Real-world outcomes for pro re nata and treat and extend regimens in exudative age-related macular degeneration

Abstract

Purpose : Evidence suggests visual outcomes in exudative age-related macular degeneration (exAMD) are better with treat and extend (TEX) than pro re nata (PRN) protocols. This has not been shown in real-world data and TEX is thought to demand more clinical resources than PRN. This is problematic as the Royal College of Ophthalmologists reports more than 200 vacant UK consultant ophthalmologist posts. We aim to establish if there is value in recommending TEX, to justify stretching resources further.

Methods : Our observational study was performed at a tertiary unit in England. The electronic medical record (EMR) identified patients receiving aflibercept intravitreal injections (IVIs) for exAMD from 2016 with three years of follow up.
Visual acuity (VA) was recorded as the best corrected vision in early treatment of diabetic retinopathy (ETDRS) letters.
A year of treatment was said to be PRN if ‘PRN’ was explicitly reported in any visit in that year. Descriptive and comparative statistics were performed with SPSS v.24. Unpaired t-tests were used to compare means between PRN and TEX groups.

Results : 175 eyes (89 left, 87% pseudophakic) from 175 patients (109 female, mean age 79.1 years) were identified with 80 eyes (44.9%) receiving PRN treatment in their second year of treatment and 68 eyes (38.2%) in their third year. PRN eyes had significantly fewer IVIs (p<0.0001) than those purely under the TEX regimen in their second (mean IVIs 3.9 (95%CI 3.6,4.2) versus 6.3 (5.9,6.6)) and third years of treatment (mean IVIs 4.5 (4.0,5.0) versus 6.0 (5.7,6.3)). The number of visits to clinic did not differ significantly between the PRN or TEX groups in the second (6.7 (6.3,7.0) and 6.1 (5.6,6.6) mean visits per year respectively (p=0.077)) year of treatment, but met an unadjusted threshold for significance in the third year of treatment (7.0 (6.5,7.4) and 6.2 (5.8,6.7) mean visits per year respectively (p=0.018)). Change in VA was equivocal between the two treatment groups in the second (p=0.19) and third year (p=0.98).

Conclusions : These data suggest that a PRN approach offers equivocal visual outcomes to TEX for exAMD patients, whilst imposing significantly fewer IVIs on patients. The burden on clinic appointments between the two regimens is comparable, but PRN’s advantages could be realised if disease monitoring was moved to primary care.

This is a 2021 ARVO Annual Meeting abstract.