cessation of additional treatment for recurrent MO after the initial treatment. MO was detected in 27 eyes (45%) at the most recent visit. These 27 eyes showed VA improvement from 0.51±0.33 to 0.27±0.23 after the initial treatment and they maintained the improvement in VA at 0.24±0.25 until the final visit. DRIL was defined as the horizontal extent in micrometres over which any boundary between the ganglion cell-inner plexiform layer complex, inner nuclear layer, and outer plexiform layer could not be identified. This was detected in 39 eyes (65%) at the final visit, and 21 eyes did not show DRIL in the evaluated area. The final VA seemed to be better in the eyes without DRIL, but the difference was not statistically significant. The factors significantly associated with final VA on univariable analysis were age, baseline VA, central subfield thickness, DRIL length, external limiting membrane (ELM) disruption length, ellipsoid zone (EZ) disruption length, cone outer segment tips (COST) visibility, and the presence of subretinal fluid (p<0.001, p<0.001, p=0.005, p=0.011, p<0.001, p<0.001, p<0.001 and p=0.003, respectively). On multivariable linear regression analysis, age and EZ disruption were the only factors found to be significantly associated with VA outcome (p<0.001 and p=0.040, respectively), whereas the other variables, including DRIL length, were not significantly correlated with VA outcome. DRIL has only a minor role in determining VA after anti-VEGF treatment in BRVO. Limitations: This was a retrospective and cross-sectional study with a small sample size. Furthermore, the authors did not evaluate changes in DRIL length over time from baseline, because retinal haemorrhage and / or poor-quality OCT images at baseline had made it difficult to evaluate DRIL.

Disorganization of the retinal inner layers after anti-VEGF treatment for macular edema due to branch retinal vein occlusion.
Nakano E, Ota T, Jingami Y, et al.
OPHTHALMOLOGICA
2018;240:229-34.