We have recently reported in the LIRE study that long dosing intervals ≥ Q12W were achieved in a real-life setting in 38% of eyes treated for exudative AMD (16). Here, we focused on the other extreme, i.e. short intervals in a real-life setting, by defining an intensive treatment profile (first year of treatment without achieving a Q8W dosing interval) and analyzing the outcomes. In our cohort, a quarter of our exudative AMD patients received intensive treatment according to a T&E regimen in the first year. This finding is consistent with the results of the ALTAIR study (30%) [17] and those of a recent real-life study of the Fight Retinal Blindness (FRB) registry based on European data showing a rate of intensively treated patients of 25%, although the definitions of intensive treatment may vary. Boudousq et al had defined intensive treatment as patients maintaining a mean dosing interval of Q6W after more than 2 years of treatment [18], whereas in our study we chose the criterion < Q8W during the first year of therapeutic management. Despite this, we found the same rate. This could be explained by changes in the injection profiles we analyzed, showing that less than half of these intensively treated patients (44%) were able to achieve the > Q8W dosing interval, but only after a very long mean time of 4.5 years of intensive treatment. This long time could be explained by the slow change in neovascular membrane, which was initially very active and eventually became fibrosed over time.
This rate of 25% of intensively treated patients therefore accounts for a non-negligible proportion of suboptimally treated patients, also referred to in the literature as poor responders, or even "recurrent" or "recalcitrant" patients [19, 20]. They largely contribute to the unmet needs currently under discussion. The use of new molecules could reduce this rate. Pivotal studies assessing treatment regimens sometimes limited to a minimum Q8W threshold can only partially answer this question, and new real-life studies are needed to improve our knowledge.
Regarding baseline characteristics, the mean age of our intensively treated cohort was 84.3 ± 7.5 years, which is higher than that of patients in other French studies such as the GEFAL study (79 years) [21], but closer to that reported in the Landscape study (81 years). In our study, there was a clear male predominance with 67% of men, whereas we have recently reported the opposite with a female predominance (67%) in the French Landscape epidemiological study [22].
The VA remained stable or even improved in the long term after 5 years of treatment, confirming the efficacy of anti-VEGF therapy, even in this very specific profile of intensively treated patients. Due to the aggressiveness of neovascular membrane activity, poorer functional outcomes could have been expected. This is therefore a positive message for our intensively treated patients.
We could also highlight a better VA in group 2 (< Q8W dosing interval). This could be explained by the lower rate of atrophy, as well as by the high frequency of intravitreal injections and patient adherence. The mean follow-up duration was longer for group 1 than for group 2 (7.4 and 4.2 years, respectively), and we compensated for this bias by analyzing the VA and anatomical criteria at fixed timepoints (2, 3, 4 and 5 years).
We also investigated the impact of the CNV type. Initially intensively treated eyes with type 1 CNV were more likely to remain intensively treated in subsequent years.
Regarding anatomical biomarkers, only the SRF height was really impacted by intensive treatment, with a significant drop from the first year of treatment. Conversely, the PED height and the CRT remained fairly stable and unchanged from the second year of treatment.
The persistence of IRF over time, found in about 70% of our patients, could explain why the CRT did not decrease, although SRF resorbed. Exudative signs persisted 4 weeks after an intravitreal injection in 33% of anti-VEGF-treated AMD patients in a recent Greek study, highlighting the existence of poor responders to anti-VEGF [23]. In our study, this rate was higher, since we only analyzed poor responders. We observed that the eyes of group 1 had significantly less fluid than the persistent eyes of group 2, showing a better response, albeit partial, and suggesting their potential future fluid extent.
The distribution of CVN in our study also showed a predominance of type 1 CVN, found in 64% of the whole cohort, and in 78.6% of eyes with persistent intensive treatment. This is consistent with the results reported by Mathis et al, indicating that type 1 CNV required more intensive treatment with anti-VEGF intravitreal injections than other CNV types [24], and were also associated with less atrophy [25]. The distribution of type 2 CVN was also very uneven, predominating in eyes of group 1 (45.5% versus 16.7%), which could explain the greater progression of macular atrophy observed (associated with type 2 CNV), but also the poorer functional prognosis. The area of atrophic patches increases over time, and this evolution is well known as a factor limiting the long-term visual prognosis [26, 27].
Regarding dosing intervals, in group 1, the mean maximum dosing interval was 13 weeks. Furthermore, at the last follow-up visit, it was interesting to note that two thirds of the eyes achieved a ≥ Q12W dosing interval (40% at Q12W, and 27% at ≥ Q14W).
These results showed the emergence of 2 almost equally represented profiles among intensively treated patients: those whose regimen remained persistent, and those who were able to switch to longer dosing intervals, even if this lengthening was achieved late. The VA maintained at 5 years was another very good sign, as it is an important information to provide to our intensively treated patients, to encourage them to continue injections and maintain their adherence.
In the future, these results could be further improved by the advent of two new molecules, faricimab and brolucizumab, as well as the new 8mg dosage of aflibercept. The HAWK and HARRIER studies have indeed shown an anatomical superiority of brolucizumab over aflibercept 2 mg, but it is especially important to note that there is also a 50% reduction in poor responders with this new anti-VEGF [28]. The TENAYA and LUCERNE studies assessing faricimab have reported the efficacy of this multi-target molecule over long Q16W dosing intervals, although 21% of patients maintained a Q8W interval at 2 years. While these results are encouraging, they highlight the fact that some patients would still require intensive treatment [29]. Regarding the new dosage of aflibercept 8 mg, the PULSAR study has reported that 17% of patients maintained a Q8W dosing interval after 48 weeks [30, 31]. Real-life studies are needed to obtain additional results, overcoming the Q8W thresholds of pivotal studies.
Finally, 10% of these patients experienced a macular hematoma at 5 years, despite active treatment. Boudousq et al. have recently reported a lower incidence of 4% at 10 years. Matsunaga et al have also reported that the occurrence of macular hematoma was not related to the extent of injection intervals but rather resulted from mechanical stress on the neovascular membrane [32]. In our cohort, hematomas occurred early: more than 60% during the first year of treatment and 40% during the second year. They were thus more common than in the FRB series (incidence of 1% and 1.6% respectively after 10 and 20 intravitreal injections). They could thus reflect the level of neovascular membrane activity, which was aggressive in our cohort.
This study has some limitations, including its retrospective, monocentric design and its small sample size, with only 75 eyes studied. It nevertheless presents long-term results (up to more than 10 years) under a T&E regimen, a rarely reported dosing interval follow-up, and only complete cases were included. The literature data available on the 5-year outcome of these intensively treated patients is limited. This cohort allowed identifying two profiles among intensively treated patients: patients whose dosing interval could be extended late, and patients whose intensive treatment persisted (elderly men with predominantly type 1 CNV and significant PED at baseline). The important message for patients remains the good visual prognosis, since the VA was maintained or even improved at 5 years with this sustained injection interval.