Acute effects of intravitreal aflibercept injections on intraocular pressure in vitrectomized and silicone-oil-filled eyes (NH_SiOP)

Study type

• Study topic:
  Medical procedure
• Study type:
  Clinical trial
• Scope of the study:
  Safety study (incl. comparative)
• Data collection methods:
  Primary data collection

Clinical trials

• Clinical trial regulatory scope:
  Post-authorisation interventional clinical trial
• Clinical trial phase:
  Therapeutic use (Phase IV)
• Clinical trial randomisation:
  Non-randomised clinical trial
• Clinical trial types:
  Pragmatic clinical trial

Study drug and medical condition

• Medicinal product name:
  EYLEA
• Study drug International non-proprietary name (INN) or common name:
  AFLIBERCEPT
• Anatomical Therapeutic Chemical (ATC) code:
  (S01LA05) aflibercept

  aflibercept
• Medical condition to be studied:
  Macular oedema

  Retinal vein occlusion

  Neovascular age-related macular degeneration

  Vitrectomy

Population studied

• Short description of the study population:
  Patients requiring intravitreal aflibercept are enrolled in one of the three study arms and analyzed. The G-SiO group includes previously vitrectomized eyes that had undergone silicone oil (SiO) tamponade. The G-PPV group consists of previously vitrectomized eyes with 23G pars plana vitrectomy (PPV) surgery performed more than 3 months before enrollment, did not have SiO tamponade, or had undergone prior SiO tamponade. The G-NVIT group includes eyes with intact vitreous bodies. Being treatment-naïve to intravitreal injections is not a prerequisite for participating in the trial, whereas all participants’ eyes are to be treatment-naïve to antiglaucoma medications (not even temporary IOP lowering treatment was administered following SiO implantation or PPV surgery) and should have no signs of glaucomatous optic nerve disease. Patients were of Caucasian ancestry and ≥18 years of age.
• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Estimated number of subjects:
  51

Study design details

• Study design:
  This study is designed as a prospective, single-center, single-blind interventional cohort trial. Patients requiring intravitreal aflibercept were enrolled in one of the three study arms (silicone oil, vitrectomized or unaltered) and analyzed.
• Main study objective:
  To assess and compare acute intraocular pressure (IOP) changes following intravitreal aflibercept injections in vitrectomized eyes with and without silicone oil tamponade and in nonvitrectomized eyes.
• Setting:
  Patients requiring intravitreal aflibercept are enrolled in one of the three study arms at the Department of Ophthalmology, University of Szeged, Hungary, between March 2022 and February 2025. The G-SiO group included previously vitrectomized eyes that had undergone silicone oil (SiO) tamponade. The G-PPV group consisted of previously vitrectomized eyes with 23G pars plana vitrectomy (PPV) surgery performed more than 3 months before enrollment, did not have SiO tamponade, or had undergone prior SiO tamponade. The G-NVIT group included eyes with intact vitreous bodies.
• Interventions:
  Intraocular pressuse (IOP) was evaluated before and immediately after intravitreal aflibercept injection and at 5, 15, 30, 60, and 180 min, day 1, and week 1 postinjection. IOP measurements were taken with iCare-100 rebound tonometry (RBT) and Goldmann applanation tonometry (GAT) in the seated position sequentially.
• Comparators:
  No comparator drug was used
• Data analysis plan:
  Sample size estimation was based on a two-way repeated-measures ANOVA (between-groups within-time interaction), assuming a standardized effect size of f = 0.25 (medium), 3 independent groups, 9 repeated measurements, power = 95%, α = 0.05, correlation among measures = 0.40, and a Greenhouse–Geisser ε = 0.50. The minimum required sample size was 51 patients, computed in G*Power 3.1.9.7.; Continuous data were expressed as mean ± standard deviation (SD) or median (first quartile [Q1] and third quartile [Q3]) for symmetrical or skewed distributions, respectively. Categorical data were expressed as the number of cases (frequencies) or percentages (relative frequencies). ; The relationships between the categorical variables were investigated by the Chi-squared test for independence.; Continuous variables in the three cohorts were compared with the one-way analysis of variance (ANOVA), Welch ANOVA, or Kruskal–Wallis test for symmetrical or skewed distributions, respectively. Post hoc comparisons for Welch ANOVA were conducted by Games–Howell tests.; IOP was analyzed with a linear mixed-effects model including fixed effects for group (vitreous status), time, and their interaction. Patient clustering was modeled with a random intercept, and within-eye repeated measurements. Estimated marginal means for group (vitreous status) at different timepoints were obtained and Bonferroni-adjusted between-group comparisons at each time point were performed. This specification accommodates unequal variances over time, serial correlation within eyes, and patient-level clustering.; IOP levels at all timepoints with respect to all examined parameters such as age, sex, AL, ACD, CCT, lens, and angle status were analyzed also with a linear mixed-effects model.; The agreement between GAT and RBT was analyzed with the Bland–Altman method; Calculations were conducted using IBM SPSS Statistics version 29.0.0.0 (241). P-values <0.05 were regarded as significant.