Abstract and Introduction
Abstract
Background The beneficial effect of intravitreal ranibizumab in the treatment of neovascular age-related macula degeneration (nAMD) is well known. Outcome data for eyes presenting with visual acuity better than 6/12 is limited.
Aims To assess the effect of baseline vision on outcome in ranibizumab-treated nAMD eyes, including a subgroup with baseline vision ≥6/12 (<0.30 logmar).
Design Prospective, consecutive and interventional case series.
Methods A consecutive cohort of patients treated with intravitreal ranibizumab for nAMD with 52-week follow-up were studied. Patients who had received previous treatment for nAMD were excluded. Eyes were stratified according to baseline logmar visual acuity into four groups: <0.30 (>6/12), 0.30–0.59 (6/12–6/24), 0.60–0.99 (6/24–6/60) and 1.00–1.20 (6/60–6/96). Intravitreal ranibizumab (0.5 mg in 0.05 ml) was administered in three loading monthly doses followed by PRN dosing according to optical coherence tomography (OCT) findings.
Results A total of 615 eyes were studied including 88 eyes with baseline vision <0.30. The mean change in logmar letters at 52 weeks was +5.5 (entire study group), −0.5 (<0.30 subgroup), +2.2 (0.30–0.59 subgroup), +6.5 (0.60–0.99 subgroup) and +15.3 (1.00–1.20 subgroup). In the <0.30 subgroup, 60 of 88 eyes (68%) had best-corrected visual acuity (BCVA) equal to or better than baseline and 82 of 88 eyes (93%) lost <15 letters at 52 weeks. Within this subgroup 56 of 67 eyes (84%) maintained UK driving standard BCVA visual acuity over the study period.
Conclusions This study provides evidence that intravitreal ranibizumab treatment stabilises good vision in nAMD presenting with vision better than 6/12 over 52 weeks follow-up.
Introduction
Age-related macular degeneration (AMD) is the leading cause of permanent visual impairment in the developed world, accounting for over half of blind and partial sight registrations in those over 50 years in the United Kingdom. Neovascular AMD (nAMD) rapidly progresses, if untreated, leading to irreversible central vision loss within 3 months and significant economic consequences.
Intravitreal ranibizumab (Lucentis, Novartis Pharma AG, Basel, Switzerland; Genetech Inc., San Francisco, CA, USA) is a recombinant, humanised, monoclonal Fab antibody fragment, which inhibits all VEGF-A isoforms and is currently the standard treatment for nAMD in the United Kingdom. It has been found to improve visual acuity by at least 15 letters in one-third of patients and prevent visual loss of at least 15 letters in 90% of cases, after 2 years of monthly intravitreal injections.
Outcome data for ranibizumab in nAMD has until recently been limited to baseline best-corrected visual acuities (BCVAs) between 6/12 and 6/96 due to the inclusion criteria of the major clinical trials. As baseline vision was not a limiting factor for outcome in these studies and all baseline vision subgroups benefited from ranibizumab, a favourable response could also be expected for eyes with baseline BCVA better than 6/12. This subgroup has the potential to maintain vision for driving and reading.
The CATT study is the first large-scale multicentre trial to include eyes with baseline BCVA better than 6/12 (inclusion criteria 20/25–20/320 (6/7.5–6/96)). However, outcome for this specific group of eyes with the best baseline BCVA was not specifically addressed.
Published data for eyes with better that 6/12 vision is limited to a small retrospective case series of 14 eyes by Raja et al, which found an improvement in mean logmar vision from 0.18 to 0.13 after a 12-month follow-up with a mean 7.5 injections. All but one maintained vision over the same period.
The Royal College of Ophthalmologists AMD guidelines recommend intravitreal ranibizumab treatment for active nAMD, if baseline BCVA is equal to or better than 6/96. However, clinical practice varies throughout the United Kingdom. In England, NHS funding is typically based on the National Institute for Health and Clinical Excellence (NICE) 2008 guidelines, which uses the 6/12 to 6/96 baseline vision range used in clinical trials. In Wales, Welsh Assembly Government funding is possible if a Consultant Retinal Ophthalmologist recommends treatment. This clinical decision is based on the Royal College of Ophthalmologists guidelines and thus includes eyes with baseline vision above 6/12.
We report the effect of baseline BCVA on the outcome in ranibizumab treatment of nAMD in the South East Wales with particular focus on eyes with baseline BCVA above 6/12.