Abstract
Purpose: :
To evaluate the correlation of macular thickness and visual acuity in patients with persistent macular edema.
Methods: :
315 patients with persistent macular edema (>90 days duration) refractory to medical or laser treatment were randomly assigned to observation or treatment with 350 mcg or 700 mcg dexamethasone in a biodegradable drug delivery system (Dex–DDS). Macular edema was assessed using optical coherence tomography (OCT) in one eye of 80 of these patients at baseline and at day 90. Best–corrected visual acuity (BCVA) was measured using the standardized Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Pearson correlation coefficients were calculated to estimate the correlation between macular thickness and BCVA.
Results: :
Of the 80 patients with OCT readings at baseline and at day 90, 44 had diabetic macular edema, 25 had macular edema associated with retinal vein occlusion, and 11 had macular edema associated with uveitis or Irvine–Gass syndrome. At baseline, greater retinal thickness was correlated with worse visual acuity for all 80 eyes (r=0.406, p<0.001) and for the 44 eyes in patients with diabetic macular edema (r=0.369, p=0.014). In eyes treated with 700 mcg Dex–DDS a decrease in macular thickness between baseline and day 90 was correlated with improvement in BCVA over this time period (r=0.530, p=0.009).
Conclusions: :
While the range of visual acuity for any given retinal thickness was large, significant correlations were found between greater retinal thickness and worse visual acuity in eyes with persistent macular edema. Correlations were also found between decreases in macular thickness following corticosteroid therapy and improvement in visual acuity.
Keywords: macula/fovea • corticosteroids • visual acuity