{
  "abstract": "Purpose\n\nTo evaluate aqueous humor concentrations of nepafenac following topical administration of 0.3% and 0.1% formulations, to assess the influence of timing of instillation on intraocular exposure.Methods\n\nAqueous humor samples collected during anterior segment surgery were analyzed. Nepafenac concentrations were quantified in 151 samples (0.3% instilled once daily: n = 73; 0.1% instilled three times daily: n = 78). Amfenac was quantified only in the nepafenac 0.3% group (n = 73), owing to the stepwise validation of the analytical method (see Limitations). Due to right-skewed distributions, concentrations were summarized as median (IQR) and geometric mean with 95% confidence intervals Mann-Whitney U test and Spearman's rank correlation coefficient were applied. Postoperative optical coherence tomography was performed at 1, 2, and 3 months to assess the occurrence of Irvine-Gass syndrome.Results\n\nGeometric mean nepafenac concentrations were 22.13 nM (95% CI 15.85-30.91) for 0.3% and 21.73 nM (95% CI 13.29-35.53) for 0.1% (p = 0.319). Within the 0.1% group, instillation timing significantly influenced concentrations (p < 0.001), with markedly higher levels approximately 30-60 min after instillation compared with the 10-12 h subgroup. Amfenac correlated with nepafenac (ρ = 0.56, p < 0.001). No cases of clinically evident Irvine-Gass syndrome were observed.Conclusion\n\nNo cases of clinically evident Irvine-Gass syndrome were observed; however, the study was not powered or designed to assess clinical efficacy. Timing of instillation is a major determinant of aqueous humor nepafenac concentrations. Preoperative instillation shortly before surgery may optimize intraoperative drug availability and support maintenance of mydriasis. Standardized sampling is essential for robust pharmacokinetic comparisons.",
  "abstract_shown": true,
  "affiliations": [
    "IRCCS AOM Azienda Ospedaliera Metropolitana - Ospedale Policlinico San Martino, Genoa, Italy.",
    "Department of Experimental Medicine (DIMES), University of Genoa, Genoa, Italy.",
    "Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy.",
    "Department of Internal Medicine (DIMI), Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Angelo Macri"
    },
    {
      "affs": [
        1
      ],
      "name": "Annalisa Salis"
    },
    {
      "affs": [
        2
      ],
      "name": "Margherita Tarallo"
    },
    {
      "affs": [
        2
      ],
      "name": "Michele Iester"
    },
    {
      "affs": [
        1
      ],
      "name": "Gianluca Damonte"
    },
    {
      "affs": [
        3
      ],
      "name": "Francesca Mattioli"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9j2jfdx9yzffe.bib",
  "cited_by": 0,
  "doi": "10.3389/fmolb.2026.1913752",
  "fulltext_url": "https://europepmc.org/articles/PMC13677355",
  "id": "9j2jfdx9yzffe",
  "issns": [
    "2296-889X"
  ],
  "landing_url": "https://europepmc.org/article/MED/42898129",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2731|Ocular Infections and Treatments"
    ]
  ],
  "openalex": "W7219867973",
  "pdf_url": "https://europepmc.org/articles/PMC13677355?pdf=render",
  "pmcid": "PMC13677355",
  "pmid": "42898129",
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9j2jfdx9yzffe.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:37Z",
      "native_id": "MED:42898129",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42898129"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "journal-openalex:1312|Protein Structure and Dynamics",
      "subfield": "molecular-biology"
    }
  ],
  "title": "Instillation timing as the main determinant of aqueous humor nepafenac exposure.",
  "title_text": "Instillation timing as the main determinant of aqueous humor nepafenac exposure.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:37Z",
  "url": "https://research.draconitic.com/paper/9j2jfdx9yzffe",
  "venue": "Frontiers in molecular biosciences",
  "versions": []
}