Abstract
Purpose:
To investigate the relationships between baseline HbA1c quartiles and change in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline to week 52 in DME patients, and to determine if these relationships are treatment-group dependent.
Methods:
VISTA and VIVID randomized 872 patients to compare efficacy and safety of IAI with laser for DME. Sub-analyses focused on comparison within each treatment group: laser and IAI (2 mg q4 weeks [2q4] and 2 mg q8 weeks following 5 monthly doses [2q8] groups combined). HbA1c was partitioned by quartiles (Q1: 4.5%-<6.7%; Q2: 6.7%-<7.4%; Q3: 7.4%-<8.6%, and Q4: 8.6%-14.7%) using all data available at baseline. Repeated measures models were used to report summary measures; least square means are reported.
Results:
Age, BCVA, and CRT were similar among quartiles at baseline. In the IAI group, the adjusted mean BCVA changes from baseline to week 52 were 11.7, 11.9, 11.7, and 11.1 letters in Q1 through Q4; the mean changes were independent of quartiles. In the laser group, the corresponding adjusted mean changes in BCVA were 4.1, 1.9, 0.8 and -0.3 letters in Q1 through Q4, and decreasing changes in BCVA were associated with increasing HbA1c levels (P< 0.05). For CRT, the corresponding decreases at week 52 were -201, -196, -195, and -188 mm in the IAI group, and -102, -83, -69 and -43 mm in the laser group. No association between changes in CRT and HbA1c was observed in the IAI group whereas decreasing changes in CRT were associated with increases in HbA1c in the laser group. Similar findings for both BCVA and CRT changes were observed at week 100 for IAI and laser. The most frequent ocular serious adverse event in a pooled analysis of the VISTA and VIVID studies was cataract (2.4%, 1.0%, and 0.3% for 2q4, 2q8, and laser).
Conclusions:
In eyes treated with laser, higher baseline HbA1c levels correlated with decrease in visual and anatomic outcomes. In eyes treated with IAI, there was no apparent correlation between increasing baseline HbA1c levels and visual or anatomic outcomes.