Pro Re Nata versus treat-and-extend anti-VEGF dosing strategies for the treatment of macular oedema in retinal vein occlusion: 12-month outcomes

Abstract

Purpose : Anti-VEGF injections for macular oedema secondary to branch and central retinal vein occlusions (BRVO, CRVO) can be administered via treat and extend (TE) and pro re nata (PRN) protocols, amongst others. We compared 12 month outcomes from treatment-naïve patients commencing aflibercept therapy on these regimens.

Methods : Retrospective study at the Oxford Eye Hospital, UK. Patients diagnosed with BRVO/CRVO who received aflibercept injections with follow-up of 52 weeks, were identified via electronic medical records. Visual acuity (VA), central subfield thickness (CST), number of hospital visits and injections received at 52 weeks were compared in patients started on PRN treatment in 2018 and TE therapy in 2022.

Results : 166 eyes (165 patients: 82 males, 83 females) were included: 93 eyes (56%) treated with PRN and 73 eyes (44%) with TE aflibercept.

BRVO (PRN n=51; TE n=44):
Baseline VA (PRN: 57±19 ETDRS letters vs. TE: 60±21 letters, p=0.57) and CST (PRN: 485±167µm vs. TE: 448±139µm, p=0.25) were similar. At 52 weeks, VA improved by 12±17 letters in the PRN and 12±18 letters in the TE group, p=0.44. CST improved by 191±186µm in the PRN and 163±135µm in the TE group, p=0.4. Fewer injections were given in the PRN compared to the TE group (6.6±2.1 vs. 8.0±1.5, p<0.01) but total visits were higher in the PRN group (11.2±2.4 vs. 9.5±1.6, p<0.01).

CRVO (PRN n=42; TE n=29):
Baseline VA was similar in both groups (PRN: 49±18 ETDRS letters vs. TE: 48±20 letters, p=0.78). Baseline CST was higher in the PRN than in the TE group (607±236µm vs. 507±140µm, p<0.05). At 52 weeks, VA improved by 8±14 letters in the PRN and 16±16 letters TE group(p<0.05). CST improved by 212±267µm in the PRN and 233±152µm in the TE group, p=0.7. Fewer injections were given in the PRN group (6.8±2 vs. TE: 8.4±1.2, p<0.01), but number of hospital visits was not significantly different (PRN: 11.3±2.3 vs. TE: 10.4±2.1, p=0.09).

Conclusions : PRN and TE regimens are effective in managing macular oedema in BRVO and CRVO. Visual and anatomical outcomes were comparable in BRVO, but VA gain was higher in CRVO patients with a TE regimen in this cohort. The PRN regimen resulted in fewer injections over 12 months, but more frequent hospital visits, which has implications for patients and healthcare resources. Further research is warranted to evaluate the long-term cost implications of these regimens.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.