Sir,

The article by Ricci et al1 carries several shortcomings that prevent the validation and extrapolation of their results and that can be specifically summarized as follows:

1. Except for the morphological findings of the pigment epithelium detachment (PED) and choroidal neovascularization (CNV) presented in details, there were no data on the other anatomical types of neovascular maculopathy including serous and/or hemorrhagic detachment of the neurosensory retina, retinal hard exudates, subretinal and subretinal pigment epithelium fibrovascular proliferation, and disciform scar.

2. There were relevant baseline differences between the two groups. Thus, patients in the fixed regimen had greater best-corrected visual acuity (BCVA) score (68 vs 63 Early Treatment Diabetic Retinopathy Study (ETDRS) letters), significantly greater central retinal thickness (CRT 480 vs 346 μm), and higher time of CVN diagnosis (22 vs 18 months), than those in the pro re nata (PRN) regimen. Accordingly, a comparison between the two groups of patients seems questionable.

3. In the assessment of the final results of this study, we considered the current assertion that evaluation of the outcomes has to be guided by anatomical measure data with visual changes as a secondary guide.2 Thus, patients in the PRN group lost a median of 3 ETDRS letters and the CRT decreased significantly to a median of 252 μm, a value considered within normal limits.3 In contrast, patients in the fixed regimen gained a median of 3 ETDRS letters and the CRT significantly decreased to a median of 332 μm. Of note, this CRT value is more than the cutoff (315.2 μm) for the upper level of the normal CRT (270±22.5 μm) plus 2 standard deviations.3 We believe that the persistence of this high value of CRT in patients with fixed regimen highlights unresolved macular edema and indicates that the disease process is still active and progressive requiring further treatment with anti-angiogenic agents. The better efficacy of the PRN therapy against the fixed regimen was also substantiated by the greater proportions of the dry macula (58 vs 42%), the greater number of complete PED flattening (3 vs 1), and the smaller number of intravitreal injections (3.5 vs 7).

Altogether, we believe that the results of the PRN strategy in the present study have been better than those achieved in the fixed regimen in terms of visual improvements in switching therapy.