Anatomic Biomarkers of Macular Edema Associated with Retinal Vein Occlusion

Abstract

Purpose: To assess the relationship between best-corrected visual acuity (BCVA) and anatomic features in patients with macular edema (ME) related to retinal vein occlusion (RVO).

Design: Post hoc analysis of 3 clinical trials, which included verified diagnoses, protocol refractions, and the assessment of OCT and fluorescein angiography (FA) images at a masked reading center.

Participants: Patients diagnosed with RVO-ME.

Methods: Correlation analyses were performed to determine the correlation between BCVA and macular anatomy at baseline and at 12 and 24 weeks and between changes from baseline to 12 and 24 weeks.

Main outcome measures: The correlations between BCVA and central subfield thickness (CST), ellipsoid zone (EZ) integrity, intraretinal fluid (IRF), subretinal fluid, central leakage, and ischemia were assessed.

Results: In a total of 828 eyes with RVO-ME, the mean age, BCVA, and CST at baseline was 64.7 years, 51.1 letters, and 656.9 μm, respectively. At baseline, a moderate negative correlation was observed between BCVA and CST (r = - 0.56, P < 0.001). At weeks 12 and 24, the mean BCVA of eyes with definitely abnormal (absent) EZ was statistically significantly worse than that of eyes with normal EZ. At week 12, a moderate negative correlation was observed between changes in BCVA and changes in CST (r = - 0.35, P < 0.001), with a similar degree of association noted at week 24 (r = - 0.35, P < 0.001). At weeks 12 and 24, eyes that showed any improvement in central IRF showed a greater improvement in BCVA than eyes that showed no improvement worsening (week 12: 463 eyes, 18.3 letters vs. 177 eyes, 13.0 letters, respectively, P < 0.001) and (week 24: 332 eyes, 20.2 letters vs. 131 eyes, 13.3 letters, respectively, P < 0.001). With respect to the correlation between baseline BCVA and fluorescein leakage or capillary nonperfusion, the Pearson correlation coefficients were - 0.41 (P < 0.001) and - 0.16 (P = 0.060), respectively.

Conclusions: In addition to CST, there are important clinically relevant relationships between BCVA and both OCT and FA anatomic features in patients with RVO-ME.

Keywords: Central subfield thickness; Macular edema; Retinal vein occlusion; Visual acuity.

Figure 1.

Scatterplots showing retinal vein occlusion. A, Central subfield retinal thickness and ETDRS best-corrected visual acuity (BCVA) at baseline. B, Presence and location of intraretinal fluid and ETDRS BCVA at baseline. C, Presence and location of subretinal fluid and ETDRS BCVA at baseline. D, Area of fluorescein leakage and ETDRS BCVA at baseline. E, Area of capillary nonperfusion and ETDRS BCVA at baseline. Linear regression lines (solid) are plotted along with lines (dashed) outlining 95% confidence intervals for mean predicted values.

Figure 2.

Scatterplots showing retinal vein occlusion. A, Baseline central subfield retinal thickness and change in ETDRS best-corrected visual acuity (BCVA) from baseline to week 24. B, Presence and location of intraretinal fluid at baseline and change in ETDRS BCVA from baseline to week 24. C, Presence and location of subretinal fluid at baseline and change in ETDRS BCVA from baseline to week 24. D, Baseline area of fluorescein leakage and change in ETDRS BCVA from baseline to week 24. E, Baseline area of capillary nonperfusion and change in ETDRS BCVA from baseline to week 24. Linear regression lines (solid) are plotted along with lines (dashed) outlining 95% confidence intervals for mean predicted values.

Figure 3.

Scatterplots showing retinal vein occlusion. A, Change in central subheld retinal thickness and ETDRS best-corrected visual acuity (BCVA) from baseline to week 24. B, Change in the presence and location of intraretinal fluid and ETDRS BCVA from baseline to week 24. C, Change in the presence and location of subretinal fluid and ETDRS BCVA from baseline to week 24. D, Change in the area of fluorescein leakage and ETDRS BCVA from baseline to week 24. E, Change in the area of capillary nonperfusion and ETDRS BCVA from baseline to week 24. Linear regression lines (solid) are plotted along with lines (dashed) outlining 95% confidence intervals for mean predicted values.

Figure 4.

Scatterplots showing retinal vein occlusion. Ellipsoid zone integrity and ETDRS best-corrected visual acuity (BCVA) at week 12 (A) and week 24 (B).