Individualized treat-and-extend regime for optimization of real-world vision outcome and improved patients' persistence

Abstract

Background: Intravitreal injections are a mandatory treatment for macular edema due to nAMD, DME and RVO. These chronic diseases usually need chronic treatment using intravitreal injections with anti-VEGF agents. Thus, many trials were performed to define the best treatment interval using pro re nata regimes (PRN), fixed regimes or treat-and-extend regimes (TE). However, real-world studies reveal a high rate of losing patients within a 2-year interval of treatment observation causing worse results. In this study we analyzed retrospectively 2 years of real-world experience with an individualized treat-and-extend injection scheme.

Methods: Since 2015 our treatment scheme for intravitreal injections has been switched from PRN to TE. Out of 102 patients 59 completed a follow up time of 2 years. Every patient received visual acuity testing, SD-OCT and slit lamp examination prior to every injection. At each visit an injection was performed and the treatment interval was adjusted mainly on SD-OCT based morphologic changes by increasing or reducing in 2-week steps. Individual changes of the treatment protocol by face-to-face communication between physician and patient were possible.

Results: After 1 year of treatment visual acuity gain in nAMD was 7.4 ± 2.2 ETDRS letters (n = 34; injection frequency: 7.4 ± 0.4) respectively 6.1 ± 4.7 in DME (n = 9; injection frequency: 8.4 ± 1.1) and 9.7 ± 4.5 in RVO (n = 16; injection frequency: 7.6 ± 0.5). After 2 years of treatment results were as following: nAMD: visual acuity gain 6.9 ± 2.1 (injection frequency: 12.6 ± 0.7); DME: 11.1 ± 5.1 (injection frequency: 14.0 ± 1.0); RVO: 7.5 ± 5.0 (injection frequency: 11.2 ± 0.9). Planned treatment exit after 2 year was achieved in 29.4% of patients in nAMD (0% after 1 year); 0% in DME (0% after 1 year); and 31.3% in RVO (0% after 1 year). Patients' persistence was 94.1% during the follow-up.

Conclusion: Using a consequent and individualized TE regime in daily practice may lead to a high patients' persistence and visual acuity gains nearly comparable to those of large prospective clinical trials. Crucial factors are face-to-face communication with the patient as well as a stringent management regime. At this time TE may be the only instrument for proactive therapy which should therefore be regarded as a first-line tool in daily practice.

Keywords: Anti-VEGF; Intravitreal injection; Macular edema; PRN; TE; Treatment strategies.

Fig. 1

Injections per year and gain in visual acuity per year for (a) nAMD, b DME and c RVO and baseline as well as (d) end-ETDRS letters. [injections] = numbers, [visual acuity] = amount of EDTRS-letter-increase. Data are mean ± SEM. nAMD n = 34, DME n = 9, RVO n = 16

Fig. 2

Injection interval per disease in percent of all injections for that disease. [injections] = numbers. Data are total injection numbers. nAMD n = 34, DME n = 9, RVO n = 16

Fig. 3

TE injection scheme in RVO (baseline visual acuity 0.1): a) baseline and 1st injection. b) dry macula after first injection, extend possible but postponed in shared decision making with the patient. c) dry macula, now extension of intervals to enable a personalized regime. d) dry macula, further extension. e) dry macula, further extension. f) new fluid after extension to 10-week interval, 6th injection and fallback to last stable interval (8 weeks). g) dry macula after 8 weeks, new attempt for 10-week interval extension. h) dry macula 10 weeks after last injection, attempt to extend to 12 weeks. In total, eight injections were needed in the first year and a stable visual acuity gain to 0.5 was maintained