Outcome measures

In this study, the primary endpoint was median BCVA and CRT 6 months after initiation of treatment, and the secondary endpoint was median BCVA and CRT 12 months after initiation of treatment. BCVA was measured using a standard Japanese Landolt VA chart, and the decimal VA measured was converted to the logarithm of the minimum angle of resolution for statistical analyses. Additional outcomes included the number of IAIs administered until the CRT first decreased below 300 µm, the median number of IAIs administered during the 12 months, and the effects on DR. To evaluate the number of IAIs administered until CRT first decreased below 300 µm, patients for whom CRT never decreased below 300 µm at the time of dropout were classified into a separate group. We investigated whether there was any observable difference in baseline characteristics among groups showing different numbers of IAIs administered until CRT first decreased below 300 µm. DR was evaluated using the Early Treatment Diabetic Retinopathy Study (ETDRS) diabetic retinopathy severity scale (DRSS) score [¹⁴] at baseline and at 6 and 12 months after initiation of treatment. DRSS scores were assigned by two retina specialists (HM and NT). Patients with a history of panretinal photocoagulation were graded as a minimum severity level of 60; such patients may worsen in retinopathy severity but, by definition, cannot improve to severity level less than 60, as reported previously [¹⁵].