Evidence map›Paper›PMID 41661511›Full record

ArticleDrug delivery and translational research2026

A gel-forming antioxidant eye drop for photoreceptor protection in retinitis pigmentosa.

Matthew B Appell, Yogita Kanan, Kiersten Malmberg, Tejaswini Appidi, Mahmood Khan, Peter A Campochiaro, Laura M Ensign

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Drug delivery and translational research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Emerging ophthalmic drug delivery.Drug delivery and translational research · 2026
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Matthew B AppellThe Center for Nanomedicine, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N Broadway, Baltimore, MD, 21231, USA.
Yogita KananThe Center for Nanomedicine, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N Broadway, Baltimore, MD, 21231, USA.
Kiersten MalmbergThe Center for Nanomedicine, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N Broadway, Baltimore, MD, 21231, USA.
Tejaswini AppidiThe Center for Nanomedicine, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N Broadway, Baltimore, MD, 21231, USA.
Mahmood KhanDepartment of Ophthalmology, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N. Broadway, Baltimore, MD, 21231, USA.
Peter A CampochiaroDepartment of Ophthalmology, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N. Broadway, Baltimore, MD, 21231, USA.
Laura M EnsignThe Center for Nanomedicine, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N Broadway, Baltimore, MD, 21231, USA. lensign@jhmi.edu.

Funding

Wilmer Core Grant for Vision ResearchP30EY001765 · NEI · JOHNS HOPKINS UNIVERSITY · PI JEFFREY MUMM · 1985 to 2026
$22.1M
Visual Science Training ProgramT32EY007143 · NEI · JOHNS HOPKINS UNIVERSITY · PI Laura Ensign, JEREMY NATHANS · 1995 to 2026
$6.2M
Eye drop formulations for enhanced penetration of water soluble antibiotics to treat infectionsR01EY033386 · NEI · JOHNS HOPKINS UNIVERSITY · PI Laura Ensign, Justin S. Hanes · 2022 to 2026
$2.4M
A novel hypotonic gelling eye drop for topical treatment of retinal degenerative diseasesR01EY031041 · NEI · JOHNS HOPKINS UNIVERSITY · PI CAMPOCHIARO, PETER A, ENSIGN, LAURA · 2020 to 2023
$1.6M
Topical drug delivery formulations for neuroprotection in glaucomaR01EY034902 · NEI · JOHNS HOPKINS UNIVERSITY · PI Laura Ensign, Justin S. Hanes · 2024 to 2026
$1.6M
Topical delivery of HIF-1 inhibitors for retinal and choroidal vascular diseasesR01EY036027 · NEI · JOHNS HOPKINS UNIVERSITY · PI Peter A Campochiaro, Laura Ensign · 2024 to 2026
$1.2M
NEI NIH HHS P30EY001765NEI NIH HHS R01 EY031041NEI NIH HHS R01EY031041NEI NIH HHS R01 EY033386NEI NIH HHS R01 EY034902NEI NIH HHS R01 EY036027NEI NIH HHS T32EY007143
6 · The paper itself

Abstract

Retinitis pigmentosa (RP) is a chronic genetic condition that leads to progressive loss of photoreceptor cells and vision. While gene therapy is available for a small subset of patients with specific mutations, developing a therapeutic that broadly targets the cellular stresses that lead to cell death could address a major unmet need. One such option would be utilizing antioxidant therapies to neutralize reaction oxygen species (ROS) in the retina that underlie RP progression. Here, we describe an approach for delivering the antioxidants N-acetyl cysteine (NAC) or N-acetyl cysteine ethyl ester (NACET) with a gel-forming eye drop previously demonstrated to provide therapeutic drug delivery in the posterior segment in animals. We demonstrated therapeutic protection of photoreceptor structure and function in a chemically-induced rat model of RP (48% increase in photopic b-wave amplitude), as well as some limited protection in an aggressive genetic mouse model (rd10) of retinal degeneration (~ 31% increase in photopic b-wave amplitude) with once daily application. However, antioxidants have inherent stability issues when stored in solution, so we investigated the use of additional excipients to improve stability and retain potency. While a promising approach, future work to address product stability and efficacy in larger eyes is needed for further development.

Indexed as

AcetylcysteineAntioxidantsPhotoreceptor Cells, VertebrateRetinitis PigmentosaAnimalsDisease Models, AnimalGelsMaleMiceOphthalmic SolutionsRatsAcetylcysteineAntioxidantsGelsOphthalmic SolutionsAntioxidant deliveryGel-forming eye dropProduct stabilityRetinitis pigmentosa

Identifiers

PMID41661511
PMCPMC12956921

What OpenQuestion holds

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LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.