Treatment Outcome of Wet Age-Related Macular Degeneration Management in Thailand: A Retrospective Real-World Study (TOWER Study)

Abstract

Introduction: To present real-world outcomes of neovascular age-related macular degeneration (nAMD) management in Thailand.

Methods: This multicenter retrospective study reviewed medical records of naive nAMD patients diagnosed from 1 January 2016 until 31 December 2018. The patients received at least one intravitreal anti-vascular endothelial growth factor (VEGF) treatment and had captured visual acuity (VA) at baseline and at month 12. Treatment outcomes were assessed at month 12, 24, and 36. The primary outcome was a mean change in VA from baseline to month 12.

Results: Five hundred seventy-two (572) eyes were included in this study and of these eyes, 222 and 96 had 2- and 3-year follow-up periods, respectively. At month 12, the mean improvement of VA (ETDRS letter) was six letters (P < 0.0001), and central retinal thickness (CRT) decreased on average by 104 microns (P < 0.0001). However, visual improvement by 0.1 letters at month 36 did not show statistical significance. The presence of fluid was found in approximately half of patients throughout the study period (45.98%, 48.85%, and 50.91% at month 12, 24, and 36, respectively). Mean number of injections (SD) was 6.06 (3.00), 3.44 (2.94), and 2.71 (3.07) for years 1, 2, and 3, respectively. The mean number of visits (SD) in year 1 was 9.01 (2.60) and declined to 5.67 (2.69) in year 2 and 4.93 (2.49) in year 3. Patients who had an average injection interval of ≤ 8 weeks were 74.46% in year 1, 51.28% in year 2, and 45.24 in year 3; 35.31% of patients were lost to follow-up.

Conclusions: This analysis reflects real-world nAMD management with significant improvement of outcomes. At the same time, the study reveals unmet needs in anti-VEGF therapy in nAMD including persistent disease activities, inadequacy of available treatment, and lack of treatment adherence leading to visual deterioration in the long-term.

Keywords: Aflibercept; Anti-VEGF; Bevacizumab; Neovascular age-related macular degeneration; Ranibizumab; Real-world study; nAMD.

Fig. 1

Patient disposition in this cohort study

Fig. 2

Number of patients enrolled and lost to follow-up from 1 to 36 months. Green bars show time of enrollment by month. Gray bars show the number of lost follow-up cases defined as patients who had a follow-up period for < 3 years and lack of follow-up visit for > 6 months prior to the end of the study

Fig. 3

Mean visual acuity (VA) (ETDRS letter) from baseline to month 36 stratified by treatment intensity. High intensity is shown in blue, low intensity in red, and total in green. Data are represented as mean VA with 95% confidential interval (CI). Significance: P ≤ 0.05

Fig. 4

Mean central retinal thickness (CRT) from baseline to month 36 stratified by treatment intensity. High intensity is shown in blue, low intensity in red, and total in green. Data are represented as mean CRT in microns (μm) with 95% confidential interval (CI)

Fig. 5

Mean change in central retinal thickness (CRT) from baseline to month 36 stratified by treatment intensity. High intensity is shown in blue, low intensity in red, and total in green. Data are represented as mean CRT in microns (μm) with 95% confidential interval (CI). Significance: P ≤ 0.05. The mean change with 95% CI was calculated based on generalized estimating equations (GEEs)

Fig. 6

Presence of disease activity at years 1, 2, and 3. Data are represented as the percentage (%) of patients with disease activity in low-intensity group, high-intensity group, and total

Fig. 7

Mean injection interval at years 1, 2, and 3. Data are represented as the percentage (%) of patients in each of the five different time intervals within each year