Early Thrombolysis and Outcomes in Central Retinal Artery Occlusion: An Individual Participant Data Meta-Analysis

BACKGROUND: This individual participant data meta-analysis aimed to determine whether time to treatment influences the effect of intraarterial thrombolysis (IAT), intravenous thrombolysis, and conservative standard therapy on visual outcomes in nonarteritic central retinal artery occlusion. METHODS: We searched MEDLINE, CENTRAL, and Embase up to June 2023 for studies reporting treatment modality and peri-treatment best-corrected visual acuity (BCVA) for ≥5 participants, excluding patients with nonsevere vision loss (BCVA <1.0 logarithm of the minimum angle of resolution logMAR) or treated after 24 hours of symptom onset. The primary outcome was recovery from severe vision loss (final BCVA <1.0 logMAR). We used mixed-effect models and local polynomial regression to investigate nonlinear relationships between time to treatment and recovery from severe vision loss. RESULTS: Of 4074 screened studies, individual participant data were sought from 52, with 35 contributing individual participant data for 1038 participants. In total, 783 patients met inclusion criteria (age, 64.8±13.3 years; 35.5% female; baseline BCVA, 2.3±0.5 logMAR). For every hour decrease in time to treatment, thrombolysis was associated with greater improvement in BCVA (intraarterial, 0.02 logMAR 95% CI, 0–0.04; intravenous, 0.04 logMAR 95% CI, 0.00–0.07) than conservative standard therapy (0.01 logMAR 95% CI, 0–0.02). A nonlinear relationship was detected for intraarterial thrombolysis with a changepoint at 8 hours (95% CI, 6.7–9.4). Thrombolysis was associated with increased recovery from severe vision loss compared with conservative standard therapy (intraarterial within 6 hours: odds ratio, 2.72 95% CI, 1.02–7.28, 27.2% versus 12.0%; intravenous within 4.5 hours: odds ratio, 3.32 95% CI, 1.24–8.92, 28.8% versus 11.1%). Findings were consistent in subgroup analysis restricted to patients receiving recombinant tissue-type plasminogen activator. Monte-Carlo simulations showed that a randomized controlled trial would require 95 participants per group to achieve 80% power to detect an odds ratio of 3.0 for recovery from severe vision loss. CONCLUSIONS: Early intervention in nonarteritic central retinal artery occlusion is associated with improvement in visual recovery, with intraarterial thrombolysis and intravenous thrombolysis outperforming nonthrombolytic treatments. These findings warrant confirmation in sufficiently powered randomized controlled trials.