gms | German Medical Science

Background: Visual acuity (VA) can be preserved by 4-weekly intravitreal injections (IVI) of ranibizumab over >2 years (yrs). The CATT-trial showed that a PRN (pro re nata) treatment (TX) based on a monthly follow up (FU) is not inferior to a monthly IVI TX. In Germany, most insurance companies do not reimburse a monthly FU based on OCT. However, a PRN-TX based on visual acuity (VA) changes rather than OCT changes has less favourable results. The aim of this study is to investigate the long term development of wet AMD under real life conditions.

Methods: Retrospective analysis of 77 patients with wet AMD, initially treated with either 3 IVI of bevacizumab (1.5mg) or ranibizumab (0.5 mg), followed by PRN-IVI. Main outcome parameters were the VA change after a follow up (FU) of >4 yrs, the total number of IVI needed and the frequency of IVI in the 1^st, 2^nd , 3^rd and 4^th yr of TX.

Results: 88 eyes (77 patients) had a FU of >4 yrs. Mean FU time was 4.33 yrs. 12.6±7.3 IVI were performed within the FU-time. Mean no. of IVIs in 1^st yr was 4.6±1.5 (median 4.5, range 3–8), in 2^nd year 2.8±2.2 (median 3, range 0-8), in 3^rd yr 2.7±2.5 (median 3, range 0–10) and in 4^th yr 2.2±2.8 (median 0, range 0–10), and beyond 4^th year 2.27±2.72 (median 1, range 0–9). 51/88 (58%) required 3 or more IVIs in yr 3, and 37/88 (42%) in yr 4 (Fig. 5). No significant increase of VA could be registered, as compared to a strict monthly OCT guided monitoring system. At least, VA remained stable over 2 yrs (LogMAR 0,64 at baseline, at 2 yrs 0.68), but then deteriorated to 0.84 at 4yrs. Patients younger than 78 yrs (mean 70.4±6.8 yrs) had a better baseline VA (LogMAR 0,54) and a better final VA (LogMAR 0,76) at 4 yrs than those older than 77 (mean 82,4±3.1 yrs, baseline VA 0.73, at 4 yrs 0.92).

Conclusions: As in Germany neither monthly injections nor a monthly FU, based on OCT, was reimbursed by most insurance companies, our results based on a VA guided PRN TX were inferior to a TX based on monthly OCT guided FU at 2 yrs (as performed in the CATT-trial). Younger patients have a more favourable outcome of VA after a 4 yr TX of wet AMD. In both age groups, those younger and those older than 78 years, we noted a drop of VA in the 3^rd year of follow up, indicating that the timing of intervention was less strict than within the first two years of follow up. As a significant part of the patients require 3+ IVIs even in yr 3 and 4, we have to realize, that a close (monthly) monitoring is still necessary beyond two years of TX, possibly for the whole life, for a successful PRN-TX.